HK1131703B - Antenna assemblies with tapered loop antenna elements and reflectors - Google Patents

Description

Antenna assembly with antenna element and reflector

Technical Field

The present disclosure relates generally to antenna assemblies configured for receiving television signals, such as High Definition Television (HDTV) signals.

Background

The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

Many people enjoy watching television. Recently, the experience of watching television has been greatly improved due to High Definition Television (HDTV). Many people pay for HDTV through their existing cable or satellite television service providers. Indeed, many people are unaware that HDTV signals are typically carried over a free public band. This means that HDTV signals can be received for free via a suitable antenna.

Disclosure of Invention

According to various aspects, exemplary embodiments of antenna assemblies are provided. In one exemplary embodiment, an antenna assembly generally includes at least one antenna element. The antenna assembly may further include at least one reflector element spaced apart from the antenna element to reflect electromagnetic waves generally toward the antenna element.

Other aspects and features of the present disclosure will become apparent from the detailed description provided hereinafter. Furthermore, any one or more aspects of the present disclosure may be implemented alone or in combination with any one or more other aspects of the present disclosure. It should be understood that the detailed description and specific examples, while indicating exemplary embodiments of the disclosure, are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.

Drawings

The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.

Fig. 1 is an exploded perspective view including a tapered loop antenna element, a reflector, a housing (with end pieces removed for clarity), and a PCB balun (balun) according to an exemplary embodiment;

FIG. 2 is a perspective view illustrating the antenna assembly shown in FIG. 1 after the components have been assembled and enclosed within a housing;

fig. 3 is a perspective end view showing the tapered loop antenna element, reflector and PCB balun shown in fig. 1;

FIG. 4 is a side view of the components shown in FIG. 3;

fig. 5 is a front view of the tapered loop antenna element shown in fig. 1;

fig. 6 is a rear view of the tapered loop antenna element shown in fig. 1;

fig. 7 is a bottom plan view of the tapered loop antenna element shown in fig. 1;

fig. 8 is a top plan view of the tapered loop antenna element shown in fig. 1;

fig. 9 is a right side view of the tapered loop antenna element shown in fig. 1;

fig. 10 is a left side view of the tapered loop antenna element shown in fig. 1;

FIG. 11 is a perspective view illustrating an exemplary use of the antenna assembly shown in FIG. 2 supported on the top of a television, connected to the television by a coaxial cable so that the antenna assembly may be used to receive signals and transmit the signals to the television via the coaxial cable;

fig. 12 is an exemplary graph showing computer simulated gain/directivity and S11 versus frequency (in megahertz) for an exemplary embodiment of an antenna assembly having an unbalanced coaxial feed of 75 ohms;

fig. 13 is a view of another exemplary embodiment of an antenna assembly with two tapered loop antenna elements, a reflector and a PCB balun;

fig. 14 is a view of another exemplary embodiment of an antenna assembly with a tapered loop antenna element and a support member, and also showing the antenna assembly supported on a countertop or table top;

FIG. 15 is a perspective view of the antenna assembly shown in FIG. 14;

fig. 16 is a perspective view of another exemplary embodiment of an antenna assembly with a tapered loop antenna element and an indoor wall mount/support, and also showing the antenna assembly mounted to a wall;

fig. 17 is a perspective view of another exemplary embodiment of an antenna assembly with a tapered loop antenna element and support member, and further showing the antenna assembly mounted outdoors on a vertical mast or pole;

FIG. 18 is another perspective view of the antenna assembly shown in FIG. 17;

fig. 19 is a perspective view of another exemplary embodiment of an antenna assembly having two tapered loop antenna elements and a support member, and further showing the antenna assembly mounted outdoors on a vertical mast or pole;

FIG. 20 is an exemplary graph illustrating computer-simulated directivity and S11 versus frequency (in megahertz) for the antenna assembly shown in FIG. 13 in accordance with an exemplary embodiment;

fig. 21 is a perspective view of another exemplary embodiment of an antenna assembly configured to receive VHF signals;

FIG. 22 is a front view of the antenna assembly shown in FIG. 21;

FIG. 23 is a top view of the antenna assembly shown in FIG. 21;

FIG. 24 is a side view of the antenna assembly shown in FIG. 21; and

fig. 25 is an exemplary graph illustrating computer-simulated directivity and VSWR (voltage standing wave ratio) versus frequency (in megahertz) for the antenna assemblies shown in fig. 21-24 according to an exemplary embodiment.

Detailed Description

The following description is merely exemplary in nature and is in no way intended to limit the present disclosure, application, or uses.

Fig. 1-4 illustrate an example antenna assembly 100 implementing one or more aspects of the present disclosure. As shown in fig. 1, the antenna assembly 100 generally includes a tapered loop antenna element 104 (also shown in fig. 5-10), a reflector element 108, a balun 112, and a housing 116 having a removable end piece or end 120.

As shown in fig. 11, the antenna assembly 100 may be used to receive a digital television signal (a High Definition Television (HDTV) signal is one type of digital television signal) and transmit the received signal to an external device such as a television. In the illustrated embodiment, coaxial cable 124 (fig. 2 and 11) is used to transmit signals received by antenna assembly 100 to a television (fig. 11). The antenna assembly 100 may also be positioned on other generally horizontal surfaces, such as a table top, coffee table top, book shelf, and the like. Alternative embodiments may include antenna assemblies positioned elsewhere and/or supported by other means.

In one embodiment, the antenna assembly 100 may include a 75 ohm RG6 coaxial cable 124 equipped with an F-type connector (although other suitable communication links may be used). Alternate embodiments may include other coaxial cables or other suitable communication links.

As shown in fig. 3, 5 and 6, the tapered loop antenna element 104 has a generally annular shape defined cooperatively by an outer or peripheral portion 140 and an inner or peripheral portion 144. The outer peripheral portion or portion 140 is generally circular. The inner or inner peripheral portion 144 is also generally circular, such that the tapered loop antenna element 104 has a generally circular opening 148.

In some embodiments, the tapered loop antenna element has an outer diameter of about 220 mm and an inner diameter of about 80 mm. In some embodiments, the inner diameter is offset from the outer diameter such that the center of the circle generally defined by inner peripheral portion 144 (the midpoint of the inner diameter) is located about 20 millimeters below the center of the circle generally defined by outer peripheral portion 140 (the midpoint of the outer diameter). In other words, the inner diameter may be offset from the outer diameter such that the midpoint of the inner diameter is about 20 millimeters below the midpoint of the outer diameter. Thus, the offset of the inner and outer diameters provides the tapered loop antenna element 104 with a tapered shape such that at least one portion thereof (the top portion 126 shown in fig. 3, 5, and 6) is wider than another portion (the end portion 128 shown in fig. 3, 5, and 6). It has been found that the tapered shape of the tapered loop antenna element 104 improves performance and aesthetics. As shown in fig. 1, 3, 5 and 6, the tapered loop antenna element 104 includes a first half or bend 150 and a second half or bend 152 that are generally symmetrical, such that the first half or bend 150 is a mirror image of the second half or bend 152. Each bend 150, 152 extends generally between the respective ends 128 and then tapers or increases in width until the middle or top 126 of the tapered loop antenna element 104. The tapered loop antenna element 104 and the housing 116 may be positioned in an orientation such that the wide portion 126 of the tapered loop antenna element 104 is at an upper portion and the narrower end portion 128 is at a lower portion.

With continued reference to fig. 3, 5 and 6, the tapered loop antenna element 104 includes spaced apart ends 128. In one particular embodiment, the ends 128 of the tapered loop antenna element 104 are spaced apart by a distance of about 2.5 millimeters. Alternative embodiments may include antenna elements with ends spaced apart by more or less than 2.5 millimeters. For example, some embodiments include antenna elements having ends spaced apart by a distance of about 2 millimeters to about 5 millimeters. The spaced apart ends may define an open slot therebetween that is used to provide a gap feed for balanced transmission lines.

The end portions 128 include fastener holes 132, the pattern of these fastener holes 132 corresponding to the fastener holes 136 of the PCB balun 112. Accordingly, mechanical fasteners (e.g., screws, etc.) may be inserted through the fastener holes 132, 136 after they are aligned to connect the PCB balun 112 to the tapered loop antenna element 104. Alternative embodiments may include differently configured fastener holes (e.g., more or less, different shapes, different sizes, different locations of holes, etc.). Additional embodiments may include other attachment methods (e.g., welding, etc.).

As shown in fig. 4 and 7-10, the tapered loop antenna element 104 is shown as being substantially flat and having a substantially constant or uniform thickness. In one exemplary embodiment, the thickness of the tapered loop antenna element 104 is approximately 3 mm. Other embodiments may include thicker or thinner antenna elements. For example, some embodiments may include an antenna element (e.g., 1 oz copper, etc.) having a thickness of about 35 microns, wherein the antenna element is fixed, supported, or mounted on a printed circuit board. Other embodiments may include free-standing, self-supporting antenna elements made of aluminum, copper, etc. having a thickness of about 0.5 mm to about 5 mm, etc. In another exemplary embodiment, the antenna element comprises a relatively thin aluminum foil encapsulated within a supporting plastic cover that is employed to reduce material costs associated with aluminum.

Alternative embodiments may include antenna elements having a different configuration than the tapered loop antenna element 104 shown in the figures. For example, other embodiments may include a non-tapered loop antenna element with a centered (non-offset) opening. Other embodiments may include loop antenna elements defining a substantially circular complete loop or hoop without spaced free ends 128. Other embodiments may include antenna elements having outer/outer perimeters, inner/inner perimeters, and/or different opening sizes or shapes, such as having non-circular shapes (e.g., oval, triangular, rectangular, etc.). The antenna element 104 (or any portion thereof) may also be provided in various configurations (e.g., shapes, sizes, etc.), depending at least in part on the intended end use and the signal to be received by the antenna assembly.

Various materials may be employed for the antenna assembly 104. For example only, the tapered loop antenna element 104 may be formed from a metal conductor such as aluminum, copper, stainless steel, or other alloys. In another embodiment, the tapered loop antenna element 104 may be stamped from sheet metal or formed by selectively etching a copper layer on a printed circuit board substrate.

Fig. 1, 3, and 4 illustrate an exemplary reflector 108 that may be used with antenna assembly 100. As shown in fig. 3, reflector 108 includes a generally flat or planar surface 160. Reflector 108 also includes a baffle, rim or sidewall portion 164 that extends outwardly relative to surface 160. The reflector 108 may generally be used to reflect electromagnetic waves generally toward the tapered loop antenna element 104.

As for the size of the reflector and its distance to the antenna element, the inventors noted the following. The size of the reflector and its distance to the antenna element have a strong influence on the performance. Placing the antenna element very close to the reflector will give the antenna a good gain, but a narrow impedance bandwidth and a poor VSWR. In addition to size reduction, such designs are not suitable for the intended broadband application. If the antenna element is placed too far from the reflector, the gain drops due to improper phasing. If the dimensions and proportions of the antenna elements, the size of the transmitter, the size of the baffle, and the distance between the antenna elements and the reflector are appropriately selected, an optimum configuration results which takes full advantage of the close-range coupling with the electrically smaller reflector elements, resulting in increased impedance bandwidth while mitigating the phase-canceling effect. The overall effect is to create an exemplary balance between impedance bandwidth, directivity or gain, transmission efficiency, and physical size.

In the illustrated embodiment, the reflector 108 is generally square with four peripheral side walls 164. Alternative embodiments may include reflectors having different configurations (e.g., different shapes, sizes, fewer sidewall portions, etc.). It is even possible to invert the side wall so that it points to the opposite side of the antenna element. The effect of the sidewalls is to slightly increase the effective electrical size of the reflector and to increase the impedance bandwidth.

Dimensionally, the reflector 108 of one exemplary embodiment has a generally square surface 160 having a length and width of about 228 millimeters. Moreover, reflector 108 may also have peripheral side walls 164 that are each approximately 25.4 millimeters in height relative to surface 160. The dimensions provided in this paragraph (as with all dimensions set forth herein) are merely examples provided for purposes of illustration, and thus any antenna component disclosed herein may be configured with different dimensions, e.g., depending on the particular application and/or the signals to be received or transmitted by the antenna assembly. For example, another embodiment may include a reflector 108 having a baffle, rim, or peripheral sidewall portion 164 having a height of about 10 millimeters. Another embodiment may have a baffle, reflector 108 with edges facing in the opposite direction of the antenna element. In such embodiments, a top may also be added to the open box, which may serve as a shield for the receiver board or other electronic components.

Referring to FIG. 3, a cutout, opening, or recess 168 may be provided in the reflector's outer peripheral side wall 164 to facilitate mounting of the reflector 108 within the housing 116 and/or attachment of the housing end piece 120. In an exemplary embodiment, reflector 108 may be slidably positioned within housing 116 (FIG. 1). The fastener holes 172 of the housing end piece 120 may be aligned with the openings 168 of the reflector so that fasteners may be inserted through the aligned openings 168, 172. Alternative embodiments may have reflectors without these openings, cutouts, or notches.

Fig. 1, 3, and 4 illustrate an exemplary balun 112 that may be used with the antenna assembly 100 to convert a balanced line to an unbalanced line. In the illustrated embodiment, the antenna assembly 100 includes a printed circuit board having a balun 112. The PCB with balun 112 may be connected to the tapered loop antenna element 104 (fig. 3) by fasteners and fastener holes 132 and 136. Alternative embodiments may include different means for connecting the balun 112 to the tapered loop antenna element and/or different types of transformers other than the printed circuit board balun 112.

As shown in FIG. 1, the housing 116 includes an end piece 120 and a middle portion 180. In this particular embodiment, the end piece 120 is removably connected to the central portion 180 by mechanical fasteners, fastener holes 172, 174, and threaded socket 176. Alternative embodiments may include a housing with an integrally formed, fixed end piece. Other embodiments may include a housing having one or more removable end pieces that snap fit, friction fit, or interference fit with the middle of the housing without the need for mechanical fasteners.

As shown in fig. 2, the housing 116 is generally U-shaped having spaced apart upright portions or members 184 connected by generally horizontal members or portions 186. In the present embodiment, these members 184, 186 cooperatively define a generally U-shaped profile for the housing 116.

As shown in fig. 1, the tapered loop antenna element 104 may be positioned on an upright member 184 different from the upright member 184 where the reflector 108 is positioned. In one particular embodiment, the housing 116 is configured (e.g., shaped, sized) such that the tapered loop antenna element 104 is spaced apart from the reflector 108 by about 114.4 millimeters when the tapered loop antenna element 104 and the reflector 108 are positioned on different respective sides of the housing 116. Further, the housing 116 may be configured such that the sides 184 of the housing are generally square with a length and width of about 25.4 centimeters. Thus, the antenna assembly 100 may thus be provided with a relatively small overall footprint. These shapes and dimensions are provided for illustrative purposes only, as the particular configuration (e.g., shape, dimensions, etc.) of the housing may vary, for example, depending on the particular application.

The housing 116 may be formed from a variety of materials. In some embodiments, the housing 116 is formed of plastic. In those embodiments in which the antenna assembly is to be used as an outdoor antenna, the housing may be formed of a weatherable material (e.g., a water and/or ultraviolet resistant material, etc.). In addition, the housing 116 (or the bottom thereof) may also be formed of a material that provides a relatively high coefficient of friction for the bottom surface of the housing 116. This, in turn, helps prevent the antenna assembly 100 from sliding relative to a surface of the support assembly 100 (e.g., a top surface of a television, as shown in fig. 11, etc.).

In some embodiments, the antenna assembly may also include a digital tuner/converter (ATSC receiver) built into or located within the housing. In these exemplary embodiments, a digital tuner/converter may be used to convert the digital signals received by the antenna assembly into analog signals. In one exemplary embodiment, a reflector with inverted baffle and cover can be used as a shield for an ATSC receiver. The shield can reduces the effect of transmit or receive interference acting on the tuner circuit. Placing the tuner within the enclosure saves space and eliminates (or reduces) the possibility of coupling the antenna element to the tuner, which would otherwise adversely affect the impedance bandwidth and directivity of the antenna.

In various embodiments, the antenna assembly 100 is tuned (and optimized in some embodiments) to receive signals having a frequency associated with High Definition Television (HDTV) having a frequency range of about 470mhz to about 690 mhz. In such embodiments, tuning the antenna assembly 100 to receive the HDTV signals within a narrow range allows the antenna element 104 to be smaller yet still function adequately. By this smaller individual physical size, the overall size of the antenna assembly 100 may be reduced, thereby providing the antenna assembly 100 with a reduced footprint, which may be advantageous, for example, when using the antenna assembly 100 indoors and placing the antenna assembly 100 on top of a television (e.g., fig. 11, etc.).

Exemplary operating parameters of the antenna assembly 100 will now be provided for illustrative purposes only. These operating parameters may vary for other embodiments, for example, depending on the particular application and the signal to be received by the antenna assembly.

In some embodiments, the antenna assembly 100 may be configured to have operating parameters substantially as shown in fig. 12, which fig. 12 illustrates a computer-simulated gain/directivity and S11 versus frequency (in megahertz) for an exemplary embodiment of the antenna assembly 100 having a 75 ohm unbalanced coaxial feed. In other embodiments, a 300 ohm balanced dual lead may be used.

Fig. 12 generally illustrates that the antenna assembly 100 has a relatively flat gain curve over about 470Mhz to about 698 Mhz. In addition, fig. 12 also shows that the antenna assembly 100 has a maximum gain (decibels of isotropic gain) of about 8dBi and an output impedance of about 75 ohms.

In addition, FIG. 12 also shows that S11 is below-6 dB in the frequency band from about 470MHz to about 698 MHz. Values of S11 below this value ensure that the antenna is well matched and operates at higher efficiency.

Further, the antenna assembly may also be constructed to a degree that is not necessarily directed at the target. In such exemplary embodiments, the antenna assembly does not have to be redirected or redirected each time the television channel is changed.

Fig. 13 illustrates another embodiment of an antenna assembly 200 implementing one or more aspects of the present disclosure. In the illustrated embodiment, the antenna assembly 200 includes two generally side-by-side tapered loop antenna elements 204A and 204B, generally in a figure 8 configuration (as shown in fig. 13). The antenna assembly 200 also includes a reflector 208 and a printed circuit board balun 212. The antenna assembly 200 may be provided with a housing that is the same as or different from the housing 116. Antenna assembly 200 may be operated and constructed similarly to the antenna assembly of at least some embodiments of antenna assembly 100, except that there are two tapered loop antenna elements 204A and 204B (and the improved antenna range achieved thereby). Fig. 20 is an exemplary graph of computer-simulated directivity and S11 versus frequency (in megahertz) for the antenna assembly 200 according to an exemplary embodiment.

Fig. 14-19 illustrate other exemplary embodiments of antenna assemblies embodying one or more aspects of the present disclosure. For example, fig. 14 and 15 show an antenna assembly 300 having a tapered loop antenna element 304 and a support 388. In the exemplary embodiment, the antenna assembly 300 is supported on a horizontal surface 390, such as the top surface of a table or counter top. The antenna assembly 300 may also include a printed circuit board balun 312. In some embodiments, an antenna assembly may include a tapered loop antenna element (e.g., 304, 404, 504, etc.) having openings (e.g., holes, notches, voids, recesses, etc.) along a central portion and/or first and second bends of the antenna element, where the openings may be used, for example, to help align and/or retain the antenna element to a support. For example, a relatively thin metallic antenna element having such an opening may be supported by a plastic support structure having a protrusion, boss or projection aligned with and frictionally received in the opening of the antenna element, such that the frictional engagement or snap-fit helps retain the antenna element to the plastic support structure.

As another embodiment, fig. 16 shows an antenna assembly 400 with a tapered loop antenna element 404 and an indoor wall mount/support 488. In this embodiment, the antenna assembly is mounted to a wall 490. The antenna assembly 400 may also include a printed circuit board balun. However, this balun is not shown in fig. 10 since it is blocked by the support 488.

The antenna assemblies 300 and 400 shown in fig. 14-16 do not include reflectors similar to reflectors 108 and 208. In some embodiments, the antenna assemblies 300, 400 also provide good VSWR (voltage standing wave ratio) without a reflector. However, in other embodiments, the antenna assemblies 300 and 400 include such reflectors. The antenna assemblies 300 and 400 may be operated and constructed similarly to the antenna assemblies in at least some embodiments of the antenna assemblies 100 and 200. The circular shape of the supports 388 and 488 as shown in fig. 14-16 is merely an exemplary embodiment. The supports 388 and 488 can have various shapes (e.g., square, hexagonal, etc.). Removing the reflector may result in the antenna having less gain but a wider bi-directional pattern, which may be advantageous for some situations where the signal strength level is high and the signal comes from multiple directions.

Other exemplary embodiments of antenna assemblies for installation outdoors are shown in fig. 17-19. Fig. 17 and 18 show an antenna assembly 500 with a tapered loop antenna element 504, a printed circuit board balun 512, and a support member 588, where the antenna assembly 500 is mounted outdoors on a vertical post or mast 592. Fig. 19 shows an antenna assembly 600 with two tapered loop antenna elements 604A and 604B and a support 688, wherein the antenna assembly 500 is mounted outdoors on a vertical post or pole 692.

Antenna assemblies 500 and 600 include reflectors 508 and 608. Unlike the substantially solid planar surfaces of reflectors 108 and 208, reflectors 508 and 608 have grid or mesh surfaces 560 and 660. Reflector 508 also includes two peripheral flanges 564 and reflector 608 includes two peripheral flanges 664. Grid reflectors are generally preferred for outdoor applications, which can reduce wind loads. For outdoor applications, the size is usually less important, so that the grid reflector can be made slightly larger than a comparable indoor model to compensate for the grid inefficiency. The increased size of the grid reflector also eliminates or reduces the need for baffles, which are generally more important on indoor models that tend to be near the size versus performance curve boundary.

Any of the various embodiments shown in fig. 14-19 may include one or more components (e.g., balun, reflector, etc.) similar to the components of the antenna assembly 100. Further, the various embodiments shown in fig. 14-19 may be operated and configured similarly to the antenna assemblies of at least some embodiments of the antenna assembly 100.

According to some embodiments, the antenna elements for signals in the Very High Frequency (VHF) range (e.g., 170 mhz to 216 mhz, etc.) may not be circular in shape, but still be based on the basic electrical geometry of the antenna elements disclosed herein. For example, VHF antenna elements may be configured to provide more than one segment of an electrical path along the inner and outer perimeters of the antenna element. A suitable combination of these elements with an electrically smaller reflector may create an excellent balance between directivity, efficiency, bandwidth, and physical size as other example antenna assemblies disclosed herein.

For example, fig. 21-24 illustrate exemplary embodiments of an antenna assembly 700 that may be used to receive VHF signals (e.g., signals within a frequency bandwidth of 170 megahertz to 216 megahertz, etc.). As shown, the antenna assembly 700 includes an antenna element 704 and a reflector 708.

The antenna element 704 has an outer peripheral portion or portion 740 and an inner peripheral portion or portion 744. The peripheral portion or portion 740 is generally rectangular. Inner peripheral portion 744 is also generally rectangular. In addition, the antenna assembly 704 further includes a tuning rod 793 disposed or extending generally between the two side members 794 of the antenna element 704. The tuning rod 793 is substantially parallel to the top member 795 and the bottom member 796 of the antenna element 704. The tuning rod 793 extends across the antenna element 704 such that the antenna element 704 includes a generally rectangular lower opening 748 and a generally rectangular upper opening 749. The antenna element 704 also includes spaced apart ends 728.

With the tuning rod 793, the antenna element 704 includes first and second electrical paths of different lengths, with the shorter electrical path including the tuning rod 793 and the longer electrical path not including the tuning rod 793. The longer electrical path is defined by the outer loop of the antenna element 704, which includes the spaced apart ends 728 of the antenna element, a bottom member 796, side members 794, and a top member 795. The shorter electrical path is defined by the inner loop of the antenna element 704, which includes the spaced apart ends 728 of the antenna element, the bottom member 796, portions of the side members 794 (i.e., the portion between the tuning rod 793 and the bottom member 796), and the tuning rod 793. The electrical path defined by the inner and outer loops of the antenna element 704 enables efficient operation in some embodiments in the VHF bandwidth range of about 170 mhz to about 216 mhz, in accordance with complex coupling theory. Due to the higher efficiency, the size of the antenna assembly may be reduced (e.g., by 75% of the size, etc.), but still provide satisfactory operating characteristics.

The tuning rod 793 may be configured (e.g., sized, shaped, positioned) to provide impedance matching to the antenna element 704. In some example embodiments, the tuning rod 793 may provide the antenna element 704 with an impedance that more closely matches a 300 ohm transformer.

In a particular embodiment, the ends 728 of the antenna element 704 are spaced apart a distance of approximately 2.5 millimeters. As another example, the antenna element 704 may be configured to have a width (left to right in fig. 22) of about 600 millimeters, a height (top to bottom in fig. 22) of about 400 millimeters, and a tuning rod 793 located a distance of about 278 millimeters above the bottom member 796. Various materials may be employed for the antenna element 704. In one exemplary embodiment, the antenna element 704 is made of an aluminum hollow tube having a cross-section of 3/4 inches by 3/4 inches in a square shape. In this particular embodiment, the various portions (728, 794, 795, 796, 793) of the antenna element 704 are all formed from the same aluminum tube, but this is not required for all embodiments. Alternative embodiments may include constructing the antenna elements differently, such as being constructed of different materials (e.g., other materials than aluminum, the antenna elements having portions formed of different materials, etc.), having a non-rectangular shape, and/or having different dimensions (e.g., end spacing greater than or less than 2.5 millimeters, etc.). For example, some embodiments include antenna elements having ends spaced apart by about 2 millimeters to about 5 millimeters. The spaced apart ends may define an open slot therebetween that is used to provide a gap feed for balanced transmission lines.

With continued reference to fig. 21-24, the reflector 708 includes a grid or mesh surface 760. The reflector 708 also includes two peripheral flanges 764. The peripheral flange 764 may extend outwardly from the grid surface 760. Additionally, members 797 may be disposed behind grid surface 760 to provide reinforcement to grid surface 760 and/or to provide a means for supporting or coupling grid surface 760 to a support structure. For example only, the reflector 708 may be configured to have a width (left to right in fig. 22) of about 642 mm, a height (top to bottom in fig. 22) of about 505 mm, and a distance of about 200 mm from the antenna element 704, i.e., the distance the grid surface 760 of the reflector is spaced from the back surface of the antenna element 704. Also by way of example only, the peripheral flange 764 may be about 23 millimeters in length and extend outwardly from the grid surface 760 at an angle of about 120 degrees. Various materials may be employed for the reflector 708. In an exemplary embodiment, the reflector 708 comprises steel coated with a polyethylene based film. Alternative embodiments may include configuring the reflector differently (e.g., different materials, shapes, sizes, locations, etc.), having no reflector, or having the reflector positioned farther or closer to the antenna element.

Fig. 25 is an exemplary graph illustrating computer-simulated directivity and VSWR (voltage standing wave ratio) versus frequency (in megahertz) for the antenna assembly 700 according to an exemplary embodiment.

Accordingly, embodiments of the present disclosure include antenna assemblies that may be extended to any number (i.e., one or more) of antenna elements, for example, depending on the particular end use, the signals to be received or transmitted by the antenna assembly, and/or the desired operating range of the antenna assembly. By way of example only, another exemplary embodiment of an antenna assembly includes four tapered loop antenna elements that may work together to improve the overall range of the antenna assembly.

Other embodiments relate to methods of making and/or using antenna assemblies. Various embodiments relate to a method of receiving a digital television signal such as a high definition television signal having a frequency range of about 174 megahertz to about 216 megahertz and/or a frequency range of about 470 megahertz to about 690 megahertz. In one exemplary implementation, a method generally includes connecting at least one communication link from an antenna assembly to a television to transmit signals received by the antenna assembly to the television. In this method embodiment, the antenna assembly (e.g., 100, etc.) may include at least one antenna element (e.g., 104, etc.) and at least one reflector element (e.g., 108, etc.). In some embodiments, there may be a free-standing antenna element without any reflector elements, which may provide good impedance bandwidth but low directivity for very compact solutions operating in strong signal areas.

The antenna assembly may include a balun (e.g., 112, etc.) and a housing (e.g., 116, etc.). The antenna assembly may be used to receive high definition television signals having a frequency range of about 470 megahertz to about 690 megahertz. The antenna element may have a generally annular shape with an opening (e.g., 148, etc.). The antenna element 104 (as well as reflector size, baffle and spacing) may be tuned to at least one electrical resonant frequency to operate within a bandwidth from about 470 megahertz to about 690 megahertz. The reflector element may be spaced apart from the antenna element for reflecting electromagnetic waves generally toward the antenna element and generally affecting the impedance bandwidth and directivity. The antenna element may include first and second spaced apart end portions (e.g., 128, etc.), a central portion (e.g., 126, etc.), first and second curved portions (e.g., 150, 152, etc.) extending from the respective first and second end portions to the central portion, such that the loop shape and the opening of the antenna element are generally circular. The first and second curved portions may gradually increase in width from the respective first and second end portions toward the central portion such that the central portion is wider than the first and second end portions and the outer diameter of the antenna element deviates from the diameter of the generally circular opening. The first bend may be a mirror image of the second bend. The center of the substantially circular opening may be offset from the center of the substantially circular ring shape of the antenna element. The reflector element may include baffles (e.g., 164, etc.) to deflect electromagnetic waves. The baffle may be positioned at least partially along at least one peripheral edge portion of the reflector element. The reflector element may include a substantially planar surface (e.g., 160, etc.) substantially parallel to the antenna elements, with at least one sidewall portion (e.g., 164, etc.) extending generally outwardly relative to the substantially planar surface toward the tapered loop antenna element. In some embodiments, the reflector element includes a sidewall portion along an outer peripheral edge portion of the reflector element, the sidewall portion being substantially perpendicular to the substantially planar surface of the reflector element such that the sidewall portion can act as a baffle to deflect electromagnetic wave energy.

Embodiments of the antenna assemblies disclosed herein may be configured to provide one or more of the following advantages. For example, embodiments disclosed herein may provide an antenna assembly that is physically and electrically small, but still operates and functions similarly to a physically and electrically large antenna assembly. The disclosed exemplary embodiments may provide a relatively small and unobtrusive antenna assembly that may be used to receive signals (e.g., signals associated with digital television (of which high definition television signals are one type), etc.) indoors. Also by way of example, exemplary embodiments disclosed herein may be specifically configured for receiving (e.g., tuning and/or pointing to) the year 2009 Digital Television (DTV) spectrum (e.g., HDTV signals located within a first frequency range of about 174 megahertz to about 216 megahertz and signals within a second frequency range of from about 470 megahertz to about 690 megahertz, etc.). Exemplary embodiments disclosed herein may thus have relatively high efficiency (e.g., about 90%, about 98% at 545MHz, etc.) and relatively good gain (e.g., a maximum gain of about 8dBi, a good impedance curve, a flat gain curve, relatively uniform gain within the 2009DTV spectral domain, relatively high gain, with a mesa area of only about 25.4 centimeters by about 25.4 centimeters, etc.). With such relatively good efficiency and gain, higher quality television reception may be achieved without or without amplification of the signals received through some of the exemplary antenna embodiments. Additionally, or alternatively, exemplary embodiments may also be configured to receive VHF and/or UHF signals.

Exemplary embodiments of antenna assemblies (e.g., 100, 200, etc.) for receiving digital television signals, such as HDTV signals, have been disclosed herein. However, alternative embodiments may include antenna elements tuned to receive non-television signals and/or signals having frequencies unrelated to HDTV. Other embodiments may be used to receive AM/FM radio signals, UHF signals, VHF signals, and the like. Accordingly, embodiments of the present disclosure should not be limited to receiving only television signals having frequencies associated with digital television or HDTV, or frequencies within a frequency range associated with digital television or HDTV. Alternatively, the antenna assemblies disclosed herein may be used in conjunction with various electronic devices, such as radios, computers, and the like. Accordingly, the scope of the present disclosure should not be limited to use only with televisions and television-related signals.

The numerical dimensions and specific materials disclosed herein are provided for illustrative purposes only. The particular dimensions and specific materials disclosed herein are not intended to limit the scope of the present disclosure, as other embodiments may be formed with different dimensions, with different shapes, and/or from different materials and/or processes, e.g., depending on the particular application and intended end use.

Some terminology is used herein for the purpose of reference only and is not intended to be limiting. For example, terms such as "upper," "lower," "above," "below," "upward," "downward," "forward," and "rearward" refer to directions in the drawings to which reference is made. Terms such as "front," "back," "rear," "bottom," and "side," describe the orientation of portions of an element within a consistent but arbitrary frame of reference that will be made clear by reference to the text and the associated drawings describing the element in question. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of homology. Likewise, the terms "first," "second," and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context.

When introducing elements or features and the exemplary embodiments, the articles "a", "an", "the" and "the" are intended to mean that there are one or more of such elements or features. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements or features other than those specifically stated. It should also be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It should also be understood that other steps may be employed or steps may be substituted.

The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the gist of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.

Cross Reference to Related Applications

This chinese application claims priority from U.S. provisional patent application No.60/992,331 filed on 5/12/2007, U.S. utility model patent application No.12/040,464 filed on 29/2/2008, U.S. design patent application No.29/304,423 filed on 29/2/2008, and U.S. provisional patent application No.61/034,431 filed on 6/3/2008. The disclosure of the above application is incorporated herein by reference.

Claims (41)

1. An antenna assembly, comprising:

at least one tapered loop antenna element having an opening, the antenna element having a generally annular shape; and

at least one reflector element spaced apart from said tapered loop antenna element for reflecting electromagnetic waves generally toward said tapered loop antenna element, said reflector element comprising:

a substantially planar surface substantially parallel to and spaced from said tapered loop antenna element; and

at least one sidewall portion extending generally outwardly relative to the substantially planar surface toward the tapered loop antenna element,

wherein the tapered loop antenna element includes a substantially circular inner circumferential portion and an outer circumferential portion, such that the loop shape and the opening of the tapered loop antenna element are substantially circular,

wherein the tapered loop antenna element is configured such that the diameter of the substantially circular inner peripheral portion is offset from the diameter of the substantially circular outer peripheral portion, and wherein at least one portion of the tapered loop antenna element is wider than at least another portion.

2. The antenna assembly as in claim 1, wherein the tapered loop antenna element has spaced apart ends defining an open slot extending at least partially between the spaced apart ends, whereby the open slot can be used to provide gap feeding for balanced transmission lines.

3. The antenna assembly of claim 1, wherein the diameter of the substantially circular outer perimeter is approximately 220 millimeters.

4. The antenna assembly of claim 1, wherein a midpoint of a diameter associated with the generally circular inner perimeter portion is located below a midpoint of a diameter associated with the generally circular outer perimeter portion, such that the tapered loop antenna element has a wider upper portion.

5. The antenna assembly of claim 1, wherein the tapered loop antenna element has spaced apart end portions, and wherein the width of the tapered loop antenna element increases from the spaced apart end portions toward a wider central portion.

6. The antenna assembly of claim 5, further comprising a housing for the tapered loop antenna element and reflector element, and wherein the tapered loop antenna element is positioned with the housing in an orientation such that the wider central portion is above the spaced apart end portions.

7. The antenna assembly of claim 1, wherein the tapered loop antenna element comprises:

a middle part;

first and second end portions; and

first and second bends extending from the respective first and second end portions toward the central portion, the first and second bends each having a width that gradually increases from the respective first and second end portions toward the central portion such that the central portion is wider than the first and second end portions.

8. The antenna assembly of claim 7, wherein the first bend is a mirror image of the second bend.

9. The antenna assembly of claim 1, 5 or 6, wherein the at least one sidewall portion of the reflector element includes a sidewall portion along an outer peripheral edge of the reflector element and substantially perpendicular to a substantially planar surface of the reflector element, whereby the sidewall portion is operable to increase an electrical size of the reflector element and to improve impedance matching of the antenna element coupled thereto.

10. The antenna assembly of claim 1, 5, or 6, further comprising a balun.

11. The antenna assembly of claim 1, 5 or 6, further comprising a printed circuit board having a balun.

12. The antenna assembly of claim 11, wherein the tapered loop antenna element includes spaced apart ends, and wherein the printed circuit board is attached to at least one of the spaced apart ends.

13. The antenna assembly of claim 1 or 5, further comprising a housing including first and second spaced apart housing portions for receiving the tapered loop antenna element and the reflector element, respectively, spaced apart by a spacing.

14. The antenna assembly of claim 13, wherein the housing further includes a central portion extending between the first and second spaced apart housing portions such that the central portion and the first and second spaced apart housing portions cooperatively define a generally U-shaped profile of the housing.

15. The antenna assembly of claim 14, further comprising a digital tuner within the housing for converting digital signals received by the antenna assembly to analog signals.

16. The antenna assembly of claim 1, 5 or 6, wherein the tapered loop antenna element is configured to operate within a bandwidth from about 470 megahertz to about 690 megahertz.

17. The antenna assembly of claim 16, wherein the tapered loop antenna element is configured to operate within a second bandwidth from about 174 megahertz to about 216 megahertz.

18. The antenna assembly of claim 1, 5 or 6, further comprising a balun for converting between balanced and unbalanced signals, and wherein the antenna assembly is configured to have a maximum gain of about 8dBi and an output impedance of about 75 ohms.

19. The antenna assembly of claim 1, 5 or 6, wherein the antenna assembly comprises two or more of the tapered loop antenna elements.

20. The antenna assembly of claim 1, 5 or 6, wherein the antenna assembly comprises two of the tapered loop antenna elements arranged generally side by side in a generally figure 8 configuration.

21. The antenna assembly of claim 1, 5 or 6, wherein the tapered loop antenna element includes a generally circular outer peripheral portion and a generally circular inner peripheral portion offset from the generally circular outer peripheral portion such that a center of a circle generally defined by the inner peripheral portion is about 20 millimeters below a center of a circle generally defined by the outer peripheral portion.

22. The antenna assembly of claim 1, 5, or 6, wherein at least one sidewall portion of the reflector element is along at least one peripheral edge of the reflector element and substantially perpendicular to the substantially planar surface of the reflector element, and wherein the at least one sidewall portion has a height of about 2.54 centimeters.

23. The antenna assembly of claim 1, 5 or 6, wherein the reflector element is spaced apart from the tapered loop antenna element by about 114.4 millimeters.

24. An antenna assembly, comprising:

at least one antenna element, the antenna element comprising:

first and second end portions;

a middle part;

first and second curved portions extending from the respective first and second end portions toward the central portion such that the antenna element has a generally circular ring shape with a generally circular opening;

the first and second curved portions gradually increasing in width from the respective first and second end portions toward the central portion such that the central portion is wider than the first and second end portions and such that an outer diameter of the antenna element is offset from an inner diameter of the generally circular opening;

at least one reflector element spaced apart from the antenna element for reflecting electromagnetic waves generally toward the antenna element, the reflector element comprising:

a substantially planar surface substantially parallel to and spaced from said antenna element; and

an outer peripheral side wall substantially perpendicular to the substantially planar surface of the reflector element, the outer peripheral side wall operable as a baffle to deflect electromagnetic energy.

25. The antenna assembly of claim 24, wherein the antenna assembly is tuned to at least one electrical resonance frequency for operation within a bandwidth from about 470 megahertz to about 690 megahertz.

26. The antenna assembly of claim 25, wherein the antenna assembly is tuned to a second electrical resonance frequency for operation within a second bandwidth from about 174 megahertz to about 216 megahertz.

27. The antenna assembly of claim 24, 25, or 26, wherein the first and second ends are spaced apart from one another.

28. The antenna assembly of claim 24, 25 or 26, further comprising a housing for the antenna element and the reflector element, and wherein the antenna element is positioned with the housing in an orientation such that the central portion is located above the end portions.

29. The antenna assembly of claim 24, 25, or 26, wherein the first bend is a mirror image of the second bend.

30. The antenna assembly of claim 24, 25, or 26, wherein the at least one antenna element comprises two or more of the antenna elements.

31. An antenna assembly configured to operate within a bandwidth from about 470 megahertz to about 690 megahertz, the antenna assembly comprising:

an antenna element, the antenna element comprising:

first and second spaced apart end portions;

a middle part;

first and second curved portions extending from the respective first and second end portions toward the central portion such that the antenna element has a generally circular ring shape with a generally circular opening;

the first and second curved portions gradually increasing in width from the respective first and second end portions toward the central portion such that the central portion is wider than the first and second end portions and the outer diameter of the antenna element deviates from the diameter of the generally circular opening;

the first bend is a mirror image of the second bend,

the center of the generally circular opening is offset from the center of the generally circular ring shape; and

at least one reflector element spaced apart from the antenna element for reflecting electromagnetic waves generally toward the antenna element.

32. The antenna assembly of claim 31, wherein the antenna element has an outer diameter of approximately 220 millimeters.

33. The antenna assembly of claim 31 or 32, wherein a midpoint of a diameter of the substantially circular opening is spaced apart from a midpoint of an outer diameter of the antenna element by about 20 millimeters.

34. The antenna assembly of claim 31 or 32, wherein the antenna element is configured to operate within a second bandwidth from about 174 megahertz to about 216 megahertz.

35. An antenna assembly operable to receive high definition television signals having a frequency ranging from about 470 megahertz to about 690 megahertz, the antenna assembly comprising:

at least one antenna element having a generally annular shape with an opening and configured to operate within a bandwidth from about 470 megahertz to about 690 megahertz; and

at least one reflector element spaced apart from the antenna element for reflecting electromagnetic waves generally toward the antenna element,

wherein the antenna element comprises:

first and second spaced apart end portions;

a middle part;

first and second bends extending from the respective first and second end portions toward the central portion such that the loop shape and opening of the antenna element are generally circular;

the first and second curved portions have widths that gradually increase from the respective first and second end portions toward the central portion such that the central portion is wider than the first and second end portions and an outer diameter of the antenna element deviates from a diameter of the generally circular opening.

36. The antenna assembly of claim 35, wherein the first bend is a mirror image of the second bend.

37. The antenna assembly of claim 35 or 36, wherein a center of the substantially circular opening is offset from a center of the substantially circular ring shape.

38. The antenna assembly of claim 35 or 36, wherein the reflector element comprises a baffle for deflecting electromagnetic waves.

39. The antenna assembly of claim 38, wherein the baffle is positioned at least partially along at least one peripheral edge portion of the reflector element.

40. The antenna assembly of claim 35 or 36, wherein the reflector element comprises:

a substantially planar surface substantially parallel to the antenna element; and

at least one sidewall portion extending generally outwardly toward the antenna element relative to the substantially planar surface.

41. The antenna assembly of claim 35 or 36, wherein the reflector element comprises:

a substantially planar surface substantially parallel to the antenna element; and

a sidewall portion along an outer peripheral edge portion of the reflector element and substantially perpendicular to the substantially planar surface of the reflector element, such that the sidewall portion is capable of acting as a baffle to deflect electromagnetic wave energy.