CN105896057A - Slot antenna with coaxial feed capacitor loading - Google Patents

Abstract

A slot antenna loaded with a coaxial feed capacitively relates to a slot antenna, which includes a dielectric substrate (1), a metal ground (2) on the dielectric substrate (1), a radiation slot (3), a coaxial feeder (4 ); there is a radiation slot (3) on the metal ground (2); the two ends (6) of the radiation slot (3) are short-circuited; there are several capacitors (7) connected in parallel across the edge of the radiation slot (3); One end of the coaxial feeder (4) is the port (8) of the antenna, and the inner conductor (9) at the other end of the coaxial feeder (4) crosses the radiation slot (3), at the edge (10) of the radiation slot (3). ), connected to the metal ground (2). The antenna can reduce antenna size, cross polarization.

Description

Slot Antenna Loaded by Coaxial Feed Capacitance

technical field

The invention relates to a slot antenna, in particular to a slot antenna loaded with coaxial feeding capacitance.

Background technique

The slot antenna is the dual antenna of the dipole antenna and has a wide range of applications. However, the ordinary slot antenna not only needs half the wavelength of the radiation slot itself, but also needs a large metal ground area around the radiation slot, usually the length of the metal ground is 1/2 larger than the length of the slot One wavelength, the width of the metal ground is one-half wavelength larger than the width of the slot. A larger metal ground will make the slot antenna unsuitable for multiple-input multiple-output (MIMO) applications, resulting in poor cross-polarization of the antenna, which will lead to a decrease in spectral efficiency and channel capacity. At the same time, the impedance of the slot is very large, which also makes it difficult to match the impedance of the slot antenna feeding transmission line.

Contents of the invention

Technical problem: The object of the present invention is to propose a slot antenna loaded with coaxial feeding capacitance, which can reduce the length of the radiation slot and the area of the metal ground, and has the effect of suppressing cross polarization.

Technical solution: The slot antenna loaded with coaxial feeding capacitance of the present invention includes a dielectric substrate, a metal ground and a radiation slot arranged on the dielectric substrate, and a coaxial feeder; one side of the dielectric substrate is a metal ground, and the outer surface of the coaxial feeder is The conductor is connected to the metal ground; the two ends of the radiation slot are short-circuited; several capacitors are connected in parallel across the two edges of the radiation slot, so that the characteristic impedance of the radiation slot becomes lower; one end of the coaxial feeder is the port of the antenna , the inner conductor at the other end of the coaxial feeder crosses the radiation slot, and is connected to the metal ground at the edge of the radiation slot.

By changing the quantity, capacitance and spacing of the loading capacitors, the characteristic impedance of the radiation slot can be adjusted, and the working frequency of the antenna, the width of the working frequency band and the electrical length of the radiation slot can be changed.

Capacitors are loaded in parallel to the two edges of the radiation slot, which not only reduces the characteristic impedance of the slot transmission line to easily match the feed transmission line, but also reduces the phase velocity of the slot transmission line, reducing the length of the half-wavelength radiation slot. Small, realize the miniaturization of the radiation slot and the antenna. The working frequency of the slot antenna loaded by the coaxial feed capacitor is mainly determined by the resonant frequency of the radiation slot, but the size of the metal ground and the position where the conductor in the coaxial feed line is connected to the radiation slot can also affect the working frequency and matching of the antenna. Adjust the degree.

Beneficial effect: the beneficial effect of the slot antenna loaded with coaxial feeding capacitance of the present invention is that the antenna can reduce the electric size of the whole antenna, realize miniaturization, and at the same time have the effect of suppressing the cross polarization of the antenna.

Description of drawings

FIG. 1 is a schematic diagram of the overall structure of a slot antenna loaded with a coaxial feeding capacitor.

In the figure there are: dielectric substrate 1, metal ground 2, radiation slot 3, coaxial feeder 4, outer conductor 5, two ends 6, capacitor 7, port 8, inner conductor 9 and edge 10.

detailed description

The present invention will be further described below in conjunction with drawings and embodiments.

The embodiment adopted in the present invention is: the slot antenna loaded by coaxial feeding capacitance includes a dielectric substrate 1, a metal ground 2 arranged on the dielectric substrate 1, a radiation slot 3, and a coaxial feeder 4; one side of the dielectric substrate 1 It is the metal ground 2, the outer conductor 5 of the coaxial feeder 4 is connected to the metal ground 2; there is a radiation slot 3 on the metal ground 2, the shape of the radiation slot 3 is rectangular, and the radiation slot 3 is located in the center of the metal ground 2 The two ends 6 of the radiation slot 3 are short-circuited; several capacitors 7 are connected in parallel across the two edges of the radiation slot 3, so that the characteristic impedance of the radiation slot 3 becomes lower; one end of the coaxial feeder 4 is the port 8 of the antenna , the inner conductor 9 at the other end of the coaxial feeder 4 crosses the radiation slot 3 and is connected to the metal ground 2 at the edge 10 of the radiation slot 3 .

Changing the number, capacitance and spacing of the loading capacitors 7 can adjust the characteristic impedance of the radiation slot 3 , and can change the operating frequency of the antenna, the width of the working frequency band and the electrical length of the radiation slot 3 .

The operating frequency of the slot antenna loaded with coaxial feed capacitance is mainly determined by the resonant frequency of the radiation slot 3, but the size of the metal ground 2 and the position where the inner conductor 9 of the coaxial feed line is connected to the radiation slot 3 can also affect the antenna's Adjust the working frequency and matching degree.

In terms of technology, the slot antenna loaded with coaxial feeding capacitors can be realized by either ordinary printed circuit board (PCB) technology, low temperature co-fired ceramic (LTCC) technology or integrated circuit technology such as CMOS and Si substrates. Capacitor 7 can select the chip capacitor 7 of corresponding package according to the working frequency, and select the width of the radiation slot 3 according to the distance between the electrodes of the two pins of the capacitor 7 .

According to the above, the present invention can be realized.

Claims (2)

1. the slot antenna of a coaxial feed capacitive load, it is characterised in that this antenna includes medium substrate (1), sets Put metal ground (2) on medium substrate (1) and the radiation line of rabbet joint (3), coaxial feeder (4)；Medium substrate (1) One side be metal ground (2), the outer conductor (5) of coaxial feeder (4) is affixed with metal ground (2) and is connected；Metal ground (2) having the radiation line of rabbet joint (3) on, the shape of the radiation line of rabbet joint (3) is rectangle, the radiation line of rabbet joint (3) with being positioned at metal (2) Center；Two ends (6) short circuit of the radiation line of rabbet joint (3)；Several electric capacity (7) is had to be connected in parallel across radiating the line of rabbet joint (3) Two edges so that radiation the line of rabbet joint (3) characteristic impedance step-down；One end of coaxial feeder (4) is the port of antenna (8), the inner wire (9) of coaxial feeder (4) other end strides across the radiation line of rabbet joint (3), on the limit of the radiation line of rabbet joint (3) Edge (10), with metal (2) be connected.

The slot antenna of a kind of coaxial feed capacitive load the most according to claim 1, it is characterised in that change and add Carry quantity, capacitance and the spacing of electric capacity (7), the characteristic impedance of the radiation line of rabbet joint (3) can be regulated, thus it is possible to vary antenna Operating frequency, the width of working band and radiation the line of rabbet joint (3) electrical length.