JP3375591B2 - Automatic alignment device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic microwave matching device for load fluctuations in a waveguide circuit.

[0002]

2. Description of the Related Art In recent years, the field of application of microwave power has expanded and is used for various purposes. The microwave power which is generated by the oscillator (microwave power) effectively applied to the load, it is important quality control to always stabilize the microwave power to the applied. Therefore, it is widely used to cancel the reflected power from the load by matching the impedance between the power source and the load by using a matching device .

Conventionally, so-called stubs are often used as matching devices in waveguide circuits. In the case of a rectangular waveguide, a stub is a combination of two or three stubs that generate a reflected wave by inserting a metal rod from a wide surface (E surface) or a narrow surface (H surface). It will be easy.

However, as the microwave power used increases, the power withstanding characteristic when using the stub becomes a problem. For example, increasing the electric field strength by concentrating the electric field at the tip of the metal rod of the stub, increasing the temperature rise of the metal rod, preventing radio wave leakage due to the connection structure of the stub with the waveguide surface, and increasing the electric field strength in the choke structure. There are various problems that should be addressed.

[0005]

The present invention invention is to solve the above has been proposed in view of the above circumstances, the use of a matching device in place of the matching device using a stub, excellent and easy to control small in power handling capability It is intended to realize such a system.

[0006]

SUMMARY OF THE INVENTION To achieve the above object, the present invention is directed to an automatic alignment disposed between an oscillator and a load.
It is a combination device, the automatic matching device is a waveguide branch variable
Reactance is provided in three places, and the waveguide branch variable reactor
One side of the chest is used as a short-circuit plane, and this position is made variable.
Tube branch variable reactance length in the range of 0 to λg / 4
It has a variable matching device, and it is taken out at the input side of the matching device.
The calculated signal is processed to eliminate the reflection coefficient at this position.
Obtain the signal of logarithm │Γ│ and phase angle θ and adjust by this signal.
Impedance and matching looking at the load from the output side of the synthesizer
Calculate the conditions and adjust each waveguide branch variable reactance of the matching box.
The position of the short-circuited surface so that the value of
The automatic matching device is characterized by the above.

[0007] The present invention provides a waveguide circuit that transmits microwave power, three waveguides to the waveguide transmission line connected between the load and the oscillator branching variable reactance (hereinafter simply "variable It is an automatic matching device with a "reactance". In the case of a rectangular waveguide, the branch circuit has a wide surface (E surface)
The method of providing the variable reactance has an advantage that the structure that forms the variable reactance is small, but it is also possible to use a narrow surface (H surface).

Although there are various methods of forming the variable reactance, for example, a method using a movable short circuit (short circuit plate) having a simple structure can be adopted. If 0~λg / 4 the movable distance of the short-circuiting plate (lambda] g is abbreviated guide wavelength, hereinafter) Li <br/> reactance in 0~jX (Ω), X takes the 0 to ∞. By taking the interval of the variable reactance to an integral multiple of lambda] g / 4, it operates in <br/> a matching device capable of covering the entire range of Smith chart.

[0009] provided a directional coupler to the oscillator side of this matching unit, coupled to the traveling wave power reflected power, the reflected power signal theta ₁ and theta _{2 (e.g.} theta ₁ ≒ 0 °, theta ₂ ≉90 °), and the traveling wave power signal is divided into θ ₃ and θ ₄ (for example, θ
₃ ≈ 0 °, θ ₄ ≈ 180 °) divided signals are obtained, and the absolute value of the reflection coefficient of the load │Γ│ and the phase angle θ seen from the directional coupler are calculated with them, and the absolute value of this reflection coefficient is calculated. The variable reactance can be driven and the matching operation can be performed using the signal of the value | Γ | and the phase angle θ.

[0010] In the automatic matching device according to the present invention, integer
Three or more capacitive coupler the oscillator side of the waveguide transmission line from engager disposed lambda] g / 8 intervals, thereby detecting the respective signals taken out, the reflection coefficient of the load by performing arithmetic processing It is also possible to calculate the absolute value | Γ | and the phase angle θ, and drive the variable reactance and perform the matching operation by using the signals of | Γ | and θ.

As a method of driving the variable reactance, a ball screw may be used or a pulse motor may be used. Alternatively, both of them may be used, and the pulse motor and the ball screw driving unit may be coupled by two pins provided on the rotary plate . The reference position of the reactance to the waveguide surface and the same surface, may be determined maximum movement width select the number of steps corresponding to the number of pulses from this position.

Similarly, in the coaxial tube circuit,
A matching box can be configured by connecting a coaxial tube transmission line between a vibrator and a load, and using three coaxial tube branch variable reactances on the transmission line.

Measurement at the input section of the automatic matching device , arithmetic processing
Absolute value │Γ│ and by calculating the electrical angle values for each re-A <br/> reactance and the interval by a phase angle theta, the reflection coefficient of the load in the position of the variable reactance closest to the load of the reflection coefficient The absolute value of | Γ _L | and the phase angle θ _L are calculated. Normalized load impedance Z at this point
₁ = R ₁ + jX ₁ (jX ₁ <0), R ₁ =
1 or R ₁ <1 or R ₁ > 1 is determined, and the matching device is configured to drive three variable reactances by performing arithmetic processing according to each case. You can

Further, in the above standardized load admittance Y ₁ = G ₁ + jB ₁ (jB ₁ <0), G ₁ = 1 or G ₁ <1 or G ₁ >.
It is also possible to configure the matching device so as to determine the three cases of 1 and perform arithmetic processing according to each case to drive the three variable reactances.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of the automatic aligning device of the present invention is shown in FIG. 1, and the present invention will be described in detail. In Figure 1, the transmission line 4 of the rectangular waveguide is connected between the microwave oscillator 5 and the load 6, the three E-Plane Waveguide branch circuits 1 and 3 in the lambda] g / 4 intervals It is provided. Movable short circuits 1a, 2a and 3a are provided in this waveguide branch circuit, and operate as variable reactances 1, 2 and 3 by completely reflecting the incident wave. The movable distance of the short-circuit surfaces 1b, 2b and 3b of the movable short circuiter is d
If _{(d 1, d 2, d} 3) and, the value of reactance that reference the position of the waveguide surface as 0 jtan (β · d)
(Beta phase constant) since it expressed as, reactance that were normalized to d as 0~λg / 4 is inductive reactance 0
In jX, X has a value of 0 to ∞. 7 is a directional coupler.

FIG. 2 shows two waveguide branch circuits close to the load side.
That is a Smith chart showing a matching area by linear Retsuri reactance of the variable reactance (in this case, the impedance chart). Since the variable reactances (1, 2 and 3 in FIG. 1) act as a series circuit with respect to the transmission circuit, of the three variable reactances arranged at intervals of λg / 4, the two that are close to the load (in FIG. 1). 3 and 2), as shown in FIG. 2, the shaded area of the Smith chart (impedance chart) becomes the matching range. 3 on the most power source side
Looking at the position of the second variable reactance (1 in FIG. 1),
The above non-matching range is moved to the symmetrical position on the Smith chart. Therefore, these three variable reactances can match the entire Smith chart.

[0017] For three variable reactance of equally spacing lambda] g / 4, if the scaled reactance is capacitive, the admittance Y = jB, B is 0~∞
Therefore, the entire Smith chart (admittance chart in this case) can be matched. The short-circuit surface of the movable short-circuit device may have a choke structure or, depending on the case, a contact piece structure. A ball screw or a pulse motor may be used to drive the movable short circuiter. Alternatively, in the variable reactance driving method, the pulse motor and the ball screw driving unit may be coupled by two pins provided on the rotary plate . The reference position of the reactance to the waveguide surface and the same surface, may be determined maximum moving width by selecting the number of steps corresponding to the number of pulses from this position.

[0018] The front that is consistency of these variable reactance
A directional coupler is provided on the oscillator side of the converter to couple the traveling wave power and the reflected wave power, and the reflected wave power signal is divided into 0 ° and 90 °, and the traveling wave power signal is 0 ° or 180 ° or 0 °. ° give 180 ° divided signals, by using the absolute value │Γ│ and phase angle θ of the reflection coefficient thereof as viewed from the directional coupler by the load, the value of each reactance electrical angle that interval By calculating the absolute value │Γ _L │ of the reflection coefficient of the load at the position of the variable reactance closest to the load.
And the phase angle θ _L are calculated.

Load impedance normalized by the characteristic impedance at this point Z ₁ = R ₁ + jX
₁ (jX ₁ <0), R ₁ = 1 or R ₁ <1,
Alternatively, it is possible to configure the matching device so as to perform determination in three cases of R ₁ > 1, and perform arithmetic processing according to each case to drive the three variable reactances.

Normalized load impedance Z ₁ = R
₁ + jX ₁ is the absolute value of reflection coefficient │Γ _L │ , phase angle θ
It is calculated from the following equation using _L.

[0021] _{R 1 = (1-Γ L} 2) / (1-2Γ L cosθ L + Γ L 2) X 1 = 2Γ L sinθ L / variable as described _{(1-2Γ L cosθ L + Γ L} 2) already Since the reactance- standardized reactance + jX acts as a series circuit with respect to the transmission circuit, in order to establish matching at this position, R
₁ = 1 and jX ₁ <0 must be satisfied. Similarly, R ₁ <1, jX ₁ <0, or R ₁ > 1, jX ₁ <
It is possible to configure the matching device so as to determine the case of 0 and drive the three variable reactances by the arithmetic processing according to each case.

FIG. 3 shows another example of the automatic alignment apparatus according to the present invention. In FIG. 3, 8 is a capacitive coupler, and other reference numerals are the same as those in FIG. 3 λg three capacitive coupler 8 in place of the directional coupler 7 in Figure 1, in the oscillator side of the waveguide transmission line from the position of the variable reactance / 8
The case where they are arranged at intervals is shown. Each signal extracted by the capacitive coupler 8 is detected, and an arithmetic process is performed to calculate the absolute value | Γ | of the reflection coefficient of the load and the phase angle θ.
It is also possible to drive the variable reactance and perform the matching operation by using the signals of | and θ.

The operation procedure of the matching circuit of the automatic matching apparatus according to the present invention will be described in detail below with reference to FIG. 1) The initial settings d ₁ = 0, d ₂ = 0, and d ₃ = 0 are set to zero. 2) Set d ₁ , d ₂ and d ₃ according to the memory value. 3) Measure the normalized input impedance Z ₁ or complex reflection coefficient Γ ₁ of the matching circuit with the load connected. The presence or absence of the external setting signals Z ₁ ″ and Γ ₁ ″ is determined. When there is an external setting signal, a vector obtained by adding the external setting signal vectorally to the above is expressed as Z ₁ or Γ ₁ . 4) Calculate Xs ₁ = tan βd ₁ , Xs ₂ = tan βd ₂ , Xs ₃ = tan βd ₃ . 5) Z ₁ −jXs ₁ = Z ₁ ′ is calculated to obtain the complex reflection coefficient Γ ₁ ′ and its absolute value | Γ ₁ ′.
|, Calculate the phase angle θ ₁ ′. 6) From the phase angle θ _{2 where} θ ₂ = θ ₁ '+ π / ₂ and the absolute value | Γ ₁ ' |, the complex reflection coefficient Γ
₂ and the normalized input impedance Z ₂ are calculated. 7) Z ₂ −jXs ₂ = Z ₂ ′ is calculated to obtain the complex reflection coefficient Γ ₂ and its absolute value | Γ ₂ ′.
│, the phase angle θ ₂ 'is calculated. 8) The complex reflection coefficient Γ ₃ and the standardized input impedance Z ₃ are calculated from the phase angle θ _{3 where} θ ₃ = θ ₂ ′ + π / 2 and the absolute value | Γ ₂ ′ |. 9) Obtain Z ₃ −jXs ₃ = Z ₁ and calculate the following formula. Z ₁ = R ₁ + jX ₁ , 1 / Z ₁ = Y ₁ = G ₁ + jB ₁ complex reflection coefficient Γ ₁ and its absolute value | Γ ₁ |, phase angle θ
Calculate ₁ . 10) Display Z ₁ , θ ₁ , | Γ ₁ | , Y ₁ .

The matching operation will be described corresponding to the following three cases. Case (a) R ₁ = 1 and X ₁ <0 Case (b) R ₁ <1, X ₁ <0 or G ₁ > 1, B
₁ <0 Case (c) Cases other than the above.

Case (a) (when R ₁ = 1 and X ₁ <0) (11 to 1
3) ₁₁₎ from _{Xs 1 = 0, -X 1 =} Xs 1 become Xs ₁ as _Xs 2 = 0 calculates the _{d 1.} 12) Compare the current d ₁ with the new d ₁ and drive the motor. 13) calculating the Xs ₁ newer _{d 1} confirms that become _Z 3 = 1.

Case (b) (R ₁ <1, X ₁ <0, or G ₁ > 1, B ₁ <0) (21 to 29) 21) Z ₃ = Z ₁ + jXs ₃ Y ₃ = G ₃ + jB ₃ Is calculated, and Xs ₃ when G ₃ = 1 is calculated. Calculate d ₃ from the value of Xs ₃ . 22) Calculate the difference from d ₃ from the position of the short-circuited surface and drive the motor. 23) Xs ₃ is calculated from the new d _3, and the complex reflection coefficient Γ ₃ and the phase angle θ ₃ are calculated from Z ₃ = Z ₁ + jXs ₃ . 24) From the phase angle θ ₂ 'where θ ₂ ' = θ ₃ -π / 2 and the absolute value | Γ ₃ |, the complex reflection coefficient Γ
₂ ′ and the normalized input impedance Z ₂ ′ are calculated. 25) Xs ₃ is calculated from the new d ₃ and Z ₂ = Z ₂ '+
JXS ₂ and to _{= C 2 '+ j (D} 2' + Xs 2) for calculating a _{d 2} a second term in this equation from Xs ₂ That -D ₂ '= Xs ₂ to 0. 26) calculating the complex reflection coefficient gamma ₂ and the phase angle theta ₂ from _{Z 2.} 27) From the phase angle θ ₁ ′ with θ ₁ ′ = θ ₂ −π / 2 and the absolute value │Γ ₂ │, the complex reflection coefficient Γ
₁ ′ and normalized input impedance Z ₁ ′ are calculated. 28) Since Xs ₁ = 0, Z ₁ = Z ₁ ′ and Γ ₁ = Γ ₁ ′. 29) When there is an external signal, Γ ₁ + Γ ₁ ′ = Γ ₁ Z ₁ + Z ₁ ″ = Z ₁ and return to 5).

In case (c) [states other than cases (a) and (b) above] (31 to 39) 31) Xs ₃ = 0, d ₃ = 0. From Z ₁ , the complex reflection coefficient Γ ₁ and its absolute value │Γ ₁ │,
Calculate the phase angle θ ₁ . 32) From the phase angle θ ₂ 'where θ ₂ ' = θ ₁ -π / 2 and the absolute value | Γ ₁ |, the complex reflection coefficient Γ
₂ ′ and the normalized input impedance Z ₂ ′ are calculated. 33) Calculate Xs ₂ where Z ₂ = Z ₂ + jXs ₂ , Y ₂ = G ₂ + jB ₂ G ₂ = 1 and calculate d ₂ . 34) Motor drive 35) Xs ₂ is calculated from the new d _2, and Z ₂ = Z ₂ + jXs ₂ is calculated. The complex reflection coefficient Γ ₂ and the phase angle θ ₂ are calculated from Z ₂ . 36) From the phase angle θ ₁ 'where θ ₁ ' = θ ₂ −π / 2 and the absolute value | Γ ₂ |, the complex reflection coefficient Γ
₁ ′ and normalized input impedance Z ₁ ′ are calculated. 37) Calculate Xs ₁ that satisfies Z ₁ = Z ₁ ′ + jXs ₁ , Y ₁ = G ₁ + jB ₁ G ₁ = 1 and calculate d ₁ . 38) Drive the motor with the difference between the current d ₁ and the new d ₁ . 39) Confirm that Z ₁ = Z ₁ ′ + jXs ₁ Γ ₁ = 0 and Z ₁ = 1.

[0028]

Since the automatic aligning device according to the present invention has the above-mentioned structure, it has the following effects. (1) It can be used with high microwave power because of its structure with excellent power resistance. (2) Since the short-circuit surface can be used as a branch reactance from the waveguide surface, the shape can be downsized. (3) Simple structure and high reliability.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a matching circuit according to the present invention.

[Figure 2] Smith chart showing a matching area by two straight Retsuri reactance close to the load side (impedance chart)

FIG. 3 is a diagram showing another example of a matching circuit according to the present invention.

[Explanation of symbols]

1,2,3 waveguide branching variable reactance 1a, 2a, 3a movable short-circuit unit 1b, 2b, 3b shorting plane 1d, 2d, 3d moving distance 4 rectangular waveguide transmission circuit 5 Oscillating unit 6 load 7 directional coupler Unit 8 Capacitive coupler

Continuation of the front page (56) Reference JP-A-2-249301 (JP, A) JP-A-6-188221 (JP, A) JP-A-64-16102 (JP, A) JP-A-63-15502 (JP , A) Actual Kaihei 7-20702 (JP, U) Funayama Kiyochika, “Commentary / Microwave Technology”, Denki Shoin, 1969, page 85 Keiji Suzuki, “Microwave measurement”, Corona Publishing Co., Ltd. 1960, pp.139-140 (58) Fields investigated (Int.Cl. ⁷ , DB name) H01P 5/04 601

Claims (4)

(57) [Claims] 1. An automatic adjuster arranged between an oscillator and a load.
And a waveguide branch variable relay.
The reactance branching variable reactor is provided at three places.
This position is made variable by using one surface of the waveguide as a short-circuit surface.
The length of the branch variable reactance can be in the range of 0 to λg / 4
It has a changed matching device, and it was taken out at the input side of the matching device.
Absolute value of reflection coefficient at this position by processing the signal
Obtaining the signal of │Γ│ and the phase angle θ,Each signal is guided by this signal
Calculate the value of the tube branch variable reactance and the electrical angle of the interval
The waveguide branch variable reactor closest to the load.
Absolute value of inverse coefficient of load at position of chest | │ _L │
And the phase angle θ _L Calculated and normalized load at this point
Impedance Z _L = R _L + JX _L (JX _L <0)
K, R _L = 1, R _L <1 and R _L In the three cases of> 1,
Or standardized load admittance Y _L = G _L + JB
_L (JB _L G in <0) _L = 1, G _L <1 and G _L
Discriminates in 3 cases of> 1 and in each case
According toLoad from the output side of the matching box
Calculate the impedance and matching conditions you saw,
The value of each waveguide branch variable reactance meets the matching condition.
As described above, the position of the short-circuited surface is made variable.
Dynamic matching device. 2. A directional coupler is provided on the oscillator side of the matching device, a part of the traveling wave power and the reflected wave power is taken out by this directional coupler, and the absolute value of the reflection coefficient of the load | Γ | And the phase angle θ is calculated. 3. The oscillator side of the matching unit is provided with 3 at an interval of λg / 8.
The automatic matching according to claim 1, wherein at least two capacitive couplers are provided, each signal extracted from the capacitive couplers is detected, and an arithmetic process is performed to calculate the absolute value | Γ | of the reflection coefficient of the load and the phase angle θ. apparatus. 4. An automatic matching device using a coaxial tube branch variable reactance instead of the waveguide tube branch variable reactance of claim 1.