SU1442962A1 - Meter of transmission coefficient of nonmutual microwave four-pole network - Google Patents

Abstract

This invention relates to a radio measuring technique. The purpose of the invention is to reduce the measurement time. The meter contains rr-1, valve 2, bidirectional couplers 3 and 5, investigated non-reciprocating microwave quadruple 4, detectors 6 and 12, indicators 7 and 13, attenuator 8, phase shifter 9, electrically controlled phase shifter 10, short cut 11 and rr 14 low frequency. Before the measurement starts, the meter is balanced. Change coef. transmission attenuator 8 and phase shifter 9 with respect to their values when balancing correspond to the module coefficient. transmission and phase coefficients. four-port 4 transmissions, respectively, in the forward and reverse directions. The meter allows you to determine the complex frequency. Transmitting four-pole 4: valves and circulators without changing the direction of the latter in the path, which ensures the achievement of the goal. 1 il. (L with

Description

thirty

 ).

d, c JT-dJ

+ S, r, d, (l-d G, zGh1) / (1 - - X 1 1 KV

cf

II

2I1

+ + V "+ yd, (2)

- V d, where

Xi

ofp e ° the transfer coefficient of the quadrupole 4 under investigation in the opposite direction (from short-span I Gh, I the reflection coefficient

35

loneVon - vj.

It is easy to check the occurrence of the V minimum by the presence of the maximum signal on the first indicator 7. In addition, for exclusion. , 1 lpni false lows when measuring

11 to the generator 1)} tOп “.

iit, on the second indicator 13, the 1-reflection coefficient under study,

, the quadrupole 4 must be included in the i-inputs of the quadrupole 4. „.,

measuring tract in such a way that, while balancing, instead of

followed by a quadrupole into the path („generator 1) it had large

includes a segment of a regular wave- 45 "reverse wave (from

short circuit 11 to generator 1),

water. Presumably there are no losses in it, in expressions (l) and (2) they substitute

those. 3

ghr

i toSp.

Then, the gQ th quadrupole 4 and the signal on

oGy

exp

G l

G L J

Gh,

h

 about.

Where

21 (1 L)

 electric length of a segment of a regular waveguide.

The minimum signal on the first indicator 7 is subject to

II

2I1

+ + V "+ yd, (2)

- V d,

loneVon - vj.

It is easy to check the occurrence of the Vth minimum by the presence of the maximum signal on the first indicator 7. In addition, for excluding the t. 3

ghr

i toSp.

Then, the gQ th quadrupole 4 and the signal on

The first detector 6 is in general a sum of two signals, one of which is phase modulated by a low frequency generator. 14. The amplitude - gg and the signal taken from the first detector 6 varies with a frequency that is a multiple of the frequency of the generator 14, as long as both signals are present. With the help of an attenuator 8 and the first one

Video 9 achieves the minimum mgg of the amplitude-modulated signal envelope on the screen of the oscillographic indicator 7, thus eliminating the influence of the reflections from the output of the quadripole 4 under study on the measurement error of the transmission coefficient.

Then the modulus and phase of the transmission coefficient of the studied quadrupole in the forward direction from (1) taking into account the balancing (3) are determined by the change in the transmission coefficient of the attenuator 8 and the phase rotator 9 relative to the balancing on the first indicator 7

etc

- L

one

 g

where l is the change in the coefficient of transmission (attenuation) of the attenuator 8;

 +

2111

7i

where l | - change in the phase shift introduced by the first phase with the grower 9.

Since a microwave non-reciprocal device — valves, circulators have a large isolation (large difference between forward and return losses), on the order of 10–20 dB or more, the signal on the second detector 12 with the non-reciprocal quadripole 4 included in the path is amplitude modulated signal. Using an attenuator 8 and the first phase shifter 9, the envelope amplitude of the amplitude-modulated signal on the second indicator 13 is achieved, which corresponds to the presence of only the signal reflected from the quadrupole 4 input on the second detector 12. The difference between the attenuator 8 and the first phase shifter 9 in this case in the case of balancing on the second indicator 13 corresponds to the module and phase of the transfer of the quadrupole 4 in the opposite direction

r off

where is the change in the attenuation coefficient of the attenuator 8 in this case;

2I1 lb

five

five

where cf is the change in the phase shift of the first phase shifter in this case. The proposed meter makes it possible to determine the complex transmission coefficients of non-reciprocal microwave quadrupoles (valves and circulators) without changing the direction of their inclusion in the path, which significantly reduces the complexity of the measurements. To reduce the measurement error, the first and second bidirectional actuators must be three-separable. If one calibrates the first and second detectors according to the level of incident power, one can measure additionally the modules of reflection coefficients from the input and output of a non-reciprocal quadrupole (or CWS) without re-aligning the microwave path of the meter.

Claims (1)

Invention Formula Non-reciprocal microwave quadrupole transmission coefficient meter, containing a generator connected in series, a valve, a first bidirectional coupler, a second bidirectional coupler connected in series, a first detector and a first indicator, as well as an attenuator, the output of which is connected to the second output of the second bidirectional otvetovitel, while the output of the first bidirectional coupler and the input of the second bidirectional coupler are respectively an input and output for connecting a non-reciprocating microwave fourpole, characterized in that, in order to reduce the measurement time, a phase shifter is inserted, connected between the second output of the first bidirectional coupler 45 and an attenuator input, a second detector connected in series, the input of which is connected to the third output of the first bidirectional coupler, and a second indicator electrically controlled phase shifter connected to the third output of the second bidirectional coupler, mounted on the output of the electrically controlled f55 and a low frequency generator connected to the control input of the electrically controlled phase shifter. 0