SU842633A1 - Device for measuring loss in nonreciprocal four-terminal networks - Google Patents

Description

The invention relates to radio engineering, as well as to measuring equipment and can be used as a microwave loss meter for non-reciprocal two-port networks. A device for measuring non-reciprocal quadrupole losses is known, comprising a tunable super high frequency generator, the output voltage of which is connected to horizontal deflection plates of a cathode ray tube, and two circuits each of which consist of series-connected valves, directional taps and forward waves with detectors in secondary channels and a microwave switch, and also two adders one of which is connected to the outputs of the secondary channels direct coupler, and the other from output1O1 of the secondary channels of the directional feedback couplers, and the outputs of the adders are connected to the corresponding inputs of the ratio meter, the output of which is connected to the vertical deflection plates of the CRT, and some outputs of the microwave switches are connected through a segment of the calibration waveguide, and the other non-reciprocal quadripole L11 is connected to the others. However, the known device has large errors in the measurement of forward and return losses associated with the presence of misalignments in the path, which lead to reflections from the input and output of the measured quadrupole, and, consequently, additional systematic error. direct and return loss measurements. For this, a known device for measuring the loss of non-reciprocal four-port network, comprising a tunable microwave generator, the output of which oscillating voltage is connected to the horizontal deflection plates of the cathode ray tube, and two circuits, each of which consists of series-connected gates, directional directors and directors reverse waves with detectors in the secondary channels, and a microwave switch, and also two adders, the inputs of one of which are connected to the outputs of the secondary the other channels are connected to the outputs of the secondary channels of the directional taps of the return wave, and the outputs of the adder are connected to the corresponding inputs of the ratio meter, the output of which is connected to the vertical deflection plates of the electron-bundle tube, while some outputs of the superhigh-frequency the switches are connected via a cut-off section of the calibration waveguide, and the other is connected to the Q- following non-reciprocating quadrupole, a three-junction hybrid connection with electrically control- attenuators connected at its outputs, while the input of a three-digit hybrid connection is connected to the output of a tunable microwave generator, and the output of each electrically controlled attenuator is connected to the input of the corresponding valve, and their control 20 inputs are connected to anti-phase outputs of the inserted control unit .

The drawing shows a structural electrical circuit of the proposed device.

A device for measuring non-reciprocal quadrupole losses includes a tunable microwave generator 1, a cathode ray tube (CRT) 2, valves 3 and 4, directional couplers 5 and forward wave, directional couplers 7 and 8 of the reverse wave with detectors in secondary channels, microwave switches 9 and 10, two adders 11 and 12, a ratio meter 13, a segment 14 of a calibration waveguide, a nonreciprocal quadrupole under study 15, a three-digit hybrid connection 16 connected to electrically controlled atoms enyu- 40 ator 17 and 18, the control unit 19. The device works as follows.

In calibration mode, the microwave switches 9, and 10 us- E are set to d and c (,

the tunable microwave generator 1 and the control unit 19 are transferable to manual mode, and the frequency of the microwave signal is set to an equal to the average operating frequency of the non-reciprocal quadrupole under test 15. At this, the control unit 19 is set to a position where the controlled attenuator 17 is turned on, and the attenuator 18 is off, and the outputs of the adders 13 and 12 are connected to the inputs of the ratio meter 13. In this state of the measuring signal, the microwave signal comes from microwave generator 1 to 60 soeineni decibel hybrid 16 where poovnu is distributed between the two channels. Signal

from the second output of the three-digit hybrid compound 16 absorbs- 5

with the attenuator 18 controlled and cheaper, the measuring path does not arrive. The signal from its first output passes through controlled attenuator 17, valve 3, main waveguide channels of directional couplers 5 and 7, microwave switch 9, segment 14 of the calibration waveguide, microwave switch 10, main waveguide channels of directional couplers 8 and b, and is absorbed by valve 4 In this case, the outputs of the detector sections of the directional couplers 5 and 8 appear signals corresponding to the power level at, the input and output of the segment 14 of the calibration waveguide, and at the first input measure ate 13 is the relationship of the signal (the quadratic detection)

(one)

R-, .

Where P - power level at the input

tract 7-9-14-10;

K - transmission coefficient path 5-11.

At the second output of the meter 13 ratios, a signal appears

(2:

a - 9 10 where K is the path transmission coefficient 8-12;

S is the transfer coefficient of the corresponding device node index. At the same time, Sy Adjust the path transmission ratio 8-12, set the ratio meter to O dB. This happens when U Ki,, (3)

TO-,

Where

TO

 Sg- S- ,,

In the next calibration step, the control unit 19 is set to a position in which the signal from the tunable microwave generator 1 passes sequentially through a three-junction hybrid 16, an attenuator 18, a valve 4, directional couplers 6 and 8, a microwave switch 10, a segment 14 of the calibration waveguide, a microwave switch 9, directional couplers 7 and 5 are absorbed by valve 3.

In this case, at the first input of the meter 13 ratios, sig 1) appears - p (C)

and - to g / 2, O;

where f / 2. - the level of the SECH-power at the entrance of the path 8-10-14-9; k is the path gain of 6-11, and a signal appears at the second input of the ratio meter

u4 - 4 Sg Sg S. R,. (6) By adjusting the path gain 7-12, the relationship meter is set to O dB, with Ul. (7)

-

Kj

to

Where

(eight)

Claims (1)

KA, SS Sto Sg In the measurement phase, the high-frequency switches 9 and 10 are set to position b and b, and the tunable microwave generator 1 and the control unit 19 are switched to automatic mode. The ramp voltage from the oscillation frequency f is supplied from the tunable microwave generator 1 to the deflecting plates of the CRT as a sweep voltage, and the control unit 19 produces control pulses with such frequency F. iriuoi I, - 1 ak and Mctijhio /, where n determines the number of measuring points within the swing bar. On a CRT screen, a beam delineates two lines, one of which represents the SSS RPR function) (9 where the EPR is the direct loss of the non-reciprocated four-pole KaF Microwave signal being investigated, and the other is the function (yp з z.). When the microwave signal enters the measuring path through the attenuator 17, at the first input of the meter 13 ratios there will be a voltage j - 3 Y taking into account the expression Ud P-, At the output of the meter 13 ratios will be% P 204 If- 20e (| where A is the measured direct loss in dB. When the microwave signal is n steps into the measuring path through the attenuator 18, at the second input of the meter 13 ratios there will be voltage SII.P.K, Sg- taking into account the expression i.k; .p, ogr- a- (15 At the output of the meter 13 ratios will be -. o. (16 where L gr is the measured background loss (13 Thus, the proposed device provides high accuracy in the automatic measurement mode. Claims of the invention A device for measuring the losses of non-reciprocal quadrupoles, containing a tunable microwave generator, the output voltage of which is connected to horizontal deflecting plates of a cathode-ray tube, and two circuits, each consisting of series-connected valves, directional taps of forward and backward waves with detectors in the secondary channels, and a microwave switch, and also two adders, the inputs of one of which are connected to the outputs of the secondary channels the directional taps of the direct wave, and the other with the outputs of the secondary channels of the directional taps of the return wave, and the outputs of the adders are connected to the corresponding inputs The ratio of the output is connected to the vertical deflection plates of the cathode-ray tube, while some outputs of the microwave switches are connected through a segment of the calibration waveguide, while others are connected to a non-reciprocated quadrupole, in order to improve the accuracy in measuring forward and return losses , a three-digit hybrid connection is introduced with electrically controlled attenuators connected at its outputs, while the input of a three-digit hybrid connection with one with a yield of a tunable microwave oscillator and Ks1Zhdogo electrically controllable output attenuator coupled to the input of the respective gate, and their control inputs connected to the antiphase outputs inputted control unit. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 192871, cl. G 01 R 27/32, 1967 (prototype).