SU1490654A1 - Device for measuring amplitude-phase field distribution in antenna apperture - Google Patents

Abstract

The invention relates to radio measurements. The purpose of the invention is to reduce the measurement time of the amplitude-phase distribution of the field in the aperture of the antenna. The device contains a microwave generator 1, phase handles 2 and 3, measuring probes 4 and 5, the test antenna 6, phase detectors 7 and 9, phase shifter 8 by 90 °, synchronous detectors 10-13, generator 14 square-wave pulses, digital dividers 15, 16 and 18, an inverter 17 and a control and processing unit 19. In the device, by simultaneously probing the field in two columns and simultaneously processing the signals, the measurement time is halved. 2 Il.

Description

1

The invention relates to radio measurements and can be used to measure the amplitude-phase distribution of the field in the aperture of the antenna.

The purpose of the invention is to reduce the measurement time of the amplitude-phase distribution of the field in the aperture of the antenna.

FIG. 1 shows a structural electrical circuit diagram of a device for measuring the amplitude-phase distribution of a field in the aperture of an antenna;

The signal from the output of the microwave generator 1 through phase handles 2 and 3 is fed to the measuring probes 4 and 5 ,. which are set apart from each other, a multiple of the scanning step with the possibility of simultaneous movement, as a result of which, when probes 4 and 5 are moved vertically, a field is probed in two columns simultaneously. The signals emitted by probes 4 and 5 are received by the antenna 6 under study, fed to the input of the phase detector 7 directly and

in fig. 2 - voltage plots on the output 5 to the input of the phase detector 9 through a de-generator of rectangular pulses.

A device for measuring the amplitude-phase distribution of the field in the aperture of the antenna includes a microwave generator 20 1, the output of which is successively connected through the first 2 and second 3 phase handlers connected respectively to the inputs of the first 4 and second 5 measuring probes installed with 25 simultaneously moving apart from each other, a multiple of the scan step. The output of the investigated antenna 6 is connected to the first input of the first phase detector 7 and after 30 the phase shifter 8 90 to the first input of the second phase detector 9. The second inputs of the phase detectors 7 and

9connected to microwave output

1, The output of the first phase detector s5 7 is connected to the first inputs of the first

10 and the second 11 synchronous detectors, and the output of the second phase detector 9 .- to the first inputs of the third

12 and fourth 13 synchronous detectors, 40 tori. The output of the generator 14 rectangular pulses through the first 15 and second 16 digital dividers is connected

to the second input of the first phase handler 2 and the second input of the second 11 and third 12 synchronous detectors. The output of the first digital divider 15 is through an inverter 17. and the third digital divider 18 is connected to the second input of the phase key 3 and the second input of the first 10 and fourth 13 synchronous detectors. The outputs of synchronous detectors 10, 11, 12 and

13 are connected to the corresponding inputs of the control and processing unit 19. 55

A device for measuring the amplitude-phase distribution of the field in the aperture of the antenna works as follows.

50

phase shifter 8 by 90. A reference signal is supplied to the second inputs of phase detectors 7 and 9 from the output of the microwave generator 1. The output signal of the phase detector 7 is the sum of two low-frequency signals of the rectangular form, whose amplitudes are proportional to A, cos), and Ajj Coaq. (where A, and q, are the pits and phase of the field at the point where probe 4 is located; A ,, and (jf2 at the point at which probe 5 is located) is fed to the synchronous inputs of the detectors 10 and 11, and the output signal of the phase detector 9 A sum of two low-frequency signals, whose amplitudes are proportional, and AjSinif, is fed to the inputs of synchronous detectors 12 and 13 The output signal of the generator 14 is fed into a digital divider 15, where the pulse duration is ensured is equal to two with a high density, then through a digital divide 16 is fed to the second inputs (control) of the phase shift key 2 and synchronous detectors 11 and 12, and through the inverter 17 and the third digital divider 18 to the control inputs of the phase manipulator 3 and synchronous sensors 10 and 13.

Thus, the control signals differ in phase by 90 (regardless of the oscillator frequency 14) and, in the turns of the synchronous detectors 10, 11, 12 and 13, signals in the form of direct voltages are allocated, the levels of which are proportional to A, coscp ,, A costf

A sinep

i sinif

accordingly.

The signals are fed to the corresponding inputs of the control and processing unit 19.

Imagine the measurement process in de mathematical relationships.

5 to the input of the phase detector 9 through

0 5 0

five

0

five

0

phase shifter 8 by 90. A reference signal is supplied to the second inputs of phase detectors 7 and 9 from the output of microwave generator 1. The output signal of the phase detector 7 is the sum of two low-frequency square-wave signals, whose amplitudes are proportional to A, cos, and Ajj Coaq. (where A, and q, are the amplitude and phase of the field at the point where probe 4 is located; A ,, and (jf2 at the point where probe 5 is located) is fed to the inputs of synchronous detectors 10 and 11, and the output signal of phase detector 9 as a sum of two low-frequency signals, whose amplitudes are proportional, and AjSinif, are fed to the inputs of synchronous detectors 12 and 13. The output signal of the generator 14 enters the digital divider 15, where the pulse duration is ensured, is two with high accuracy, then through the digital divider 16 is fed to the second inputs (control) phase ma ipul torus and two synchronous detectors 11 and 12 and through an inverter 17 and a third digital divider 18 - to the inputs of the phase control manipulator 3 and the synchronous detectors 10 and 13.

Thus, the control signals differ in phase by 90 (regardless of the oscillator frequency 14) and at the outputs of synchronous detectors 10, 11, 12 and 13, signals in the form of constant voltages are allocated, the levels of which are proportional to A, coscp ,, A costfj, ,

A sinep

i sinif

respectively. These

The signals are fed to the corresponding inputs of the control and processing unit 19.

Imagine the measurement process in the form of mathematical relationships.

ten

The signal at the output of the antenna 6 has the form,), t + qi, + (t) +

+4 i + t2 (t). where A, A and

Cj,, cpj are the amplitudes and phases of the field, respectively, at the opening of the antenna at the points of location of the probes 4 and 5; B - reference amplitude;

(t) (1) - laws of modulation of the microwave - W,

signal using phase manipulators 2 and 3.

The modulating signals differ from each other in phase shift by T / 2. The control input of phase manipulator 2 receives a signal having 20 Bcos2 Ft, where F is the frequency; and B - the amplitude of the generator (at the output of block 16, Fig. 2).

The control input of the manipulator 3 receives a signal from the output of block 18, which differs from the first controlled signal only by a phase shift of, i.e. this signal has the form

15

The signal I, which comes from the two orthogonal clock arrives at the first input synchronous detectors. Since the second input inputs are synchronous detected by two orthogonal signals, in turn, are associated with component parts 1 (the indicated components are in the form of A coscp , and A cosip at the outputs of synchronous de and 11. Respectively, the components de A, sinLp | and AJ sinCf are separated from the synchronous detec tion points. As in the devices, the parameters of the antennas are open, the measurement time is spent moving from the probe through a large number of then the proposed mouth will almost double and 25 measurement time (by measuring the field by two simultaneous processing, resulting in a decrease in the errors introduced by

.Bsin2 Ft.

Thus, the output signal of ai-30. Equipment stability, they 6 can be represented as

X f SiD-ii ll / Z) GSA, BCOS (,), sin mnt-b

mrl 2AjBcos (cOot + 4 i) cosmSltJ,

where 91 2 n Ft.

This signal is fed to the fao inputs.

the crank 8 by 90 and the phase detector 7, the output of which produces a signal having the form

, cosq, sinrzt + KA, jCoscp cosS2t, (1) where K is the phase transfer coefficient

detector 7.

The output signal of the antenna 6, the passage through the microwave phase shifter 8 takes the form

90

.-- -7r --- - i (Ht-c /.) Sinszt.

 t n t /. I- + AjBsin (a), t + q) cosntJ,

those. the carrier frequency is lagging in phase. Further, this signal, having passed through the phase detector 9, is converted to the form

, sinqi, sinqt + KAj singijCosnt. (2)

0

0

five

The signal I, which consists of the sum of two orthogonal parts (1), is fed to the first input of the low-frequency synchronous detectors 10 and 11. Since the second input (to the reference inputs) of the synchronous detectors receives two orthogonal signals, which, in turn, are pairwise synchronous with the component frequencies of the signal 1 (the indicated components I, in the form of A coscp, and A cosip, are separated at the outputs of synchronous detectors 10 and 11, respectively. Exactly at the outputs of synchronous detectors 12 and 13, components 1 (2) in the form of A, sinLp | and AJ sinCf respectively. So to In devices for measuring, parameters of antennas across the field in their opening, the measurement time basically goes to move the measuring probe over a large number of columns, the proposed device allows to reduce the measurement time by almost two times (with the simultaneous sounding field in two columns and simultaneous signal processing), as a result of which the errors introduced by the time span are also reduced.

0

five

0

five

Claims (1)

Formula inventions A device for measuring the amplitude-phase distribution of the field in the antenna opening, which includes a microwave generator, a first phase manipulator, a first measuring probe mounted with the ability to move in the aperture of the antenna under study, two phase detectors, a phase shifter 90 °, two synchronous detector, square pulse generator, control and processing unit, characterized in that, in order to reduce the measurement time of the amplitude-phase distribution of the field in the opening of the receiving antenna, a second meter is inserted into it The first probe, the second phase P1pul tor, the third and fourth synchronous detectors, three digital dividers and an inverter, the first and second measuring probes being mounted with simultaneous distance from each other, a multiple of the scanning step, and their inputs through the first and second The second phase handlers are connected to the output of the microwave generator, the output of the antenna under study is connected to the first input of the first phase detector and through the phase shifter 90 to the first input of the second phase detector, the reference inputs of the first and second phase detectors are connected to the output of the microwave generator, the first inputs of the first and second synchronous detectors are connected to the output of the first phase detector, the first inputs of the third and fourth synchronous detectors are connected to the output of the second phase detector, the outputs of the first, second, third, and fourth synchronous detectors are connected to the corresponding the inputs of the control unit Ilok W G7 The first digital divider, the output of which is connected to the output of the square pulse generator, and the second digital divider, the output of which is connected to the second input of the first phase switch and the second inputs of the second and third synchronous detectors connected in series with the inverter, . The input of which is connected to the output of the first digital divider and the third digital divider, the output of which is connected to the second input of the second phase handler and the second inputs of the first and fourth of synchronous detectors.