SU1647463A1 - Method for measuring phase antenna array parameters - Google Patents

Abstract

The invention relates to the technique of antenna measurements and is intended to measure the parameters of a phased antenna array (PAA) during its adjustment and testing using collimating systems. The purpose of the invention is to improve the accuracy and decrease the distance between the investigated PAR and the collimator. The measurement method consists in forming and emitting a quasi-planar electromagnetic wave using a collimator, exposing it to the investigated PAR, measuring the amplitude and phase of the received PAR signal and determining it from the results of measuring the PAR parameters; free amplitude, and measure the amplitude of the signal received by the PAR of the signal closest to it, and then place the examined PAR in front of the open collie At the same time, the amplitude of the signal received by the nearest Element of the FAR signal being measured when the distance between the collimator and the phased lamp under investigation is measured again, the minimum distance between them is determined when the amplitude of the signal received by the closest element of the studied PAR signal is placed in its free space, and then The studied PARA is performed with a minimum distance between the collimator and the investigated PARA, and an amendment is added to the measured phase value, which is determined by the resulting field. The increase in measurement accuracy is due to the compensation of changes in the mutual relations between the elements of the HEADLIGHTS caused by the collimator, as well as taking into account phase distortions. 2 Il. (L o o 4 x | 4 o 00

Description

The invention relates to the technique of antenna measurements and can be used to measure the parameters of a phased antenna array (PAA) during its setup and testing using collimating systems.

The purpose of the invention is to improve the accuracy and decrease the distance between the investigated PAR and the collimator.

FIG. Figure 1 shows an electrical block diagram of a device for measuring PAR parameters; in fig. 2 is a diagram of the signal propagation process.

A device that implements a method for measuring PAR parameters includes a collimator 1 with a signal generator 2 connected to it, a signal meter 3 connected to the required channels of the studied PAR 4, while the generator output 2 signals

commutes either to the input of the collimator 1, or to the input of the desired element PHAR 4 using the switch 5.

The method is carried out as follows.

Consider first the physical model of the process. In the absence of a collimator, the connection between the nearest PAR elements 4 is determined by the wave Vi propagating from the element AI to the element AA (Fig. 2). When measuring, the collimator 1 is positioned in front of the HEADLIGHT 4 parallel to it and, in addition to the wave Vi, to the element A2, after reflection from the aperture of the collimator 1, the wave Va falls.

The resulting field at the location of the A2 element can be written as the sum of the instantaneous values of the waves,

 coswt (1)

and reflected from the collimator aperture 1

Е2-Л-Ґ со. (Ш | -АгЛЈ-.у) .г

d + L-, “T where A is the amplitude constant;

WITH)

D g Vd 2 + 4 I - d is the difference in the path of the rays.

Sum (1) and (2), get

- l№f + i4 & -t 4№PP ™ i & + r

XCOS ((ut -ip)

s-j + sKAr-r + y), L

Fulfillment of conditions

F (ft)

Rd

F (0TJ

45

2l:

+ COs (Vd2 + 4 | 2 d) (5)

leads to the mutual compensation of the second term (due to the Va wave) and the third (interference) term in the expression (3) under the radical sign, which eliminates communication distortions between the nearest PAR elements 4, and the amplitude of the received Aa emitter is equal to the amplitude of the signal received by this emitter when the FAR 4 is placed in free space.

five

10 15

2Q

25

thirty

35

45

50 55

Due to the periodicity of the interference term with respect to the cosine argument of such optimal distances I, when condition (5) is satisfied, there may be several. The choice of the minimum of them allows to achieve the goal.

For items that are from one another through 1, 2, ..., etc. the emitter does not fully compensate for the distortion, however, not only by these distortions, but also by the influence of the connections between the non-adjacent elements of PAR 4 on its parameters can be neglected due to their smallness.

A device that implements the proposed method works as follows.

The signal generator 2 is connected via a switch 5 to a selected element of the HEADLAMP (to element A2 of FIG. 2). In this case, the collimator 1 is removed from the aperture of the HEADLACE 4. Using the meter 3, the amplitude of the AO signal received by the element Aa closest to the element At is measured. After that, the collimator 1 is placed in front of the aperture of the HEADLIGHT 4 and, by measuring the amplitude of the signal received by the A2 element, the distance mehda by the collimator 1 and the HEADLARE 4 is changed. where they are placed, After that, the PAR parameters 4 are measured by switching the signal generator 2 to the input of collimator 1, and the measured phase sign of the received PAR or its signal element is corrected by the value & p calculated by the formula (four).

The use of the invention permits the measurement of PAR parameters with high accuracy on minimal areas, so that it is possible to use smaller anechoic chambers that are cheaper than large anechoic chambers used for similar measurements using the collimator method.

Claims (1)

The method of measuring parameters of a phased antenna array, including the formation and emission of a quasi-plane electromagnetic wave by the collimator, exposing it to the phased antenna array under study, measuring the amplitude and phase of the received PAR signal, and determining the results of measuring the PAR parameters, in that , in order to increase accuracy and reduce the distance between the studied PAR and the collimator, before starting the measurements excite one of the elements of the investigated PAR, placed in free space and measured by the amplitude of the signal received by the PAR of the signal closest to it, then placed by the PAR in front of the opening of the collimator, the amplitude of the signal received by the same closest element of the studied PAR in the distance between the collimator and HEADLIGHTS, fix the minimum distance between them min, at which the amplitudes measured in the first and second measurements are equal to each other, after which the measurement of the parameters of the investigated PAR is performed at minimum flax distance of 1 min between the collimator and the studied headlight, and an amendment is added to the measured phase value, which is determined by the formula F (ft V +4 tg tgesh  V (12 + 4, -d) - + r)  co $ I (v. -) - Ґ- + rl where Ri, y-module and phase of the complex reflection coefficient from the collimator aperture, respectively: F (c) is the normalized pattern of the element of the studied phased array; 01/2; ft - arctg (L / 21min): d is the minimum distance between the elements of the studied PAR; I am the wavelength. Phie.1 FIG. 2