SU1224747A1 - Method of determining calibration ratio of loop aerial - Google Patents

Abstract

This invention relates to a radio measuring technique. Provides - the ability to measure the calibration coefficient. in the range of ptot at production P (UpprnfU „ep & 0 1 MD - g, () r and r - average radius of the IRA and PRA 2; X - wavelength; D - distance frequency. Voltmeters 8 and 9 measure and pp - voltage from generator 3, arriving at the transmitting frame antenna - (PRA) 2 through connection R 6, and Uf, p - voltage at load 7 of test frame antenna (IRA) 1. Then U is measured, - voltage at load 7 when the auxiliary loop antenna is connected to the generator 3 and U is the voltage at load 7 when the control gear 2 and IRA 1 are connected in series to the load 7. Value calibration factor f h and h-lam:. IRA 1N gear 2 are determined by h, and h i2 hTlUj / U, () (A I between the IRA and gear 2. 2-yl.

Description

This invention relates to a radio measuring technique.

The purpose of the invention is to provide the possibility of measuring the calibration coefficient in the frequency range at an arbitrary frequency.

Figures 1 and 2 depict structural electrical diagrams of devices for determining the calibration factor of a coil antenna.

The device for determining the calibration factor of the frame antenna contains the test frame antenna 1, transmitting frame antenna 2, generator 3, T-junction transitions 4 and 5, resistance 6 in the chain of the transmitting frame antenna 2, load 7 of the test frame antenna 1, voltmeters 8 and 9 AC, auxiliary loop antenna 10.

The method is carried out as follows.

The voltage from generator 3 is supplied to transmitting frame antennas 2 through resistance 6.

The current in the transmitting frame antenna 2 creates an alternating magnetic field H in the test frame antenna 1, in which an emf 6 is induced. Through the load 7 of the test frame antenna 1, a current 1pr-e flows which creates a load U on the load 7

According to the principle of reciprocity

 (one)

Hlief s - -

E

R

or

  T-

(2)

Coefficient has dimension of conductivity.

From the measurement scheme taking into account (2) it follows:

Unp i. Rh

(3)

According to the law of electromagnetic induction

, (four)

where S is the frame area.

Between the electric and magnetic field strengths in a traveling wave, the relation

E

 n

120 ir

(five)

l, HI effective length of the frame antenna

t t

(6)

The average value of the intensity of the magnetic field H in the plane of the studied loop antenna 1, created by the current, is equal to

tt nef- g

 .

1 (D

+ 2g

2

OR

Inep sf

(7)

() 4tr4D + 2r 7

(eight)

and taking into account (2)

where D is the distance between the test and transmitting frame antennas and 2; d - their average radius. Substituted in (W). the value of f from (4) taking into account (5), (7), (8), we get:

%, s 1 "p. / 3

subject to (2)

Uj, p a. 03JU RH pUnep,

(9)

from where

0. -l

.one.

 s

y ,, 1

(ten)

U (, ep cojoR S

On the other hand, the substitution in (6) is the value from (3) with regard to (4) and the value E from (5), we get the calibration coefficient (effective length)

4S

 ojuSRoiSRH hT2bt-

(P)

Substitute here the value of s (10) and taking into account that cofu ----,

finally

SO

and tip RH

and

per

or

3 $

(12)

3 1

If the transmit antenna and frame antennas 1 and 2 are not identical, then H is written as:

H

what do you think

2 (D% rffr

3/2

u (), 13)

where g is the average radius of the transmitting

loop antenna 2; g, is the average radius; investigated

loop antenna 1. In this case, h is the geometric mean of the effective lengths of the two antennas and is recorded as;

h

(14)

 To determine the effective length of each antenna, they are compared to each other (FIG. 2) using an auxiliary grid antenna 10, used as transmitting and calibration factors for transmitting antenna 2 and antenna I, are calculated using the formulas:

where h is determined from (14);

and is the output voltage of antenna 2;

and - the voltage at the antenna input 1,

The measurement sequence is carried out as follows: all the blocks are connected, as indicated in FIG. 1, the receiving frame antenna 1 under test and the transmitting frame antenna 2 are positioned coaxially and the Unep and Unp measurements are made using voltmeters 8 and 9.

The second stage of the measurements is carried out as follows: all the blocks are connected as indicated in Fig. 2, the auxiliary frame antenna 10, the transmitting frame antenna 2 and the studied frame antenna 1 are installed at the same distance from the auxiliary frame antenna 10. Then, the test frame antenna 1 and the auxiliary frame antenna 10 face each other (set

224747

coaxially) and measure the voltage U (at the input of the loop antenna 1. The transmitting loop antenna 2 and 5 are set to measure the voltage U2.

The values of the calibration coefficients h, and h are calculated using formulas (14 and 15).

Claims (1)

10 claims A method for determining the calibration factor of a frame antenna, including the irradiation of the frame being studied. antenna by means of a transmitting frame antenna connected to the generator and located in its near zone at a distance D from it and measuring the voltage U at a load of 20 ka of the frame antenna being studied, due to the fact that, in order to make it possible to measure the calibration factor in frequency range at an arbitrary frequency, additionally measure the voltage Unp at the output of the generator when connected to its output, a transmitting loop antenna through a resistance R ,, equal to the resistance on 30 loads of the studied loop antenna, the voltages U and U are measured at the load of the loop antenna being studied when the auxiliary loop antenna is connected to the generator, and connected in series with the load of the loop antenna of the transmitting loop antenna and the loop antenna being studied, and calibration coefficients h and h The research and transmitting frame antennas are determined by the formulas 35 h where, and g ,, - the average radius of the investigated and transmitting frame antennas; - wavelength. iO / / Editor A.Revin Compiled by V. Rabinovich Tehred N. Bonkalo Proofreader M. Pojo Order 1947/45 Circulation 728 Subscription  VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4