SU1350619A1 - Method of determining microwave power radiated by antenna - Google Patents

Abstract

The invention relates to a technique for measuring microwave power and improves the accuracy of measurements. A device that implements sp-b contains a bi-directional coupler 1, a microwave switch 2, bridges 3-7 on connected lines with microwave loads 8-12, divider 13 i-power, receiving converters 14-17, LF switch 18, power meter 19, computer 20 with interface device 21, control unit 22, display unit 23, pass-through load as a variable length line, wattmeter 25. absorbed power. 1 il. about sy

Description

113

The invention relates to methods for measuring microwave power and can be used to measure and control the microwave power emitted by an antenna about

The purpose of the invention is to improve accuracy.

The drawing shows a structural electrical circuit of a device that implements a method for determining the microwave power emitted by an antenna.

The device contains a bi-directional coupler 1, a microwave switch 2, bridges 3-7 on connected lines with SBCh-loads 8-12, power divider 13, receiving transducers 14-17, low-frequency switch 18, power meter 19, computer 20 with device 21 interface, control unit 22, display unit 23, load through passage 24 in the form of a line of variable length, wattmeter 25 of absorbed power.

The method is carried out as follows.

The source of the microwave signal through the bi-directional coupler 1 and the microwave switch mutator 2 is connected to the antenna. Bridges 3-7 with loads of 8-12 and divider 13.power are designed to form the first, secondJ of the third and fourth signals U (- 04, each of which arrives at receiving converters 14–17; detector heads are used as KOTOpFjix.

The signals and, and have the form

(one)

where K Kg - complex constants, reflecting the transmission coefficients of the bidirectional coupler 1, bridges 3-7, the power divider 13. The computer 20, controlled through the control unit 22 by the low-frequency switch 18, sequentially connects the power meter 19 to the receiving converters 14-17, and the powers of the P - P signals Uj are measured

P, A.IU /

R, -

92

RE AJUJ R. A, | and, And

(2)

where -A, -A are the conversion factors of the receiving transducers 14-17.

The value of the power P emitted by the antenna is determined by the expression

Р В, Р, + В, Р, +, (3)

"five

five

0

five

0

where B, - B - unknown coefficients.

To determine the coefficients B, B, on command of the computer 20, the control unit 22, controlling the microwave switch 2, connects a wattmeter 25 of the absorbed power to the microwave source instead of the antenna via a variable length line 24.

Four different lengths of the variable length line 24 are made, the power measurements of the P - P signals U, - 0 are made. The measurements of the powers P, - P at the output of the variable length line 24 are made by a wattmeter 25, the results of the measurements are recorded in the computer memory 20, and unknown coefficients, B, - B are determined from the system of equations

b, p; h-b, p; + b, p; + v, p;

- n - g

 B, P +.

(four)

G 4 -. four

 R

The results of the calculations are displayed by the display unit 23 numerically. In the transition to a new frequency, the process of determining the coefficients B is repeated in accordance with CTB1-III with (4).

The additional formation of the third and fourth signals and the measurement of their mobility make it possible to get rid of the random error component due to the finite directivity of the bi-directional coupler 1, because the coefficients B do not depend on the nature of the load.

Claims (1)

Invention Formula The method of determining the microwave power emitted by an antenna, including the allocation using a directional from 3. 135 of the microwave signal supplied to the antenna, the first signal O, representing a linear combination of signals proportional to the voltages of the incident and reflected waves, and the second signal representing a linear combination of signals proportional to the voltages of the reflected and the incident wave, and the power measurement of the first P,, and second P signals, characterized in that, in order to increase the accuracy, a third signal is additionally formed equal to the sum of the signals proportional to the first and second signals, and the fourth signal differences of signals proportional to the first and second, the phase of which is changed by an additional 90, signals, the powers of the third Pj and the fourth P4 signals are measured, and the microwave power P is calculated by the formula B, B, B P B, P, + B, jPj. + B, P, B4p4, and the coefficients B, B, B, are found by measuring the powers p, Pj, P and P with a fourfold replacement of the antenna for the feed-through load and measuring the power Pn n pass load output and solving linear equation systems p B, P; + + B, P, +; p + + v, p, + B4P ;, where n 1,2,3,4 - serial number substitutions.