SU1737373A1 - Device for measuring antenna power gain - Google Patents

Abstract

The invention relates to the technique of antenna measurements and can be used to measure the gain / capacitor / antenna during its setup and testing. The purpose of the invention is to reduce the time spent on measuring the antenna KU in the frequency band. This goal is achieved by discrete tuning using the first, second and third elements OR 1-3, generators 17 and 14 of single and square pulses of the RS flip-flop 15, key 7, first and second counters 8 and 9, and a digital-to-tax converter 10 4 signals in the range of measured frequencies, by the radiation of the first signal 23 of the generator 23 being examined by the generator 4, measuring the power of the received signal at the output of the second antenna under study 24, identical to the first antenna under investigation, often measuring by digital frequency meter 11 emitted signal, measurement and fixation using standby multivibrator 18, differentiation unit 19, inverter 20, power meter 5, square root extraction unit 6, first and second multiplicators 12 and 13, shaping memory block 16 and digital recorder 21 numerical values the gain of the antenna under study and the frequency at which this measurement is made. 2 Il. Yo

Description

The invention relates to the technique of antenna measurements and can be used to measure the gain factor (QA) of the antenna in the frequency band during its tuning and testing.

The purpose of the invention is to reduce the time spent on measuring the antenna KU in the frequency band.

FIG. 1 shows a block diagram of a device for measuring the antenna KU; in fig. 2 - plots showing his work.

A device for measuring antenna gain comprises first, second and third elements OR 1, 2 and 3,

4 signal generator, digital power meter 5, square root extraction unit 6, key 7, first and second binary counters 8 and 9, digital-to-analog converter 10, digital frequency meter 11, first and second multiplications blocks 12 and 13, generator 14 rectangular pulses, RS trigger 15, memory block 16, single pulse generator 17, standby multivibrator 18 with the waiting time required to measure the antenna gain at one frequency, differentiation unit 19, inverter 20, digital recorder 21, delay element 22. In fig 1

VI

WITH

VI with VI with

Identical antennas 23 and 24 under study are also shown. In this case, a generator of 14 rectangular pulses, a key 7 and a first counter 8 are connected in series, a second counter 9, the first (counting) input of which is connected to the output of key 7, and a digital-to-analog converter 10, output generator 4 is connected to the input of the first antenna under study 23, a strip power meter 5 is connected in series, the input of which is connected to the output of the second antenna under study 4, the square root extraction unit b, the control input of which connected to the output of inverter 20, first multiplier 12, second multiplier 13, a second input connected to the output of the block memory 16 and the recorder 21, the second input of which is connected to the output 11 of the frequency; the input of the digital frequency meter 11 is connected to the output of the second antenna under study 24, the control input is connected to the output of differentiation unit 19, and the output is connected to the second input of the first multiplication unit 12. The input of the delay element 22 is connected to the output of the inverter 20, and the first, second and the third outputs of it are connected respectively to the control inputs of the first and second blocks of multiplication 12 and 13 and the recorder 21. A generator 17 of single pulses is connected in series, the output of which is also connected to the installation input of the second counter 9, and ne left element OR 1, the output of which is connected to the installation input of the first counter 8; a second element OR 2 is connected in series, the input of which is connected to the output of the generator 17 of single pulses, and an RS flip-flop 15, the direct output of which is connected to the control input of the key 7; The waiting multivibrator 18 is connected in series, the input of which is connected to the second output (last output of the higher bit) of the first counter 8, differentiation unit 19, the output of which is also connected to the second input of the first element OR 1, and the third element OR 3, the second input of which connected to the second output (the last output of the higher bit) of the second counter 9, and the output is connected to the R input of the RS flip-flop 15, the input of the inverter 20 is connected to the output of the differentiation unit 19, and the output is connected to the second input of the second element OR 2.

Device for measuring the antenna KU works as follows.

The antennas 23 and 24 under study are located at a distance R of the far zone in such a way that the main maxima of their radiation patterns are oriented one at a time towards each other.

Using the start element of the generator 17, a single square-shaped pulse is generated at its output, which is fed to the installation input of the second counter 9 directly, and to the installation input of the first counter 8 and the S input of the RS flip-flop 15 through the first and second elements OR

1 and 2 respectively. The first and second counters 8 and 9 are transferred to the initial state, and the RS flip-flop 15 assumes the state of logical 1. At this, the voltage Ih (Fig. 2a) of logical 1 is generated at its forward output the input of the key 7. The key 7 is opened and from the output of the generator 14, rectangular pulses 112 (Fig. 2 b) in the form of pulses Ua (Fig.

2c) are fed to the counting inputs of the first and second counters 8 and 9, the filling volumes of which are selected, based on the necessary sampling frequency tuning generator 4 and the bit of the digital-to-analog converter 10, respectively. As a result of the arrival at the counting inputs of the first and second counters 8 and 9 of the rectangular pulses Us, their volumes are smoothly filled, and the current values of logic voltages are formed at their outputs in the binary code. At the same time, from the bit outputs of the second binary counter 9, the current values of logic voltages are supplied to the bit inputs of the digital-to-analog converter 10. At the output of the digital-to-analog converter 10, an amplitude amplitude sawtooth voltage 1M (Fig. 2d) is formed, which, when entering the generator input 4, causes a change in its frequency. When the volume of the first binary counter 8 is filled, a rectangular pulse Us (Fig. 2e) is formed at its last output of the higher bit n (Fig. 2e), which is fed to the input of the waiting multivibrator 18. The waiting multivibrator 18 is started, and a positive pulse Ue is formed at its output (Fig 2, e), which is fed to the input of the differentiation unit 19. The pulse front Ue is differentiated by the differentiation unit 19 and as a positive pulse U (Fig. 2, g) through the first and third elements OR 1 and 3 is fed to the setup input of the first counter 8 and the R input of the RS flip-flop 15 and to the input of the frequency meter 11 directly . The frequency meter 11 is transferred to the frequency measurement mode f 1, the first counter 8 is set to the initial state, and the RS flip-flop 15 returns to the logical O position. At the direct output of the RS flip-flop 15, a logical O voltage is applied to the control key input 7. The key 7 is closed and the arrival of the rectangular pulses UG to the counting inputs of the first and second counters 8 and 9 is stopped. The voltage DA at the output of the digital-to-analog converter 10 takes on the value LMi (Fig. 2, d), and the frequency of the generator 4 is tuned to the frequency fi (Fig. 2, C).

The electromagnetic signal from the generator 4 output is fed to the input of the first antenna 23 under study and is radiated into space. The signal received by the second antenna 24 is fed to the inputs of the power meter 5 and the frequency meter 11. From the output of the power meter 5, the measured value of the power Pcp of the signal is fed to the input of the square root extraction unit 6. At the end of the pulse duration of the standby multivibrator 19, the duration of which is selected based on the measurement time of the power Rpr by the power meter 5, its cut is differentiated and a negative impulse O arrives at the input of the inverter 20. At the output of the inverter 20, a positive pulse Us is formed (Fig. 2, and) which is fed to the inputs of the delay element 22. the square root extracting unit 6, and through the second element OR 2 to the S input of the RS flip-flop 15. The root square recovery unit 6 is triggered, and at its output in binary code the result of the RDR 1 is generated, which is fed to the input of the first the multiplication unit 12, and the second input in the binary code receives the logical voltage value of the frequency fi, generator 4. From the first output of the delay element 22, a delayed pulse Us is fed to the control input of the first multiplication unit 12. The first multiplication unit 12 operates and the axis estvl an operation of multiplying f Prec. From the output of the first multiplier 12, the result of multiplication in binary code goes to the first input of the second digital multiplier 13, the second input of which is supplied with a constant value of 4 lK / s Pr from the output of the memory block 16, where R is the distance between the antennas 23 and 24; Pr is the power of the signal supplied to the antenna 23 from the generator 4, c is the speed of light. From the second output of delay element 22, the pulse Us is delayed by 2ri arrives at the control input of the second multiplication unit 13 and starts it, the second multiplication unit 13 is triggered, and the gain GI of the antenna under investigation at the frequency fi of generator 4 is generated at its output in binary code. From the output of the second multiplier 13, the GI value of the antenna gain is fed to the first input of the recorder 21, to the second

the input of which in binary code is supplied with a logical voltage fi. From the third output of delay element 22 delayed by 3 Ti impulse Us is fed to the control input of the digital recorder

21. Digital recorder 21 is turned on and captures the value of the frequency fi and the gain Gi of the antenna under investigation at this frequency. The value of t is chosen based on the inertia of blocks 6, 12 and 13.

At the same time, the RS flip-flop 15 is transferred to the position of logical 1 and at its direct output a voltage LH of logical 1 is formed again (Fig. 2, a), which is fed to the control input of the key 7.

The key 7 is again opened and, from the output of the generator 14, rectangular pulses of positive polarity are again fed to the counting inputs of the first and second counters 8 and 9. The number of incoming to the second

Binary counter 9 of pulses continues to increase, which causes respectively the increase in voltage U4 at the output of the digital-analog converter 10 (Fig. 2, d). At the moment of the end of the secondary filling of the volume of the first binary counter 8 at its second output (the last output of the higher bit) a second positive pulse Us is generated (Fig. 2, e) which is fed to the input of the waiting multivibrator 18. The waiting multivibrator 18 is restarted and The output is formed by a second pulse Ue (Fig. 2, e), which is fed to the block 19 of differentiation. The pulse front Ue is differentiated by the differentiation unit 19 and as the second positive pulse U (Fig. 2, g) through the first and third elements OR 1 and 3 is fed to the setup input of the first counter 8 and the R input of the RS flip-flop 15, respectively, and to the input frequency meter 11 - directly. The frequency meter 11 is switched to the frequency measurement mode h, the first binary counter 8 is set to the initial state, the RS flip-flop 15 returns to

the position of the logical O, and the key 7 is closed. In this case, at the output of the digital-to-analog converter 10, the voltage U4 becomes equal to the voltage i42 (Fig. 2. d), and the generator 4 of the signals is tuned

to the frequency i and the process of measuring the gain factors GI at frequencies fi continues. When full, the volume of the second counter 9 (the upper limit of the frequency tuning of the generator 2 signals) on

its last higher-order output is formed by a rectangular pulse Ug (Fig. 2, k), which through the third element OR 3 is fed to the R input of the RS flip-flop 15. RS-flip-flop 15 is switched to the logical O position, and the measurement process continues. In this case, using blocks 6, 12, 13 and 16, calculate the capacitor array of the antenna under investigation using the formula

G lЈRfv

Wg

where f is the signal frequency;

Ppr - the value of the received signal power.

Thus, the digital recorder 21 records in discrete form a graph of the antenna gain factor G as a function of the frequency f, which can be represented in continuous form by approximation.

The use of this invention allows, by automatically measuring the antenna gain in a wide frequency band, to shorten the measurement time by a factor of ten and to extend the functionality of the device.

Claims (1)

Invention Formula An apparatus for measuring the antenna gain factor, comprising a signal generator, the output of which is an output for connecting a first antenna under study, a power meter whose input is an input for connecting a second antenna under test, identical to the first antenna under investigation, In order to reduce the time spent on measuring the antenna gain in the frequency band, serially connected square root extraction units are introduced, the input of which is connected to the output of the meter the first multiplication unit, the second multiplication unit and the recorder, the frequency meter whose input is connected to the output of the second antenna under investigation, and the output to the second input of the first multiplication unit and to the second input of the recorder, the memory unit whose output is connected to the second input of the second block multiply, serially connected square pulse generator, key, first counter, standby multivibrator, differentiation unit, inverter and delay element, the first, second and third outputs of which are connected to the control input of The first and second multipliers and the recorder, respectively, the control input of the square root extraction unit are connected to the inverter output, the control input of the frequency meter is connected to the output of the differentiation unit, the single pulse generator connected in series and the first OR element, whose output is connected to the setup input of the first counter, and the second input is connected to the output of the differentiation unit, the second counter connected in series, the input of which is connected to the key output, and the installation input to output of the single pulse generator, and a digital-analog converter, the output of which is connected to the input of the signal generator, are connected in series to the second OR element, the first input of which is connected to the output of the single pulse generator, and the second input to the output of the inverter, and RS trigger, direct the output of which is connected to the control input of the key, and the R input to the output of the input of the third OR element, the first and second inputs of which are connected to the output of the differentiation unit and to the second output of the second counter, respectively but.