SU1004891A2 - Device for measuring aerial input resistance - Google Patents

Description

The invention relates to radio engineering technology and can be used to create devices for measuring the impedance of antenna systems.

According to the main author. St. 834540, a device for measuring the input impedance of antennas is known, comprising a generator, the output of which is connected to one of the inputs of a power amplifier, the other input of which is connected to the input of a unit for maintaining a constant current, and the input of a current transformer, the first output of which is connected respectively to the output of the device and a CO with a voltage divider input, a phase detector, the output of which is connected to the phase indicator input, and a module indicator, two synchronous detectors and an additional indicator, while the inputs are phase Leu are connected: to the generator output, their outputs are connected to the first inputs of synchronous detectors: and to the corresponding inputs of the phase detector, and the second inputs of synchronous detectors are connected respectively to the output of the voltage divider and to the second output of the current transformer, and the output of one of the synchronous detectors

connected to the indicator input of the module, and the output of the other is connected to the response. with the control input of the control unit with a constant current value and. with additional / 1 indicator 13 input.

The disadvantages of this device are the lack of reliability due to the possibility of the device being out of operation at the levels of interference on the measured

10 to an antenna that exceeds the level of the measuring signal, or the antenna fails when a measurement signal is applied to its input that is higher than the allowable value for the given antenna.

15

The purpose of the invention is to increase the reliability of the device ..

The goal is achieved by the fact that the device for measuring the input impedances of the antennas, containing

20 generator, the output of which is connected to one of the inputs of the power amplifier, the other input of which is connected to the input of the unit for maintaining a constant current, and the output to the input of the current transformer 25, the first signal of which is connected respectively to the output of the device and cf. input voltage divider, phase detector, the output of which is connected to the input of the indicator, and

Claims (1)

The inputs of the phase converters are connected to the generator output, their outputs are connected to the first inputs of synchronous detectors and the corresponding inputs of the phase detector, and the second inputs of synchronous detectors are connected respectively to the output of the voltage divider and the output of the synchronous detectors is connected The module is connected to the indicator input, and the output of the other is connected, respectively, to the –controlling drive of the unit for maintaining a constant V current value and to the input of the additional indicator, The amplitude detector, the protection unit and the key are 7, the transformer output is connected through a series-connected amplitude detector, and the protection unit with one input of the first switch connected between the output of the power amplifier and the transformer input, and the output of the protection unit connected to the inputs of the second and third keys connected respectively between the input of the transformer and the input of the first synchronous detector, as well as between the output of the voltage divider and the input of the second synchronous detector. The drawing shows a block diagram of the device. The device comprises a generator 1, a power amplifier 2, a current transformer, blocks 4 for maintaining a constant current value. The first input of the current transformer 3 is connected to the device’s d output and to the input of a voltage divider 5, two phase shifters 6 and 7, synchronous detectors 8 and 9, a phase detector 10 and an additional indicator 11, the inputs of phase shifters b and 7 being connected to the output of the generator 1, and the outputs are with the first inputs of the respective synchronous detectors 8 and 9 and the corresponding inputs of the phase detector 1 as well as the indicator module 12, the phase indicator 13 connected in series to the amplitude detector 14 and the protection unit 15 with adjustable threshold and keys 16-18. The initial position of the executive bodies of the protection unit 15 is such that when the meter is connected to the antenna being measured, the keys 16-18 are open,. In this case, the output of the current transformer 3 is a voltage proportional to the voltage of the noise on the measured antenna, which is detected by the amplitude detector 14 and fed to the input of the protection unit 15. The trigger threshold of the protection unit 15 is set on the basis of the rated power for which the measured antenna is calculated (assuming that power amplifier 2 can increase any power value) or the outcome of the permissible interference power at the antenna. If the voltage of the amplitude detector 14 exceeds the threshold of the protection unit 15, then the initial position of the keys 16-18 does not change and no measurements are taken. In the case where the voltage at the output of the amplitude detector 14 is less than the threshold of the protection 15, the keys 16 - 18 connects power amplifier 2, synchronous detectors 8 and 9 to current transformer 3 and divider 5. stress and cheating; phase shifter 7 phase voltage, achieve maximum indications of the indicator 12 module. Since the current in the measured antenna is kept constant, the maximum indications of the indicator 12 of the module correspond to the true value of the input impedance module of the measured antenna,. Simultaneously, the signals from the outputs of the phase shifters are fed to the inputs of the phase detector 10, the output of the phase detector 10 is connected to the indicator 13, on the scale of which the value of the phase angle between the voltages is counted. Since the maximum voltages at the inputs of the synchronous detectors B and 9 correspond to a zero phase shift between si-i signals, the indications of the phase indicator 13 correspond to the value of the phase angle between the current and the voltage operating in the measured antenna, t, e. antenna impedance argument. Signals are free from interference, as they are received from a source that is not electrically connected to the antenna being measured. An apparatus for measuring the input impedances of antennas according to avtsev, no. 834540, characterized in that, in order to increase the reliability of the device, an amplitude detector, a protection unit and three keys are inserted in it, the output of the transformer being connected through a series-connected amplitude detector and unit protection with one input of the first key connected between the output of the power amplifier and the input of the transformer, as well as the output of the protection unit is connected to the inputs of the second and third keys connected respectively between the output of the trans the format and the input of the first synchronous detector, as well as between the output of the voltage divider and the input of the second synchronous detector. Sources of information taken into account in the examination of G, USSR Copyright Certificate No. 834540, class G 01R 17 / 10,25,10,79. I "3 H  f with "about J to