SU708523A1 - Device for automatic measuring of relative power level of parasite radiation of radio transmitter - Google Patents

Description

The invention relates to radio engineering and can be used for measurements in the manufacture of radio transmitters and for monitoring them during operation. A device for automatically measuring the relative power level of the parasitic radiation of a radio transmitter, containing a communication element, the output of which is connected to the first input of the first signal divider, is known. the first output of which is connected to the input of a bandpass filter, the second output of the first signal splitter is connected via a serially connected signal level adjustment unit and a phase shifter to the input of a compensation unit whose output is connected to one of the inputs of the second signal splitter. However, this device takes a lot of time for its measurement of the relative power level of spurious radiation. The circuit of the invention is to reduce the measurement time of the relative power level of the parasitic radiation. For this purpose, into the device for automatic measurement of the relative power level of the spurious radiation of a radio transmitter, containing a communication element whose output is connected to the first input of the first signal amplifier, the first output of which is connected to the input of a bandpass filter, the second output of the first signal divider is connected via a serially connected unit adjusting the signal level h the phase shifter to the input of the compensation unit, the output of which is connected to one of the inputs of the second signal divider, the amplitude control unit is entered and signal phase, limiting filter, third signal divider, attenuator, noise generator, comparison unit, master oscillator, sound generator, modulator, while the output of the bandpass filter is connected to the first input of the third signal divider, one of whose outputs is connected to the second

input of the compensation unit, and the second output is connected to one of the inputs of the comparator unit, the other input of which is connected to the output of the second signal divider, the second output is connected via successively connected limiting filter AND the control unit of the amplitude and signal phase with the control inputs of the phase rotator and the adjustment unit signal level, and the output of the noise generator is connected to the third input of the first signal divider, and the other output through an attenuator, the second output of which is connected to the second input of the second signal splitter, connected to the second input of the third divider signal, the outputs of the master oscillator and the sound generator are connected to respective inputs of the modulator, the output of kotoro- connected to the second input of the first signal divider.

The drawing shows a structural electrical circuit of the device for automatic measurement of the relative power level of the parasitic radiation of a radio transmitter.

The proposed device for automatic measurement of the relative power level of the parasitic radiation of a radio transmitter includes a communication element 1, a first divider 2 signal, a band-pass filter 3, a signal adjustment unit 4, a phase shifter 5, a compensation unit 6, a signal divider 7, an amplitude and phase control unit 8 , a limiting filter 9, a third signal divider 10, an attenuator 11, a noise generator 12, a comparison block 13, a master oscillator 14, a sound generator 15, a modulator 16.

The device for automatically measuring the relative power level of the spurious radiation of the radio transmitter works as follows.

From the output of the radio transmitter, the signal under study goes through the communication element 1 to the second divider 7, which divides the incoming signal power in terms of ft-o 2/3 of it to the band-pass filter 3, and 1/3 of the power to the level adjustment block 4, and then to the phase shifter 5, where the signal is converted to an opposite phase signal. The band-pass filter 3 cuts out from the signal only that part of the emission spectrum of the radio transmitter, which is normalized for the given transmitter, taking into account the type of work. Thus, the third divider 10 receives the reference signal of the normalized frequency band, where the signal energy is divided into equal parts so that the same power is applied to the inputs of the compensation unit 6 and the comparison unit 13. The inputs of block 6 receive signals of the same spectrum with equal amplitudes, but opposite in phase. In block 6, the amplitudes are compensated; the spectrum of which is located in the normalized band of the band-pass filter 3. The second divider 7 receives the remaining spectrum after compensation, which is the parasitic radiation of the radio transmitter. If in the normalized band shallow compensation, then on the block

8 control through restrictive filter

9, a control signal is provided that allows automatic monitoring of the depth of suppression of the reference signal. The spurious signal enters the power comparison unit 13 of the main

and the spurious radiation of the radio transmitter, where it is compared with the signal coming from the third divider 1O, whose spectrum is in the transparency band of the bandpass filter 3, the scale of the comparison unit 13, calibrated in decibels, shows the relative power level of the parasitic radiation of the radio transmitter. A generator 12 and an attenuator 11 serve to calibrate the comparison unit 13.

The proposed device for automatic measurement of the relative power level of the parasitic radiation of a radio transmitter allows one to automate the measurement process, to carry out fast continuous monitoring of the level of parasitic radiation during the operation of the radio transmitter, and to rearrange it depending on the type of operation of the transmitting device.

Claims (1)

1. US patent No. 3648176, CL. 325-133, 1972 (prototype)