SU478418A1 - Filtering device - Google Patents

Description

(54) FILTERING DEVICE

The invention relates to radio engineering and can be used in extreme object control optimizers. A filtering device is known which contains a series-connected band-pass filter and a receiving unit, as well as a band-pass filter connected in parallel to the first input, and the filter outputs are connected via a series-connected switch, amplifier with automatic gain control, detector, DC amplifier, second switch, the memory circuit, the comparator, the threshold element, for example, the Schmidt trigger, the reverse trigger and the integrator are connected to the control input of the second band-pass filter. However, the known filtering device has a mismatch of the amplitude-frequency characteristics of the main and additional filters; at their reorganization in the working range of frequencies. The purpose of the invention is to ensure the amplitude-frequency characteristics matching of the band-pass filters during the tuning process, i To do this, a correction channel was inserted containing the waiting multivibrator, whose input is connected to the output of the reverse trigger and the output to the control inputs of the first and second switches, the output of the latter is connected to the control input of the first band-pass filter through a series-connected second memory circuit, an integrator with i reset, the second input of which is connected to the output of the first memory circuit Minani, and an adder, connected through a filter with the output of the integrator. In the drawing. shows a block diagram of the filtering device. The filtering device contains the first band-pass filter 1, turned on at the input of the receiving device 2, and the second band-pass filter 3. The output of filters 1 and 3 are connected to switch 4, in series with which amplifier 5 is connected. Automatic gain control, detector 6, constant amplifier Ji

7, memory circuit 8, comparator 9, Schmidt trigger 1O, reverse trigger 11 and integrator 12.

The correction channel consists of a standby multivibrator 13, a switch 14, a second memory circuit 15, an integrator 16 with a reset, an adder 17 and a filter 18, the integrator 16 consists of a key 19, a Schmidt trigger 2O and an integrator 21.

The filter device operates as follows.

To obtain the correction voltage B of the gap between the reverse pulses, the output voltages of the first and second 3 filters are compared. The reverse signal turns on the waiting multivibrator 13, producing a pulse strobe, which through switches 4 and 14 connects the output of the first band-pass filter 1 to the input of the second memory circuit 15. Thus, the memory circuit 8 will record the signal amplitude from the second band-pass filter 3, and The second 15-amplitude memory circuit of the signal from the first band-pass filter 1, the output voltages of the memory circuits 8 and 15 are fed to the integrator 12, the output of which through the filter 18 is connected to the adder 17. The second input of the adder 17 is smoothed The second control voltage of the second bandpass filter 3 is summed. The sum signal from the adder 17 is fed to the input of the first bandpass filter 1.

Since when changing the output voltage of the integrator 16, the sign of the correction voltage is unknown, it is necessary to reset the integrator 16 to zero at the maximum value of the correction voltage. The reset is performed with a key 19 and a 1ShiDt 2 O trigger.

Subject invention

A filtering device containing a series-connected band-pass filter and a receiving unit, as well as a band-pass filter connected in parallel with the first one; at the input, with the filter outputs: via a series-connected switch: switch, amplifier with automatic gain control, detector, DC amplifier, second switch, memory circuit, comparator, threshold element, for example, Schmidt trigger, reverse trigger, and integrator connected to the control input of the second bandpass filter, characterized in that, in order to match the amplitude-frequency characteristics

5 bandpass filters in the process of tuning-: ki, a correction channel is inserted, containing a waiting multivibrator, the input of which is connected to the output of the reverse trigger, and the output to the control inputs of the first one.

0 and the second switch, the additional output of the latter is connected to the control input of the first band-pass filter through a series-connected second memory circuit, the integrator with

5 by a reset, the second input of which is connected to the output of the first memory circuit, and an adder connected via a filter to the integrator output.

W

go