SU1354124A2 - Device for measuring frequency of input signal of panoramic radio receiver - Google Patents

Abstract

The invention relates to a radio measuring technique, can be used, for example, in spectrum analyzers, frequency meters and allows to increase the measurement accuracy. The device contains an input circuit 2, a high-frequency amplifier 3, a mixer 4, a local oscillator 5, an intermediate frequency amplifier 6, an amplitude detector 7, a video amplifier 8, a key 9, an oscillographic indicator 10, a frequency sweep forming unit 11, a rectifier 14, and a element 15 match. In addition, the device has a frequency detector 16, a differentiating element 23 and a control unit 25. To achieve this goal, frequency detector 12, differentiation links 13, 17, and 18, counting pulse generator 19, counter 20, rectifiers 21, registration unit 24, are introduced, and new functional connections are formed. 2 Il. i (L 5 with SP

Description

The invention relates to radio metering technology and can be used in panoramic radio receivers, spectrum analyzers and frequency meters and is an improvement to the device according to author. No. 1180804.

The aim of the invention is to increase the measurement accuracy.

FIG. 1 shows a block diagram of the device. I

FIG. 2 - time diagrams,

on the principle of its work.

The device contains a series-connected receiving antenna 1, an input circuit 2, a high-frequency amplifier 3, a mixer 4, the second input of which is connected to the output of a local oscillator 5, an intermediate frequency amplifier 6, an amplitude detector 7, a video amplifier 8, a key 9 and vertical plates of the oscillographic indicator 10 , the horizontal plates of which are connected to the output of the frequency sweep generation unit 11, are connected to the output of the intermediate frequency amplifier 6 a frequency detector 12, a differentiating link 13, are straightened The coil 14 and the coincidence element 15, the second input of which is connected to the output of the amplitude detector 7, and the output are connected to the control input of the key 9, are connected in series to the output of the local oscillator 5 frequency detector 16, the differentiating link 17, the differentiating link 18, the counting pulse generator 19 and a counter 20, the reset input of which is connected to the output of the differentiating element 18 via the counter 21 and the read input through the series-connected rectifier 22 and the differentiating element 23 connected to the output of the key 9, and the output is connected to the unit 24 registrations. The outputs of the control unit 25 are connected respectively to the control inputs of the input circuit 2, the high frequency amplifier 3, the local oscillator 5 and the frequency sweep generation unit 11.,

The device works as follows.

Viewing a given frequency range D is carried out by means of a control unit 25, which periodically with a period T, according to the sawtooth law, changes the setting of the input circuit 2, the high-frequency amplifier 3 of the local oscillator 5. At the same time

This block controls the horizontal scanning of the beam on the screen of the oscillographic indicator 10, which is used as a frequency axis. Key 9B of the original state is always closed.

The received continuous harmonic signal after passing the antenna 1, the input circuit 2 and the intermediate frequency amplifier 6 is fed to the first input of the mixer 4, to the second input of which the voltage of the local oscillator 5 of the linearly varying frequency is applied.

At the output of the mixer 4, voltage combinations are generated. The amplifier 6 isolates the voltage of the intermediate (differential) frequency,

U, p (t) and „p co5 (co„ p t + 7 at tV-Kfnp).

which simultaneously arrives at the inputs of amplitude 7 and frequency 12 detectors. Amplitude detector 7

selects the signal envelope that goes to the first input of the coincidence element 15 and through the video amplifier -. the first input key 9. With the output of the frequency detector 12 video signal,

the form of which corresponds to the law of varying the frequency of the local oscillator 5, is fed to the input of the differentiating link 13, the output signal of which through the rectifier 14 is fed to the second input of the coincidence element 15. Rectifier 14 transmits only positive pulses to its output. In this case, the local oscillator 5 is tuned by the amount of bandwidth

intermediate frequency amplifier 6 for the time interval Since the voltages arriving at the two inputs of the cochlea 15 coincidence occupy the same interval on the time axis,

then the coincidence element 15 is triggered and opens the key 9 with its output voltage. In this case, the voltage from the output of the amplitude detector 7 after preamplification in video amplifier 8 through the open key 9 goes to the vertical plates of the oscillographic indicator 10. As a result, a label whose position on the frequency scan uniquely identifies the carrier frequency cOj of the received signal. Observed frequency mark on the screen of the oscillographic indicator 10,

You can visually estimate the carrier frequency cOj. received signal.

The voltage of the local oscillator 5 is fed to the input of the frequency detector 16, the output voltage of which corresponds to the law of variation of the frequency of the local oscillator 5 o This voltage is successively applied to two differentiating links 17, with the help of which it is converted into a sequence of short polarized pulses. These pulses control

When received through the mirror channel, at the output of the intermediate frequency amplifier 6, a pulse is formed, the frequencies of which change according to the law of a linearly falling saw. The pulse of the working generator of the 19 counting pulses g is temporarily fed to the input of the amplitudes. Moreover, this generator is started with positive, and stopped with negative impulses (Fig. 2k). The counting pulses of the generator 19 in each cycle of tuning the local oscillator 5 are counted by the counter 20. The counter 20 is reset by positive pulses (Fig. 2i) received from the output of the differentiator 18 through the rectifier 21. To read the code of the corresponding carrier frequency of the received signal from the counter 20 the registration unit 24 uses positive pulses (Fig. 2e), which are formed as follows

Suppose that a device receives a continuous signal at the CO frequency (Fig. 2a). The signal converted in frequency (Fig. 2b) from the output of the intermediate-frequency amplifier 6 through the amplitude detector 7 (Fig. 2b), the video amplifier 8 and the public key 9 simultaneously arrives at the vertical plates of the oscillographic indicator 10 and at the input of the differentiating link 23. The output different-polar impulses of the differentiating link 23 (Fig. 2d) are fed to the input of the rectifier 22, which transmits only positive pulses (Fig. 2e). These are fed to the read input of counter 20, B. As a result, the carrier frequency from the received signal to

7 and frequency 12 detectors. The amplitude detector 7 selects the pulse envelope that goes to the first input of the matching element 15 and through the video amplifier 8 to the first input of the key 9. From the output of the frequency detector 12, the video signal is fed to the input of the differential link 13, the output of which is not

25 passes the rectifier 14. Therefore, a spurious signal received in the image channel is suppressed.

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Claims (1)

Invention Formula A device for measuring the frequency of the input signal of a panoramic radio receiver by auth.St. No. 1180804, which means that, in order to increase the measurement accuracy, a frequency detector, three differentiating links, two rectifiers, a generator of counting pulses, a counter and a recording unit are added, the frequency detector is sequentially connected to the heterodyne output and the second differentiating link, a counting pulse generator, a counter, the reset input of which is connected to the output of the second differentiating link via the first rectifier, and the read input through the second rectifier connected in series Or the third differentiating link is connected to the key output, the counter output is connected to the registrar input. The digital code (Fig. 2L) is fixed in block 24 of the registration. The described operation of the proposed device corresponds to the case of measuring and recording the carrier frequency CO (, input signal received on the main channel (Fig. 2). When receiving a mirror channel at the output of the amplifier 6 intermediate; frequency, a pulse is formed, the frequency of which varies according to the law of a linear falling saw. The pulse is simultaneously fed to the input of amplitude 7 and frequency 12 detectors. The amplitude detector 7 selects the pulse envelope that goes to the first input of the coincidence element 15 and through the video amplifier 8 to the first input of the key 9. From the output of the frequency detector 12, the video signal is fed to the input of the differential link 13, the output of which is not skips rectifier 14. Consequently, a spurious signal received in the image channel is suppressed. Invention Formula A device for measuring the frequency of the input signal of a panoramic radio receiver by auth.St. No. 1180804, which means that, in order to increase the measurement accuracy, a frequency detector, three differentiating links, two rectifiers, a counting pulse generator, a counter and a recording unit are added, and a frequency detector is connected in series to the heterodyne output, the first and second differentiating links, a counting pulse generator, a counter, the reset input of which through the first rectifier is connected to the output of the second differentiating link, and the read input through the serially connected second rectifies l and third differentiating element is connected to the output of the key counter output is connected to yhodom registrar. (jSt 8 d t and (/ 191 / WIIIHC  imiinillHlliMIIIHIIMII HllltlMlinHIHIiinilMII liinitllU b  I.II Tiiitiiiii Iliniilli Editor A.Vorovich shimimipmp Phi2.2 Compiled by A.Gubanov Tehred L.Oliynyk Corrector C, Cherni Order 5689/40 Circulation 730 Subscription VNIIPI USSR State Committee for Inventions and Discoveries 4/5, Moscow, Zh-35, Raushsk nab. 113035 Production and printing company, Uzhgorod, st. Project, 4 Corrector C, Cherni