SU1241499A1 - Multichannel radio reception device - Google Patents

Abstract

The invention relates to radio and can be used in measuring equipment for the simultaneous coherent reception of two groups of radio signals that differ in frequency and are located in two frequency bands. The purpose of the invention is to reduce phase distortion. The device contains two frequency channels 1 and 2, each consisting of a linear receiving path 3 with a double frequency converter, two frequency multipliers 4 and 10, a tunable letter-frequency synthesizer 5 and mixer 6, a reference frequency multiplier (DF) 7, a second heterodyne frequency driver (VHF) 8 and the reference frequency divider (DRC) 9. Frequency channels 1 and 2 are designed to receive signals of the corresponding frequency range. Introducing UOCCH 7, VHF 8, POD 9 and frequency multipliers 10 allows to completely eliminate the frequency shift of signals of different letter frequencies in the bands immediately after the first frequency conversion of received signals due to the constant of the first intermediate frequency for any letter frequencies of the respective ranges. This ensures high stability of the phase shifts of the signals and, therefore, reduces phase distortion. 2 Il. with S (L fie. /

Description

one

The invention relates to radio and can be used in measuring equipment, the simultaneous coherent reception of two groups of radio signals that differ in frequency and are located in two frequency bands.

The purpose of the invention is to reduce phase distortion.

Figure 1 shows a structural electrical circuit of a multi-channel receiving device; Fig. 2 is a structural electrical circuit of an embodiment of a tunable letter-frequency synthesizer.

The multichannel radio receiver contains the first and second frequency channels 1 and 2, linear receiving paths 3 with double frequency conversion, the first multiplier 4 frequencies, a tunable synthesizer 5 of lettered frequencies, a mixer 6, a multiplier 7 of the reference frequency, a driver 8 of the second heterodyne frequency, a divider 9 reference frequency, the second multiplier 10 frequency.

Linear receiving paths 3 contain amplifiers 11 high frequency, first mixers 12 linear receiving paths, first amplifiers 13 intermediate frequency, second mixers 14 linear receiving paths, second amplifiers 15 intermediate frequency.

Tunable synthesizer 5 includes a phase detector 16, tunable synthesizer frequency amplifier 17, tunable frequency synthesizer low-pass filter 18, voltage controlled oscillator 19, pulse counter 20, and reference element 21.

Multichannel radio receiver works as follows.

Received radio signals ;; located in two frequency bands: (i 1,2) in the form of grids of the numbers of the letters of the frequencies of the frequencies fg ,. , f; , ..., fp ,; where j is the serial number of the letter frequency signal counted from the beginning of the range.

The signals of the same letter frequency numbers of the first and second frequency ranges are related as follows:

2414992

|, (2M, + 1) (fo-juf) ;;

   2M -1) (), j

(one)

where fo is a constant value that is a multiple of the largest common divisor and f frequency shifts of the signals, the lettered frequencies of the first and second ranges, i.e. fj ,,,, -f and fj. ,, +

+ f j, j, respectively.

The first frequency channel 1 is designed to receive signals from the first frequency range fy; the second frequency channel 2 is intended to

receiving signals of the second frequency range fj.j ..

The radio signals fj and fj arrive at the corresponding linear receiving paths 3, where they are selected by band. Then pass through the amplifiers 11 and arrive at the first inputs of the first mixers 12. At the second inputs of these mixers, respectively, receive the lettered frequencies of the first and second frequency ranges, the signals of the first heterodyne frequencies, i.e. . and, these heterodyne frequencies are formed in such a way

so that the signals of the first intermediate frequencies f, n4 P and the reception of signals of the usual lettered frequencies in the range are constant and equal to each other, a. exactly

j, P4. J, 104 f fn4

Condition (2) ensures the passage of signals f, ni in the same region of the phase-frequency characteristic of the band-pass filter of the first amplifier 13.

In view of (1), the law of the formation of the signals of the first heterodyne frequencies is described by the expressions

,, n (M, + t) (f, + JAf ,,,); F.,. (2M, -1) (fo + jif ,,) J

(3)

J, 1f2

50

Taking into account that fo is a multiple of the greatest common divisor of if - frequency shifts of the lettered frequency signals of the first and second frequency, 5 ranges, as well as the values of the lettered frequency signals at (see (1)), the choice of the first intermediate frequency values f, p, i (made

It also leads to the condition of observance of the multiplicity of the greatest common divisor of if, namely

f fo + PAf; where, l1, i2, ... (4

Formed at the output of the first amplifier 11, the signal f, p is fed to the first input of the second mixer 1A, the second input of which receives the signal of the second heterodyne frequency Fj. This signal is formed from a reference frequency in common for both channels of the driver 8. The circuit of the latter is a typical multiplying chain, including amplification-multiplication stages, mixers and filters. The specific values of the Fjp frequencies are usually chosen from conditions whereby the effect of the combined interference on the output signal is excluded.

At the output of the second mixer 14, a signal of the second intermediate frequency P b is formed, which passes through the second amplifier 15 and is fed to the output of the corresponding frequency channel.

The law of formation of the signals of the first heterodyne frequencies describe the expressions

G}, w --I.f —N, Auf / M,); Fj, ir. M, (2f-5 ,,, - NjBuf / M,),

where Nj P-j, A 2nf +1, B 2M-1

Expression (5) is obtained by substituting (4) and (3) and solving heterodyne frequencies.

Expression (5) reflects the functional structure of the paths of the formation of the first heterodyne frequencies. In it, the divider is 9 reference frequency form-E,. Then, it is signaled by A and B and it signals the signal j.

F cash

second multipliers x 10. At the outputs of the second multipliers 10, we have FjAF, and, for the first and second frequency channels 1 and 2, respectively. The FJ signals are fed to the inputs of tunable synthesizers 5 frequencies, namely, to the first input of the phase detector 16, and to its second input receives the signal of the reference frequency F: of a given letter. At the output of the phase detector 16 form 1241499

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A reference voltage U proportional to the difference of the frequencies and phases of the signals FJ and Fj is measured. The signal F is fed through the amplifier 17 and the filter 18 to the input of the voltage controlled oscillator 19, and its output generates a phase locked loop signal Fj, which is fed to the C input of the pulse counter 20, from which bit outputs the signals are sent to the B-group of inputs of the comparison element 21, on the D-rpynny inputs of which the code of the number given by the j-ro number of the letter frequency arrives. At the moments of coincidence of the signal levels on the B and D groups of the inputs of the element 21, a pulse is formed at its output, which is fed to the P input of the pulse counter 20 and sets it to its initial state. Thus, the signal is divided by the coefficient Nj. The signal F is fed to one of the inputs of the phase detector 16, where it is used as a comparison with the reference signal.

The signal FJ f from the second output of the generator 19 is fed to the input of the mixer 6, to the other input of which the reference signal f is fed. At the outputs of the bandpass filters of the mixers 6, the signals Fj 2f, f, are formed; -NJ Auf / M, (for the first frequency channel 1) and Fj. 2f, pi, -Nj BAf / M (for the second frequency channel 2). These signals come to the inputs of the first multipliers 4, at the outputs of which the signals F are generated;, p | . (J, ri - M, F ;, which are fed to the heterogeneous inputs of the first mixers 12.; The reference frequency multiplier 7 converts the reference frequency signal Fon into a frequency signal, c. In general, this signal is generated by multiplying the reference frequency Fg by. L coefficient

Claims (1)

Invention Formula A multichannel radio receiver, containing first and second frequency channels, whose inputs and outputs are inputs and outputs of a multichannel radio receiver, each frequency channel contains a linear double frequency conversion receiving channel, whose input and output are respectively the input and output of the corresponding frequency channel , the first frequency multiplier, the output of which is connected to the input of the first heterodyne frequency of the linear receiving path with double conversion part You are connected to a serially tunable letter-frequency synthesizer, the control input of which is the input for setting the number of the letter frequency of a multi-channel radio receiving device, and a mixer, characterized in that, in order to reduce phase distortions, a reference frequency multiplier, frequency divider and driver are introduced into it the second heterodyne frequency, whose inputs are the reference frequency input of a multi-channel receiving device, the output of the frequency multiplier is connected to other inputs see CITEL, the output of the second heterodyne frequency is connected to the input of the second heterodyne frequency of reception paths linear double frequency converter, each frequency channel is entered a second frequency multiplier having an input connected to the output of reference frequency divider and an output connected to an input of a tunable synthesizer lettered frequency, in each frequency channel, the output of the mixer is connected to the input of the first frequency multiplier. k) 7 S tS Fi .. Z Compiled by N. Melnikov Editor A. Dolinich. Tekhred - L. Oleynik Proof-reader V. But ha Order 3615/57 Circulation 624 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing company, Uzhgorod, st. Project, 4