SU1385236A1 - Single-band signal generator - Google Patents

Abstract

The invention relates to radio engineering and provides a reduction in the remainder of the suppressed sideband when exposed to destabilizing factors. The shaper contains phase manipulators (FMP) 1, 2, a balance modulator 3, a fl bandpass filter 4, a source 5 of carrier frequency signals and a generator of 6 clock pulses. FMP 1, 2 m. made in the form of a phase splitter at 90 ° C; and switch. The manipulating signal of the meander type arrives at the FMP 1.2c of the generator 6. In a balanced modulator 3, the modulated signal of the FMP 2 is modulated by the FMN signal 1. At the output of the balanced modulator, the signal of the lower sideband does not undergo phase shift keying, and the signal of the upper sideband is manipulated out of phase on the oscillator signal 6. The side components of the phase-shifted signal of the upper sideband are suppressed in the bandpass filter 4. To suppress the lower sideband and highlight the upper sideband atochno include inverter 11 between the generator 6 and one of the FMP. 3 il. F (L

Description

eleven

The invention relates to radio engineering and can be used to generate single band signals in radio transmitters and radio measuring devices.

The purpose of the invention is to reduce the remainder of the suppressed sideband under the influence of destabilizing factors.

FIG. Figure 1 shows a structural electrical circuit of a single-band signal driver; in fig. 2 - the same, with a special case of performing a balanced modulator; in fig. 3 - explanatory diagrams of the operation of a single sideband signal generator.

The shaper of single-band signals (Fig. 1 and Fig. 2) contains the first and second phase handlers 1 and 2, the balanced modulator 3, the band-pass filter 4, the source 5 of the carrier frequency signals, the generator 6 clock pulses.

In the particular case of performing a single-band signal generator (Fig. 2), the balanced modulator 3 contains the first and second amplitude balanced modulators 7 and 8 and the first and second phase splitters 9 and 10 and. adder 12.

The single-band signal driver operates in the following way.

The modulating signal Uf (t) cosSlt (received amplitude per unit) is fed to the input of the manipulated signal of the second phase switch 2, which can be performed, for example, in

as a series of phase splitters on 90 and switch. To the input of the manipulating signal of the second phase handler 2, the output pulses of the square wave type are output from the generator 6. In this case, the signal at the output of the second phase shift key will be

Ut. (T) cos9t with O t

U; (t) cos (ntV-) with

I t

27

Where

L is the pulse duration of the generator 6.

The carrier signal Uj- (t) cosoJ t: (amplitude taken per unit) is fed to the input of the manipulated signal of the first phase manipulator 1, which can also be performed, for example, as a sequence

connected phase splitters by 90 ° and a switch.

To the input of the manipulating signal of the first phase handler 1, the clock of the square wave type is output from the generator 6.

In this case, the signal at the output of the first phase shift key will have the form

U |. (T) cosu; jt

at O

D

Ur (t) cos (tO, t + M with t 2t

The signal from the output of the first phase handler 1 is fed to the input of the modulating signal of the balanced modulator 3, and the signal from the output of the second phase handler 2 to the input of the modulated signal of the balanced modulator 3.

Since the polarities of the pulses entering the first and second phase switches 1 and 2 from generator 6 are the same, a voltage is generated at the output of the balanced modulator 3

Ub (t) cos (+ fl) t

 (t) cos (cj t + nt + n)

when O - t i G when t t 2

35

for the upper sideband, and U6, (t) cos (c4-fl) -l at O t ic Up M (t) cos (4t-3 t + i - |) cos (a) - ") t

when f t "2V

for the lower sideband, (only sum and difference frequency signals are considered).

Thus, the signal of the lower sideband does not undergo phase manipulation, and the signal of the upper sideband turns out to be manipulated in phase on the JT signal of generator 6 with a duty cycle of two (square wave). The spectrum of such a signal contains components with frequencies

u) j + ft + n 2jif, where n 1, 3, 5 ...

The frequency of the pulse generator 6 is chosen from the condition f

 L-flff + p where & F is the passband of the bandpass filter; F, is the highest frequency in the L spectrum of the modulating signal.

Due to this, the resulting side components of the phase-manipulated signal of the upper sideband are suppressed in the band-pass filter 4, i.e. the signal of the upper sideband does not pass to the output of the single-band signal driver,

If it is required to select the upper sideband and suppress the lower one, then it is sufficient to switch on the inverter 11 between the output of the generator 6 and the input of the manipulating signal of one of the phase manipulators 1 and 2.

FIG. The spectrum of the signal at the output of the balanced modulator 3 is shown with the generator 6 clock pulses turned off, FIG. 36 - the spectrum of the signal at the output of the balanced modulator 3 when the generator 3 is on.

The dotted line shows. The amplitude-frequency characteristic of the band-pass filter, f and f, respectively, the lower and upper lateral frequencies. : In the particular cases of the execution of the single-band signal driver shown in FIG. 2, the formation of a single-band signal occurs as follows

. .

Upon receipt at the inputs of the manipulated and manipulating signals of the second phase manipulator 2, respectively, the modulating signal Uj (t) cosftt and clock pulses from the output of the generator 6, p. the output of the second phase split l 10 a signal is formed

for t for L with t 2 AC

. When the manipulated and manipulating signals of the first phase manipulator 1 are received at the inputs of the carrier frequency from the U source 5 (t) cosoJ t and clock pulses from the generator 6, respectively, the output of the first phase splitter 9 produces a signal

fu (t) cos4tnpnO: t

Ur (t) cos (u), t + |). at t

When these signals arrive at the first balanced modulator 7, a voltage is formed at its output:

Ug .. (t) cos (4 + Sl) t

at Oh. t t

l-U6M (t) .cos (u) t + Slt + 7 /) at t t 2b of the upper sideband, and

U5 (t) cos (u) -m) t

ii F-

2 G

U .. ,, (t) cosHt-ftt + | - |) cos (u) eat -) t

at t t 2t

l

C

for the lower sideband.

When recording the output voltage, only the sum and difference frequency signals are taken into account.

Thus, the signal of the lower sideband does not undergo phase shift manipulation, and the signal of the upper sideband appears to be manipulated in phase on the JT signal of generator 6 with a duty cycle of two. In the spectrum of such a signal are components

(Ur + Sl ± n.2f, where n 1,3,5 ....

 The pulse frequency of the generator 6 is selected from the condition

, uZuQE + F.

2

Due to this, the side components of the phase-shift keyed signal, the upper sideband are suppressed in the bandpass filter 4, t, e, the signal of the upper sideband does not pass to the output of the former i singleband signals.

0

five

I

Thus, the first balanced modulator 1 generates a signal from the lower sideband. If it is required to select the upper band and suppress the lower frequency band, then turn on the inverter between the output of the generator 6 and the input of the manipulating signals of one of the phase manipulators 1 and 2.

The second amplitude balanced modulator 8 operates similarly to the first amplitude balanced modulator 7 with the only difference that the modulating and modulated signals for it will be signals:

Up (t) cos (Slt + |) U (t) co6 (Gt + al)

at 0 t

at -i t

and

Uf (t) cos () Ur (t) cos (u) t + 4i)

at about t iI at tit-i 2f

Therefore, the output voltage of the amplitude balanced modulator 8 is

UgM (t) cos (u), t + “t + Ji)

cos (iJr + Sl) t о о t

and .... (t) cos (a), t + Ut + 24l)

(

cos () t

at t t - 2i

dLA upper sideband and U (t) cos (a), - a) t + | - | l cos (ix) -SO t for t V

U5M (t) cos (u) -SOt + J-4t

cos (.) t

when t i t 2 (.

for the lower sideband.

The comparison of the output voltages of the first and second amplitude balance modulators 7 and 8 shows that the signals of the lower sideband in the corresponding time intervals t are in phase, and the signals of the upper sideband are in antiphase,

In real conditions at the output of a single-band shaper with

the operation of the first amplitude balance modulator 7 remains some small value of &, the non-suppressed remainder of the inactive sideband. When the second amplitude balanced modulator 8 is in operation, the non-surplus balance

non-working sideband (in this case, the upper one) is equal to Sni ji & Therefore, at the output of the band-pass filter 4, which receives a signal from the output of the adder 12, the resulting residue & 2 S of the suppressed sideband will form a single-band signal will be further reduced.

ten

Formula

and 3

gaining

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0

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0

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A single-band signal shaper containing a source of carrier frequency signals and a series-connected balanced modulator and a band-pass filter, characterized in that, in order to reduce the remainder of the suppressed sideband when subjected to destabilizing factors, the first and second phase handlers are inserted into it, -. The ports of which are connected respectively to the input of the modulated signal of the balanced modulator and the input of the modulating signal of the balanced modulator, a clock generator of the type square wave, the output of which is connected to the input of the manipulating signal of the first phase manipulator and the input of the manipulating signal of the second phase manipulator of the top, while the input - the nullable signal of the first phase handler is connected to the code of the source of the carrier frequency signals, the input of the manipulated signal of the second phase handler is in building, modulating signals, and the output of bandpass filter - the output of the single-sideband signals, wherein the repetition frequency of signal generator vyhrdnyh clock type meander

 f is selected from the ratio

f, F, where ... P

etc

- strip

band-pass filter transmission; F is the highest frequency in the spectrum of the modulating signal.

J

FIG. 2

Claims (1)

Claim - f A single-band signal generator comprising a source of carrier frequency signals and a balanced modulator and a bandpass filter connected in series, characterized in that, in order to reduce the remainder of the suppressed sideband when exposed to destabilizing factors, the first and second phase manipulators are inserted into it. which are connected respectively to the input of the modulated signal of the balanced modulator and the input of the modulating signal of the balanced modulator, a clock pulse generator of the meander type, the output of which is connected to the input of the manipulating signal of the first phase manipulator and to the input of the manipulating signal of the second phase manipulator, while the input of the manipulated signal of the first phase manipulator connected to the output of the carrier frequency signal source, the input of the manipulated signal of the second phase manipulator is an input th modulating signals, and the output of bandpass filter - the output of the single-sideband signals, wherein the repetition frequency of signal generator output clock pulses of the meander type f is selected from the relation f? +, where d F _{n <p} is the passband of the band-pass filter, F _{M is the} highest frequency in the spectrum of the modulating signal. FIG. 2 \ ________ _v J * ^j r ^v --------- Y ---- κ>. ₈ -ί "Λ Fig"U'Y * ·