SU1518867A1 - Device for shaping fm-signals - Google Patents

Abstract

The invention relates to radio engineering and can be used in radio communication and radar systems. The purpose of the invention is to increase speed. The device contains a controlled rr 1, an analog adder 2, a low-pass filter 3, a shaper of 4 pulses, a modulator 5, a synchronizer 6, a meter 9 of the time error. A multiplier 7 codes, a counter 8, an adder 10 codes and two memory blocks 11, 12 are entered into the device. The occurrence of each new pulse at the output of the driver 4 leads to a change in the state of the counter 8 and, consequently, the addresses of the memory block 11. At the output of the multiplier 7, the magnitude of the phase mismatch is formed, which through the filter 3 enters the adder 2 and corrects the initial phase mismatch. 1 il.

Description

ate

00 00

The invention relates to radio engineering and can be used in radio communication and radar systems.

The purpose of the invention is to increase speed.

The drawing shows a structural electrical circuit of a device for generating frequency-modulated signals.

The device for generating frequency-modulated signals contains a controlled oscillator 1, an analog adder 2, a low-pass filter 3, a pulse shaper A, a modulator 5, a synchronizer 6, a code multiplier 7, a counter 8, a time error meter 9, 10 codes, the first memory block 11, the second memory block 12.

The device for generating frequency-modulated signals operates as follows.

At the second output of the synchronizer 6, a 1-pulse sequence with a follow-up frequency F is formed, and at the first output of the synchronizer 6, pulses are formed that determine the modulation duration Tg (with 1

-). Impulses from the first output

Those.

the synchronizer 6 sets the initial state of the counter 8, the modulator 5, the meter 9 and the second memory block 12. At the same time, at the output of the counter 8, a starting address is set for the first memory block 11, according to which zero is written in the first block 11 of the memory block. At the output of the modulator 5 there is a voltage corresponding to the initial frequency of the frequency-modulated signal. At the outputs of the meter 9, the adder Id codes and the second memory block, there is a zero code. At the outputs of the multiplier 7 and filter 3 - zero. After the end of the pulse, a sawtooth modulating voltage begins to form at the output of the synchronizer 6, and at the output of the controlled oscillator a frequency-modulated signal of the form

and (T) A sin7 “P (T) + Y (G), (1)

one

ABOUT

where A is the amplitude of the signal; F (T) is the required modulation law;

Y From) is the deviation from the required modulation law due to the formation errors, T is the current time normalized to the duration T. Voltage (1) takes zero values at time points T (I) where M is not

L is the transition number zero from the start of modulation. Zna (M)

is determined from

 I) + Y t (M) M (2)

Shaper 4 separates the zeros of function (1), and the position of the pulses at the output of shaper 4, calculated from the moment of the start of modulation, corresponds to the values of T (H)

In the absence of errors, i.e. when Y SG) 0, have

(THEM,

where T (M) is the desired position of the zeros of the function (1).

I

The distance between adjacent zeros

the frequency modulated signal is defined as

D (H) T (H) T (Ji-l) - in the absence of errors.

D (I) t C) -T (M-1) - in the presence of errors.

The presence of a phase mismatch (Y ct) leads to the appearance of a time mismatch E (T), defined as follows:

 (M) in (H) - D (H) (3)

The value of E t (M) is formed at the output of the meter 9. At the output of the sum of the matrix of 10 codes, the value 0 is generated, equal to (I)

 E (I) + F t (K-1). In this case, the number is written to the second memory block 12 on the leading edge of the pulse of the driver 4, and the formation of O) at the output

meter 9 - on the falling edge of this pulse. Thus, while the output of the adder 10 of the codes contains the value F T (H) J, at the input of the second memory block 12, the value F T (H-1). At the exit

multiplier 7 is formed by a value proportional to the phase mismatch Y t (M).

So to l to

Y t (M)

F t 01)

 (M) - (M)

t (M) - T (M). (D), (5)

88676

Let be. And (1RMIRORNNY to T TPK (CH1 ITmeismgilfzy of frequency-modulon

With iGNLLRLRN

F (T)

G -

C (i) T

(6)

then, by excluding the value T (H) from equations (D) and (5), the dependence Y (T) is obtained.

In a specific example, it is seen how the phase mismatch Y (T) is generated.

N g Y t (M) -F t (M) C (i) 01) - those) (M) - T 01) (7)

Relation (7) shows that by multiplying by a variable in the transition from the Y (T) mismatch of the kphas-time function, the values of which in the Y mismatch of Y (T) and the times T (f) are multiplied by

N

to t (I) -ZLcd) t (I) - t (M) / t Of) - TOD

in view of the fact that (H) IT 01) conditions are met,

K t Ol) - -f.Ca) TOl) (9)

Since the values on the right-hand side of (9) are known, the Kt (H) values, beginning with the address 0 .., 01, are recorded in the first block, 11 memories. The appearance of each new pulse at the output of the driver 4 leads to a change in the state of the counter 8, and therefore, the addresses of the first memory block 11. The multiplier 7 performs the operation in accordance with the expression (7) and at its output a phase mismatch value Y T Ol) J is formed, which, through filter 3, goes to the analog adder 2 and corrects the initial phase mismatch. The function K m 0) is the multiplier that compensates for the change in the transmission coefficient of the self-tuning ring over time.

Claims (1)

The claims of the device for the formation of frequency-modulated signals containing in series connected1 {low pass filter, analog adder, controlled-oscillator, driver Relation (6) corresponds exactly to the polynomial frequency modulation law (for N 2, the linear etc.). Relation (6) can be considered as the representation of an arbitrary frequency modulation law in the form of a series with a limited number of terms. (eight) five 0 pulse and temporal spacing meter, as well as a modulator, the output of which is connected to the second input of the analog adder, and a synchronizer, while the modulator input is combined with the second input of the time error meter and connected to the first synchronizer output, the second output of which is connected to The third input of the time error meter, characterized in that, with a speed improvement, serially connected between the first output of the synchronizer and the input of the low-pass filter the counter, the first block of 5 m and the code multiplier, as well as the second memory block connected in series and the code adder, the code input of the second memory block combined with the second input of the code multiplier, and connected to the output of the code adder second input which is connected to the output of the time error meter, the first output of the synchronizer is connected to the setup input of the second memory unit, the clock input of which is combined with the counting input of the counter and connected to the output of the pulse shaper. 0 five