SU720685A1

SU720685A1 - Frequency-phase discriminator

Info

Publication number: SU720685A1
Application number: SU752160971A
Authority: SU
Inventors: Виктор Григорьевич Головин; Илья Наумович Гуревич; Валерий Михайлович Кузьмин; Борис Александрович Павлов
Original assignee: Предприятие П/Я А-7672
Priority date: 1975-08-08
Filing date: 1975-08-08
Publication date: 1980-03-05

Description

Изобретение относится к' piaflHOTexHHке и может использоваться в радиотехнических устройствах для автоматической Подстройки частоты и фазовой разности двух сигналов.The invention relates to 'piaflHOTexHHke and can be used in radio engineering devices for automatically tuning the frequency and phase difference of two signals.

Известен частотно-фазовый дискримиминатор, содержащий фазовый детектор, к выходу которого подключена дифферен— ¹ цирующая цепь, и фильтр нижних частот ш.Known frequency diskrimiminator phase comprising a phase detector, which is connected to the output of the differential circuit ¹ tsiruyuschaya and lowpass filter w.

Однако известный дискриминатор имеет низкую крутизну частотной характеристики.However, the known discriminator has a low frequency response slope.

Цель изобретения — повышение крутизны частотной характеристики.The purpose of the invention is to increase the steepness of the frequency response.

Для достижения поставленной цели в частотно-фазовый дискриминатор, содержащий фазовый детектор, к выходу которого подключена дифференцирующая цепь, и фильтр нижних частот, введен алгебраический сумматор, выход которого подключен к входу фильтра нижних частот, и две дополнительные пели, состоящие каждая из последовательно соединенных дио—To achieve this goal, a frequency-phase discriminator containing a phase detector, to the output of which a differentiating circuit is connected, and a low-pass filter, an algebraic adder is introduced, the output of which is connected to the input of the low-pass filter, and two additional singers, each of which are connected in series to the diode -

Да и одновибратора, -включенные между выходом дифференцирующей цепи и входами алгебраического сумматора, при этом диоды подключены к выходу дифференцирующей цепи разнополярными электродами, а фазовый детектор выполнен с пилообразной характеристикой.Yes, and a single-vibrator, connected between the output of the differentiating circuit and the inputs of the algebraic adder, while the diodes are connected to the output of the differentiating circuit by multipolar electrodes, and the phase detector is made with a sawtooth characteristic.

На чертеже представлена структурная электрическая схема предложенного устройства.The drawing shows a structural electrical diagram of the proposed device.

Частотно-фазовый дискриминатор содержит фазовый детектор 1, дифференцирующую цепь 2, фильтр 3 нижних частот ФНЧ, алгебраический сумматор 4, две дополнительные цепи 5, 6, состоящие из диодов 7, 8 и одновибраторов 9, 10, причем дифференцирующая цепь 2 состоит из конденсатора 11 и сопротивления 12.The frequency-phase discriminator comprises a phase detector 1, a differentiating circuit 2, a low-pass filter 3, an LPF, an algebraic adder 4, two additional circuits 5, 6, consisting of diodes 7, 8 and single-vibrators 9, 10, and the differentiating circuit 2 consists of a capacitor 11 and resistance 12.

Устройство работает следующим образом.The device operates as follows.

Пусть измеряемая частота f_u больше эталонной частоты f₃ , тогда на выходе фазового детектора 1 существует пилообразное напряжение, период которого >Л'АLet the measured frequency f _u more than the reference frequency f ₃ , then at the output of the phase detector 1 there is a sawtooth voltage, the period of which>L'A

I равен периоду разностной частотыI is equal to the period of the difference frequency

9.р. После дифференцирования выходного напряжения фазового детектора 1 образуется последовательность импульсов отрицательной полярности, период следования которых равен периоду разностной частоты. Диоды 7 и 8, служат для разделения импульсов после дифференцирующей цепи 2 на два канала в зависимости от знака расстройки. Импульсы, запускающие одновибратор 10 отсутствуют. Одновибратор 9 запускается отрицательными импульсами, проходящими через диод 7. На выходе одновибратора 9 образуется последовательность импульсов длительности έ с периодом повторения равным периоду разностной частоты. Выходное напряжение одновибратора 10 равно О. Постоянная напряжения на выходе одновибратора 9 определяется выражением9.R. After differentiating the output voltage of the phase detector 1, a sequence of pulses of negative polarity is formed, the repetition period of which is equal to the period of the difference frequency. Diodes 7 and 8, are used to separate the pulses after the differentiating circuit 2 into two channels, depending on the sign of the detuning. The pulses that trigger the single vibrator 10 are absent. The one-shot 9 is triggered by negative pulses passing through the diode 7. At the output of the one-shot 9 a sequence of pulses of duration έ is formed with a repetition period equal to the period of the difference frequency. The output voltage of the single-shot 10 is equal to 0. The constant voltage at the output of the single-shot 9 is determined by the expression

720685 4......720 685 4 ......

ГО получают напряжение, величина постб;____. .. ’вых?GO receive voltage, postb value; ____. .. ’out?

F.xQp . Алгебраический сумматор 4 служит для алгебраического сложения выходных напряжений одновибрато^ров 9 и 10, При равенстве частот Ι₃ = ϊ_υ *с выхода фазового детектора 1 поступает постоянное напряжение, пропорциональное разности фаз входных сигналов. В этом случае отсутствуют запускающие импульсы на оба одновибратора 9 и 10 и выходное напряжение с фильтра 3. Крутизна преобразования частота-напряжение такого Дискриминатора определяется только параметрами одновибратора (амплитудой Ik тельностью выходного импульса) висит от частот сравниваемых ci. и может быть резко увеличена lie нию с достигаемой в схемах.F.xQp. The algebraic adder 4 serves for the algebraic addition of the output voltages of single-shots 9 and 10, When the frequencies частот ₃ = ϊ _υ * are equal, a constant voltage proportional to the phase difference of the input signals comes from the output of the phase detector 1. In this case, there are no triggering pulses for both one-vibrator 9 and 10 and the output voltage from filter 3. The steepness of the frequency-voltage conversion of such a discriminator is determined only by the parameters of the single-vibrator (amplitude Ik of the output pulse) depends on the frequencies compared ci. and can be sharply increased lie with what is achieved in the schemes.

янной составляющей которого равна υwhich is equal to υ

1и длиI, не за— сигналов1 and length I, not for - signals

—.....— „о сравне· применяемых ранее . 25 где Е - амплитуда импульса на выходе одновибратора 9.—.....— „about the same · applied earlier. 25 where E is the amplitude of the pulse at the output of a single vibrator 9.

X - длительность импульса одновибратора 9.X is the pulse duration of the one-shot 9.

Крутизна преобразования частота- ₃₀ напряжение $ соответственно равнаяThe steepness of the frequency conversion is $ _{30; the} voltage is respectively equal

S-Ex (Определяется только параметрами одновибратора 9.S-Ex (Defined only by the parameters of a single vibrator 9.

В случае ί₃>£_υ производная величины выходного напряжения на выходе фа- ₃₅зового детектора 1 меняет свой знак на обратный. Тогда при дифференцировании выходного напряжения фазового детектора 1 получается последовательность положительных импульсов, которые не прой- 4Q дут через диод 7 на вход одновибратора 9, а поступают через диод 8 на одновибратор 10.In case ί _3> £ _υ derivative value of the output voltage at the output ₃₅ the Optional zovogo detector 1 changes its sign reversed. Then, when differentiating the output voltage of the phase detector 1, a sequence of positive pulses is obtained, which do not pass 4Q through the diode 7 to the input of the single-vibrator 9, but pass through the diode 8 to the single-vibrator 10.

Так как запускающие импульсы на одновибратор 9 отсутствуют, то напряжение на его выходе равно 0. Аналогично случаю f _э < f на выходе одновибратораSince there are no triggering pulses to the single-shot 9, the voltage at its output is 0. Similarly to the case f _e <f at the output of a single-shot

Claims

The invention relates to radio engineering and can be used in radio engineering devices to automatically adjust the frequency and phase difference of two signals. The known frequency}) azov discriminator containing a phase detector, to the output of which a differentiating circuit is connected, and a low-pass filter. However, the known discriminator has a low frequency slope. The purpose of the invention is to increase the slope of the frequency response. To achieve this goal, an algebraic summptor, the output of which is connected to the lowpass filter hopper, and two additional circuits consisting of a phase-discriminator containing a phase detector, the output of which is connected to a differentiating circuit and a low-pass filter. each of the last / yuggre diode and one-shot, connected between the output of the differentiating circuit and the inputs of the algebraic adder, while the diodes are connected to the output of the differentiating circuit by different polarity electrodes, and The detector is made with a sawtooth characteristic. The drawing shows a structural electrical circuit of the proposed device. The frequency-base discriminator contains a phase detector 1, differentiating circuit 2 ,. lowpass filter 3 lowpass filter, algebraic adder 4, two additional circuits 5, 6, consisting of diodes 7, 8 and one-shot 9, 10, and differentiating circuit 2 consists of a capacitor 11 and sotrotizzleng 12. The device works as follows. Let the measured frequency f 6o; ibuie the reference frequency f-,, then at the peak of the phase detector 1, it is suusively sawtooth, the life of the 1st | south-t is equal to the period of the difference frequency p. After the differentiation of the output voltage of the phase detector 1, a sequence of impulses of negative polarity is formed, the follow-up period of which is equal to the peribda of the difference frequency. Diodes 7 and v / serve to separate the pulses after differentiating circuit 2 into two channels, depending on the mismatch sign. The pulses that trigger the one-shot 10 are absent. The one-stage 9 is started by negative pulses passing through the diode 7. At the output of the one-cycle 9, a sequence of pulses of duration t is formed: with a repetition period equal to the difference frequency period. The output voltage of the one-shot 10 is O. The voltage across the output of the one-shot 9 is determined by the expression. where E is the amplitude of the pulse at the output of the one-oscillator 9. C is the duration of the pulse of the one-oscillator 9. The slope of the frequency conversion S voltage is equal to S-Em I is determined only by the parameters of the one-oscillator 9. In the case of the derivative, the output voltage at the output of the phase detector 1 changes your sign on the back. Then, by differentiating the output voltage of phase phase cop 1, a sequence of positive pulses is obtained that are not passed through diode 7 to the input of the single-oscillator 9, but received through diode 8 to the single-oscillator 10. Since the triggering pulses to the single vibrator 9 are absent, then the output at its output is equal to O. Similarly to the case of f 3 fj at the output of the one-shot 5 4-;: GO, I receive a fault, the magnitude of the constant component of which is -g ,,. o-ehlr. The algebraic adder 4 serves to algebraically add the output voltages of single vibrators 9 and 10. If the frequencies {3 are equal, the post detector 1 receives a postbalance voltage proportional to the phase difference of the input signals. In this case, there are no triggering pulses on both single-oscillators 9 and 10 and the output voltage from filter 3. The incidence of transformation of the frequency-voltage of such a discriminator is determined / only by the parameters of the one-oscillator {amplitude 1 and the duration of the output pulse), does not depend on ol frequencies to compare signals and can be dramatically increased compared with that achieved in earlier applied schemes. The invention is a frequency discriminator containing. a phase detector, to the output of which a differentiating circuit is connected, and a low-pass filter, characterized in that, in order to observe the steepness of the frequency response, an algebraic adder, the output of which is connected to the input of the low-pass filter, is inserted into it, and two additional circuits each of the series-connected diode and one-shot connected between the output of the differentiating circuit and the inputs of the algebraic adder, while the diodes are connected to the output of the differentiating circuit by different polarity electrodes, and zovy detector configured sawtooth characteristic. Sources of information taken into account in the examination 1. Shahgild V. V, V., L Khovkin A. A. Phase-locked loop systems M., Sv, 1972, p. 329-331 (prototype).