SU1272469A1

SU1272469A1 - Phase modulator

Info

Publication number: SU1272469A1
Application number: SU843803148A
Authority: SU
Inventors: Игорь Сергеевич Некрасов; Борис Константинович Лукьянчиков; Юрий Носонович Марголин
Original assignee: Курский Политехнический Институт
Priority date: 1984-10-18
Filing date: 1984-10-18
Publication date: 1986-11-23

Abstract

Изобретение относитс к радиотехнике . Цель изобретени - увеличение девиации фазы. Устр-во содержит тр-р I с первичной и вторичной обмотками 2 и 3, конденсатор 4, зл-т с управл емым активным сопротивлением, выполненный в виде полевого транзистора 5, источник сигнала несущей частоты 11. Вновь введен конденсатор 6, трансформатор 7 с первичной и вторичной обмотками 8 и 9, цепь смещени 10. Обмотка 3, конденсатор 4 и транзистор 5 представл ют собой 1-й LC-колебательиый контур, а обмотка 8 и конденсатор 6 - 2-й LC-колеба Л тельный контур. 1 ил. ji Udx.MoS.The invention relates to radio engineering. The purpose of the invention is to increase the phase deviation. The device contains tr-p I with primary and secondary windings 2 and 3, capacitor 4, zl-t with active resistance, made in the form of a field-effect transistor 5, the source signal of the carrier frequency 11. The capacitor 6 is newly introduced, the transformer is 7 s the primary and secondary windings 8 and 9, the bias circuit 10. The winding 3, the capacitor 4 and the transistor 5 are the 1st LC oscillating circuit, and the winding 8 and the capacitor 6 are the 2nd LC oscillating circuit. 1 il. ji Udx.MoS.

Description

Изобретение относится к радиотехнике и может использоваться для формирования фазомодулированных сигналов в различных устройствах в радиосвязи, радиолокации и при радиоиэмерениях.The invention relates to radio engineering and can be used to form phase-modulated signals in various devices in radio communications, radar and radio measurements.

Цель изобретения - увеличение девиации фазы.The purpose of the invention is the increase in phase deviation.

На чертеже представлена принципиальная электрическая схема фазового модулятора.The drawing shows a circuit diagram of a phase modulator.

Фазовый модулятор содержит первый трансформатор 1 с первичной 2 и вторичной 3 обмотками, первый конденсатор 4, элемент с управляемым активным сопротивлением, выполненный в виде полевого транзистора 5, второй конденсатор 6, второй трансформатор 7 с первичной 8 и вторичной 9 обмотками, цепь 10 смещения и источник 11 сигнала несущей частоты.The phase modulator comprises a first transformer 1 with primary 2 and secondary 3 windings, a first capacitor 4, an element with controlled resistance, made in the form of a field effect transistor 5, a second capacitor 6, a second transformer 7 with a primary 8 and secondary 9 windings, a bias circuit 10 and carrier frequency signal source 11.

Фазовый модулятор работает следующим образом.The phase modulator operates as follows.

Вторичная обмотка 3 первого трансформатора 1, конденсатор 4 и полевой транзистор 5 представляет собой первый LC-колебательный контур, а первичная обмотка 8 второго трансформатора 7 и конденсатор 6 - второй LC-колебательный контур.The secondary winding 3 of the first transformer 1, the capacitor 4 and the field effect transistor 5 is the first LC oscillatory circuit, and the primary winding 8 of the second transformer 7 and the capacitor 6 is the second LC oscillatory circuit.

Сигнал с выхода источника 11 сигнала несущей частоты поступает в первый LC-колебательный контур, настроенный на несущую частоту.The signal from the output of the carrier frequency signal source 11 enters the first LC oscillatory circuit tuned to the carrier frequency.

Модулирующий сигнал поступает на затвор полевого транзистора 5 и изменяет активное сопротивление его ка нала. При этом меняется добротность первого LC-колебательного контура и, как следствие этого, осуществляется . фазовая модуляция сигнала несущей частоты и наряду с ней возникает и паразитная амплитудная модуляция. Промодулированный по фазе и амплитуде сигнал с первого LC-колебательного контура поступает на второй LC-колебательный контур, /В котором также под действием изменения активного сопротивления канала полевого транзистора 5 осуществляется фазовая и амплитудная модуляция. При этом за счет включения второго LC-колебательного контура между средней точкой вторичной обмотки 3 первого трансформатора 1 и стоком полевого транзистора 5 амплитудная модуляция сигнала в нем осуществляется в противофазе по отношению к амплитудной модуляции в первом LC-колебательном контуре, т.е. равна нулю, а фазовая модуляция складывается с фазовой модуляцией, возникшей в первом LC-колебательном 5 контуре, т.е. равна суммарному значению отклонений фазы несущей частоты под действием модулирующего сигнала в первом и втором LC-колебательнах контурах.The modulating signal enters the gate of the field effect transistor 5 and changes the active resistance of its channel. In this case, the quality factor of the first LC-oscillatory circuit changes and, as a consequence of this, is carried out. phase modulation of the carrier frequency signal and, along with it, spurious amplitude modulation also occurs. The signal, modulated in phase and amplitude, from the first LC-oscillatory circuit enters the second LC-oscillatory circuit, / In which phase and amplitude modulation is also carried out by changing the active resistance of the channel of the field-effect transistor 5. In this case, due to the inclusion of the second LC-oscillatory circuit between the midpoint of the secondary winding 3 of the first transformer 1 and the drain of the field-effect transistor 5, the amplitude modulation of the signal in it is carried out in antiphase with respect to the amplitude modulation in the first LC-oscillatory circuit, i.e. is equal to zero, and the phase modulation is added to the phase modulation that occurred in the first LC-oscillatory circuit 5, i.e. equal to the total value of the phase deviations of the carrier frequency under the action of the modulating signal in the first and second LC-oscillatory circuits.

1® При этом процессы протекают в фазовом модуляторе следующим образом.1® In this case, the processes proceed in the phase modulator as follows.

При подаче на затвор полевого транзистора 5 напряжения модулирующе15 го сигнала сопротивление его канала меняется в больших пределах. Если это сопротивление мало отличается от нуля (R^XO) и в рассматриваемый момент времени точка а имеет положи20 тельный потенциал, а точка δ - отрицательный, тогда ток 1₁ из точки а протекает через конденсатор 4 и канал полевого транзистора 5 к точкеWhen a modulating signal voltage is applied to the gate of the field-effect transistor 5, the resistance of its channel varies over a wide range. If this resistance differs little from zero (R ^ XO) and at the point in time, point a has a positive potential and point δ is negative, then the current 1 ₁ from point a flows through capacitor 4 and the channel of field-effect transistor 5 to point

8. Ток из точки В при этом протекает ²⁵ через первичную обмотку 8 второго трансформатора 7 и конденсатор 6, че рез канал полевого транзистора 5 к точке б . Ток 1₂, протекающий через .первичную обмотку 8 второго трансфор 30 матора 7, создает на ней падение напряжения U_?j, которое передается на вторичную обмотку 9 и далее на нагрузку. При этом сдвиг по фазе между напряжением U_ag и отсутствует.8. The current from point B flows ²⁵ through the primary winding 8 of the second transformer 7 and the capacitor 6, through the channel of the field-effect transistor 5 to point b. The current 1 ₂ flowing through the primary winding 8 of the second transformer 30 of the mattor 7 creates a voltage drop U _? j, which is transmitted to the secondary winding 9 and then to the load. In this case, a phase shift between the voltage U _a g and is absent.

В случае, когда сопротивление R _кпод действием напряжения модулирующего сигнала удовлетворяет условию R_K>> 0, точка а также в рассматриваемый момент имеет положительный по 40 тенциал, а точка δ - отрицательный, ток 1₃ из точки а через конденсатор 4 и первичную обмотку 8 второго трансформатора 7 протекает к точке В . При этом ток I* из точки В че2 рез первичную обмотку 8 второго трансформатора 7 и канал полевого транзистора 5 протекает к точке 8In the case when the resistance R _to under the action of the voltage of the modulating signal satisfies the condition R _K >> 0, the point and at the moment in question has a positive potential of 40, and the point δ is negative, the current 1 ₃ from point a through the capacitor 4 and the primary winding 8 of the second transformer 7 flows to point B. In this case, the current I * from point B through 2 through the primary winding 8 of the second transformer 7 and the channel of the field effect transistor 5 flows to point 8

Токи и Г создают на первичной 5° обмотке 8 второго конденсатора 7 падение напряжения которое равно векторной сумме напряжений, создаваемых на ней за счет протекания токов и 1₃ .The currents and G create on the primary 5 ° winding 8 of the second capacitor 7 a voltage drop which is equal to the vector sum of the voltages created on it due to the flow of currents and 1 ₃ .

При выполнении условия ^Хс4 ^{> Х}гй ’ где Х_С4- реактивное сопротивление конденсатора 4;Under the condition ^X c4 ^{> X} gy 'where X _C4 is the reactance of capacitor 4;

Х_?9“ реактивное сопротивление первичной обмотки 8 второго трансформатора 7, и при изменении R* от нуля до вели- 5 чины R _к >> О между входным напряжением (и_л£) и выходным напряжением (U₅g ) фазового модулятора происходит сдвиг 2 д Ч’ > 90°. Амплитудная модуляция выходного напряжения (между ¹⁰точками г ид) отсутствует. Цепь 10 смещения служит для выбора рабочей точки полевого транзистора 5. Конденсатор 6 позволяет настраивать второй LC-колебательный контур в резо- 15 нанс,. что уменьшает энергию, потребляемую им.X _{? 9} “reactance of the primary winding 8 of the second transformer 7, and when R * changes from zero to a value of R _k >> 0, a shift occurs between the input voltage (and _l £) and the output voltage (U ₅ g) of the phase modulator 2 d H '> 90 °. Amplitude modulation of the output voltage (between ¹⁰ points r id) is absent. The bias circuit 10 serves to select the operating point of the field effect transistor 5. The capacitor 6 allows you to configure the second LC-oscillatory circuit in resonance 15 nans. which reduces the energy consumed by him.

Claims

The invention relates to radio engineering and can be used to generate phase-modulated signals in various devices in radio communications, radiolocation and radio measurements. The purpose of the invention is to increase the phase deviation. The drawing shows a circuit diagram of a phase modulator. The phase modulator contains the first transformer 1 with the primary 2 and secondary 3 windings, the first capacitor 4, the element with controlled resistance, made in the form of a field-effect transistor 5, the second capacitor 6, the second transformer 7 with the primary 8 and secondary 9 windings, circuit 10 displacement and carrier source 11. Phase modulator works as follows. The secondary winding 3 of the first transformer 1, the capacitor 4 and the field-effect transistor 5 is the first LC oscillating circuit, and the primary winding 8 of the second transformer 7 and the capacitor 6 are the second LC oscillating circuit. The signal from the output of the source 11 signal of the carrier frequency enters the first LC-oscillating circuit tuned to the carrier frequency. The modulating signal arrives at the gate of the field-effect transistor 5 and changes its resistance to current. This changes the quality factor of the first LC oscillatory circuit and, as a result, is realized. Phase modulation of the carrier signal and, along with it, parasitic amplitude modulation, modulated in phase and amplitude, the signal from the first LC circuit oscillates on the second LC oscillation circuit, which also is affected by the change in the channel resistance The field-effect transistor 5 performs phase and amplitude modulation. At the same time, due to the inclusion of the second LC oscillatory circuit between the midpoint of the secondary winding 3 of the first transformer 1 and the drain of the field-effect transistor 5, the amplitude modulation of the signal in it occurs in antiphase with respect to the amplitude modulation in the first LC oscillatory circuit, t, e is equal to zero, and phase modulation is added to the phase modulation occurring in the first LC-oscillatory circuit, t, e, is equal to the total value of the deviations of the phase of the carrier frequency under the action of the modulating signal in the first and second LC-oscillatory Contours. When this process proceeds in the phase modulator as follows. When a field-effect transistor 5 is applied to the gate of a modulating signal, the resistance of its channel varies within wide limits. If this resistance is a little different from zero () and at the considered time point and has a positive potential, and point 6 is negative, then the current I from point o flows through capacitor A and the channel of the field-effect transistor 5 to point 6, the current from point ft at This flows through the primary winding 8 of the second transformer 7 and the capacitor 6, through the channel of the field-effect transistor 5 to the point b. The current I flowing through the primary winding 8 of the second transformer 7 creates a voltage V on it, which is transmitted to the secondary winding 9 and then to the load. In this case, the phase shift between the voltage and U. is absent. In the case when the resistance R under the action of the voltage of the modulating signal satisfies the condition R 0, the point and also at the considered moment has a positive potential, and point 5 - negative, the current I- from point a through the capacitor 4 and the primary winding 8 of the second transformer 7 flows to point 6, while the current l from point B through the primary winding 8 of the second transformer 7 and the channel of the field-effect transistor 5 flows to point 8. The currents 1 and I create on the primary winding 8 of the second capacitor 7 a voltage drop u which is equal to the vector sum of the voltages generated on it due to the flow of the currents Ij and Ij. When the condition is met, the reactance of the capacitor 4; X is the reactance of the primary winding 8 of the second transformer 7, and when k changes from zero to a value of R O, a shift of 2 d H 90 ° occurs between the input voltage (s) and the output voltage (Uja) of the phase modulator. The amplitude modulation of the output voltage (between the points id) is absent. The bias circuit 10 is used to select the operating point of the field effect transistor 5. The capacitor 6 allows the second LC oscillating circuit to be tuned to resonance. which reduces the energy consumed by it. The invention includes a phase modulator containing a first transformer, the primary winding of which is connected to the output of the modulated signal source, and the secondary winding is connected to a ring with the first capacitor and an element with a controllable resistance, the control input of which is the modulating signal of the phase modulator , while the element with controlled resistance is made in the form of a field-effect transistor, which is characterized by the fact that, in order to increase the phase deviation, a second transformer is introduced into it p and the second capacitor, and the bias circuit is connected to the gate of the field-effect transistor; the source of the field-effect transistor is connected to the second output of the secondary winding of the first transformer and to the common bus; the drain of the field-effect transistor is connected to the first output of the primary winding of the second transformer, with the first output The second capacitor and the second output of the first capacitor, the second output of the primary winding of the second transformer and the second output of the second capacitor are connected to the midpoint of the secondary winding of the first transform torus, the secondary winding of the second transformer is the output of the phase modulator, and the gate of field effect transistor - the control input element with controllable internal resistance.