RU2341889C1 - Method for demodulation of phase-modulated radio frequency signals and device for its realisation - Google Patents

Abstract

FIELD: radio communication.

SUBSTANCE: in method and device for demodulation (DM) of phase-manipulated and phase-modulated (PM) signals that consists in the fact that DM is connected between source of radio frequency (RF) PM signals and low frequency (LF) load and is arranged from quadripole, non-linear element, low-pass filter, PM signal is converted to APM signal by means of supply of this signal to the right or left slope of dependence of module of one of complex elements of resistance matrix or conductivity of non-linear element from frequency. With the help of non-linear element spectrum of APM signal is destroyed into HF and LF components. As non-linear element three-pole element is used, which is connected between source of RF PM signals and quadripole or between quadripole and introduced HF load according to the circuit with common emitter, base or collector. Quadripole is arranged from resistive dipoles, at least two, parameters of which are selected based on condition of provision of required depth of amplitude modulation of APM signal.

EFFECT: higher noise immunity of receiver.

11 cl, 9 dwg

Description

The invention relates to radio communications and can be used to demodulate phase-shifted as well as phase-modulated signals.

A known method of demodulating phase-modulated signals (PMS), consisting in the fact that two non-linear elements simultaneously fed in phase out of phase high-frequency PMS and in phase high-frequency reference oscillation with a frequency equal to the carrier frequency of the PMS. As a result, the FMS phase changes in time and the constant phase of the reference oscillation is compared, as a result of which the FMS is converted into an amplitude-modulated and phase-modulated signal (AFMS). In this case, the amplitude changes according to the law of phase change. This signal then undergoes the same transformations as in the amplitude demodulator [S. Baskakov Radio circuits and signals. M.: Higher School, 1988, pp. 286-292]. This means that on nonlinear elements the AFMS spectrum is destroyed into low-frequency and high-frequency components. Then, using the low-pass filter, a low-frequency component is extracted, the amplitude of which changes according to the law of phase change of the input FMS. Then, using the separation capacitance included in the longitudinal circuit (sequentially), the constant component that occurs on non-linear elements as a result of interaction with the AFMS is eliminated. After that, low-frequency vibrations containing useful information are allocated to the low-frequency load.

The disadvantage of this method and device for its implementation is that in order to isolate a low-frequency signal, the amplitude of which varies in accordance with the law of the phase change of the high-frequency PMS, the presence of a reference oscillator is necessary.

The closest in technical essence and the achieved result (prototype) is a method of demodulating phase-modulated signals, which consists in the fact that to demodulate the FMS, a frequency detector is used, consisting of a cascade-connected amplitude limiter, a frequency-modulated signal converter (HMS) in the amplitude-frequency modulated signal (AFMC) in the form of a parallel oscillatory circuit and a conventional amplitude demodulator. Further, the process of isolating the low-frequency component is also carried out as described above. The peculiarity of using a frequency detector for FMS demodulation is that if the frequency of the FMS carrier signal is located on the right slope of the amplitude-frequency characteristic (AFC) of the circuit, then the low-frequency component is fed to the differentiating circuit. If the frequency of the carrier signal of the FMS is located on the left slope of the frequency response of the circuit, then the low-frequency component is fed to the integrating circuit [S. Baskakov Radio circuits and signals. M.: Higher School, 1988, pp. 286-292]. If necessary, between the source of modulated signals and the nonlinear element or between the nonlinear element and the load include a reactive or resistive four-terminal network for matching and additional signal and interference selection. As a result, at the output of the device, we have a low-frequency oscillation, the amplitude of which changes according to the law of variation of the envelope of the input high-frequency phase-modulated oscillation.

The disadvantage of the method and device for its implementation is that after converting the FMS to AFMS, the depth of amplitude modulation of the AFMS is not controlled and, as a rule, is insignificant in size, which impairs noise immunity [S. Baskakov. Radio circuits and signals. M.: Higher School, 1988, pp. 286-292. Gonorovsky I.S. Radio circuits and signals. M .: Radio and communications, 1986, p. 247-252]. Another disadvantage is the additional presence of an oscillatory circuit for converting FMS to AFMS. This drawback is due to the fact that the classical theory of radio circuits assumes that the nonlinear element is purely resistive and inertia-free, and therefore does not react to a change in the frequency and phase of the input signal, but only responds to a change in amplitude. Meanwhile, everyday experience shows that nonlinear elements have internal capacitances and inductances, which have a significant effect on the formation of the dependence of their conductivity (resistance or elements of the matrix of conductivities or resistances) on frequency and phase. This is especially significant with an increase in frequency, which is currently mainly sought by designers of new systems and means of radio communications.

The technical result of the invention is to provide demodulation of the FMS without using the reference oscillator and parallel oscillatory circuit with the conversion of the FMS to AFMS using the high-frequency part of the demodulator at a given depth of amplitude modulation of the AFMS at high frequency load, which increases the noise immunity of the receiver.

1. The specified result is achieved by the fact that in the method of demodulating phase-modulated signals, consisting in the fact that the demodulator is turned on between the source of the radio-frequency phase-modulated signals and the low-frequency load, and it is made of a four-terminal device, a nonlinear element, a low-pass filter, the phase-modulated signal is converted into an amplitude-phase-modulated signal using a nonlinear element destroy the spectrum of the amplitude-phase modulated signal into high-frequency and low-frequency components, with the help of A low-pass filter isolates an informational low-frequency signal, the amplitude of which varies according to the law of phase change of the phase-modulated input signal, in addition, a three-pole element is used as a nonlinear element, which is connected between a source of radio-frequency phase-modulated signals and a four-terminal or between a four-terminal and an introduced high-frequency load according to the scheme with a common emitter, base or collector, a four-terminal is made of resistive two-terminal, not less vuh, the parameter values of which are selected to ensure the required depth of amplitude modulation of the amplitude-phase-modulated signal, the phase-modulated signal is converted into the amplitude-phase-modulated signal by applying this signal to the right slope of the frequency dependence of the module of one of the complex elements of the non-linear element resistance matrix, the low-frequency component is amplitude -phase-modulated signal is fed to a differentiating circuit, or phase-modulated conversion The needle in the amplitude-phase-modulated signal is carried out by supplying this signal to the left slope of the frequency dependence of the module of one of the complex elements of the resistance matrix of the nonlinear element, while the low-frequency component of the amplitude-phase-modulated signal is fed to the integrating circuit, or the phase-modulated signal is converted into the amplitude-phase-modulated signal by applying this signal to the right slope of the dependence of the module of one of the complex elements of the conductivity matrix n the linear element of the frequency, the low-frequency component of the amplitude-phase-modulated signal is fed to the integrating circuit, or the phase-modulated signal is converted into the amplitude-phase-modulated signal by supplying this signal to the left slope of the frequency dependence of the module of one of the complex elements of the conductivity matrix of the nonlinear element, while the low-frequency component the amplitude-phase modulated signal is fed to a differentiating circuit.

2. This result is achieved by the fact that in the device for demodulating phase-modulated signals connected between the source of phase-modulated signals and the low-frequency load and consisting of a converter of phase-modulated signals into an amplitude-phase-modulated signal, a nonlinear element, a four-terminal device, a low-pass filter, a three-pole element is additionally used as a nonlinear element an element, a converter of phase-modulated signals into an amplitude-phase-modulated signal is made in the form of this a linear element, the type of which is selected in such a way that the left or right slope of the dependence of one of the complex elements of its conductivity matrix on the frequency coincides with the frequency of the carrier wave of the phase-modulated signals, the non-linear element is connected between the phase-modulated signal source and the four-terminal network according to a circuit with a common emitter, base, or collector , when choosing the left slope of the indicated dependence, a differentiating circuit was used as a low-frequency load, and when choosing the right slope, the integrating circuit pi, the four-terminal network is made up of at least two resistive two-terminal networks, the parameter values of which are selected from the condition for ensuring the required depth of amplitude modulation of the amplitude-phase modulated signal by using the following mathematical expressions:

- given elements of the conductivity matrix of a nonlinear three-pole element in two states ( ^I and ^II ), determined by the two extreme frequency values of the input phase-modulated signal; m is the specified ratio of the transmission coefficient modules of the high-frequency part of the demodulator in two states of the input signal, characterized by two extreme frequency values of the phase-modulated signal; φ is the known phase difference of the input signal in its two states, characterized by two extreme frequency values of the phase-modulated signal; M ₂₁ - the depth of the amplitude modulation of the amplitude-phase modulated signal; z _{n1, n2} = r _{n1, n2} + jx _{n1, n2} , z _01.02 = r _01.02 + jx _01.02 are the specified complex resistances of the high-frequency load and the source of the phase-modulated signal in its two states.

3. The specified result is achieved by the fact that in the device for demodulating phase-modulated signals according to claim 2, the resistive four-terminal is made in the form of a L-shaped connection of two resistive two-terminal, the resistive r ₁ , r _{2 of the} two-terminal components making up the L-shaped connection are selected using the following mathematical expressions:

D₁, D₂, E, F имеют тот же смысл, что и в п.2.Where

D ₁ , D ₂ , E, F have the same meaning as in claim 2.

4. The specified result is achieved by the fact that in the device for demodulating phase-modulated signals according to claim 2, the resistive four-terminal is made in the form of a symmetrical blocked T-connection of four resistive two-terminal, resistive r ₁ , r ₂ r ₃ = r ₁ , r ₄ = r ₂ bipolar, making up an overlapped T-shaped connection, selected using the following mathematical expressions:

D₁, D₂, E, F имеют такой же смысл, как и в п.2; значение сопротивления r₂ выбирается из условия обеспечения физической реализуемости сопротивления r₁, r₃, r₄.Where

D ₁ , D ₂ , E, F have the same meaning as in claim 2; the resistance value r ₂ is selected from the condition of ensuring the physical realizability of the resistance r ₁ , r ₃ , r ₄ .

-образного соединения двух резистивных двухполюсников, резистивные сопротивления r₁, r₂ двухполюсников, составляющих

-образное соединение, выбраны с помощью следующих математических выражений:5. The specified result is achieved by the fact that in the device for demodulating phase-modulated signals according to claim 2, the resistive four-terminal device is made in the form

-shaped connection of two resistive bipolar, resistive r ₁ , r ₂ bipolar components

-shaped connection, selected using the following mathematical expressions:

D₁, D₂, E, F имеют такой же смысл, как и в п.2.Where

D ₁ , D ₂ , E, F have the same meaning as in claim 2.

6. The indicated result is achieved by the fact that in the device for demodulating phase-modulated signals according to claim 2, the resistive four-terminal is made in the form of a symmetrical T-shaped connection of three resistive two-terminal, resistive r ₁ , r ₂ , r ₃ = r ₁ two-terminal components that make up a symmetrical T- shaped connection, selected using the following mathematical expressions:

D₁, D₂, E, F имеют такой же смысл, как и в п.2.Where

D ₁ , D ₂ , E, F have the same meaning as in claim 2.

7. The indicated result is achieved by the fact that in the device for demodulating phase-modulated signals according to claim 2, the resistive four-terminal is made in the form of an asymmetric T-shaped connection of three resistive two-terminal, resistive r ₁ , r ₂ two-terminal, making up an asymmetric T-shaped connection, are selected using the following mathematical expressions:

D₁, D₂, E, F имеют такой же смысл, как и в п.2; значение сопротивления r₃ выбирается из условия обеспечения физической реализуемости сопротивления r₁, r₂.Where

D ₁ , D ₂ , E, F have the same meaning as in claim 2; the value of resistance r ₃ is selected from the conditions for ensuring the physical feasibility of resistance r ₁ , r ₂ .

8. The indicated result is achieved by the fact that in the device for demodulating phase-modulated signals according to claim 2, the resistive four-terminal is made in the form of an asymmetric T-shaped connection of three resistive two-terminal, resistive r ₁ , r ₃ two-terminal, making up an asymmetric T-shaped connection, are selected using the following mathematical expressions:

D₁, D₂, E, F имеют такой же смысл, как и в п.2; значение сопротивления r₂ выбирается из условия обеспечения физической реализуемости сопротивления r₁, r₃.Where

D ₁ , D ₂ , E, F have the same meaning as in claim 2; the value of resistance r ₂ is selected from the conditions for ensuring the physical feasibility of resistance r ₁ , r ₃ .

9. The specified result is achieved by the fact that in the device for demodulating phase-modulated signals according to claim 2, the resistive four-terminal is made in the form of an asymmetric T-shaped connection of three resistive two-terminal, resistive r ₂ , r ₃ two-terminal, making up an asymmetric T-shaped connection, are selected using the following mathematical expressions:

D₁, D₂, E, F имеют такой же смысл, как и в п.2; значение сопротивления r₁ выбирается из условия обеспечения физической реализуемости сопротивления r₂, r₃.Where

D ₁ , D ₂ , E, F have the same meaning as in claim 2; the resistance value r ₁ is selected from the condition of ensuring the physical realizability of the resistance r ₂ , r ₃ .

10. The specified result is achieved by the fact that in the device for demodulating phase-modulated signals according to claim 2, the resistive four-terminal is made in the form of a bridge circuit for connecting four resistive two-terminal, resistive r ₁ , r ₂ , r ₃ = r ₁ , r ₄ = r ₂ two-terminal, components of the bridge connection, selected using the following mathematical expressions:

D₁, D₂, E, F имеют такой же смысл, как и в п.2.Where

D ₁ , D ₂ , E, F have the same meaning as in claim 2.

11. The specified result is achieved by the fact that in the device for demodulating phase-modulated signals according to claim 2, the resistive four-terminal is made in the form of a symmetrical U-shaped connection of three resistive two-terminal, resistive r ₁ , r ₂ , r ₃ = r ₁ two-terminal components that make up a symmetrical P- shaped connection, selected using the following mathematical expressions:

D₁, D₂, E, F имеют такой же смысл, как и в п.2.Where

D ₁ , D ₂ , E, F have the same meaning as in claim 2.

Figure 1 shows a diagram of a device for demodulating phase-modulated RF signals (prototype).

Figure 2 shows the structural diagram of the proposed device according to claim 1.

Figure 3 shows a diagram of a four-terminal device of the proposed device according to claim 2.

Figure 4 shows a diagram of a four-terminal device of the proposed device according to claim 3.

Figure 5 shows a diagram of a four-terminal device of the proposed device according to claim 4.

Figure 6 shows a diagram of a four-terminal device of the proposed device according to claim 5.

Figure 7 shows a diagram of the four-terminal devices of the proposed devices according to claims 6-8.

In Fig.8 shows a diagram of a four-terminal device of the proposed device according to claim 9.

Figure 9 shows a diagram of a four-terminal device of the proposed device according to claim 10.

The prototype device contains a source 1 of phase-modulated signals, a four-terminal 2, a nonlinear element 3, a low-pass filter 4 on the elements R, C, a separation capacitance 5 on the element C _p and a low-frequency load 6 on the elements R _n , C _n

The principle of operation of the device demodulation phase-modulated signals (prototype) is as follows.

The phase-modulated signal from source 1 is supplied to the demodulator from a series-connected semiconductor diode to a low-pass filter. The principle of operation of the device that implements this method is that, using a reactive four-terminal 2, which is a parallel oscillatory circuit and connected between the FMS source and the nonlinear element, the FMS is converted into AFMS, using the nonlinear element 3, the AFMS spectrum is destroyed into high-frequency and low-frequency components . The latter are selected using a low-pass filter 4 and fed to the low-frequency load 6. A differentiating circuit is selected as the load if the input FMS is applied to the right slope of the frequency response of the circuit or an integrating circuit is selected as load if the input FMS is fed to the left slope of the frequency response of the circuit. The separation tank 5 eliminates the constant component. As a result, at the output of the device, we have a low-frequency oscillation, the amplitude of which changes according to the law of variation of the envelope of the input high-frequency amplitude-modulated oscillation.

The disadvantage of the method and device for its implementation is that when passing the FMS through the specified circuit, after converting the FMS to AFMS, the depth of the amplitude modulation of the latter is insignificant. This is due to the large width of the FMS spectrum, i.e. with low quality factor of a contour. On the other hand, the narrower the bandwidth of the circuit, the greater the distortion of the received signal.

The high-frequency part of the structural diagram of the generalized proposed device (up to the low-pass filter) according to claim 2 (Fig. 2) consists of a cascade-connected source of FMS 1, a three-pole nonlinear element 3, a resistive four-terminal 2 and a high-frequency load 7. The low-frequency part of the structural circuit contains a filter low frequencies 4, separation capacitance 5 and low-frequency load 6.

The principle of operation of this device is that when supplying the FMS from source 1 with resistance z ₀ as a result of a special choice of the values of the parameters of the classical transmission matrix of the two-terminal network 2 from the conditions for ensuring a given depth of amplitude modulation AFMS converted from the input FMS on the left or right slope of the module of one of the complex elements of the conductivity matrix of a nonlinear element versus frequency, after passing it through the high-frequency part, a minimum of distortions of the input signal is achieved . At the same time, the AFMS spectrum is destroyed by a nonlinear element 3 connected between the phase-modulated signal source and the four-terminal network according to the scheme with a common emitter, base, or collector, the low-pass filter 4 selects a low-frequency component, the constant component is eliminated using a separation capacitance 5. If the left slope of the indicated dependence is selected , then a differentiating circuit is used as a low-frequency load, and if the right slope of the indicated dependence is selected, then as a low-frequency load and an integrating circuit is used.

As a result, the low-frequency oscillation, the amplitude of which varies according to the law of phase change of the input FMS, is allocated to the low-frequency load 6.

The proposed FMS demodulation device according to claim 3 differs from the device according to claim 2 in that the resistive four-terminal 11 (FIG. 3) is made of two two-terminal 5, 6 with resistive r ₁ , r ₂ connected to each other in a L-shaped scheme. The values of the resistances r ₁ , r _{2 of the} two-terminal 5, 6 depend on the optimal values of the elements of the transmission matrix of the four-terminal and the given complex resistance of the signal source and load. The principle of operation of this device is similar to the principle of operation of the device according to claim 2.

The proposed FMS demodulation device according to claim 4 differs from the device according to claim 2 in that the resistive four-terminal (Fig. 4) is made in the form of a symmetrical overlapped T-shaped circuit for connecting four resistive two-terminal with resistances r ₁ , r ₂ , r ₃ = r ₁ , r ₄ . The principle of operation of this device is similar to the principle of operation of the device according to claim 2.

-образной схемы соединения двух резистивных двухполюсников с сопротивлениями r₁, r₂. Принцип действия этого устройства аналогичен принципу действия устройства по п.2.The proposed FMS demodulation device according to claim 5 differs from the device according to claim 2 in that the resistive four-terminal device (Fig. 5) is made in the form

-shaped connection of two resistive bipolar with resistance r ₁ , r ₂ . The principle of operation of this device is similar to the principle of operation of the device according to claim 2.

The proposed FMS demodulation device according to claim 6 differs from the device according to claim 2 in that the resistive four-terminal (Fig. 6) is made in the form of a symmetrical T-shaped connection of three resistive two-terminal with resistances r ₁ , r ₂ , r ₃ = r ₁ . The principle of operation of this device is similar to the principle of operation of the device according to claim 2.

The proposed FMS demodulation device according to claim 7 differs from the device according to claim 2 in that the resistive four-terminal (Fig. 7) is made in the form of an asymmetric T-shaped connection of three resistive two-terminal with resistances r ₁ , r ₂ , r ₃ . In this case, the optimal values of the resistances r ₁ , r _{2 are} determined explicitly using mathematical expressions. The resistance value r ₃ is selected from the condition of ensuring the physical realizability of the resistance r ₁ , r ₂ (ensuring their non-negative). The principle of operation of this device is similar to the principle of operation of the device according to claim 2.

The proposed FMS demodulation device according to claim 8 differs from the device according to claim 2 in that the resistive four-terminal device (Fig. 7) is made in the form of an asymmetric T-shaped connection of three two-terminal devices. In this case, the optimal values of the resistances r ₁ , r _{3 are} determined explicitly using mathematical expressions. The resistance value r ₂ is selected from the condition of ensuring the physical realizability of the resistance r ₁ , r ₃ (ensuring they are non-negative). The principle of operation of this device is similar to the principle of operation of the device according to claim 2.

The proposed FMS demodulation device according to claim 9 differs from the device according to claim 2 in that the resistive four-terminal device (Fig. 7) is made in the form of an asymmetric T-shaped connection of three two-terminal devices. In this case, the optimal values of the resistances r ₂ , r _{3 are} determined explicitly using mathematical expressions. The value of resistance r ₁ is selected from the conditions for ensuring the physical realizability of the resistances r ₂ , r ₃ (providing them non-negative). The principle of operation of this device is similar to the principle of operation of the device according to claim 2.

The proposed FMS demodulation device according to claim 10 differs from the device according to claim 2 in that the resistive four-terminal (Fig. 8) is made in the form of a bridge circuit for connecting four two-terminal devices. In this case, the optimal values of the resistances r ₃ = r ₁ , r ₄ = r _{2 are} determined explicitly using mathematical expressions. The principle of operation of this device is similar to the principle of operation of the device according to claim 2.

The proposed FMS demodulation device according to claim 11 differs from the device according to claim 2 in that the resistive four-terminal (Fig. 9) is made in the form of a symmetric U-shaped connection of three two-terminal devices. In this case, the optimal values of the resistances r ₁ , r ₂ , r ₃ = r _{1 are} determined explicitly using mathematical expressions. The principle of operation of this device is similar to the principle of operation of the device according to claim 2.

An analysis of the physical feasibility conditions of these nine embodiments of a resistive quadripole (Fig. 3-9) of the proposed device (Fig. 2) shows that of this number of options for arbitrary given resistances of the signal source and load, there is always such an option that the values of the resistive resistances of this quadripole calculated according to the above formulas will be positive, that is, physically feasible. On the contrary, for each individual option there will always be such values of the resistances of the signal sources and the load that the values of the resistive resistance of the four-terminal devices, calculated according to the above formulas, will be physically feasible.

Let us prove the feasibility of implementing these properties.

где U_н, ω_н - амплитуда и частота несущего высокочастотного колебания; m_φ - индекс фазовой модуляци; φ_о - начальная фаза; Ω - частота первичного информационного низкочастотного сигнала. Поскольку частота определяется производной от фазы, то одновременно с изменением фазы в фазомодулированном колебании будет происходить изменение частоты по следующему закону:

Поэтому, если ФМС подать на правый склон зависимости одного из комплексных элементов матрицы проводимостей нелинейного элемента, включенного между источником ФМС и четырехполюсником, от частоты, то произойдет преобразование ФМС в АФМС. При этом амплитуда АФМС будет изменяться по закону (минус sin( Ωt)). Следовательно, для того чтобы закон изменения амплитуды АФМС повторял закон изменения фазы ФМС, необходимо проинтегрировать преобразованный сигнал, т.е. подать на интегрирующую цепь. Если ФМС подать на левый склон зависимости одного из комплексных элементов матрицы проводимостей нелинейного элемента, включенного между четырехполюсником и высокочастотной нагрузкой, от частоты, то также произойдет преобразование ФМС в АФМС. При этом амплитуда АФМС будет изменяться по закону (sin( Ωt)). Следовательно, для того чтобы закон изменения амплитуды АФМС повторял закон изменения фазы ФМС, необходимо продифференцировать преобразованный сигнал, т.е. подать на дифференцирующую цепь. Из анализа этих зависимостей следует, что положение левого и правого склона можно изменять по частотной оси путем изменения постоянного напряжения смещения. Кроме того, это возможно путем параллельного подключения емкости или последовательно индуктивности к нелинейному элементу. Изменение положения склонов возможно также путем выбора типа нелинейного элемента. Выбор осуществляется таким образом, что левый или правый склон зависимости одного из комплексных элементов матрицы проводимостей от частоты совпадает с частотой несущего колебания фазомодулированных сигналов.Let the phase-modulated oscillation act on the input of the demodulator

where U _n , ω _n - the amplitude and frequency of the carrier high-frequency oscillations; m _φ — phase modulation index; φ _about - the initial phase; Ω is the frequency of the primary information low-frequency signal. Since the frequency is determined by the derivative of the phase, then at the same time as the phase changes in the phase-modulated oscillation, the frequency changes according to the following law:

Therefore, if the FMS is applied to the frequency dependence of one of the complex elements of the conductivity matrix of the nonlinear element connected between the FMS source and the four-terminal, the FMS will be converted to AFMS. In this case, the amplitude of the AFMS will change according to the law (minus sin (Ωt)). Therefore, in order for the law of the amplitude change of the AFMS to repeat the law of the phase change of the FMS, it is necessary to integrate the converted signal, i.e. apply to the integrating circuit. If the FMS is applied to the left slope of the dependence of one of the complex elements of the conductivity matrix of the nonlinear element connected between the four-terminal network and the high-frequency load on the frequency, then the FMS will also be converted to AFMS. In this case, the amplitude of the AFMS will change according to the law (sin (Ωt)). Therefore, in order for the law of the amplitude change of the AFMS to repeat the law of the phase change of the FMS, it is necessary to differentiate the converted signal, i.e. apply to the differentiating circuit. From the analysis of these dependencies it follows that the position of the left and right slopes can be changed along the frequency axis by changing the constant bias voltage. In addition, this is possible by connecting a capacitor in parallel or inductance in series to a non-linear element. Changing the position of the slopes is also possible by choosing the type of non-linear element. The choice is made in such a way that the left or right slope of the dependence of one of the complex elements of the conductivity matrix on the frequency coincides with the frequency of the carrier wave of the phase-modulated signals.

The input modulated high-frequency signal S _in and the high-frequency signal transformed by a demodulator (before the low-pass filter) S _out are interconnected as follows: S _out = S ₂₁ S _in , where the input and output signals mean the input and output voltages; S ₂₁ - gear ratio.

Consider phase-modulated oscillations in two states characterized by extreme values of the amplitude range of the AFMS on a nonlinear element.

(модуль АФМС в двух состояниях различен);

Таким образом на выходе высокочастотной части демодулятора модули коэффициента передачи и входного сигнала перемножаются, а их фазы складываются. Выходные напряжения в двух состояниях связаны между собой следующим образом:We write the indicated physical quantities in two states in complex form

(AFMS module in two states is different);

Thus, at the output of the high-frequency part of the demodulator, the transmission coefficient and input signal modules are multiplied, and their phases are added up. The output voltages in two states are interconnected as follows:

Where

при m₂₁>1 или

при m₂₁<1;

и

- модули коэффициентов передачи высокочастотной части демодулятора в первом и втором состояниях; φ - разность фаз входного ФМС в двух крайних его состояниях.The ratio of the transmission coefficient modules of the high-frequency part of the demodulator m ₂₁ is related to the depth of amplitude modulation of the AFMS as follows:

for m ₂₁ > 1 or

when m ₂₁ <1;

and

- modules of transmission coefficients of the high-frequency part of the demodulator in the first and second states; φ is the phase difference of the input FMS in its two extreme states.

If the carrier oscillation frequency is selected as indicated above, or, conversely, the position of the left or right slope is selected as indicated, then in these two extreme states corresponding to the extreme values of the AFMS amplitude, which correspond to the extreme values of the AFMS frequency, the nonlinear element takes two values of the complex conductivity y _{1 , 2} = g _1,2 + jb _1,2 . Suppose, in addition, the complex resistances of the high-frequency load z _{n1, n2} = r _{n1, n2} + jx _{n1, n2} and the signal source z _01.02 = r _01.02 + jx _01.02 at the extreme frequencies of the AFMS are known.

Conductivity matrices Y _T ^{I, II} transistors in two states are also known:

where y ₁₁ ^{I, II} = g ₁₁ ^{I, II} + jb ₁₁ ^{I, II} ; y ₁₂ ^{I, II} = g ₁₂ ^{I, II} + jb ₁₂ ^{I, II} ; y ₂₁ ^{I, II} = g ₂₁ ^{I, II} + jb ₂₁ ^{I, II} ; y ₂₂ ^{I, II} = g ₂₂ ^{I, II} + jb ₂₂ ^{I, II} .

The conductivity matrix (1) corresponds to the classical transfer matrix [Feldstein A.L., Yavich L.R. Microwave four-terminal and eight-terminal synthesis. M.: Communication, 1965. 40 p.]:

Where

The resistive four-terminal is described by the transfer matrix:

a, b, с, d - элементы классической матрицы передачи [Фельдштейн А.Л., Явич Л.Р. Синтез четырехполюсников и восьмиполюсников на СВЧ. М.: Связь, 1965. 40 с.].Where

a, b, c, d - elements of the classical transmission matrix [Feldstein A.L., Yavich L.R. Microwave four-terminal and eight-terminal synthesis. M.: Communication, 1965. 40 p.].

The equivalent circuit of the demodulator is presented in the form of 4 cascade-connected quadrupoles (figure 2).

The general normalized classical demodulator transmission matrix has the form:

Using the well-known connection of the elements of the scattering matrix [Feldstein A.L., Yavich L.R. Microwave four-terminal and eight-terminal synthesis. M .: Communication, 1965. 40 pp.], We obtain the expression for the transmission coefficient of the high-frequency part of the demodulator S ₂₁ ^{I, II} in two states of the transistor:

Let it be required to determine the resistive four-terminal circuit and the values of the parameters of the resistive elements of the two-terminal circuits included in it, at which it is possible to provide a given law of change in the transmission coefficient (1) with the accepted notation.

Substituting (6) into expression (1) and separating the real and imaginary parts from each other, we obtain for the first state determined by one of the extreme values of the amplitude and the corresponding extreme frequency AFMS, a system of two equations:

последнее выражение изменяется а_1,2=r_н1,н2; b_1,2=x_н1,н2: After denormalizing the transmission coefficient (6) by multiplying by

the last expression changes and _1,2 = r _{n1, n2} ; b _1,2 = x _{n1, n2} :

g ₁ ^{I, II} = g ₂₁ ^{I, II} r _{n1, n2} -b ₂₁ ^{I, II} x _{n1, n2} ; b ₁ ^{I, II} = g ₂₁ ^{I, II} x _{n1, n2} + b ₂₁ ^{I, II} r _{n1, n2} .

The denormalized transmission coefficient is associated with a physically feasible transfer function as follows

The solution to system (7) has the form of interconnections between the elements of the classical quadrupole transmission matrix:

Where

The physical feasibility condition α + βγ> 0 leads to a restriction on the phase difference of the input FMS in two states determined by the extreme frequency values. The equation of this boundary has the form:

The solution of equation (9) gives an expression for the boundary value of the phase difference of the transmission coefficients in two states of the controlled element:

where I _o = A _o1 C _o1 -B _o1 H _o1 ; N _o = -A _o1 C _o2 -C _o1 A _o2 + B _o1 H _o2 -B _o2 H _o1 ;

L _o = -A _o1 C _o3 -A _o3 C _o1 -B _o1 H _o3 + B _o3 H _o1 ; _{M o = A o2 C o2 +} B o2 H o2;

A _o1 = g _22o ^II b ₁ ^I + g ₁ ^I b _22o ^II ; A _o2 = g ₁ ^II b _22o ^I + b ₁ ^II g _22o ^I ; A _o3 = g ₁ ^II g _22o ^I -b ₁ ^II b _22o ^I ;

The field of physical realizability is the region of variation of the phase difference φ> φ _g under the condition x _n > 0 or φ <φ _g under the condition x _n <0. To ensure this area of physical realizability, it is necessary that the radical expression in (10) be non-negative. From this condition we find the limitation on the square of the ratio of the transmission coefficient modules in two states of the controlled element:

- частотное качество управляемого трехполюсного элемента, включенного в состав манипулятора вместе с резистивным четырехполюсником, источником сигнала и нагрузкой с комплексными сопротивлениями. Понятие "частотное качество управляемого трехполюсного элемента" введено здесь впервые по аналогии с качеством управляемого двухполюсного элемента [Kawakami S. Figure of Merit Associated with a Variable Parameter One-Port for RF Switching and Modulation // IEEE Trans: 1965. CT-12. №3. С.320-328; Головков А.А., Минаков В.Г. Взаимосвязи между элементами матрицы сопротивлений и их использование для синтеза согласующе-фильтрующих устройств амплитудно-фазовых манипуляторов. Телекоммуникации, 2004, №8, с.29-32] на фиксированной частоте. Частотное качество трехполюсного управляемого элемента характеризует меру различия элементов его матрицы проводимости (сопротивления) в двух состояниях, определяемых двумя крайними частотами входного ФМС, с учетом изменений сопротивлений источника сигнала и нагрузки.Where

- frequency quality of a controlled three-pole element included in the manipulator together with a resistive four-terminal, a signal source and a load with complex resistances. The concept of “frequency quality of a controlled bipolar element” was introduced here for the first time by analogy with the quality of a controlled bipolar element [Kawakami S. Figure of Merit Associated with a Variable Parameter One-Port for RF Switching and Modulation // IEEE Trans: 1965. CT-12. Number 3. S.320-328; Golovkov A.A., Minakov V.G. The relationship between the elements of the resistance matrix and their use for the synthesis of matching-filtering devices of amplitude-phase manipulators. Telecommunications, 2004, No. 8, p.29-32] at a fixed frequency. The frequency quality of a three-pole controlled element characterizes the measure of the difference in the elements of its conductivity matrix (resistance) in two states determined by the two extreme frequencies of the input FMS, taking into account changes in the resistance of the signal source and load.

The root expression in (11) is always positive. It should be noted that the calculations show that when choosing phase differences of transmission coefficients close to φ _gr (10), or when choosing a ratio of modules close to m _cr , not only physical feasibility, but also the largest frequency band is provided.

The expression for frequency quality can be reduced to the following form:

Полученная система двух взаимосвязей (8) между элементами матрицы передачи резистивного четырехполюсника означает, что фазовые демодуляторы должны содержать не менее чем два независимых резистивных элемента, значения параметров которых должны удовлетворять системе двух уравнений, сформированных на основе этих взаимосвязей. Для отыскания оптимальных значений параметров резистивного четырехполюсника необходимо выбрать какую-либо схему из М≥2 элементов, найти ее матрицу передачи, элементы которой выражены через параметры схемы резистивного четырехполюсника, и подставить их в (8). Сформированная таким образом система уравнений должна быть решена относительно выбранных двух параметров. Значения остальных М-2 параметров могут быть отнесены к сопротивлению z_o или заданы произвольно. После использования описанного алгоритма с помощью высокочастотной части демодулятора будет реализована операция преобразования входного ФМС в АФМС с заданной глубиной амплитудной модуляции.

The resulting system of two relationships (8) between the elements of the transmission matrix of a resistive four-terminal network means that phase demodulators must contain at least two independent resistive elements whose parameter values must satisfy a system of two equations formed on the basis of these relationships. In order to find the optimal values of the parameters of the resistive four-terminal network, it is necessary to select a circuit of M≥2 elements, find its transmission matrix, the elements of which are expressed through the parameters of the resistive four-terminal circuit, and substitute them in (8). The system of equations formed in this way should be solved with respect to the selected two parameters. The values of the remaining M-2 parameters can be attributed to the resistance z _o or set arbitrarily. After using the described algorithm, using the high-frequency part of the demodulator, the operation of converting the input FMS to AFMS with a given amplitude modulation depth will be implemented.

It should be noted that even under the assumption of the inertia of a nonlinear element (with its frequency quality equal to two), the high-frequency part of the FMS demodulation device synthesized in this way will have an AFC whose left or right slope will exactly correspond to the frequency range of the input FMS, which automatically ensures its conversion to AFMS with a given amplitude modulation depth.

Based on the use of the described algorithm for a four-terminal circuit in the form of an L-shaped connection of two resistive two-terminal devices (Fig. 3), mathematical expressions are obtained for an amplifying manipulator to determine the resistance values of r ₁ , r _{2 of} two-terminal devices. Here you can also find the transfer matrix and expressions for determining the parameters and transfer matrices of the other four-terminal devices declared.

For the L-shaped connection (figure 3):

For a symmetrical overlapped T-shaped connection (figure 4):

-образной схемы соединения (фиг.5):For

-shaped connection diagram (figure 5):

For a symmetrical T-shaped connection scheme (Fig.6):

For three variants of an asymmetric T-shaped connection scheme (Fig.7):

one)

;

;

2)

3)

For the bridge connection scheme (Fig. 8):

For a symmetric U-shaped connection scheme (Fig.9):

-образной схемы, симметричной Т схемы, в виде трех вариантов несиметричной Т схемы, мостовой схемы и симметричной П схемы), параметры которых определены по соответствующим математическим выражениям. При этом разрушение спектра АФМС на высокочастотные и низкочастотную составляющие и выделение последней происходит обычным образом с помощью нелинейного элемента, фильтра нижних частот, разделительной емкости, интегрирующей или дифференцирующей цепей.The proposed technical solutions are new, because the phase demodulation device providing the conversion of the PMF to AFMS with a given amplitude modulation depth, consisting of a nonlinear three-pole element connected between the PSM source and the input of the resistive four-terminal, is unknown in the public domain, and the four-terminal is made in the form of a L-shaped connection two resistive two-terminal devices (symmetric overlapped T circuit,

-shaped circuit, symmetric to the T circuit, in the form of three variants of the asymmetric T circuit, the bridge circuit and the symmetric P circuit), the parameters of which are determined by the corresponding mathematical expressions. In this case, the destruction of the AFMS spectrum into high-frequency and low-frequency components and the separation of the latter occurs in the usual way using a nonlinear element, a low-pass filter, a separation capacitor, an integrating or differentiating circuit.

The proposed technical solutions have an inventive step, since it does not explicitly follow from the published scientific data and the known technical solutions that the claimed sequence of operations (the execution of a four-terminal network is resistive in the form of the nine above-mentioned circuits with a choice of their parameter values from the condition of providing a given depth of amplitude modulation AFMS, and Converts FMS to AFMS without a reference signal source and oscillatory circuit.

The proposed technical solutions are practically applicable, since semiconductor transistors and resistors commercially available from the industry that are formed into the claimed resistive four-terminal circuit in the form of the listed two-terminal connection schemes can be used for their implementation. The values of the parameters of the resistors can be uniquely determined using the mathematical expressions given in the claims.

The technical and economic efficiency of the proposed device is to simultaneously provide the operation of converting the input FMS to AFMS with a given amplitude modulation depth, which helps to increase noise immunity.

Claims (11)

1. The method of demodulating phase-modulated signals, which consists in the fact that the demodulator is turned on between a source of radio-frequency phase-modulated signals and a low-frequency load and is made of a four-terminal device, a non-linear element, a low-pass filter, a phase-modulated signal is converted into an amplitude-phase-modulated signal, and the spectrum is destroyed by a non-linear element amplitude-phase-modulated signal to high-frequency and low-frequency components, using a low-pass filter, information is extracted low-frequency signal, the amplitude of which varies according to the law of phase change of the phase-modulated input signal, characterized in that a three-pole element is used as a non-linear element, which is connected between a source of radio-frequency phase-modulated signals and a four-terminal or between a four-terminal and an introduced high-frequency load according to the scheme with a common emitter, base or by a collector, a four-terminal is made of resistive two-terminal, at least two, the parameter values of which are selected wounds from the condition for ensuring the required depth of amplitude modulation of the amplitude-phase-modulated signal, the phase-modulated signal is converted into amplitude-phase-modulated signal by applying this signal to the right slope of the frequency dependence of the module of one of the complex elements of the resistance matrix of the nonlinear element, the low-frequency component of the amplitude-phase-modulated signal is fed to a differentiating circuit, or the conversion of a phase-modulated signal to amplitude-phase-modulated the signal is carried out by supplying this signal to the left slope of the frequency dependence of the module of one of the complex elements of the resistance matrix of the nonlinear element, while the low-frequency component of the amplitude-phase-modulated signal is fed to the integrating circuit, or the phase-modulated signal is converted into the amplitude-phase-modulated signal by supplying this signal on the right slope of the frequency dependence of the module of one of the complex elements of the conductivity matrix of a nonlinear element, low the frequency component of the amplitude-phase-modulated signal is fed to the integrating circuit, or the phase-modulated signal is converted to the amplitude-phase-modulated signal by supplying this signal to the left slope of the frequency dependence of the module of one of the complex elements of the conductivity matrix of the nonlinear element, while the low-frequency component of the amplitude-phase-modulated signal is fed on a differentiating circuit. 2. A device for demodulating phase-modulated signals connected between a source of phase-modulated signals and a low-frequency load and consisting of a converter of phase-modulated signals into an amplitude-phase-modulated signal, a non-linear element, a four-terminal, a low-pass filter, characterized in that a three-pole element, a phase-modulated converter is used as a non-linear element signals in the amplitude-phase-modulated signal is made in the form of this nonlinear element, the type of which is selected In such a way that the left or right slopes of one of the complex elements of its conductivity matrix as a function of frequency coincided with the frequency of the carrier wave of the phase-modulated signals, a non-linear element is connected between the phase-modulated signal source and the four-terminal network according to the scheme with a common emitter, base or collector, when choosing the left slope of the indicated dependence, a differentiating circuit was used as a low-frequency load, and when choosing the right slope, an integrating circuit was used, the four-terminal network is made of weakly resistive two-poles, at least two, parameter values are selected to provide the desired depth of the amplitude modulation of the amplitude-phase-modulated signal by using the following mathematical expression:

- given elements of the conductivity matrix of a nonlinear three-pole element in two states ( ^I and ^II ), determined by the two extreme frequency values of the input phase-modulated signal; m is the specified ratio of the transmission coefficient modules of the high-frequency part of the demodulator in two states of the input signal, characterized by two extreme frequency values of the phase-modulated signal; φ is the known phase difference of the input signal in its two states, characterized by two extreme frequency values of the phase-modulated signal; M ₂₁ - the depth of the amplitude modulation of the amplitude-phase modulated signal; z _{n1, n2} = r _{n1, n2} + jx _{n1, n2} , z _01.02 = r _01.02 + jx _01.02 are the specified complex resistances of the high-frequency load and the source of the phase-modulated signal in its two states. 3. The device for demodulating phase-modulated signals according to claim 2, characterized in that the resistive four-terminal is made in the form of a L-shaped connection of two resistive two-terminal, resistive r ₁ , r ₂ , two-terminal, making up the L-shaped connection, are selected using the following mathematical expressions :

4. The device for demodulating phase-modulated signals according to claim 2, characterized in that the resistive four-terminal is made in the form of a symmetrical blocked T-connection of four resistive two-terminal, resistive r ₁ , r ₂ , r ₃ = r ₄ , r ₄ = r ₂ two-terminal constituting an overlapped T-joint are selected using the following mathematical expressions:

5. The device demodulation phase-modulated signals according to claim 2, characterized in that the resistive four-terminal is made in the form

-shaped connection of two resistive bipolar, resistive r ₁ , r ₂ bipolar components

-shaped connection, selected using the following mathematical expressions:

6. The device for demodulating phase-modulated signals according to claim 2, characterized in that the resistive four-terminal is made in the form of a symmetric T-shaped connection of three resistive two-terminal, resistive r ₁ , r ₂ , r ₃ = r ₁ two-terminal, making up a symmetrical T-shaped connection are selected using the following mathematical expressions:

7. The device for demodulating phase-modulated signals according to claim 2, characterized in that the resistive four-terminal is made in the form of an asymmetric T-shaped connection of three resistive two-terminal, resistive r ₁ , r ₂ two-terminal, making up an asymmetric T-shaped connection, are selected using the following mathematical expressions:

8. The device for demodulating phase-modulated signals according to claim 2, characterized in that the resistive four-terminal is made in the form of an asymmetric T-shaped connection of three resistive two-terminal, resistive r ₁ , r ₃ two-terminal, making up an asymmetric T-shaped connection, are selected using the following mathematical expressions:

9. The device for demodulating phase-modulated signals according to claim 2, characterized in that the resistive four-terminal is made in the form of an asymmetric T-shaped connection of three resistive two-terminal, resistive r ₂ , r ₃ , two-terminal, constituting an asymmetric T-shaped connection, are selected using the following mathematical expressions:

10. The device for demodulating phase-modulated signals according to claim 2, characterized in that the resistive four-terminal is made in the form of a bridge circuit for connecting four resistive two-terminal, resistive r ₁ , r ₂ , r ₃ = r ₁ , r ₄ = r ₂ two-terminal components of the bridge compound selected using the following mathematical expressions:

11. The device for demodulating phase-modulated signals according to claim 2, characterized in that the resistive four-terminal is made in the form of a symmetrical U-shaped connection of three resistive two-terminal, resistive r ₁ , r ₂ , r ₃ = r ₁ two-terminal components of a symmetric U-shaped connection are selected using the following mathematical expressions:

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