RU2591014C2 - Amplification and demodulation of fm signals and device to this end - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: claimed device consists of constant voltage source, circuit for direct transmission composed of tripolar nonlinear element, four pole circuit, external feedback circuits, high-cut filter, isolation capacitor and low-frequency load. Note here that said four pole circuit is a resistive component. Said external feedback circuit is composed by arbitrary complex four pole circuit connected to tripolar nonlinear element in serial-parallel circuit. Said tripolar nonlinear element and feedback circuit are integrated and cascade connected with complex resistor and input of resistive four pole circuit. High-frequency load is connected in between resistive four pole circuit and high-cut filter and composed of two-pole device with complex resistor. Resistive four pole circuit is composed of T-like connection of three two pole devices.

EFFECT: increased linear section of frequency FM response and expanded dynamic range at arbitrary characteristics of nonlinear element, external feedback circuit and load.

2 cl, 3 dwg

Description

The invention relates to the fields of radio communication, radar, radio navigation and electronic warfare and can be used to create multifunctional devices for amplifying the amplitude and demodulating frequency-modulated signals with an increased quasilinear portion of the frequency demodulation characteristic for arbitrary given characteristics of a nonlinear element, external feedback circuit and load.

A known method of amplification and frequency demodulation of a high-frequency signal, based on the use of the energy of a constant voltage source, the organization of internal feedback in a nonlinear element by using a bipolar nonlinear element with negative differential resistance [Radio receivers. Under the general editorship of V.I. Siforova. M .: "Soviet Radio", 1974, p. 137-150], the fulfillment of the amplification conditions by matching with a given tolerance of negative resistance with the resistance of the rest of the amplifier. The input part is made of a parallel oscillatory circuit. The output part of the amplifier is performed from a low-pass filter (low-pass filter), separation capacitance and low-frequency load [Gonorovsky I.S. Radio engineering circuits and signals - M .: "Soviet Radio", 1977, p. 190-193, 290-293, 311-316]. If the average frequency of the input frequency-modulated signal (HMS) coincides with the average frequency of the left slope of the amplitude-frequency characteristic (AFC) of the oscillating circuit, then the HMS is converted to an amplitude-modulated ChMS (AHMS). A nonlinear element destroys (splits) the frequency response spectrum into high-frequency and low-frequency components, the low-pass filter selects low-frequency components, and suppresses the rest. The separation capacity eliminates the constant component. A low-frequency signal arrives at a low-frequency load, the amplitude of which changes according to the law of changing the frequency of the input HMS. As a result, amplification and demodulation of ChMS is simultaneously provided.

A device for amplification and frequency modulation, consisting of a constant voltage source that sets the operating point in the middle of the falling section of the current-voltage characteristics of the bipolar nonlinear element with negative differential resistance [Radio receivers. Under the general editorship of V.I. Siforova. M .: "Soviet Radio", 1974, p. 137-150], an input circuit of a parallel oscillatory circuit and a reactive four-terminal, while the parameters of the circuit, a two-pole nonlinear element and a four-terminal are selected from the condition that the average frequency of the left slope of the frequency response and the average frequency of the input HMS coincide and the amplitude of the HMS is amplified [Gonorovsky I.S. Radio engineering circuits and signals - M .: "Soviet Radio", 1977, p. 190-193, 290-293, 311-316]. The principle of operation of this device is as follows. When you turn on the DC voltage (current) source, the operating point of the nonlinear element is set on the falling section of its current-voltage characteristics. Due to the presence of internal feedback in a bipolar nonlinear element, a negative differential resistance arises in a section with a falling current-voltage characteristic, which, by matching with a reactive four-terminal device, compensates for losses in the entire circuit with a given tolerance. Due to this, the input HMS with an average frequency equal to the average frequency of the left slope of the oscillating circuit is amplified to a level at which the amplitude goes beyond the falling section of the current-voltage characteristic, and the input HMS is converted to AFM. A nonlinear element splits (destroys) the frequency response spectrum into components, the low-pass filter isolates the low-frequency component, and suppresses the others, the separation capacitance eliminates the constant component. The low-frequency component, the amplitude of which varies according to the law of changing the frequency of the input HMS, is supplied to the low-frequency load. There is demodulation of the emergency response. The disadvantage of this method and device is the simple summation of the gain and frequency demodulation functions. If the device is effective in gain mode, then it is ineffective in frequency modulation mode, and vice versa, if the device is effective in frequency modulation mode, then it is ineffective in gain mode. Therefore, in the general case, undesirable frequency or nonlinear distortions occur in one of the modes.

The closest in technical essence and the achieved result (prototype) is a method of amplification and frequency demodulation of a high-frequency signal, based on the use of energy from a constant voltage source, organization of a direct transmission circuit (DPC) and external feedback circuit (OS), the fulfillment of amplification conditions by agreement with the specified tolerance of the OS and the CPU from the rest of the amplifier. If the average frequency of the input HMS coincides with the average frequency of the left slope of the frequency response, and the output of the rest of the amplifier is a low-pass filter and a low-frequency load, then simultaneously with amplification, the HMS will be converted to AHMS, the amplitude of which will change according to the law of the frequency of the input HMS, as well as the amplitude demodulation of AFMC with the formation of a low-frequency load of the LF signal, the amplitude of which varies according to the law of the frequency of the input HMS [Gonorovsky IS Radio engineering circuits and signals - M .: "Soviet Radio", 1977, p. 190-193, 290-293, 311-316].

The closest in technical essence and the achieved result (prototype) is a device for amplification and frequency demodulation of a high-frequency signal, consisting of a constant voltage source that sets an operating point in the middle of the quasilinear section of the transient current-voltage characteristic of the transistor, a direct transmission circuit in the form of a first four-terminal device for matching the output transistor electrode and load, input circuit in the form of a parallel oscillatory circuit, RC circuit of the external positive back communication (in general, the second four-terminal network for matching the control electrode of the transistor and the load) between the load and the control electrode of the transistor, the output circuit in the form of a low-pass filter, isolation capacitance and low-frequency load, while the parameters of the circuit, direct current circuit, feedback circuit and transistor selected from the condition of coincidence of the average frequency of the left slope of the frequency response of the entire device and the average frequency of the input HMS and the simultaneous amplification of the amplitude of the HMS [Gonorovsky IS Radio engineering circuits and signals - M .: "Soviet Radio", 1977, p. 190-193, 290-293, 311-316].

The principle of operation of this device is as follows. When a constant voltage (current) source is turned on, the operating point of the nonlinear element is set in the middle of the quasilinear section of its through-current voltage-current characteristic. Due to the presence of external feedback, matching the output electrode with the load and the load with the control electrode using reactive four-terminal devices, the losses in the entire circuit are compensated with a certain tolerance necessary to eliminate the possibility of excitation of the device. Due to this, the input HMS with an average frequency equal to the average frequency of the left slope of the oscillating circuit is amplified to a level at which the amplitude goes beyond the quasilinear portion of the current-voltage characteristic, and the input HMS is converted to AFM. A nonlinear element splits (destroys) the frequency response spectrum into components, the low-pass filter isolates the low-frequency component, and suppresses the others, the separation capacitance eliminates the constant component, the low-frequency component, whose amplitude changes according to the law of the frequency of the input frequency, is applied to the low-frequency load. There is demodulation of the emergency response. The disadvantage of this method and device is the simple combination of amplification and frequency demodulation. A common disadvantage of all known methods and devices is that there are no technical solutions that contribute to providing a gain mode and a frequency demodulation mode using a single radio device. If a minimum of nonlinear and frequency distortion is achieved in the frequency demodulation mode, then in the amplification mode these distortions will be maximum, and vice versa, if a minimum of nonlinear and frequency distortion is achieved in the amplification mode, then these distortions will be maximum in the frequency demodulation mode. This question arises especially sharply when designing amplification and frequency demodulation devices in the HF and UHF bands, on which, in addition, it is necessary to take into account the reactive components of the parameters of nonlinear elements. Currently, the classical theory of radio circuits does not take this into account. In addition, frequency demodulation and amplification can be achieved with resistive quadripoles, the parameters of which are independent of the frequency in a sufficiently large frequency range, which under certain conditions contributes to an increase in the quasilinear portion of the frequency demodulation characteristic, providing a given gain and dynamic range. This ensures a minimum of non-linear and frequency distortion. The basis for this invention is the definition of these conditions.

The technical result of the invention is the amplification and frequency demodulation of a high-frequency signal using a device with an increased dynamic range and a quasilinear portion of the frequency demodulation characteristic due to matching with a resistive four-terminal device according to the criterion for the formation of a quasilinear portion of the left slope of the frequency response that matches the frequency range of the input HMS. The possibility of using various options for including a three-pole nonlinear element with respect to a resistive four-terminal and various types of feedback expands the possibilities of the physical feasibility of this result.

1. The specified result is achieved by the fact that in the known method of amplification and demodulation of frequency-modulated signals, based on the use of energy from a constant voltage source, the interaction of the frequency-modulated signal with a device that is performed from a direct transmission circuit in the form of a three-pole nonlinear element, four-terminal, circuit external feedback, low-pass filter, separation capacitance and low-frequency load, meeting the conditions for matching the forward circuit with the external feedback circuit conditions for matching the external feedback circuit with the control electrode of a three-pole nonlinear element, matching conditions for the direct transmission circuit and the external feedback circuit with the rest of the device with a given tolerance, converting the frequency-modulated signal into an amplitude-frequency-modulated signal on the left slope of the amplitude frequency response, splitting the spectrum of the amplitude-frequency-modulated signal into low-frequency and high-frequency components using a three-pole nonlinear element, isolating the low-frequency component using a low-pass filter, eliminating the constant component using a dividing capacitance, and receiving a low-frequency signal at a low-frequency load, the amplitude of which changes according to the law of frequency change of the frequency-modulated signal, additionally, the four-terminal network is made resistive as an external feedback circuit use an arbitrary complex four-terminal connected to a three-pole nonlinear element in series-parallel hydrochloric scheme tripolar nonlinear element and a feedback loop as a single node in cascade inserted between the source of the frequency-modulated signal with a complex impedance and the input resistive quadripole, between the output of the resistive quadripole and lowpass filter includes high-frequency load in the form of two-terminal network with a complex impedance value of the modulus m _{p the} transfer function and the resonant frequency of the device is selected from the conditions for the formation of a given slope of the quasilinear portion of the left slope the amplitude-frequency characteristics of the device in a given frequency band that coincides with the frequency range of the frequency-modulated signal, the matching conditions by the criterion of simultaneously providing amplification and frequency demodulation are performed by realizing the set value m _p at the resonant frequency by choosing the values of the parameters of the resistive four-terminal network in accordance with the following mathematical expressions:

;

,

;

,

;

;

;

;

; A₁=r₁₁₀x₂₁-x₁₁₀r₂₁; B₁=r₁₁₀r₂₁+x₁₁₀x₂₁; A₂=r₂₂₀r₂₁+x₂₂₀x₂₁; B₂=r₂₁x₂₂₀-r₂₂₀x₂₁;Where

;

;

;

;

; A ₁ = r ₁₁₀ x ₂₁ -x ₁₁₀ r ₂₁ ; B ₁ = r ₁₁₀ r ₂₁ + x ₁₁₀ x ₂₁ ; A ₂ = r ₂₂₀ r ₂₁ + x ₂₂₀ x ₂₁ ; B ₂ = r ₂₁ x ₂₂₀ -r ₂₂₀ x ₂₁ ;

r ₁₁₀ = r ₁₂ r ₂₁ + x ₁₁ x ₂₂ -r ₀ r ₂₂ + x ₀ x ₂₂ -r ₁₁ r ₂₂ -x ₁₂ x ₂₁ ; r ₂₂₀ = - (r ₀ + r ₁₁ );

x ₁₁₀ = r ₁₂ x ₂₁ -x ₀ r ₂₂ -r ₁₁ x ₂₂ -r ₀ x ₂₂ + x ₁₂ r ₂₁ -x ₁₁ r ₂₂ ; x ₂₂₀ = - (x ₀ + x ₁₁ );

,

;

- отношения соответствующих элементов классической матрицы передачи резистивного четырехполюсника a, b, c, d; r₀, r_н, x₀, x_н - заданные значения действительных и мнимых составляющих сопротивлений источника входного частотно-модулированного сигнала и высокочастотной нагрузки на резонансной частоте; r₁₁, x₁₁, r₁₂, x₁₂, r_2l, x_2l, r₂₂, x₂₂ - заданные суммарные значения действительных и мнимых составляющих элементов смешанной матрицы H трехполюсного нелинейного элемента на резонансной частоте и соответствующих значений действительных и мнимых составляющих элементов смешанной матрицы H цепи внешней обратной связи на резонансной частоте.

,

;

- the ratio of the corresponding elements of the classical transmission matrix of the resistive quadrupole a, b, c, d; r ₀ , r _n , x ₀ , x _n - set values of the real and imaginary components of the resistance of the source of the input frequency-modulated signal and high-frequency load at the resonant frequency; r ₁₁ , x ₁₁ , r ₁₂ , x ₁₂ , r _2l , x _2l , r ₂₂ , x ₂₂ are the given total values of the real and imaginary components of the mixed matrix elements H of the three-pole nonlinear element at the resonant frequency and the corresponding values of the real and imaginary components of the mixed matrix H of the external feedback circuit at the resonant frequency.

2. The specified result is achieved by the fact that in the known device for amplification and demodulation of frequency-modulated signals made from a constant voltage source, a direct transmission circuit in the form of a three-pole nonlinear element, four-terminal, external feedback circuit, low-pass filter, separation capacitance and low-frequency load , additionally the four-terminal is made resistive, as an external feedback circuit an arbitrary complex four-terminal connected to a three-pole circuit is used a linear element in a parallel-parallel circuit, a three-pole non-linear element and a feedback circuit as a single node are cascaded between the source of the frequency-modulated signal with complex resistance and the input of the resistive four-terminal, between the output of the resistive four-terminal and a low-pass filter, a high-frequency load in the form of a two-terminal with a complex resistance, the resistive four-terminal is made in the form of a T-shaped connection of three resistive two-terminal with resistance and r _1, r _2, r _3, the resistance values r _1, r ₃ are selected from the condition score matching simultaneously provide gain and frequency demodulation in accordance with the following mathematical expression:

;

,

;

,

;Where

;

;

;

;

;

, A₁=r₁₁₀x₂₁-x₁₁₀r₂₁; B₁=r₁₁₀r₂₁+x₁₁₀x₂₁; A₂=r₂₂₀r₂₁+x₂₂₀x₂₁; B₂=r₂₁x₂₂₀-r₂₂₀x₂₁;

;

;

;

;

, A ₁ = r ₁₁₀ x ₂₁ -x ₁₁₀ r ₂₁ ; B ₁ = r ₁₁₀ r ₂₁ + x ₁₁₀ x ₂₁ ; A ₂ = r ₂₂₀ r ₂₁ + x ₂₂₀ x ₂₁ ; B ₂ = r ₂₁ x ₂₂₀ -r ₂₂₀ x ₂₁ ;

r ₁₁₀ = r ₁₂ r ₂₁ + x ₁₁ x ₂₂ -r ₀ r ₂₂ + x ₀ x ₂₂ -r ₁₁ r ₂₂ -x ₁₂ x ₂₁ ; r ₂₂₀ = - (r ₀ + r ₁₁ );

x ₁₁₀ = r ₁₂ x ₂₁ -x ₀ r ₂₂ -r ₁₁ x ₂₂ -r ₀ x ₂₂ + x ₁₂ r ₂₁ -x ₁₁ r ₂₂ ; x ₂₂₀ = - (x ₀ + x ₁₁ );

r ₀ , r _n , x ₀ , x _n - set values of the real and imaginary components of the resistance of the source of the input frequency-modulated signal and high-frequency load at the resonant frequency; r ₁₁ , x ₁₁ , r ₁₂ , x ₁₂ , r ₂₁ , x _2l , r ₂₂ , x ₂₂ are the given total values of the real and imaginary components of the elements of the mixed matrix H of the three-pole nonlinear element at the resonant frequency and the corresponding values of the real and imaginary components of the mixed matrix H of the external feedback circuit at the resonant frequency; the value of the resonant frequency and the value of the given and realized module m _{p of the} transfer function at the resonant frequency are selected from the condition that the formation of the specified slope of the quasilinear portion of the left slope of the amplitude-frequency characteristic of the device in the given frequency band coincides with the frequency range of the input frequency-modulated signal;

r ₂ - the set value of the resistance of the second two-terminal resistive four-terminal.

In FIG. 1 shows a diagram of a device for amplification and demodulation of frequency-modulated signals (prototype) that implements the prototype method.

In FIG. 2 shows a structural diagram of the proposed device according to claim 2., which implements the proposed method of amplification and demodulation of frequency-modulated signals according to claim 1.

In FIG. 3. The diagram of the matching resistive four-port network, which is part of the proposed device (Fig. 2).

The prototype device (Fig. 1), which implements the prototype method, contains a direct transmission circuit in the form of a three-pole non-linear element VT-1 connected to a constant voltage source-2, matching device SU-3 in the form of a reactive four-terminal device. An OS-4 feedback circuit is connected to the direct transmission circuit (DPC). An LPF-5, a separation capacitance C _P -6 and a low-frequency load R _n -7 are connected to the node output from the CPU and OS as a whole. A parallel oscillatory circuit KK-9 on elements L, R, C is connected in parallel between the source of the ChMS with resistance z ₀ -8 and the input of the CPU and OS.

The principle of operation of the device for amplification and demodulation of the ChMS (prototype) that implements the prototype method is as follows.

When you turn on the source of constant voltage (current) -2, the operating point of the nonlinear element-1 is set in the middle of the quasilinear section of its through-voltage-current characteristic. Due to coordination with the SU-3 output electrode with OS-4 and OS-4 with a control electrode, negative resistance arises in the circuit and losses in the entire circuit are compensated with a certain tolerance necessary to eliminate the possibility of device excitation. Due to this, the input HMS with an average frequency equal to the average frequency of the left slope of KK-9 is amplified to a level at which the amplitude goes beyond the quasilinear section of the current-voltage characteristic, and the input HMS is converted to AFM. Nonlinear element-1 splits (destroys) the frequency response spectrum into components, the low-pass filter-5 isolates the low-frequency component, and suppresses the rest, the separation capacitance C _P -6 eliminates the constant component, the low-frequency component, the amplitude of which changes according to the law of the frequency of the input HMS, on low-frequency load-7. There is demodulation of the emergency response.

The disadvantages of the prototype method and device for its implementation are described above.

, $$h_{12i}^{VT}=r_{12i}^{VT}+j{x}_{12i}^{VT}$$

, $$h_{21i}^{VT}=r_{21i}^{VT}+j{x}_{21i}^{VT}$$

, $$h_{22i}^{VT}=r_{22i}^{VT}+j{x}_{22i}^{VT}$$

на заданных частотах, подключенный к источнику постоянного напряжения-2 и соединенный по высокой частоте с цепью внешней ОС по последовательно-параллельной схеме (входы соединены последовательно, а выходы - параллельно), выполненной в виде произвольного четырехполюсника-10, сформированного в общем случае на двухполюсниках с комплексными сопротивлениями. Источник входного ЧМС с сопротивлением z_Qi=r_0i+jx_Qt-8 на заданных частотах подключен к входу узла из нелинейного элемента-1 и четырехполюсника-10. К выходу этого узда подключен согласующий резистивный четырехполюсник СРЧ-11, между выходом СРЧ-11 и ФНЧ-5 параллельно включена высокочастотная нагрузка-12 с заданными сопротивлениями z_нi=r_нi+jx_нi на заданных частотах. Произвольный четырехполюсник-10 тоже характеризуется известными значениями элементов смешанной матрицы H $$h_{11i}^{OC}=r_{11i}^{OC}+j{x}_{11i}^{OC}$$

, $$h_{12i}^{OC}=r_{12i}^{OC}+j{x}_{12i}^{OC}$$

, $$h_{21i}^{OC}=r_{21i}^{OC}+j{x}_{21i}^{OC}$$

, $$h_{22i}^{OC}=r_{22i}^{OC}+j{x}_{22i}^{OC}$$

на заданных частотах (i=1, 2… - номер частоты). Четырехполюсник-11 может быть выполнен в виде произвольного соединения произвольного количества резистивных двухполюсников. В данном изобретении этот четырехполюсник выполнен в виде T-образного соединения трех двухполюсников с сопротивлениями r₁-13, r₂-14, r₃-15 (фиг. 3). Синтез усилителя и частотного демодулятора (выбор оптимальных значений сопротивлений, первого r₁-13 и третьего r₃-15 двухполюсников СРЧ-11) осуществлен по критерию обеспечения заданной крутизны квазилинейного участка левого склона АЧХ в заданной полосе частот, совпадающей с диапазоном изменения частоты входного ЧМС, за счет реализации заданного модуля передаточной функции (коэффициента усиления) на резонансной частоте. В результате реализуется увеличенный квазилинейный участок частотной демодуляционной характеристики и динамический диапазон.The proposed device according to p. 2 (Fig. 2), which implements the proposed method according to p. 1, contains a three-pole non-linear element-1 with known elements of a mixed matrix H $$h_{\mathrm{eleven}i}^{VT}=r_{\mathrm{eleven}i}^{VT}+j{x}_{\mathrm{eleven}i}^{VT}$$

, $$h_{12i}^{VT}=r_{12i}^{VT}+j{x}_{12i}^{VT}$$

, $$h_{21i}^{VT}=r_{21i}^{VT}+j{x}_{21i}^{VT}$$

, $$h_{22i}^{VT}=r_{22i}^{VT}+j{x}_{22i}^{VT}$$

at specified frequencies, connected to a constant voltage source-2 and connected at high frequency to an external OS circuit in a serial-parallel circuit (inputs are connected in series and outputs are parallel), made in the form of an arbitrary four-terminal-10, formed generally on two-terminal devices with complex resistances. The source of the input FMC with resistance z _Qi = r _0i + jx _Qt -8 at given frequencies is connected to the input of the node from non-linear element-1 and four-terminal-10. A matching resistive quadrupole СРЧ-11 is connected to the output of this bridle, between the output of СРЧ-11 and ФНЧ-5, a high-frequency load-12 with preset resistances z _нi = r _нi + jx _нi at given frequencies is _connected in _parallel . An arbitrary quadripole-10 is also characterized by the known values of the elements of the mixed matrix H $$h_{\mathrm{eleven}i}^{OC}=r_{\mathrm{eleven}i}^{OC}+j{x}_{\mathrm{eleven}i}^{OC}$$

, $$h_{12i}^{OC}=r_{12i}^{OC}+j{x}_{12i}^{OC}$$

, $$h_{21i}^{OC}=r_{21i}^{OC}+j{x}_{21i}^{OC}$$

, $$h_{22i}^{OC}=r_{22i}^{OC}+j{x}_{22i}^{OC}$$

at given frequencies (i = 1, 2 ... - frequency number). The four-terminal-11 can be made in the form of an arbitrary connection of an arbitrary number of resistive two-terminal devices. In this invention, this four-terminal is made in the form of a T-shaped connection of three two-terminal with resistance r ₁ -13, r ₂ -14, r ₃ -15 (Fig. 3). The amplifier and frequency demodulator were synthesized (the choice of optimal resistance values, the first r ₁ -13 and third r ₃ -15 of two-terminal SRCH-11) was carried out according to the criterion of providing a given slope of the quasilinear section of the left slope of the frequency response in a given frequency band that coincides with the frequency range of the input HMS , due to the implementation of a given module of the transfer function (gain) at the resonant frequency. As a result, an enlarged quasilinear section of the frequency demodulation characteristic and a dynamic range are realized.

The proposed device operates as follows.

When you turn on the source of constant voltage (current) -2, the operating point of the nonlinear element-1 is set at the initial section of its through-current voltage-current characteristic (the mode of operation with cut-off, which allows to destroy the signal spectrum). Due to the coordination of the DPC and the OS as a whole with the help of the RF system-11 with the rest of the device, negative resistance arises in the circuit and losses in the entire circuit are compensated with a certain tolerance necessary to amplify the amplitude and eliminate the possibility of excitation of the device, and the left slope of the frequency response with a given steepness in a given frequency band. An increase in the quasilinear portion of the left slope of the frequency response occurs. Due to this, the input HMS with an average frequency equal to the average frequency of the left slope of the frequency response is amplified to a level at which the amplitude goes beyond the quasilinear section of the left slope of the frequency response, and the input HMS is converted to AFM. There is an increase in the amplitude of the AFM in the quasilinear section of the left slope of the frequency response, which is equivalent to an increase in the dynamic range. Nonlinear element-1 splits (destroys) the spectrum of the AFMC into components, the low-pass filter-5 isolates the low-frequency component, and suppresses the others, the separation capacitance CP-6 eliminates the constant component, the low-frequency component, the amplitude of which changes according to the law of the frequency of the input HMS, goes to low frequency load-7. FMD demodulation occurs, frequency and nonlinear distortions are reduced. The detection coefficient increases by a factor equal to the gain — the transfer function module of the high-frequency part (up to the low-pass filter) of the proposed device.

Let us prove the feasibility of implementing these properties.

, $$h_{12}^{нэ}=r_{12}^{нэ}+j{x}_{12}^{нэ}$$

, $$h_{21}^{нэ}=r_{21}^{нэ}+j{x}_{21}^{нэ}$$

, $$h_{22}^{нэ}=r_{22}^{нэ}+j{x}_{22}^{нэ}$$

и элементов смешанной матрицы H цепи внешней обратной связи (ОС) $$h_{11}^{ос}=r_{11}^{ос}+j{x}_{11}^{ос}$$

, $$h_{12}^{ос}=r_{12}^{ос}+j{x}_{12}^{ос}$$

, $$h_{21}^{ос}=r_{21}^{ос}+j{x}_{21}^{ос}$$

, $$h_{22}^{ос}=r_{22}^{ос}+j{x}_{22}^{ос}$$

от частоты. При последовательно-параллельном соединении четырехполюсников элементы их матриц H складываются. Суммарные зависимости элементов смешанной матрицы H от частоты: h₁₁=r₁₁+jx₁₁, h₁₂=r₁₂+jx₁₂, h₂₁=r₂₁+jx₂₁, h₂₂=r₂₂+jx₂₂. Размерности элементов матрицы H: h₁₁ (сопротивление), h₁₂ (безразмерный), h₂₁ (безразмерный), h₂₂ (проводимость). Параметры нелинейного элемента зависят, кроме того, от амплитуды низкочастотного управляющего сигнала. Для простоты аргументы (амплитуда и частота) опущены. Требуется определить значения сопротивлений r₁, r₃ (аппроксимирующие функции) первого и третьего резистивных согласующих двухполюсников СРЧ-11, оптимальные по критерию обеспечения условий формирования левого склона АЧХ и усиления амплитуды ЧМС в режиме частотной демодуляции и усиления.Let us introduce the notation of the dependences of the resistance of the signal source z ₀₁ = r ₀ + jx ₀ , the load z _n2 = r _n + jx _n and the dependences of the elements of the mixed matrix H of a nonlinear element (VT) $$h_{\mathrm{eleven}}^{n\mathrm{uh}}=r_{\mathrm{eleven}}^{n\mathrm{uh}}+j{x}_{\mathrm{eleven}}^{n\mathrm{uh}}$$

, $$h_{12}^{n\mathrm{uh}}=r_{12}^{n\mathrm{uh}}+j{x}_{12}^{n\mathrm{uh}}$$

, $$h_{21}^{n\mathrm{uh}}=r_{21}^{n\mathrm{uh}}+j{x}_{21}^{n\mathrm{uh}}$$

, $$h_{22}^{n\mathrm{uh}}=r_{22}^{n\mathrm{uh}}+j{x}_{22}^{n\mathrm{uh}}$$

and elements of the mixed matrix H of the external feedback circuit (OS) $$h_{\mathrm{eleven}}^{\mathrm{about}\mathrm{from}}=r_{\mathrm{eleven}}^{\mathrm{about}\mathrm{from}}+j{x}_{\mathrm{eleven}}^{\mathrm{about}\mathrm{from}}$$

, $$h_{12}^{\mathrm{about}\mathrm{from}}=r_{12}^{\mathrm{about}\mathrm{from}}+j{x}_{12}^{\mathrm{about}\mathrm{from}}$$

, $$h_{21}^{\mathrm{about}\mathrm{from}}=r_{21}^{\mathrm{about}\mathrm{from}}+j{x}_{21}^{\mathrm{about}\mathrm{from}}$$

, $$h_{22}^{\mathrm{about}\mathrm{from}}=r_{22}^{\mathrm{about}\mathrm{from}}+j{x}_{22}^{\mathrm{about}\mathrm{from}}$$

from frequency. With a series-parallel connection of the four-terminal network, the elements of their matrices H are added. The total dependences of the elements of the mixed matrix H on the frequency: h ₁₁ = r ₁₁ + jx ₁₁ , h ₁₂ = r ₁₂ + jx ₁₂ , h ₂₁ = r ₂₁ + jx ₂₁ , h ₂₂ = r ₂₂ + jx ₂₂ . Dimensions of matrix elements H: h ₁₁ (resistance), h ₁₂ (dimensionless), h ₂₁ (dimensionless), h ₂₂ (conductivity). The parameters of the nonlinear element also depend on the amplitude of the low-frequency control signal. For simplicity, the arguments (amplitude and frequency) are omitted. It is required to determine the resistance values r ₁ , r ₃ (approximating functions) of the first and third resistive matching two-terminal СРЧ-11, optimal according to the criterion of providing the conditions for the formation of the left slope of the frequency response and amplification of the FMR amplitude in the frequency demodulation and amplification mode.

Common mixed matrix H of a nonlinear element (VT) and a four-terminal feedback loop (OS) and the corresponding classical transmission matrix:

where | h | = h ₁₁ h ₂₂ -h ₁₂ h ₂₁ . Resistive quadripole (RMS) is characterized by a transmission matrix:

;

;

; a, b, c, d - элементы классической матрицы передачи.Where

;

;

; a, b, c, d - elements of the classical transmission matrix.

The general normalized classical transmission matrix of the high-frequency part of the amplifier and the frequency demodulator is obtained by multiplying the transmission matrix (1) and matrix (2) and taking into account normalization conditions:

Using the well-known connection between the elements of the scattering matrix and the elements of the classical transmission matrix (Feldstein A.L., Yavich L.R. Synthesis of four-terminal and eight-terminal devices on a microwave. M: Communication, 1971. P. 34-36) and the transmission matrix (3) we obtain expression for the transfer coefficient of the high-frequency part of the amplifier and the frequency demodulator in the amplification mode:

. ПоэтомуIt can be shown that the transmission coefficient (4) is related to a physically realized transfer function by a simple relation

. therefore

.

.

The transfer function (5) is reduced to a known form for the gain of a feedback amplifier:

;

- коэффициенты усиления цепи прямой передачи и цепи обратной связи.Where

;

- gains of the forward link circuit and feedback loop.

Let it be required to provide the required dependences of the module m (AFC) and phase φ (PFC) of the transfer function of the amplifier and frequency modulator on frequency:

Substitute (5) or (6) in (7). After separating the imaginary and real parts from each other, we obtain a system of two equations equivalent to (7):

where C _s = (α + γr _n ) r ₂₂₀ - (β + r _n ) r ₁₁₀ + x _n (x ₁₁₀ -γx ₂₂₀ );

S _c = (α + γr _n ) x ₂₂₀ - (β + r _n ) x ₁₁₀ -x _n (r ₁₁₀ -γr ₂₂₀ );

r ₁₁₀ = r ₁₂ r ₂₁ + x ₁₁ x ₂₂ -r ₀ r ₂₂ + x ₀ x ₂₂ -r ₁₁ r ₂₂ -x ₁₂ x ₂₁ ; r ₂₂₀ = - (r ₀ + r ₁₁ );

x ₁₁₀ = r ₁₂ x ₂₁ -x ₀ r ₂₂ -r ₁₁ x ₂₂ -r ₀ x ₂₂ + x ₁₂ r ₂₁ -x ₁₁ r ₂₂ ; x ₂₂₀ = - (x ₀ + x ₁₁ );

Solution (8) has the form of the optimal by criterion (7) interconnections between elements of the classic passive transmission matrix of the RMS:

;

;

;Where

;

;

;

;

; A₁=r₁₁₀x₂₁-x₁₁₀r₂₁; B₁=r₁₁₀r₂₁+x₁₁₀x₂₁; A₂=r₂₂₀r₂₁+x₂₂₀x₂₁; B₂=r₂₁x₂₂₀-r₂₂₀x₂₁;

;

; A ₁ = r ₁₁₀ x ₂₁ -x ₁₁₀ r ₂₁ ; B ₁ = r ₁₁₀ r ₂₁ + x ₁₁₀ x ₂₁ ; A ₂ = r ₂₂₀ r ₂₁ + x ₂₂₀ x ₂₁ ; B ₂ = r ₂₁ x ₂₂₀ -r ₂₂₀ x ₂₁ ;

The optimal characteristics (9), providing the specified slope and linearity of the left slope of the frequency response in the entire frequency range, cannot be realized. Here we propose the implementation of quasi-optimal characteristics that approximately coincide with the optimal characteristics in a certain frequency band.

It is known that the maximum frequency response is observed at a frequency at which the phase of the transfer function is zero. This frequency is called resonant. The frequency of the input FMC changes relative to the average frequency in the direction of decreasing and increasing in the amount equal to the frequency deviation. We call the maximum value of the frequency of the emergency response the upper frequency. Thus, if the resonant frequency of the device is located above the upper frequency of the ChMS, then the change in the frequency of the ChMS will occur on the left slope of the frequency response of the proposed device, as a result of which the input ChMS will be converted to the ChMS. The amplification of the amplitude of the input HMS in the proposed device is regenerative in nature - the higher the gain at the resonant frequency, the narrower the working frequency band, and vice versa. Therefore, changing the value of the transfer function modulus m _p specified and implemented by virtue of (9), equal to the value of m at the resonant frequency, we can adjust the value of the quasilinear portion of the left slope of the frequency response to ensure that it matches the frequency range of the input HMS. We set φ = 0 in (9). Get

;

. Остальные коэффициенты имеют тот же вид, что и в (9).Where

;

. The remaining coefficients have the same form as in (9).

;

;

; a подставляем в (10) и решаем полученную систему уравнений относительно двух выбранных параметров выбранной схемы СРЧ. Если в СРЧ-11 количество двухполюсников больше двух, то сопротивления остальных двухполюсников могут быть выбраны произвольно или исходя из каких-либо других физических соображений. В соответствии с этим алгоритмом получены выражения для определения оптимальных по критерию (10) сопротивлений первого и третьего двухполюсников СРЧ в виде T-образного звена (фиг. 3):The implementation of quasi-optimal characteristics (10) is as follows. We choose a typical resistive four-terminal circuit with a well-known classical transmission matrix. We find the relations of the elements of the classical transfer matrix. The coefficients thus determined

;

;

; a, we substitute in (10) and solve the resulting system of equations with respect to two selected parameters of the selected RF system. If in СРЧ-11 the number of two-terminal devices is more than two, then the resistances of the remaining two-terminal devices can be chosen arbitrarily or on the basis of any other physical considerations. In accordance with this algorithm, expressions are obtained for determining the optimal resistance of the first and third two-terminal RPS in terms of criterion (10) in the form of a T-shaped link (Fig. 3):

. Значение сопротивления r₂ может быть выбрано произвольно (но не равное нулю или бесконечности) или исходя из условия физической реализуемости, например, для обеспечения положительности подкоренного выражения в (11).Where

. The resistance value r ₂ can be chosen arbitrarily (but not equal to zero or infinity) or based on the condition of physical realizability, for example, to ensure the positivity of the radical expression in (11).

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 (using an arbitrary four-terminal device connected to a three-pole nonlinear element in a parallel-parallel circuit as the external feedback circuit, including a three-pole nonlinear feedback element and circuit as a single node between the signal source and the input of the resistive quadripole , Inclusion of high load between the output of the resistive quadripole and the low-frequency part made of a low-pass filter, the separation capacity and low-frequency loads (FIG. 2), performing the matching of the resistive quadripole a T-shaped connection of three two-terminal networks, the selection of the resistance values of the first and third resistive two-terminal r ₁ and r ₃ (Fig. 3)) simultaneously provides amplification, conversion of the HMS to AFM on the left slope of the frequency response, demodulation of the AMF, which is equivalent to frequency demodulation.

The proposed technical solutions are practically applicable, since for their implementation three-pole non-linear elements (transistors or lamps) commercially available by the industry, resistive elements formed into a T-shaped circuit of a resistive four-terminal can be used (Fig. 3). The resistance values of the resistive elements can be uniquely determined using mathematical expressions given in the claims.

The technical and economic efficiency of the proposed device is to provide amplification and frequency demodulation of a high-frequency signal by selecting the circuit and the resistance values of the resistive elements of the matching resistive four-terminal device according to the criterion for the formation of the left slope of the frequency response with the specified slope and gain, which unifies the device, increases the quasilinear portion of the frequency demodulation characteristic and dynamic range in gain mode and frequency demodulation.

Claims (2)

1. The method of amplification and demodulation of frequency-modulated signals, based on the use of energy from a constant voltage source, the interaction of the frequency-modulated signal with a device that is performed from a direct transmission circuit in the form of a three-pole nonlinear element, four-terminal, external feedback circuit, low-pass filter, separation capacitance and low-frequency load, meeting the conditions for matching the forward circuit with the external feedback circuit, matching conditions for the external feedback circuit connection with the control electrode of a three-pole nonlinear element, matching conditions for the direct transmission circuit and the external feedback circuit with the rest of the device with a given tolerance, converting the frequency-modulated signal into an amplitude-frequency-modulated signal on the left slope of the amplitude-frequency characteristic, splitting the spectrum of amplitude- frequency-modulated signal to low-frequency and high-frequency components using a three-pole nonlinear element, the selection of the low-frequency component with using a low-pass filter, eliminating the DC component using a separation capacitance, and obtaining a low-frequency signal at a low-frequency load, the amplitude of which changes according to the law of frequency change of the frequency-modulated signal, characterized in that the four-terminal is made resistive, an arbitrary complex four-terminal is used as the external feedback circuit connected to a three-pole non-linear element in series-parallel circuit, a three-pole non-linear element and nb feedback as a single node in cascade inserted between the source of the frequency-modulated signal with a complex impedance and the input resistive quadripole, between the output of the resistive quadripole and lowpass filter includes high-frequency load in the form of two-terminal network with a complex impedance value of the modulus m _p of the transfer function and a resonance frequency of the device choose from the conditions for the formation of a given slope of the quasilinear portion of the left slope of the amplitude-frequency characteristic of the device and in a predetermined frequency band coinciding with the frequency range of the frequency modulated signal matching conditions for the criterion simultaneously provide gain and frequency demodulation is accomplished by implementing a predetermined value m _p at a resonant frequency by selecting the parameter values of the resistance of quadripole according to the following mathematical expressions:

Where

- the ratio of the corresponding elements of the classical transmission matrix of the resistive quadrupole a, b, c, d; r ₀ , r _n , x ₀ , x _n - set values of the real and imaginary components of the resistance of the source of the input frequency-modulated signal and high-frequency load at the resonant frequency; r ₁₁ , x ₁₁ , r ₁₂ , x ₁₂ , r ₂₁ , x ₂₁ , r ₂₂ , x ₂₂ are the given total values of the real and imaginary components of the elements of the mixed matrix H of the three-pole nonlinear element at the resonant frequency and the corresponding values of the real and imaginary components of the elements of mixed matrix Η external feedback circuit at a resonant frequency. 2. A device for amplifying and demodulating frequency-modulated signals made from a constant voltage source, a direct transmission circuit in the form of a three-pole nonlinear element, a four-terminal, external feedback circuit, a low-pass filter, a separation capacitance, and a low-frequency load, characterized in that the four-terminal is made resistive , as an external feedback circuit, an arbitrary complex four-terminal network connected to a three-pole nonlinear element in series-parallel is used the circuit, a three-pole nonlinear element and a feedback circuit as a single node are cascaded between the source of the frequency-modulated signal with complex resistance and the input of the resistive four-terminal, between the output of the resistive four-terminal and the low-pass filter, a high-frequency load in the form of a two-terminal with complex resistance is turned on, the resistive four-terminal in the form of a T-shaped connection of three resistive two-terminal devices with resistances r ₁ , r ₂ , r ₃ , resistance values r ₁ , r ₃ select The conditions for matching according to the criterion of simultaneously providing gain and frequency demodulation in accordance with the following mathematical expressions:

Where

r ₀ , r _n , x ₀ , x _n - set values of the real and imaginary components of the resistance of the source of the input frequency-modulated signal and high-frequency load at the resonant frequency; r ₁₁ , x ₁₁ , r ₁₂ , x ₁₂ , r ₂₁ , x ₂₁ , r ₂₂ , x ₂₂ are the given total values of the real and imaginary components of the elements of the mixed matrix H of a three-pole nonlinear element at the resonant frequency and the corresponding values of the real and imaginary components of the elements of mixed matrix H of the external feedback circuit at the resonant frequency; the value of the resonant frequency and the value of the given and implemented module m _{p of the} transfer function at the resonant frequency are selected from the condition for the formation of the specified slope of the quasilinear portion of the left slope of the amplitude-frequency characteristic of the device in a given frequency band that matches the frequency range of the input frequency-modulated signal; r ₂ - the set value of the resistance of the second two-terminal resistive four-terminal.

Images