RU2224354C2 - Method for converting periodic-signal phase deviation - Google Patents

Abstract

FIELD: radio engineering. SUBSTANCE: proposed method that can be used for phase conversion with desired conversion coefficient depends on synchronization of period-signal frequencies including multiplication of first and second signals being synchronized, separation of output signal of difference or sum frequency, and recording of its initial phase relative to that of input reference signal. Then first signal being synchronized and input signal are multiplied, second difference-frequency sync signal is separated and used to synchronize second signal being synchronized. Then second signal being synchronized is multiplied by input reference signal, first difference- or sum-frequency signal is separated and used to synchronize first signal being synchronized. In addition initial phase of one of signals being synchronized is converted so that phase shift between signal being synchronized and sync signal is inverse relative to respective phase shift before conversion. EFFECT: enhanced phase deviation. 2 cl, 4 dwg

Description

 The invention relates to radio engineering and other areas of electronic engineering, which use signals with angular modulation, and can be used to convert phase deviation with any given conversion coefficient.

 As an analogue of the invention, known methods for converting phase deviation [1], which use indirect methods for converting angular modulation, can be considered.

 A disadvantage of the known methods is their complexity in technical implementation and operation only in dynamic mode.

 As a result of a search among scientific publications, patents and copyright certificates for inventions, the authors did not identify methods and devices for direct conversion (amplification) of phase deviation of a periodic signal with an arbitrary conversion coefficient greater than unity (similar to amplitude amplifiers) without intermediate conversions to other types of modulations.

 A known method of linearizing the characteristics of differential frequency sensors, which consists in the fact that the first output frequency is subtracted from the stable reference frequency and the second output frequency is synchronized with the obtained difference, and the second output frequency is subtracted from the stable reference frequency and the first frequency is synchronized with the obtained difference [2]. A device that implements the method includes a first strip amplifier, a first mixer, a second strip amplifier, a second mixer, which form a closed loop, and the output of the reference generator, a third mixer, the inputs of which are connected to the outputs of the first and second strip amplifiers, are connected to the second inputs of the mixers output to the third band amplifier. When the conditions for the balance of amplitudes and phase balance are met, in this self-oscillating system, signals with combination frequencies are generated at the outputs of the first and second band amplifiers.

 A known device that implements the method can be used to convert the phase deviation of the periodic signal, since it is possible to change the frequencies of the generated signals and, accordingly, the phase shifts in the band amplifiers by changing the frequency of the reference signal or the additional phase shift introduced into the loop of the self-oscillating system.

 The disadvantage of this method and device is the inability to obtain a conversion coefficient greater than one.

 The purpose of the invention is the conversion of the phase deviation of the periodic signal with an arbitrary conversion coefficient greater than unity in a technically feasible range.

 To this end, in the known method, instead of a signal with a stable reference frequency, a reference signal and an input signal with phase modulation are used, the first and second synchronized signals are multiplied, an output signal with a total or difference frequency is extracted, and its initial phase is recorded relative to the initial phase of the input reference signal, multiplied the first synchronized signal and the input signal, allocate a second synchronization signal with a differential frequency, which synchronizes the second synchronized signal, multiply the second synchronized signal with the input reference signal, the first synchronization signal with a difference or total frequency is isolated, which synchronizes the first synchronized signal, in addition, one of the synchronization signals additionally transforms the initial phase so that the phase shift between the synchronization signal and the synchronized signal becomes inverse relative to the corresponding phase shift before conversion.

 In order to convert the initial phase of one of the synchronization signals, the synchronization signal is multiplied by itself, the obtained signal is doubled with the initial synchronization signal, from which the initial phase is additionally shifted, a signal with a difference frequency is extracted, and the corresponding synchronized signal is synchronized with it.

 The technical results that can be obtained by using the invention are simple phase modulation devices giving large modulation indices of the output signals and having the ability to smoothly change the modulation index; amplifiers of ultra-small phase deviations of the output signals of phase-generating converters.

 Figure 1 shows graphs illustrating the conversion of the phase deviation of the input periodic signal when its frequency is equal to the sum of the frequencies of the synchronized signals.

The dependences φ (f ₂ ) and φ (f ₁ ,) of phase shifts between the synchronization signals and synchronized signals are given if the frequencies of the synchronization signals do not coincide with the partial frequencies f ₁₀ and f _{20 of the} synchronized signals (frequencies of the synchronized signals in the absence of synchronization signals).

 In FIG. 2 is a graph illustrating the conversion of the frequency deviation of the input periodic signal when its frequency is equal to the frequency difference of the synchronized signals.

The dependences φ (f ₂ ) and φ (f ₁ ) of phase shifts between the synchronization signals and synchronized signals are given if the frequencies of the synchronization signals do not coincide with the partial frequencies of the synchronized signals.

 In FIG. 3 shows a variant of the structural diagram of a device that implements this method.

 The device contains balanced mixers 1, 4, 7, synchronized generators 2, 6, a converter of the initial phase of the synchronization signal 3, a strip amplifier 5 and a phase shift recorder 8.

 In FIG. 4 shows an embodiment of a block diagram of an initial phase converter of a synchronization signal.

 The initial phase Converter contains balanced mixers 9 and 10, a strip amplifier 11 and a multi-stage strip amplifier 12.

Partial frequencies f ₁₀ and f ₂₀ synchronized signals are selected in accordance with the condition
f ₁₀ ± f ₂₀ = f ₀ , (1)
where f ₀ is the frequency of the input and reference signals.

 According to the proposed method for converting the phase deviation of the periodic signal, the following operations are performed. Multiply the input signal and the first synchronized signal. A component with a difference frequency is isolated from the resulting signal. Its initial phase is transformed and the second synchronized signal is synchronized with the received signal. The reference signal and the second synchronized signal are multiplied. A component with a difference or total frequency is isolated from the resulting signal. The received signal synchronizes the first synchronized signal. The synchronized signals are multiplied and the output signal is extracted with a difference or total frequency. Record its initial phase relative to the initial phase of the input reference signal.

In the steady state, the frequencies of the synchronized signals are equal to the frequencies of the synchronization signals, but additional phase shifts appear between them if they are not equal to the partial frequencies. In this case, a balance of phase shifts is performed. The magnitude of the phase shifts are determined by the dependences φ (f ₁ ) and φ (f ₂ ).

The balance of phase shifts is determined by the equality
φ ₁ (f ₁ ) = ± φ ₂ (f ₂ ) + φ ₀ , (2)
where φ ₀ is the value of the phase deviation of the input signal relative to the initial phase of the reference signal.

Из фиг. 1 и 2 видно, что небольшое смещение φ₀ начальной фазы входного сигнала относительно начальной фазы опорного сигнала вызывает существенное изменение частот синхронизируемых сигналов относительно парциальных частот и, соответственно, значительно большие изменения фазовых сдвигов между сигналами синхронизации и синхронизируемыми сигналами. Частота выходного сигнала равна частоте входного сигнала и, соответственно, опорного сигнала, так как определяется выражением
f₁±f₁=f_вых, (4)
а начальная фаза отличается от начальной фазы опорного сигнала на величину фазового сдвига между первым сигналом синхронизации и первым синхронизируемым сигналом. Таким образом, происходит усиление девиации фазы периодического сигнала.If the initial phase of the input signal is incremented relative to the initial phase of the reference signal, then a transition process begins during which the frequencies of the synchronized signals are changed until the conditions are met together:

From FIG. 1 and 2 it is seen that a small shift φ _{0 of the} initial phase of the input signal relative to the initial phase of the reference signal causes a significant change in the frequencies of the synchronized signals relative to the partial frequencies and, accordingly, significantly larger changes in phase shifts between the synchronization signals and the synchronized signals. The frequency of the output signal is equal to the frequency of the input signal and, accordingly, the reference signal, as it is determined by the expression
f ₁ ± f ₁ = f _out , (4)
and the initial phase differs from the initial phase of the reference signal by the amount of phase shift between the first synchronization signal and the first synchronized signal. Thus, the phase deviation of the periodic signal is amplified.

 Let us prove the validity of the conclusions analytically.

где S - крутизна фазочастотной характеристики.For clarity of analysis, we omit the amplitude factor and use the linearized phase-frequency characteristics φ (f ₁ ) and φ (f ₂ ) in the synchronization interval

where S is the steepness of the phase-frequency characteristic.

Подставляя (6) в первое выражение (5), получим

Регистрируемый фазовый сдвиг между выходным сигналом и опорным сигналом равен φ₁. Найдем чувствительность девиации фазы выходного сигнала к девиации фазы входного сигнала

Видно, что знаменатель (8) может быть каким угодно малым, поэтому чувствительность и, соответственно, коэффициент преобразования девиации фазы могут быть теоретически какими угодно большими.Solving system (3) with respect to f ₁ using (5), we obtain

Substituting (6) in the first expression (5), we obtain

The recorded phase shift between the output signal and the reference signal is φ ₁ . Find the sensitivity of the phase deviation of the output signal to the phase deviation of the input signal

It is seen that the denominator (8) can be arbitrarily small, therefore, the sensitivity and, accordingly, the conversion coefficient of the phase deviation can be theoretically arbitrarily large.

 The analysis shows that a change in the slope of one of the phase-frequency characteristics causes a change in the deviation of the detected phase of the output signal with a constant phase deviation of the input signal. There is a conversion (amplification) of phase deviation. The conversion factor can be quite large.

 To convert the initial phase of one of the synchronization signals in order to obtain an inverse phase shift between the synchronized signal and the synchronization signal, the following operations are performed. The synchronization signal is multiplied by itself, the received signal with doubled frequency is multiplied with the original synchronization signal, from which the initial phase is additionally shifted, the signal with the difference frequency is isolated and the corresponding synchronized signal is synchronized with it.

 In the steady state, when the frequency of the synchronized signal is shifted relative to its own partial frequency, the corresponding phase shift between the synchronized signal and the synchronization signal is Δφ. When a synchronization signal with a difference frequency is extracted after the initial phase is converted, a similar phase shift Δφ is added. If the additional shift of the initial phase of the synchronization signal is 3Δφ, then the equivalent phase shift between the synchronized signal and the original synchronization signal before converting the initial phase will be 2Δφ-3Δφ = -Δφ. This is true for any Δφ. Accordingly, the equivalent phase-frequency characteristic will be inverse and will take the form of the second expression (5).

 In FIG. 3 shows a structural diagram of a device that implements the proposed method for converting the phase deviation of a periodic signal. The device comprises a mixer 1, to the first input of which the output of the synchronized generator 2 is connected, and the input of the converter of the initial phase 3 is connected to the output, to the output of which the synchronized generator 6 is connected, a mixer 7, to the first input of which the output of the synchronized generator 6 is connected, and the output is connected the input of the synchronized generator 2, the mixer 4, to the inputs of which the outputs of the synchronized generators 2 and 6 are connected, and the output is connected to a strip amplifier 5, the output of which is connected to the first input of the register Ora 8, the input of the device is connected to the second input of the mixer 1, and the input of the reference signal is connected to the second inputs of the mixer 7 and the recorder 8.

 The device operates as follows.

The partial frequencies f ₁₀ and f _{20 of the} first and second synchronized generators at a known frequency f _{0 of the} input and reference signals are selected in accordance with the condition
f ₁₀ ± f ₂₀ = f ₀ , (9)
An input phase-modulated signal with frequency f ₀ is supplied to the second input of mixer 1, and a reference signal of the same frequency with a fixed initial phase ψ is supplied to the second input of mixer 7. The outputs of the synchronized generators 2 and 6 in the synchronization mode generate signals with frequencies f ₁ and f ₂ if the condition of phase balance is fulfilled. The output signals of balanced mixers 1 and 7 contain components with the total and difference frequency of the mixed signals. The output of the synchronized generator 6 generates a signal whose frequency is equal to the difference f ₀ -f ₁ or f ₁ -f ₀ depending on the sign in condition (9). At the output of the synchronized generator 2, a signal is generated whose frequency is f ₀ ∓ f ₂ in accordance with the sign in condition (9). Thanks to the initial phase converter 3, the phase-frequency characteristics of the synchronized generator 2 and the cascade connection, the initial phase converter 3 and the synchronized generator 6 have slopes of different signs (see Figs. 1 and 2).

где φ₀ - значение девиации фазы входного сигнала относительно начальной фазы опорного сигнала.The steady state in the device in question relative to the frequencies of the generated signals when the condition is met is determined by the system of equations

where φ ₀ is the value of the phase deviation of the input signal relative to the initial phase of the reference signal.

If the values of the input signal frequency and the resonant frequencies of the strip amplifiers meet condition (9), then the closed-loop phase balance mixer 1, converter 3, generator 6, mixer 7, generator 2 is performed at zero phase shifts. If at the same time φ ₀ = 0, then the frequencies of the generated signals coincide with the partial frequencies of the generators 2 and 6 (see figures 1 and 2).

Deviation of the initial phase of the input signal relative to the value ψ of the reference signal violates the phase balance. The transition process begins, consisting in changing the frequencies of the generated signals by synchronized generators until a phase balance occurs at new frequencies. The new steady state is shown in figures 1 and 2. It corresponds to the frequency f ₁ and f ₂ . Under certain conditions, the phase shifts in the synchronized oscillators φ ₁ and φ _{2 are} much larger than the phase deviation φ _{0 of the} input signal. Both generated signals are multiplied in the mixer 4. Using a strip amplifier 5, a signal is selected whose frequency is equal to the frequency f _{0 of the} input signal, and the initial phase is
φ ^* = ψ + φ ₀ + φ ₂ = ψ + φ ₁ . (eleven)
In the recorder 8 two signals of the same frequency are compared with a phase shift relative to each other equal to φ ₁ , which can be much greater than φ ₀ .
The initial phase converter 3 contains a mixer 9, the output of the strip amplifier 11 is connected to both its inputs and to the input of the multistage strip amplifier 12, the input of which is the input of the converter, mixer 10, the output of the mixer 9 is connected to its first input, and the output of the multistage strip is connected amplifier 12, and the output is the output of the converter.

 Converter initial phase 3 operates as follows.

Начальная фаза сигнала с двойной частотой на выходе смесителя 9 будет 2ψ^*. У сигнала на выходе смесителя 10 с разностной частотой, равной частоте входного сигнала преобразователя 3, после усилителя 11 начальная фаза будет равна (2ψ^*-ψ^*-3Δφ+Δφ). В синхронизируемом генераторе 6 сигнал получает дополнительный фазовый сдвиг Δφ, в результате начальная фаза генерируемого сигнала на его выходе будет равна (ψ^*-Δφ). Все указанное справедливо при любом отклонении частоты генерируемого сигнала от соответствующей резонансной частоты усилителей, равной парциальной частоте генератора. Эквивалентная фазочастотная характеристика каскадного соединения преобразователя начальной фазы 3 и генератора 6 будет инверсной по отношению к фазочастотной характеристике генератора 6.The strip amplifier 11 and all stages of the three-stage strip amplifier 12 have the same quality factor, equivalent to the steepness of the phase-frequency characteristic of the generator 6, and are tuned to its partial frequency. When the frequencies of the generated signals are shifted relative to the resonant frequencies in the amplifier 11 and in each stage of the three-stage amplifier 12, the signal acquires an additional phase shift Δφ. As a result, if the initial phase of the input signal of the converter 3 was ψ ^* , then at the output of the amplifier 12, its initial phase will be

The initial phase of the signal with a double frequency at the output of the mixer 9 will be 2ψ ^* . The signal at the output of the mixer 10 with a difference frequency equal to the frequency of the input signal of the converter 3, after the amplifier 11, the initial phase will be equal to (2ψ ^* -ψ ^* -3Δφ + Δφ). In the synchronized oscillator 6, the signal receives an additional phase shift Δφ, as a result, the initial phase of the generated signal at its output will be equal to (ψ ^* -Δφ). All of the above is true for any deviation of the frequency of the generated signal from the corresponding resonant frequency of the amplifiers, equal to the partial frequency of the generator. The equivalent phase-frequency characteristic of the cascade connection of the initial phase converter 3 and generator 6 will be inverse with respect to the phase-frequency characteristic of the generator 6.

 Thus, the proposed device allows many times to increase the phase deviation of the output signal relative to the fixed initial phase of the reference signal compared to the phase deviation of the input signal and create on its basis "phase amplifiers" by analogy with amplitude amplifiers.

Sources of information
1. Radio transmitting devices: Textbook for high schools / V.V. Shahgildyan, V.B. Kozyrev et al. - M.: Radio and Communications, 1990, 432 p.

 2. Auth. St. USSR 754442, G 06 G 7/26. A method of linearizing the characteristics of differential frequency sensors. / Shakursky V.K., Morgunov Yu.I. Publ. 08/07/80. Bull. 29.

Claims (2)

1. The method of converting the phase deviation of the periodic signal, based on the synchronization of the frequencies of the periodic signals, which consists in multiplying the first and second synchronized signals, extracting the output signal with a difference or total frequency and registering its initial phase relative to the initial phase of the input reference signal, characterized in that the first synchronized signal and the input signal are multiplied, a second synchronization signal with a difference frequency is isolated, with which the second synchronizes the signal to be synchronized, the second synchronized signal is multiplied with the input reference signal, the first synchronization signal with a difference or total frequency is isolated, which synchronizes the first synchronized signal, in addition, the initial phase is additionally converted in one of the synchronization signals so that the phase shift between the synchronization signal and the synchronized signal became inverse with respect to the corresponding phase shift before conversion. 2. The method according to claim 1, characterized in that for converting the initial phase of one of the synchronization signals, the synchronization signal is multiplied by itself, a signal with a double frequency is extracted, it is multiplied with the original synchronization signal, from which the initial phase is additionally shifted, the signal is isolated from differential frequency and they synchronize the corresponding synchronized signal.

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