RU2030116C1 - Device for formation of signals of frequency shift keying - Google Patents

Abstract

FIELD: radio engineering. SUBSTANCE: increased precision of formation is achieved by stabilization of moment of switching over of frequencies of frequency-shifted signal by insertion of five multipliers 17, 18, 21, 22, 36, two phase shifters 19, 20, three delay units 23, 24, 31, integrator 34, power supply unit 25, correction input unit 29, frequency divider 30, reference signal former 32, instruction former 39. EFFECT: increased precision of formation of frequency-shifter signals. 7 dwg

Description

 The invention relates to radio engineering.

 The purpose of the invention is to increase the accuracy of formation by stabilizing the moments of switching frequencies of a frequency-manipulated (FM) signal.

 In FIG. 1 shows a structural electrical diagram of the proposed device; in FIG. 2-4 are timing diagrams explaining its operation; in FIG. 5 is a diagram of a shaper of switched frequencies; in FIG. 6 is a diagram of a heterodyne tuning block; in FIG. 7 is a diagram of a driver of the mismatch signals.

 The device comprises a master oscillator 1, a first 2 and a second 3 phase shifters, a shaper of 4 switched frequencies, a frequency manipulator 5, a shaper of a manipulation signal 6, a frequency converter 7, a load unit 8, the first 9 and second 10 signal multipliers, an imbalance signal generator 11, a third multiplier 12 signals, the first 13 and second 14 reference frequency shapers, the reference pulse generator 15, the local oscillator tuning block 16, the fourth 17 and fifth 18 signal multipliers, the first 19 and second 20 phase shifting blocks, the sixth 21 seventh 22 signal multipliers, first 23 and second 24 delay units, subtraction unit 25, counting pulse generator 26, first key 27, first integrator 28, correction input unit 29, frequency divider 30, third delay unit 31, reference signal generator 32, second 33 and the third 34 integrators, the inverter 35, the eighth signal multiplier 36, the second 37 and third 38 keys, the shaper 39 teams.

 Shifter 4 switchable frequencies (Fig. 5) contains a driver 40 low frequency driver 41 high frequency generator 42 fixed frequency, mixers 43 and 44 frequencies.

 The local oscillator tuning block 16 (Fig. 6) comprises a phase shifter 45, an auxiliary signal generator 46, a frequency mixer 47, and a pulse-phase detector 48.

 The imbalance signal generator 11 (Fig. 7) comprises a summing unit 49, a subtraction unit 50, and a pulse generator 51.

 The device operates as follows.

 The signal of the master oscillator 1 enters through the phase shifters 2, 3 to the former 4. The generated signals are transmitted to the frequency manipulator 5, the output of which the FM signal after converting to the operating range in the frequency converter 7 is fed to the load unit 8. From the output of the load unit 8, which is the output of the device, the FM signal is fed to the signal multiplier 9, the second input of which receives the signal from the local oscillator building block 16. The output signal of block 16 is formed from the signal of the master oscillator 1, which is input to the signal input of block 16, and the local oscillator signal from the second output of converter 7 to the heterodyne input of block 16. As a result of the automatic adjustment of the output signal of block 16 relative to the pulses coming from the reference pulse generator 15 to the reference input of block 16, the phase of the output signal of block 16 becomes equal to zero. The spectrum of the output signals of the multiplier 9 contains components whose frequencies are equal to the difference and the sum of the frequencies of the multiplied signals.

 The reference signals generated from the frequency of the master oscillator 1 using the shapers 13, 14 are fed to the signal multipliers 12, 10, the other inputs of which receive a signal from the signal multiplier 9. The frequencies of the reference signals are equal to the corresponding difference frequencies in the spectrum of the signal at the output of the multiplier 9 of the signals and are multiples of the frequency of the reference pulses coming from the generator 15 of the reference pulses to the installation inputs of the shapers 13, 14. The initial phases of the signals of the reference frequencies are zero.

 The signals from the multipliers 12, 10 are fed to the shaper 11 of the mismatch signals. From the outputs of the latter, the mismatch signals are transmitted via keys 37, 38 to integrators 33, 34, where they are averaged over two elementary premises of the opposite sign. The output signals of the integrators go to the shaper 39 teams, from the outputs of which the teams control the phase shifters 2, 3. Entering into phase matching of the phase control channels of the frequency components of the FM signal occurs with an appropriate choice of the transmission coefficient of the auto-tuning circuits. Coordination of transmission coefficients is carried out using the shaper 39 teams. With the digital execution of the auto-tuning circuits in the shaper 39, the ratio between the frequencies of the command pulses arriving at the control inputs of the phase shifters 2, 3 is selected.

 Control is carried out until equilibrium occurs in the phase tracking circuits, while the phases of the frequency components of the FM signal at the output of the load block are stabilized relative to the reference frequency signals.

 In the equilibrium position, the phases of the signals of difference frequencies in the spectrum of the output signal of the multiplier 9, arriving at the first inputs of the multipliers 17, 18 of the signals, are shifted by π / 2 relative to the phases of the corresponding reference signals at the outputs of the drivers 13, 14. After the shift of the reference frequency signals in the phase-shifting units 19 , 20 on the π / 2 phase of the signals at the second inputs of the multipliers 17, 18 and the signals of the difference frequencies are aligned. In the products of these signals arriving at the first inputs of the multipliers 21, 22 of the signals, information about the shift of the modulating signal at the output of the load unit 8 is contained.

In FIG. 2d shows an FM signal with an arbitrary manipulation law at the output of the load unit 8, delayed by τ _s relative to the movable manipulation signal (Fig. 2c) coming from the driver 6 to the frequency manipulator 5. The moments of the transition from frequency to frequency are shifted by τ _cm relative to the output the signal of the driver 32 of the reference signal (Fig. 2e), synchronized with the reference pulses (Fig. 2A). The reference signal (Fig. 2e) is formed from the signal of the master oscillator 1 according to the same law as the signal at the output of the manipulator signal generator 6 (Fig. 2c), i.e., it is a copy of the manipulation signal. As a result of phase-locked loop, the phases of the components of the FM signal at the moments of transition through zero of the reference signal of manipulation (Fig. 2e) are equal to zero. When τ _cm is not equal to zero, there are jumps in the phase of the forced oscillations during the transition from frequency to frequency, which cause transients in the signal (not shown in Fig. 2d).

The second inputs of the signal multipliers 21, 22 receive a reference signal, delayed in the block 23 delay half the duration of the elementary package. The mismatch signal in the tuning circuit of the manipulation signal is formed by subtracting the output signals of the multipliers 21, 22, which are sequences of pulses of different durations corresponding to the areas of coincidence (C) and mismatch (H) of the polarity of the multiplied signals. These sequences come from the multipliers 21 and 22 to the first and second inputs of the subtraction unit 25. In block 25, sections C and H are filled with counting pulses from the counting pulse generator 26 to the third input of block 25. As a result of subtraction, the sums C ₂ + H ₂ and H ₁ + C _{2 are formed} , where the numbers 1 and 2 indicate the signals corresponding, respectively to the first and second chains. Addition is realized quite simply provided that the summed pulses do not coincide. This is achieved by using a push-pull sequence of counting pulses, with step 1 going to the first circuit and step 2 being averaged. The subtraction results are averaged in the first integrator 28, the counting pulses from the output of the subtracting unit 25 are fed to the counting input 27 through the first key 27.

 The formation of the gates that open the keys 27, 37, 38 at the inputs of the integrators 28, 33, 34 is carried out in accordance with the diagrams in FIG. 2g, h, and by multiplying in the eighth multiplier 36 an inverse reference manipulation signal (Fig. 2g) with a manipulation signal delayed by the duration of the chip (Fig. 2h). An additional (to the delay in block 23) delay by half of the reference signal is carried out in the second delay block 24. Positive strobes from the output of the multiplier 36 (Fig. 2i) open the keys 27, 37, 38 after each edge and the decay of the reference signal for the duration of the elementary burst, while excluding subsequent signal sections that do not contain a difference, i.e., do not carry information about shift signal manipulation. Zeroing the integrators 28, 33, 34 is carried out by the edges of the manipulation signal (Fig. 2e). During the time, by the nulling pulses, the integrators receive the results of the multiplication of reference signals with sendings of the opposite sign. The total averaging time is equal to twice the duration of the elementary parcel. Commands from the output of the integrator 28 control the position of the manipulation signal.

 The manipulation signal in the shaper 6 is formed from the pulses of the frequency divider 30, the input of which comes through the correction input unit 29 of the frequency of the master oscillator 1. The initial combination of the reference and mobile manipulation signals within the duration of the elementary sending is done by installing the shaper 6 with the reference pulses supplied to its installation input from the generator 15 through the third delay unit 31 (Fig. 2b). A further shift of the manipulation signal is carried out using the auto-tuning circuit. As a result of the installation by delayed pulses (Fig. 2b), the manipulation signal at the output of the shaper 6 (Fig. 2c) cannot be shifted under the action of the commands at the control input of the correction input unit 29 by more than a period of the output signal of the frequency divider 30 equal to the duration of the elementary sending of the manipulation signal .

 The mobile manipulation signal (Fig. 2c) is shifted in the direction of advancing until equilibrium occurs in the tuning chain. Since the reference manipulation signal at the second inputs of the signal multipliers 21, 22 (Fig. 2e) is shifted by half the burst relative to the synchronized signal at the output of the driver 32 (Fig. 2e), the transition moments of the FM signal at the output of the load unit 8 in the equilibrium position (Fig. 2k ) are also synchronized with the reference pulses of the generator 15 (Fig. 2A).

 At the end of auto-tuning, the transitions from frequency to frequency are carried out without phase disruption (Fig. 2k), therefore, the distortions of the output FM signal caused by transients in frequency are reduced.

 The value of the delay of the reference pulses in the block 31 of the delay received at the installation input of the shaper 6 of the manipulation signal is approximately determined as the difference between half the duration of the elementary package and the delay of the switching moment in the block 8 of the load, it is assumed that the delay in the block of the load does not exceed half the duration of the elementary parcels. The diagrams of FIG. 2 illustrates the case of adjusting the manipulation signal with an intermediate delay value of the switching moments in the load unit 8 and the corresponding delay of the synchronizing pulses in the delay unit 31.

 In FIG. 3 and 4 are diagrams of the device for two extreme cases: the maximum delay in the load block (Fig. 3) and zero delay (Fig. 4). The latter case also occurs when the device is configured without a load unit 8, i.e., when the output of the frequency converter 7 is directly connected to the signal multiplier 9. The choice of delay of block 31 is important for quickly capturing the auto-tuning circuit of the manipulation signal with an arbitrary law of alternating ones and zeros.

 When the delay in the load block is equal to half of the elementary package (Fig. 3), the delay of the synchronizing (Fig. 3a) (reference) pulses of the generator 15 in block 31 is zero (Fig. 3b). In the equilibrium position, the edges of the reference manipulation signal (Fig. 3d) are delayed relative to the moments of the frequency transition at the output of the load unit 8 (dashed line in Fig. 3d) by 0.5 T, and the installation pulse (Fig. 3b) is in the middle of the output signal shaper 6 signal manipulation (Fig. 3B). At the maximum bias (for example, when the device is turned on) of the tunable signal at the output of the manipulator 6 for the manipulation signal halfway to the right (Fig. 3g) or to the left (Fig. 3i) from the setting pulse (Fig. 3b), which limits the bias of the tuned signal within these limits, respectively, there is a complete coincidence or mismatch of the manipulation signal at the output of the load unit 8 (Fig. 3c) or (Fig. 3k) and the reference signal (Fig. 3d).

 With a zero delay in the load unit 8 (Fig. 4), the delay of the reference pulses (Fig. 4a) in the delay unit 31 is equal to half the duration of the elementary package (Fig. 4b). In the equilibrium position of the output signal (Fig. 4d), the installation pulse (Fig. 4b) is also located in the middle of the elementary signal transmission at the output of the manipulator signal generator 6 (Fig. 4c). When the adjustable signal is shifted halfway to the right (Fig. 4g) or to the left (Fig. 4i), the corresponding output signals (Fig. 4c or 4k) completely coincide or do not coincide with the reference signal (Fig. 4e). In both cases (Fig. 3, 4), the mismatch between the reference and the movable (at the output of the load block 8) manipulation signals does not exceed the duration of the elementary sending. Since the accumulation time of the summation results in the integrator 28 is determined by fixed gates (Figs. 3e, 4e) unlocking the key 27, at large shifts of the manipulation signal, the mismatch signals at the output of the integrator 28 alternately change their sign, which leads to fluctuations of the unsettled signal far from the stable equilibrium position and increase the time of entry into synchronisms.

Claims (1)

 DEVICE FOR FORMING FREQUENCY-MANIPULATED SIGNALS, containing a master oscillator, the output of which is connected to the inputs of the first and second phase shifters, the outputs of which are connected respectively to the first and second inputs of the shaper of switched frequencies, the first and second outputs of which are connected to the corresponding inputs of the frequency manipulator, to the control input which is connected to the output of the shaper of the manipulation signal, and the output of the frequency manipulator is connected to a series-connected converter from the load block, the first signal multiplier and the second signal multiplier and the mismatch signal generator, to the second input of which the output of the third signal multiplier is connected, the first input of which is connected to the first input of the second signal multiplier, and the output of the first reference driver is connected to the second input of the third signal multiplier frequency, the signal input of which is connected to the output of the master oscillator, the signal input of the second driver of the reference frequency connected by the output to the WTO the input input of the second signal multiplier, and with the input of the reference pulse generator, the output of which is connected to the installation inputs of the first and second drivers of the reference frequency and the reference input of the heterodyne tuning unit, the signal and heterodyne inputs of which are connected respectively to the output of the master oscillator and the second output of the frequency converter, and the output of the local oscillator adjustment unit is connected to the second input of the first signal multiplier, as well as two integrators, a counting pulse generator, an inverter and three keys, from which means that, in order to increase the accuracy of formation by stabilizing the moments of switching the frequencies of the frequency-manipulated signal, five signal multipliers, two phase-shifting blocks, three delay blocks, a third integrator, a subtraction block, an input of the correction, a frequency divider, a reference driver are introduced into it a signal and a command shaper, the output of the master oscillator being connected to the inputs of the reference signal shaper and the correction input unit, the output of the first signal multiplier - with the first inputs of the fourth and a fifth signal multiplier, to the second inputs of which the outputs of the first and second phase-shifting units are connected, the inputs of which are connected to the outputs of the first and second reference drivers, respectively, and the outputs of the fourth and fifth signal multipliers, with the first inputs of the sixth and seventh signal multipliers, respectively the inputs of which are connected to the output and input of the first and second delay blocks, respectively, and the outputs, respectively, with the first and second inputs of the subtraction block, one third the first input of which is connected to the output of the counter pulse generator, and the output is connected via the first key to the counting input of the first integrator connected to the control input of the correction input unit, the output of which is connected through the frequency divider to the input of the manipulator signal shaper, to the installation input of which the output of the third block is connected delays, the input of which is connected to the output of the reference pulse generator, the installation input of the driver of the reference signal, the output of which is connected to the installation inputs of the first to third about integrators and with the inputs of the first delay unit and inverter, the output of which is connected to the first input of the eighth signal multiplier, the second input of which is connected to the output of the second delay unit, and the output - with the control inputs of the first and third keys, are connected to the signal inputs of the second and third keys respectively, the first and second outputs of the mismatch signal generator, and the outputs of the second and third keys are connected to the counting inputs of the second and third integrators, respectively, the outputs of which are connected respectively with the first and second inputs of the command shaper, the first and second outputs of which are connected to the control inputs of the first and second phase shifters, respectively.

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