JPH0537317A - Pulse phase modulating circuit - Google Patents

Abstract

PURPOSE:To simplify the constitution, to obtain a deep modulation, and also, to apply this circuit to devices of a wide range. CONSTITUTION:A pulse signal S4 is inputted to a waveform shaping circuit 1, and a triangular wave signal S5 subjected to waveform shaping is inputted to a Schmitt trigger circuit 2. In this case, when an output signal S6 from a command generating circuit 3 is a low (L) level an operating point V2 of the Schmitt trigger circuit 2 is tuned on (ON), and an operating point V1 is tuned off (OFF). On the contrary, when the output signal S6 is a high (H) level, the operating point V1 is tuned on (ON), and also, the operating point V2 is turned off (OFF). In such a way, a modulated wave output signal S7 whose phase is shifted by a time shift DELTAt is obtained from the Schmitt trigger circuit 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse phase modulation circuit which sends out a control signal of a device arranged on a pulse transmission line, for example.

[0002]

2. Description of the Related Art FIG. 3 shows a configuration of a conventional pulse phase modulation circuit, and FIG. 4 shows a processed signal. The square-wave pulse signal S12 is supplied to the differential amplifier 8 through the input end a. When the low (L) level signal S14 is input to the differential amplifier 8 from the command generation circuit 10, the differential amplifier 8 outputs a signal S13 having the same waveform as the pulse signal S12. When the signal S14 of the command generation circuit 10 becomes high (H) level, the signal S13 is level-shifted by [ΔV]. This level-shifted [ΔV] signal S1
3 is input to the comparison circuit 9. Here, a modulated wave signal S15 having a waveform which is compared with the output voltage [V0] from the reference voltage generation circuit 11 and time-shifted (phase-shifted) by [Δt] compared with the waveform in the low (L) level is output. To be done.

As described above, the output waveform of the comparison circuit 9 is time-shifted according to the change of the low (L) or high (H) level of the signal S14 from the command generation circuit 10, and the modulated wave signal subjected to the phase modulation. S15 is obtained.

[0004]

However, this conventional phase modulation circuit has a simple structure, but since the differential amplifier 8 is used, there is a limit in the amount of level shift [ΔV], and time shift [. Δt] amount is small. That is, the phase shift is small and the modulation is shallow. When demodulating this modulated signal on the receiving side, a highly sensitive demodulator is required.
If the pulse signal S12 (carrier) itself has phase jitter (temporal fluctuation), it is difficult to detect the demodulated signal.

It is an object of the present invention to provide a pulse phase modulation circuit which can be simplified in structure, can obtain deep modulation, and can be applied to a wide range of devices.

[0006]

In order to achieve this object, a pulse phase modulation circuit of the present invention is a pulse phase modulation circuit for transmitting a modulated wave output signal obtained by subjecting an input pulse signal to phase modulation, A waveform shaping circuit that shapes a square wave input signal to output a triangular wave signal, a Schmitt trigger circuit that outputs a modulated wave output signal when a triangular wave signal and a signal that changes the operating point are supplied, and the operating point changes And a command generation circuit for sending a signal to the Schmitt trigger circuit.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the pulse phase modulation circuit of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of the embodiment.

The example of FIG. 1 is provided with a waveform shaping circuit 1 to which a pulse signal S4 is supplied through an input terminal A, and further,
A Schmitt trigger circuit 2 to which the triangular wave signal S5 generated by the waveform shaping circuit 1 is supplied is provided.

In this example, a command generation circuit 3 for supplying an output signal S6 that changes to a high (H) level or a low (L) level to the Schmitt trigger circuit 2 is provided. The modulated wave output signal S7 is output.

Next, the operation of this configuration will be described.

FIG. 2 shows the processed signal in the operation and its timing.

The pulse signal S4 is input to the waveform shaping circuit 1 through the input terminal A, and the triangular wave signal S5 in which the waveform of the pulse signal S4 is shaped is output.

The triangular wave signal S5 is input to the Schmitt trigger circuit 2. Here, when the output signal S6 from the command generation circuit 3 is at a low (L) level, the Schmitt trigger circuit 2 is turned on (ON) at the operating point V2 and turned off (OFF) at the operating point V1. The output waveform from the Schmitt trigger circuit 2 in this case is the pulse signal S7a in the modulated wave output signal S7 shown in FIG.

On the contrary, when the output signal S6 from the command generating circuit 3 is in the high (H) level state, the Schmitt trigger circuit 2 is turned on at the operating point V1 and turned off at the operating point V2. Becomes In this case, the output waveform from the Schmitt trigger circuit 2 is the pulse signal S7b in the modulated wave output signal S7 shown in FIG.

Therefore, the phase of the signal from the Schmitt trigger circuit 2 changes by the time shift Δt according to the high (H) level or low (L) level state of the output signal S6 from the command generating circuit 3. ..

In this way, the output waveform of the Schmitt trigger circuit 2 changes on the time axis by the change of the high (H) level or the low (L) level of the output signal S6 from the command generating circuit 3, and the phase modulation is performed. The applied modulated wave output signal S7 is output.

In this case, the time shift [Δt] corresponding to the pulse width of the pulse signal S4 is possible, and the modulated wave output signal S7 with deep modulation can be easily obtained.

By allocating a large number of baseband command pulses to the command generator 3, it is possible to control the equipment arranged on the pulse transmission path. Further, the output signal S6 of the command generator 3 may be replaced with a pulse signal to output a voice analog signal, and the voice signal or the like may be superimposed on the transmission pulse, which is applicable to a wide range of devices.

[0020]

As is apparent from the above description, the pulse phase modulation circuit of the present invention outputs the output voltage from the command generation circuit from the Schmitt trigger circuit according to the high (H) level or the low (L) level. Since the modulated wave output signal whose phase is time-shifted is output, the structure can be simplified, deep modulation can be obtained, and it can be applied to a wide range of devices.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a pulse phase modulation circuit of the present invention.

FIG. 2 is a timing chart showing a processed signal and its timing in the embodiment.

FIG. 3 is a block diagram showing a configuration of a conventional pulse phase modulation circuit.

FIG. 4 is a timing chart showing a processed signal and its timing in a conventional example.

[Explanation of symbols]

 1 waveform shaping circuit 2 Schmitt trigger circuit 3 command generation circuit S4 pulse signal S5 triangular wave signal S6 output signal S7 modulated wave output signal

Claims (1)

[Claims] 1. A pulse phase modulation circuit for transmitting a modulated wave output signal obtained by subjecting an input pulse signal to phase modulation, and a waveform shaping circuit for shaping a square wave input signal and outputting a triangular wave signal, A pulse phase that includes a Schmitt trigger circuit that is supplied with a triangular wave signal and a signal that changes the operating point and outputs the modulated wave output signal, and a command generation circuit that sends a signal that changes the operating point to the Schmitt trigger circuit. Modulation circuit.