JPS62109544U - - Google Patents

Description

【図面の簡単な説明】[Brief explanation of the drawing]

第１図は本考案の一実施例に係るＦＳＫ変調回
路の系統図、第２図は従来のＦＳＫ変調回路の系
統図である。 １：電圧制御発振回路、２：可変分周回路、３
：位相比較回路、４：低域ろ波回路、５：レベル
変換回路、６：加算回路、７：発振回路、８：デ
ータ入力、９：変調出力。 FIG. 1 is a system diagram of an FSK modulation circuit according to an embodiment of the present invention, and FIG. 2 is a system diagram of a conventional FSK modulation circuit. 1: Voltage controlled oscillation circuit, 2: Variable frequency divider circuit, 3
: Phase comparison circuit, 4: Low-pass filter circuit, 5: Level conversion circuit, 6: Addition circuit, 7: Oscillator circuit, 8: Data input, 9: Modulation output.

Claims (1)

【実用新案登録請求の範囲】[Scope of utility model registration request] 入力電圧によつて周波数の変化する電圧制御発
振回路と、電圧制御発振回路の出力を入力データ
のマークおよびスペースにより異なつた分周比で
分周する可変分周回路と、可変分周回路の出力と
基準信号との位相差を検出する位相比較回路と、
位相比較回路の出力を直流化する低域ろ波回路と
、入力データのマークおよびスペースのレベルを
変換するレベル変換回路と、低域ろ波回路の出力
と、レベル変換回路の出力とを加算し電圧制御発
振回路を制御する加算回路と、基準信号を発生さ
せる発振回路とを有することを特徴とするＦＳＫ
変調回路。 A voltage controlled oscillator circuit whose frequency changes depending on the input voltage, a variable frequency divider circuit which divides the output of the voltage controlled oscillator circuit with a frequency division ratio that differs depending on the mark and space of input data, and an output of the variable frequency divider circuit. a phase comparison circuit that detects a phase difference between the signal and the reference signal;
A low-pass filter circuit converts the output of the phase comparison circuit into DC, a level conversion circuit converts the mark and space levels of the input data, and the output of the low-pass filter circuit and the output of the level conversion circuit are added together. FSK characterized by having an addition circuit that controls a voltage controlled oscillation circuit and an oscillation circuit that generates a reference signal.
Modulation circuit.