| 摘要 |
PROBLEM TO BE SOLVED: To transmit/receive a signal while arbitrarily controlling a frequency by feeding back one part of an input signal through a feedback path, reproduc ing it, switching a capacitor in a feedback circuit and generating a clock for switching a switching means based on the output of a super reproducing means. SOLUTION: The input signal is modulated by an adder 1 and after the modulated signal is amplified, it is delayed just for time specified based on the output clock of a PLL circuit 22 so as to deviate a phase just forπthrough a switched capacitor filter(SCF) 31. The adder 1 repeats operation adding the modulated signal to the input signal from an amplifier 32 and when there is the modulated signal, an amplifier 2 outputs a high-level carrier as a super reproducing signal output. The switch is changed over synchronously with the output clock of the PLL circuit 22. The output terminal of a computing element is fed back through a capacitor having capacitance C1 to an inverted input terminal. The signal is outputted from a VCO 11 while appropriately switching the switching speed of the switch.
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