| 摘要 |
PURPOSE:To improve the frequency stability and to simplify the circuit constitution for reduction of the cost with a radio reporting device, by obtaining a transmission frequency of an (n) multiple (n=2, 3, 4...) from the oscillation frequency of a crystal oscillation circuit serving as a source oscillator in a transmitter without using a frequency converting circuit. CONSTITUTION:A NAND circuit 10 which performs a gate action to transmit the output signal of a crystal oscillation circuit 2 to a switching circuit of the next stage is inserted into the next stage of a pulse data generating circuit 3 when the output pulse data signal of the circuit 3 is kept at H. Then a switching circuit 11 is added to control the ON/OFF states of the oscillating actions of an LC oscillation circuit 12 of the next stage by means of the output signal of the circuit 10. The circuit 12 oscillates at a frequency approximate to the transmission frequency. The oscillation frequency f0 of the circuit 12 is (n) times as much as the oscillation frequency fXT of the circuit 2. Thus the circuit constitution is simplified together with decrease of the number of parts and the cost reduction since no frequency converting circuit is used.
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