Decoding device for identifying signal

Abstract

Abstract PURPOSE:To manage a band-pass filter only by one kind of band-pass filter, by using the identifying signal generation circuit of a transmission circuit at the time of reception. CONSTITUTION:A mixer circuit 11 is connected to the rear stage of a low-pass filter 8, and a frequency variable type oscillator 12 is connected to the mixer circuit 11. As the oscillator 12, the identifying signal generation circuit of the transmission circuit 13 is used. At time of decoding, a frequency by a constant value higher (or lower) than that of an identifying signal fo is oscillated in the oscillator 12, and transmission to the outside is inhibited by an antenna switch, etc. By operating the oscillator 12, since the mixer circuit 11 mixes the oscillation frequency of the oscillator 12, and a receiving frequency, and generates the frequency of a difference (or sum) between them, it is supplied to a band-pass filter 9. Therefore, It is possible to identify all of the identifying signals by the band-pass filter of one kind of center frequency as the band-pass filter 9.

Inventors

• 👤 Shoji Fujino
• 👤 昭二 藤野

Bibliographic Details