| 摘要 |
PURPOSE:To attain easy circuit forming by constituting a titled transmitter so that a spectrum inverting circuit and a frequency modulator are connected in cascade to avoid the use of an analog emphasis filter. CONSTITUTION:A signal limiting its frequency band to [f1,f2] is inputted to an input terminal T3, the spectrum is inverted by an analog spectrum inverting circuit (ANINV) 9 and a transmission wave modulated by an FM modulator 10 is irradiated from a transmission antenna 11. A PM modulator (PMT) is realized equivalently by differentiating the input signal and applying an FM modulation. Thus, an analog emphasis filter (AEMP) of a conventional system is replaced with an integration filter and a PM modulator is replaced with the circuit where the differentiation filter and the FM modulator are connected in cascade, then the circuit connecting the AEMP and the PMT in cascade is replaced with the FM modulator. |
