| 摘要 |
PURPOSE:To receive a two-frequency signal with a receiver for 1-frequency reception, by converting the 1st broadcasting wave for a plurality of areas and the 2nd broadcasting wave for a specific area in the areas into the same frequency signal. CONSTITUTION:In a wire broadcasting using carrier waves, a signal of frequency fA of a broadcast 1 of (a) for all areas passes through a BPF 21 of a converter 2, and is branched at a branching filter 23 and led to synthesizers 24 and 25. To the synthesizer 24, a signal of frequency fB of a broadcast 200 of (b) for a specific area A applied via branching filters 20 and 26 and the signal of the fA or fB is applied to a frequency converter 22, where the frequencies are converted as fC=f0-fA=fB-f0 by using a local frequency f0 and the signals of the fA and fC are synthesized at a synthesizer 25 and the result is transmitted to the area A via wires. In the area A, the signal of fC is branched at a branching filter 201 and the signal is received at a receiver receiving the frequency fC. The signal of fA is broadcast to other areas through a BPF31 of a converter 3. Thus, the broadcast of fA and fB can be received in the specific area A at the receiver of the same frequency fC. |
