| 摘要 |
PURPOSE: To prevent the occurrence of interference when an SS type radio equipment is applied to a weak radio wave type half-duplex radio equipment. CONSTITUTION: A transmitting part (modulating part) includes an input terminal 1, an information modulation part 2, a multiplying circuit 3, a double balance mixer 4, an RF amplifier 8 and an information-modulated wave subjected to high frequency conversion by the circuit 3 is subjected to spread modulation by the mixer 4. A receiving part (demodulating part) includes an RF amplifier 12 for inputting a received signal inputted through an antenna 11, a BPF 10 and a switch 9, a double balance mixer 13, an RF stage BPF 14, a mixer 15, a local oscillator 16, an IF stage BPF 17, an IF amplifier 18, an information demodulation circuit 19, frequency dividers 20, 21, a frequency conversion circuit 22, an output terminal 23. A received SS modulated wave from the amplifier 12 is subjected to inverse-spread demodulation by the mixer 13. |
