| 摘要 |
PROBLEM TO BE SOLVED: To make a reception circuit requesting a high gain into an IC. SOLUTION: A signal line from a band-pass filter 112 for a CDMA(code division multiple access) mode and the band-pass filter 113 for an FM mode to amplifiers 1 and 2, a variable amplifier circuit 114, an LPF 4a and a QPSK modulation circuit 115 and the signal line from a 1/2 frequency divider 8a to the QPSK demodulation circuit 115 are balanced and connected and also, the amplifiers 1 and 2, the variable amplifier circuit 114, the LPF 4a, the QPSK demodulation circuit 115, a frequency divider 9 for a PLL and an oscillator 10a are all constituted in a balanced type and made into the IC. The oscillator 10a outputs the oscillation signals of a frequency which is the double of signals demodulated by the QPSK demodulation circuit 115 and the 1/2 frequency divider 8a frequency-divides them to 1/2 and impresses them to the QPSK demodulation circuit 115. |
