RF architecture for cellular dual-band telephones

摘要: A dual band RF architecture including a GSM quadrature modulator for modulating an intermediate frequency (IF) wherein the of modulated IF signal is changed such that one used and another DCS 1800 band. An filter with pass covers both connected to output outputs transmit phase lock loop, which translates from either radio or signal, depending on local oscillator (LO). The receiver employs down converter provides converted selected by high side injection low centered at 400 MHz designed demodulation circuitry. single loop circuit supply, output, LO converting receive band, as well loop.