Silicon germanium and silicon bipolar RF circuits for 2.7 V single chip radio transceiver integration

A 2.7 V radio transceiver for 900/1900 MHz was realized in a 50 GHz f/sub T/ silicon germanium technology. The single chip transceiver contains the RX mixers, TX mixers, quadrature generator, amplifiers, quadrature phase shifters, the VCO and the 64/65 prescaler. Most of the circuits were realized in a 20 GHz bipolar technology before. In the 50 GHz SiGe technology the noise figure was improved by 2 dB and the additional bandwidth allows for true dual mode operation with identical gain curves for both 900 and 1900 MHz operation. The transceiver drives an external power amplifier and needs at least 15 dB external gain of a low noise amplifier in front of RX mixers. An integrated LNA is optional and feasible in the 50 GHz SiGe technology with low R/sub b/ enabling a 2 dB noise figure.