A 3.0 V front-end GaAs receiver MMIC for the CDMA/AMPS dual mode cellular phones

The front-end GaAs receiver MMIC has been developed using ETRI GaAs MMIC fo undry for CDMA/AMPS dual mode cellular phones. It consists of gain controll able LNA, double balanced resistive ring mixer, CDMA/AMPS mode selective IF amplifier, and LO buffered amplifier. For successful communication with hi gh quality in any weak signal areas, we have designed to ensure high linear ity and low noise figure characteristics using the negative feedback gain c ontrol technique of LNA. At 3.0 V supply voltage and frequency range of 869 similar to 894 MHz, developed Rx MMIC showed a low NF of 2.0 dB and high I IP3 of -7.5 dBm, gain of 25/20 dB at CDMA/AMPS mode. We can improve IIP3 by 7dB using gain control of LNA and achieved low current consumption of 39 m A/34 mA in the CDMA/AMPS mode. It satisfied the IS-95 specification which i s the standard for CDMA systems and showed excellent talk quality in the co mmercial dual mode cellular phones.