A 1.9 GHz single-chip RF front-end GaAs MMIC for personal communications

A single-chip RF front-end GaAs MMIC for the 1.9 GHz Japanese Personal Handy-phone System (PHS) is presented. RF circuits of a high power amplifier (HPA), a T/R switch (SW), two attenuators (ATTs), and a low-noise amplifier (LNA), are integrated with digital circuits of a negative voltage generator (NVG) for HPA and SW gate bias and a logic circuit to control the RF circuits. The HPA has an output power of 21.5 dBm and a high efficiency of 35% with sufficient linearity. The T/R SW combined with a receive step-ATT (0/20 dB) has loss of 1.2 dB (include the ATT loss). The LNA has a gain of 11 dB with noise figure of 1.7 dB, which is self-biased to a steep negative voltage generator during the receive mode. The IC needs only a single voltage (+3 V) DC power supply, and has a logic interface to control each mode for the TDMA/TDD scheme.