A SINGLE-CHIP GAAS RF TRANSCEIVER FOR 1.9-GHZ DIGITAL MOBILE COMMUNICATION-SYSTEMS

A 1,9-GHz single-chip GaAs RF transceiver has been successfully develo ped using a planar self-aligned gate FET suitable for low-cost and hig h-volume production, This IC includes a negative voltage generator for 3-V single voltage operation and a control logic circuit to control t ransmit and receive functions, together with RF front-end analog circu its - a power amplifier, an SPDT switch, two attenuators for transmit and receive modes, and a low-noise amplifier, The IC can deliver 22-dB m output power at 30% efficiency with 3-V single power supply. The new negative voltage generator operates with charge time of less than 200 ns, producing a low level of spurious outputs below -70 dBc through t he power amplifier. The generator also suppresses gate-bias voltage de viations to within 0.05 V even when gate current of -144 mu A flaws. T he IC incorporates a new interface circuit between the logic circuit a nd the switch which enables it to handle power out-puts over 24 dBm wi th only an operating voltage of 3 V, This transceiver will be expected to enable size reductions in telephones for I,9-GHz digital mobile co mmunication systems.