A 1.9GHZ-BAND SINGLE-CHIP GAAS T R-MMIC FRONT-END OPERATING WITH A SINGLE VOLTAGE SUPPLY OF 2V/

A single-chip GaAs Transmit/Receive (T/R)-MMIC front-end has been deve loped which is applicable to 1.9-GHz personal communication terminals such as digital cordless phones. This chip is fabricated using a plana r self-aligned gate FET useful for low-cost and high-volume production . The chip integrates RF front-end analog circuits - a power amplifier , a T/R-switch, and a low-noise amplifier. Additionally integrated are a newly developed voltage-doubler negative-voltage generator (VDNVG) and a control logic circuit to control transmit and receive functions, enabling both a single-voltage operation and an enhanced power handli ng capability of the switch, even under a single low-voltage supply co ndition of 2 V. The power amplifier incorporated onto the chip is capa ble of delivering a 21 dBm output power at a 39% efficiency, and a 30 dB associated gain with a 2 V single power supply in the transmit mode . The gain and efficiency are higher than those of the previously repo rted amplifier operating with a 2 V single power supply. The VDNVG pro duces a step-up voltage of 2.9 V as well as a negative voltage of -1.8 V from a 2 V power supply, operating with a charge time of less than 0.25 mu s. The control logic circuit on the chip has a newly designed interface circuit utilizing the step-up voltage and negative voltage, thereby enabling the chip to handle high power outputs over 24 dBm wit h a low operating voltage of 2 V. In the receive mode, a 1.7 dB noise figure and a 0.6 dB insertion loss are achieved with a current dissipa tion of 3.6 mA. The developed MMIC, which is the first reported 2 V si ngle-voltage operation T/R-MMIC front-end, is expected to contribute t o the size and weight reductions in personal communication terminals.