RF Power Amplifiers Simplify GSM/PCS Cellular Designs

A pair of RF power amplifiers has a negative voltage generator integrated on the chip, enabling cell-phone designers to gain the output power and efficiency of GaAs amplifiers without the need for a separate negative supply. The MRFIC0919 and MRFIC1819 GaAs integrated power amplifiers use an RF rectification method to generate the negative voltage, which eliminates spurious outputs often seen in designs that use a separate negative supply. They also offer a gate-drain switching function that connects the negative voltage to the gate before the positive supply is connected to the drain. This protects the amplifiers from any overcurrent situation.The 0919 and 1819 RF power amplifiers operate at 900 MHz or 1.8 to 1.9 GHz, respectively. The 0919 is a 3.6V device capable of peak output power of 3W and is intended for 2W GSM900 phones. The 1819 delivers peak output of 2W and is for 1W DCS1800 and PCS1900 phones.