High linearity 40 watt, 28V InGaP/GaAs HBT

This paper reports on a 40W high linearity InGaP/ GaAs 28V HBT. It uses a high breakdown voltage, high ruggedness HBT process developed by WJ. The device employs a dynamic bias circuit to improve ACLR under WCDMA modulation conditions. The P-1dB of the device reaches 46dBm (40W), with a gain around 14.5dB. With WCDMA one carrier modulation (PAR=8.5dBc), the device achieves an ACLR of −50dBC and an efficiency of 19.5% at an output power of 37.5dBm (5.6W) at 920–960MHz frequency band. Without the help of a DPD, the performance of this device will make it an excellent choice for base station and repeater applications.