Low-Cost Wide-Range Low-Current ConsumptionLinear HBT MMIC Power Amplifier for Portable2.4GHz WLAN Applications

A low-cost, low-current consumption 2.4- 2.5GHz MMIC power amplifier operating at 3.3V single supply has been developed for high data rate, wide-range portable WLAN applications. The MMIC utilizes a Fairchild-proprietary InGaP HBT process that enables the design of high power density and extremely linear circuits at frequencies exceeding 6GHz. The MMIC design has been constructed based on accurate HBT and passives models, focusing on performance optimization for low AM-AM and AM-PM distortion, low current consumption and minimal harmonic levels. For an OFDM modulated signal at 54Mbps data rate, the PA delivers +23.6 dBm linear output at a corresponding Error Vector Magnitude (EVM) of 4.4%(-27dB), while consuming an average packet current of less that 315mA. The MMIC is fully matched in a cost-effective 3x3mm QFN package, requiring only a small number of external passive components for efficient board layout and low total cost.