A broadband GaAs pHEMT low noise driving amplifier with current reuse and self-biasing technique

Abstract

A K/Ka-band two-stage low noise driving amplifier using a 0.15 μm GaAs pHEMT for low noise technology is designed and fabricated. In order to achieve broadband driving capability with low power consumption, current reuse technique is adopted to feed both transistors with the same DC power supply, which theoretically cuts the total current consumption in half. In addition, self-biasing technique is utilized to minimize both external power supply pads and chip footprint, which reduces the number of supply pads to a minimum of two (1 power pad and 1 ground pad). The circuit topology analysis and design procedures are also presented with an emphasis on noise figure and P1dB optimization. The low noise driving amplifier demonstrates a − 3 dB bandwidth of wider than 11 GHz, a power gain of 17 dB, an in-band mean noise figure of 2.2 dB and an in-band mean output P1dB of 6 dBm. The DC power consumption is 9.1 mA@3.3 V power supply. The chip size is 1 mm × 1.5 mm with only 1 external DC feed pad (3.3 V) and 1 ground pad (0 V). With the performance comparable to typical two-stage dual-bias low noise driving amplifier counterparts, the proposed MMIC is more attractive to chip/system users in volume-limited and power-contrained applications.