μ-watt MMIC TX/RX for wireless sensor applications

The single stage ultra-low power high gain amplifier and broadband low-loss, ultra-low power consumption transmitter/receiver (TX/RX) switch using a high performance 50 nm gate-length metamorphic high electron mobility transistor (mHEMT) is presented. The single stage ultra-low power high gain amplifier has been designed and fabricated by coplanar waveguide monolithic microwave integrated circuits process on a GaAs substrate. To realize both high gain performance and ultra low power consumption, circuit element parameters were successfully optimized. Also the single pole double throw (SPDT) monolithic switch utilizes a drain contact electrode sharing concept using a two-finger mHEMT. An optimal gate width of the mHEMT was chosen for low loss, high isolation performance and circuit compactness. The single stage amplifier operates 24 GHz band and shows typical gain of 6.5 dB, return loss of -10 dB and ±0.5 dB bandwidth of 4 GHz at dc power consumption of 0.9 mW. The switch shows a broadband operation from DC to 35 GHz with insertion loss between 1.6~2.0 dB, isolation better than 27 dB, and return loss better than 12 dB with dc power consumption of less than 6 μW. The experimental results demonstrate the outstanding potential of 50 nm gate-length metamorphic high electron-mobility transistor technology for ultra-low power application such as wireless sensor networks.