μ-watt MMIC TX/RX for Wireless Sensors Applications

The single stage ultra-low power high gain amplifier and a broadband low-loss, low power consumption transmit/receive (TX/RX) switch using a high performance 50nm gate-length metamorphic high electron-mobility transistor (mHEMT) and coplanar waveguide (CPW) transmission lines are presented in this letter. To realize both high gain performance and low power consumption, amplifier circuit element parameters were successfully optimized. The monolithic microwave integrated circuit (MMIC) single pole double throw (SPDT) switch utilizes a drain contact electrode sharing concept using one mHEMT. The gate width of the mHEMT was chosen for low loss, high isolation performance and circuit compactness. The single stage amplifier operates 24GHz band and shows typical gain of 6.5dB, return loss of -10dB and ±0.5dB bandwidth of 4GHz at dc power consumption of 0.9mW. The MMIC switch showed a broadband operation from DC to 35GHz with insertion loss of between 1.6~2.0dB, isolation of better than 27dB, and return loss of better than 12dB across the 35GHz bandwidth with dc power consumption of less than 6μW. The experimental results demonstrate the outstanding potential of 50nm gate-length metamorphic high electron-mobility transistor technology for ultra-low power application such as wireless sensor networks and ultra wideband systems.