High-speed pHEMT-based low noise amplifier for 2.4-GHz wireless communication

In the era of rapidly expanding wireless technologies, the push for larger spectrum efficiency and better signal integrity has intensified the need for high-efficient and low-noise amplifiers (LNAs). A two-stage LNA based on the GaAs/InGaAs pseudomorphic high electron mobility transistor (pHEMT) with a relatively large gate length of 2 μm is designed for high-performance 2.4-GHz wireless communication. The I - V characteristic and two-port high-frequency S -parameter of the transistor are measured by on-wafer probing techniques. The results indicate that a discrete transistor with a gate size of can provide a maximum trans-conductance of 16 mS, corresponding to a maximum current-gain cut-off frequency and maximum oscillation frequency of 7 GHz and 8 GHz, respectively, at the 1-V drain-source voltage. With the impedance matching networks based transmission line technique, an extended integrated layout structure is designed and simulated by using the momentum simulation tool embedded in Advanced Design System (ADS), targeting to alleviate the trade-off between noise figure (NF) and gain of the circuit. The findings show that the transistor based on the GaAs/InGaAs technology is capable of delivering high performance with power consumption low to 16 mW, where the maximum simulated gain and minimum NF of 21.5 dB and 2.4 dB are achieved, respectively. In terms of linearity, the proposed LNA provides terrific output 1-dB compression and output third-order intercept point values of –3 dBm and 10 dBm, respectively. The bandwidth of 0.12 GHz and figure-of-merit (FOM) of 12 are obtained, which are comparable to that of the previously reported LNAs based on pHEMT. Such a device may benefit to accelerate the development of more robust and power-efficient front-end modules in modern wireless systems, especially for advancing performance-driven applications.