Multi-Octave and Frequency-Agile LNAs Covering S-C Band Using 0.25 µm GaN Technology

This paper reports the design and measured results of a multi-octave low noise amplifier (LNA) and a frequency-agile LNA utilizing a 0.25 μm gallium nitride (GaN) integrated circuit process technology for multi-band receiver applications. The demonstrated broadband LNA covers an instantaneous bandwidth from S- to C-bands (2.2-7.0 GHz), and the frequency-agile LNA cumulatively spans across 3 distinct bands (2.2-2.4 GHz, 4.4-5.0 GHz, and 5.0-6.7 GHz). The measured noise figure (NF), output third order intercept (OIP3), and peak gain of the wideband LNA is 1.0-1.7 dB, 19.0-26.0 dBm, and 10.6 dB with a gain flatness of +/- 0.35 dB respectively at a nominal power consumption of 480 mW across the band. At the same nominal power consumption, the frequency-agile LNA demonstrated a NF of 1.3, 1.4, and 1.2 dB; OIP3 of 23, 27, and 31 dBm; and gain of 13.6, 10.6, and 10.8 dB at 2.3 GHz, 4.7 GHz, and 5.8 GHz, respectively. The performance of the frequency-agile LNA is comparable to that of optimized narrowband LNAs at S- and C-bands. Compared to the multi-octave LNA, the frequency-agile LNA demonstrated better performance in gain and OIP3 at the frequencies of interest.