A 4–22 GHz Ultra-Wideband Low-Noise Amplifier With 0.8–1.5 dB NF and 28–31 dB Gain Enhanced by the Negative Load Impedance

This paper presents an ultra-wideband 4–22 GHz three-stage low noise amplifier (LNA) that utilizes negative load impedance (NLI) and frequency compensation (FC) in the inter-stage matching network (ISMN). The NLI can effectively boost high-frequency (HF) gain and extend HF bandwidth (BW) and also suppress latter-stages noise, which further improves the overall design trade-off among gain, BW, and noise figure (NF). The FC expands low-frequency (LF) BW and improves gain flatness. Additionally, this paper presents the triple-resonant S22 design methodology that can effectively extend the output return loss BW of a common-source transistor with inductive degeneration. Fabricated in a 0.15- <tex-math notation="LaTeX">μ </tex-math> m E-mode GaAs pseudomorphic high electron-mobility transistor (pHEMT) process, the LNA achieves a remarkable 0.8–1.5 dB NF, <-9 dB input return loss, <-10 dB output return loss, 11.1–15 dBm OP1dB, 23–27.5 dBm OIP3 and 28–31 dB gain across the 4–22 GHz while drawing 50 mA from a 3.3 V supply.