Design of ultra low noise & high gain low noise amplifier using capacitive shunt feedback for UHF wind profiling radar application

This paper presents a single stage cascode pseudomorphic high electron mobility transistor (pHEMT) low noise amplifier (LNA) using a shunt feedback capacitor at 915 MHz for UHF wind profiling radar application. Capacitive shunt feedback is a solution for simultaneous noise and power match. The source degenerated inductance topology is used with the cascode transistor capacitive shunt feedback to improve stability, input and output return losses, and noise figure. Using cascode transistor capacitive shunt feedback excellent noise figure and gain (S
2
i) are obtained. Low cost and low loss dielectric substrate RT/duroid RO4003C is used in the LNA design. Simulated results of LNA show that overall gain of 25.311 dB and noise figure (NF) of 0.258 dB. Input and output return losses are less than −15 dB. To characterize linearity, third order input intercept point and third order output intercept is simulated as 50.62 ilBm, 69.60 dBm respectively.