Output Power Limited Rugged GaN LNA MMIC

Rugged GaN HEMT low-noise amplifiers are in the receive path of T/R front ends are interesting for many applications. But the common concept of achieving ruggedness by reducing the gate DC current through a high resistance in the gate bias path might not be sufficient to control the output power under overdrive conditions. This paper focuses on the protection of the subsequent stages and suggests an AlGaN/GaN LNA MMIC circuit concept based on an output attenuator with the compact dimension of 4.35×2.15 mm ² . This provides an attenuation of up to 18 dB under input overdrive condition while gain, noise figure and output power in linear operation unaffected.