Collecting accurate Earth surface data is crucial for climatology and weather modelling, especially in cold regions. However, recent missions have revealed Radio Frequency Interference (RFI) challenges within the protected L-Band, necessitating robust payloads capable of operating amidst strong RFIs. This study proposes an L-band packaged low-noise amplifier (LNA) designed to maintain performance across the 0.4 GHz−2 GHz band, using a GaN-on-SiC HEMT process. The LNA design employs a cascode architecture and achieves a small-signal gain of 20.7 ± 0.18 dB with a worst-case noise figure of 0.9 dB. To enhance survivability, an integrated limiter is added ahead of the LNA, forming a compact chain with promising performance for radiometric measurements in challenging RF environments. Chip size is 3 × 2 mm2.