Design of a Ring-Focus Antenna for Multi-Frequency Microwave Radiometer Applications

Meteorological satellites predominantly operate at frequencies of 10.65 GHz and above. Advances in comprehensive meteorological monitoring necessitate observations of parameters such as sea surface temperature and soil moisture, which benefit from measurements at lower frequencies. This research presents the design of a ring-focus antenna for a multi-frequency microwave radiometer operating across L-, C-, X-, K-, and Ka-bands. Subsequently, the radiation characteristics of the dense feed array for each frequency band were simulated, and the antenna beam pattern was analyzed using a ring-focal reflector surface. This design extends the operational range to encompass the lower L-band frequencies currently unaddressed by mainstream radiometers, thereby fulfilling the requirements for comprehensive meteorological element detection.