Digital Dual-Channel K-Band Microwave Radiometer: Architecture and Measurement Results

This paper presents a digital dual-channel passive microwave radiometer operating in the K-band. The radiometer is based on commercial satellite communication low-noise block converters, which possess an analog bandwidth of 1 GHz. An external reference clock distribution is employed to ensure channel coherence. The digital design achieves a bandwidth of 614.4 MHz with a 14-bit ADC resolution. Up to 4 GB of complex valued dual-channel time domain data can be captured and stored. Power measurements can be performed using a field programmable gate array, ensuring real-time responsivity. Phase delay, correlation and sensitivity measurements were conducted with this setup and the results show good agreement with the expected theoretical outcomes.