Design of a Low-Noise and Low-Profile K-Band Downconverter Based on LTCC Technology

This paper presents a miniaturised, lightweight K-band downconverter based on LTCC (low-temperature co-fired ceramic) technology with a noise figure (NF) of 2.1 dB. The downconverter integrates an LTCC multilayer substrate, a metal cover plate featuring fuzz button connectors, and a metallic shell. Multilayer LTCC technology enables the high-density integration and miniaturisation of components such as power dividers, striplines, and vertical transitions for the RF plane. Fuzz button connectors are employed to achieve low-loss, compact integration, effectively reducing the downconverter's noise figure. Experimental results demonstrate: port return loss better than 12 dB, single-channel gain exceeding 56.9 dB, and a noise figure below 2.1 dB. This design is compatible with low-profile satellite communication phased arrays utilising digital subarray architectures.