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

ABSTRACT 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.