Concurrent Dual-band Low Noise Amplifier Using Split-Type Filtering Networks

This paper presents the design and experimental validation of a concurrent dual-band low noise amplifier (DBLNA) with co-designed pre-described filtering selectivity. The proposed DB-LNA concept is based on a single transistor configuration and a dual-band bandpass filter (BPF) that is complex-matched and directly attached to a low noise BJT transistor. In this manner, the need for additional output matching networks or cascaded filtering is eliminated, improving the overall performance and size. Miniaturization is further enhanced using a split-type BPF architecture that is smaller than transversal resonator arrays or filter-banks using in-line coupled resonators. The DB-LNA was validated at S-band through the design, manufacturing, and testing of a prototype that has two bands centered at 2.48 GHz and 3.36 GHz, with fractional bandwidths (FBWs) of 13% and 15%, gain of 18.7 dB and 15.5 dB, and noise figure (NF) of 0.82 dB and 1.04 dB respectively.