Design and integration of a high gain low NF CG-Folded cascode inductorless balun-LNA with loaded on-chip loop antenna

Abstract

In this paper, a novel inductorless CG-Folded Cascode balun-low noise amplifier (balun-LNA) for 2.4 GHz biomedical receivers is proposed and integrated to a reactively loaded on-chip loop antenna through capacitive on-chip matching network. On-chip antenna has small feed point resistance at 2.4 GHz, hence LNA can be designed for a lower input resistance than the conventional 50 Ω. The single input balun-LNA has balanced differential outputs such that for lower input impedance, the gain and noise figure (NF) are improved. Folded cascode topology improves voltage swing and linearity. Communication range is computed by designing a power amplifier (PA) and two-turn on-chip antenna at transmitter side. Post-layout simulations of LNA, matching network and PA designed in UMC 180 nm technology are carried out using Cadence Virtuoso. LNA has a simulated gain of 21.3 dB, NF of 1.6 dB and IIP3 −1 dB, matching network has S11 of –23 dB and PA has an output power 18dBm. On-chip transmit and receive antennas designed in Advanced Design System (ADS) have a gain of −20.6 dBi and −16.7 dBi. Compared to reported LNAs integrated with on-chip antennas below 12 GHz, the proposed design has low power consumption of 2.3 mW, higher FoM, small size of 0.65 mm2 and achieves computed inter-chip communication range of 2.3 m with the designed transmitter.