An Integrated 2.4 GHz Inductorless Power Amplifier and On-Chip Two Turn Folded Loop Antenna for biotelemetry applications

Biotelemetry applications require RF transceivers that have small size and less interference with the instruments used. On-chip antennas help to provide the miniaturization required for biomedical applications. Inductorless circuits further helps in size reduction and also reduces interference, not only with the instrument but also with on-chip antenna. The power amplifiers (PA) at transmitter end, consume large space due to the inductors present in it and also are the major cause of interference. In this paper, a novel differential inductorless power amplifier is designed at transmitter side of an RF front-end and integrated to an on-chip antenna at 2.4 GHz. Matching networks are avoided by conjugately matching the PA to on-chip antenna. The proposed inductorless power amplifier has a driver stage connected to a push-pull amplifier and is connected to a two turn folded loop antenna. The design is done in UMC 180-nm technology. The on-chip antenna is simulated in Advanced Design System (ADS) and it has a gain of -20.8 dBi. The post-layout simulations carried out in Cadence Virtuoso tool give an output power and power added efficiency (PAE) of PA of 14.5dBm and 31.2%. Compared to reported PAs, inductorless PA with on-chip antenna occupies very small area of 1.44mm
²
and has comparable PAE and antenna gain. The proposed design can be utilized for short range biotelemetry applications for a range of 1.2 m.