Case Study: Ericsson achieves 22.6% conversion efficiency and doubles usable power with Keysight ADS

Ericsson and Freiburg U. Design High Q Power Harvesting Circuit Using ADS

Ericsson (with Freiburg University) needed a way to harvest enough ambient RF power to run IoT sensor nodes — targeting a few hundred nanowatts at 1 V from a 24 MHz transmitter despite very low received power (around –30 dBm) — and required trustworthy simulations to predict nonlinear behavior before fabricating prototypes. They engaged Keysight and used Keysight ADS (the ADS Harmonic Balance simulator) to model the nonlinear matching and rectifier challenges.

Using Keysight ADS, Ericsson explored the design space and implemented an impedance transformation with a high‑Q quartz crystal resonator to boost voltage across the Schottky diode. The solution roughly doubled usable power and improved conversion efficiency from <10% to 22.6%, with close simulation-to-measurement correlation (including a ~200 Hz peak shift from diode nonlinearity), demonstrating that Keysight ADS enabled reliable pre‑fabrication optimization and successful prototype performance.

Ericsson

Xavier Le Polozec

Sr Technical Subject Expert