This work presents the optimization of antenna captured low power radio
frequency (RF) to direct current (DC) power converters using Schottky diodes for
powering remote wireless sensors. Linearized models using scattering parameters show
that an antenna and a matched diode rectifier can be described as a form of coupled
resonator with different individual resonator properties. The analytical models show that
the maximum voltage gain of the coupled resonators is mainly related to the antenna, diode
and load (remote sensor) resistances at matched conditions or resonance. The analytical
models were verified with experimental results. Different passive wireless RF power
harvesters offering high selectivity, broadband response and high voltage sensitivity are
presented. Measured results show that with an optimal resistance of antenna and diode, it is
possible to achieve high RF to DC voltage sensitivity of 0.5 V and efficiency of 20% at
−30 dBm antenna input power. Additionally, a wireless harvester (rectenna) is built and
tested for receiving range performance.