Design of frequency-detecting device based on rectenna

Abstract

A frequency-detecting device based on a rectenna is presented. The rectenna is mainly composed of a frequency reconfigurable microstrip antenna, a rectifying circuit, and a low pass filter. The operating frequency of the antenna can be tuned in the range between 2 and 2.8 GHz, and, in this frequency range, the rectifier can effectively perform the conversion from RF to DC. From the measured results of the broadband rectenna, the average conversion efficiency and output DC voltage are 67 % and 4 V, respectively. A frequency-detecting device is implemented by integrating the rectenna with a preprogrammable microprocessor, and its frequency resolution is about 20 MHz.