A battery-less WiFi-BER modulated data transmitter with ambient radio-wave energy harvesting

Abstract

We have developed a new battery-less bit-error-rate modulated (BERM) data transmission technology that can directly send data to a WiFi-equipped PC without affecting WiFi communication on the PC. BER modulated data at a 5.5kbps data-rate has been successfully transmitted at a 30-cm distance between a test chip and measurement equipment. The chip also has an energy harvesting function with an active ambient-radio power searching (AAPS) architecture that enhances harvest efficiency. Harvested power was 30.8μW at a 30cm-distance from a 250mW (24dBm) emission WiFi access point (AP), and the operational frequency had a very wide range, 1.9 to 2.4GHz. © 2011 JSAP (Japan Society of Applied Physi.