Multidirectional Receiving System for RF to dc Conversion Signal

In this article, we present an original solution for radio frequency (RF) to dc conversion with multiple antennas. The presented device operates at 2.45 GHz. It combines passive parasitic element antennas (PEAs) and RF to dc converters. The proposed device collects the RF energy with six independent antennas and realizes the conversion and summation of the dc voltages. The objective is to perform uniform coverage of a room with a gain superior to a single and omnidirectional antenna. The typical application can be energy harvesting or detection for the command unit in home automation. This last application is our goal, and interest in the solution has been demonstrated through an application that aims at reducing standby mode consumption of electronic devices. The article focuses on the critical points to realize an efficient summation. The whole system has been designed and manufactured to work in rooms from 3 m to 15 m wide. The measured performances have been validated. © 1990-2011 IEEE.