Circular Waveguide Array for Radio Frequency Energy Harvesting

In this paper, a circular waveguide array for radio frequency (RF) energy harvesting application is presented. The proposed array which consists of 2×2 circular waveguide antennas working at the TM01 resonant mode is intended to operate at the frequency of 1800 MHz available for harvesting the energy of Global System for Mobile communication (GSM) signal. Through various combinations of dimension and geometry, characteristics of the array have been investigated to satisfy the expected specification. The characterization results shows that a single circular waveguide antenna with the radius of 70 mm and the height of 40 mm has the reflection coefficient (S11) value of –19.71 dB at the frequency of 1800 MHz. Meanwhile, the proposed array could reach the S11 value of –31.23 dB at the frequency of 1800 MHz.