What is Asymmetric Ground Plane

The radio frequency (RF) energy harvesting is found as an attractive alternative to existing energy resources. This chapter deals with the design and performance evaluation of different rectifying antenna circuits for RF energy harvesting. The rectifying antenna i.e. rectenna consists of an antenna to grab the RF energy and rectifier to convert the RF energy to DC power. Different circularly polarized microstrip antennas e.g. shorted square ring slot antenna and crossed monopole antenna with step ground plane are studied. The antennas are combined with voltage doubler circuits with various stages and bridge rectifier. The electromagnetic simulator CST Microwave Studio is used to design and optimization of antenna structures. The rectifier circuits are designed using SPICE software. Later the prototype of the antennas and rectifiers are fabricated and tested in the laboratory environment. The detailed study on the performance of the rectenna circuits are evaluated in terms of conversion efficiency.