| dc.description.abstract | The development and analysis of several designs of self-harmonic suppression rectenna for the wireless power harvesting system are presented. The purpose of self-harmonic suppression rectenna is to eliminate the using of a harmonic filter circuit in filtering the harmonic radiation and electromagnetic interference (EMI) in rectenna system. The motivation for this work has been inspired by the need for compact size, low cost, high efficient rectenna system and also very important is the design structure is simple in order
to reduce the error during the fabrication process. In the response to these challenging
demands, four designs of self-harmonic suppression microstrip patch antenna have been
simulated, fabricated, measured and analysed. Two designs can be classified in linear
polarization while the other two designs exhibit the circular polarization properties. The
technique to suppress the harmonics which have been introduced are the slits, slot and
notch at the patch structure and an open stub at the microstrip feeding line. Also, a defected
ground structure technique is applied to reduce the size of the patch antenna. The
perturbation technique has been introduced to the basic rectangular and circular shapes
microstrip patch antenna to produce circular polarization property. As a result, the
rectangular shape becomes a nearly-square shape, while the circular shape becomes an
elliptical-shape. Subsequently, a dual polarization of circularly polarized property is also
proposed. To obtain high output voltage, a self-harmonic suppression microstrip patch
array antenna is developed. For conversion of RF-to-DC signal, a few designs of rectifier
circuits are proposed. The proposed rectifier matching networks are capable to provide a
good impedance matching with a wide range of incident power. All the simulation has been
done by using CST Microwave Simulator and Advanced Design System (ADS). To
validate the theory and simulation, the prototypes of all designs have been fabricated and
measured. For the comparison, the prototype of the conventional linear polarization (LP)
rectangular and circular microstrip patch antenna are also have been designed and
fabricated. The measurements show an excellent result and is in line with the simulated
result. The measured of the return loss of the antennas show it resonate at the fundamental
frequency, while at the harmonic frequencies, the magnitude of the return loss were
suppressed successfully. In the wireless power harvesting system experimental work, it is
seen that a significant improvement of the output power is achieved compared to the
reference antenna without harmonic suppression. All design has been realized by using a
standard PCB process. Therefore, the fabrication technique is very simple with a very
cheap cost, thus it can be conveniently mass-produced. | en_US |
