Asymmetric Coplanar Strip Antennas
Compact antennas can be efficiently designed using an asymmetric coplanar strip (ACPS) feed. An ACPS can be easily converted into antennas by geometrical modifications. Asymmetric coplanar strip (ACPS) line is analogous to the coplanar wave guide feed except that the ACPS feed has a single lateral ground strip. ACPS has all the benefits of CPS along with compactness. Thus compact antennas can be effectively designed using asymmetric coplanar feed lines.
ACPS has many advantages like simple structure, ease of fabrication and require comparatively lesser area than conventional CPW/ CPS feed structure. Through geometrical modifications ACPS can be easily converted into an antenna. An analysis of radiation characteristics of an asymmetric coplanar strip antenna is discussed in this section. Reflection characteristics, radiation pattern and parameters which influence the pattern are discussed. Both simulation and experimental validation are also presented and discussed.
ACPS has many advantages like simple structure, ease of fabrication and require comparatively lesser area than conventional CPW/ CPS feed structure. Through geometrical modifications ACPS can be easily converted into an antenna. An analysis of radiation characteristics of an asymmetric coplanar strip antenna is discussed in this section. Reflection characteristics, radiation pattern and parameters which influence the pattern are discussed. Both simulation and experimental validation are also presented and discussed.
Pattern Reconfigurable Antennas
Reconfigurable antennas have received great attention of antenna researchers recently. Modern wireless communication systems demand for an intelligent antenna with different functionality and adjust their basic operating parameters like frequency of operation, polarization and radiation pattern according to requirement.
Reconfigurablity is the capacity of antenna to change its fundamental operating characteristics through electrical, mechanical, or other means. The reconfiguration is achieved through an intentional redistribution of the currents or the electromagnetic fields of the antenna’s effective aperture, resulting in reversible changes in the antenna impedance and/or radiation properties. Different methods are proposed to achieve reconfigurability like switching and material tuning.
Reconfigurablity is the capacity of antenna to change its fundamental operating characteristics through electrical, mechanical, or other means. The reconfiguration is achieved through an intentional redistribution of the currents or the electromagnetic fields of the antenna’s effective aperture, resulting in reversible changes in the antenna impedance and/or radiation properties. Different methods are proposed to achieve reconfigurability like switching and material tuning.
Dielectric Resonator Antenna
Dielectric resonators (DRs) emerged as a replacement to resonant metallic cavities and wave guides in microwave devices like filters, oscillators, and phase shifters. As for metallic cavities the resonant frequencies of a DR is determined by its dimensions and exhibits high Q-factors. But the main difference between the two cavities is that the wavelength in dielectric materials (non-magnetic) is reduced by a factor of one over square root of the dielectric constant, which is much higher than unity for most materials. Hence the resonator can be made smaller by choosing a high dielectric constant material. However, the reactive power stored in a DR during resonance is not strictly confined inside the resonator. The leakage fields from the resonator can be used for energy coupling, frequency tuning or radiation purpose.