A Novel Quad-Polarization Agile Patch Antenna
Résumé
In this communication we present a novel polarization-agile microstrip antenna design. To dynamically change the polarization state, the radiating patch is fed by a tunable quasi-lumped coupler. The whole structure can be dynamically altered to radiate electromagnetic waves with vertical linear, horizontal linear, right-handed circular or left-handed circular polarization simply by changing the operating mode of the quasi-lumped coupler. Due to its topology the coupler is simply reconfigured by switching the bias of two varactor diodes via a very simple DC bias circuitry: no additional capacitors or inductors are required. A prototype is fabricated with a 0.762-mm-thick upper layer substrate for the radiating element and a 0.130-mm-thick layer substrate for the coupler circuit, both with the same dielectric material relative permittivity of 2.22. The simulated and measured scattering parameters, the axial ratio in circular radiation-mode and the cross-polarization level in linear mode, the gain and the radiation patterns are presented. The agile polarization capabilities of this new antenna, as demonstrated in this communication, underscore its suitability for modern wireless communications in a multi-path propagation environment.
Mots clés
measured scattering parameters
electromagnetic wave polarisation
antenna radiation patterns
quad-polarization agile patch antenna
microstrip antenna design
tunable quasi-lumped coupler
electromagnetic waves
circular polarization
radiation patterns
Patch antennas
Electromagnetic wave polarization
Coupling circuits
Microstrip antennas
Dielectric substrates
Tunable circuits and devices
Electromagnetic scattering
Electromagnetic coupling
Circuit topology
Switching circuits
Active antennas
hybrid coupler
linear polarization
reconfigurable antennas