Reconfigurable antenna using capacitive loading to Artificial Magnetic Conductor (AMC)

Abstract

A dual band Artificial Magnetic Conductor (AMC) with capacitive tuning of reflection phase at lower band frequency is proposed. The AMC operates at upper band of fixed frequency at 5.8 GHz while the lower band reconfigurable frequency is from 2.5 GHz up to 3.1 GHz. The simulated reconfigurable frequencies are 2.5, 2.62, and 3.10 GHz. The corresponding resonance structure for each band is circular patch and circular slotted ring with single capacitor per AMC unit cell. Subsequently, the AMC is incorporated with conventional UWB antenna. The effects of AMC capacitive tuning to UWB antenna performance are studied in terms of frequency reconfigurability, gain, and radiation patterns. Measurement is also carried out for the reflection coefficient and radiation patterns. Parametrical studies of the antenna such as the misalignment between the top and bottom substrate layers, air gap between the substrate layers, and capacitance tolerance of the capacitor to the reflection coefficients are also discussed.