A Wideband U-Slot Loaded Modified E-Shape Microstrip Patch Antenna and Frequency Agile Behavior by Employing Different Height Ground Plane and Ribbon Type Switches

─ This paper presents investigation results on a wideband U-slot loaded modified Eshape (USLMES) microstrip patch antenna with frequency agile behavior by employing different height ground plane and ribbon type copper switches. The USLMES patch is excited using the notch feed mechanism by a 50  coaxial probe outside the patch surface so that coaxial probe does not contribute significantly to the peak-crosspolarization levels. The parametric study results are presented for the wideband patch antenna design and important parameters have been noted. The proposed wideband patch antenna offers impedance (S11 = −10 dB) and 3dB gain bandwidths of at least 35% (3.09GHz to 4.42GHz) with stable radiation patterns and acceptable crosspolarization levels. The effect of ground plane height variation not only alters operating frequency, but also, Gain and impedance bandwidth. Frequency agility is also achieved from 3.02GHz to 4.95 GHz by turning different combination of switches ON/OFF. The prototype antennas were fabricated and experimentally verified for both wideband patch performance and frequency agility by implementing different ground plane heights. The simulated performance is in reasonable agreement with the measured results. Index Terms ─ Frequency agile behavior, ground plane height, ribbon type switches, USLMES microstrip patch, wideband antenna.

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