A Mechanism to Enhance Antenna Performance using Notch and Defected Ground Structure

Objectives: This paper has proposed the mechanism to enhance antenna performance. The antennas are designed to be applied in communication devices. Methods/Statistical analysis: The proposed antenna characteristics had been analyzed by means of Finite Difference Time Domain (FDTD) method and had been fabricated by photolithography method on FR-4 Printed Circuit Board (PCB). Both simulation and measurement result show that the proposed antenna had three resonant frequencies 2.45GHz, 3.75GHz, and 5GHz with Return Loss (RL) are -40dB, -25dB and -20dB, respectively. Findings: All four antenna designs show characteristics of the mechanism. The antenna 1 is the reference design, after the first mechanism of antenna 2 which is to give the notch line on the both side of the antenna 2. The improvement of this first mechanism shows the RL. The second mechanism is rotated 60 degrees of the resonator of the antenna 2, show that the surface current adds more significant and give better RL. The third mechanism adds the defected ground structure on the both ground plane, the result gives the antenna a better RL from all the mechanism. The mechanism steps that applied on proposed antenna give enhance on such as RL, bandwidth, and radiation pattern. Application/Improvements: The radiation patterns show the omni direction in frequency 2.45 GHz and bi-direction in both 3.75 and 5 GHz with HPBW around 80 degrees. The proposed antenna was suitable for communication devices.