Flexible EBG Structure Antenna for ISM Band Applications

The electromagnetic bandgap (EBG) antenna, designed for ISM band applications, demonstrates a sophisticated interaction of structural and electrical parameters to optimize performance. This antenna is carefully engineered with an overall size of 70mm × 80mm to ensure efficient radiation characteristics and operation at 2.4 GHz and 5.8 GHz. The proposed antenna design uses an EBG ring structure, with an inner diameter of 3mm and an outer diameter of 6mm, FR-4 substrate, for featuring a dielectric constant of 3.8, and a precisely calculated feed-line width of 2.4mm × 20.7mm to ensure the optimal impedance matching, reducing signal losses. The 0.035mm thick copper conductor is used in reinforcing the conductivity, while the 1.6mm thick substrate is used for further supporting the structural integrity. Additionally, the 20mm EBG radius aids in controlling electromagnetic interference and improving radiation control. The proposed antenna design minimizes signal reflection, by maintaining the return loss (S11) below -10 dB, as well as ensuring a better transmission efficiency. A VSWR value between 1 and 2 further confirms superior impedance matching, preventing excessive power loss, while the gain, ranging from 3 to 6 dBi, highlights strong signal radiation capabilities.