Enhanced Bandwidth for Slotted Patch Antenna with Defective Ground Structure

In a communication system, the bandwidth is one of the most important and scarce resources, extending the same is limited due to finances, supply and technology, also if the antenna or transmission lines are not perfectly matched then there will be return loss and loss of signal power. Here we demonstrate a method to enhance both the parameters viz. the return loss and bandwidth of microstrip patch antenna (MPA). To further enhance the antenna performance, defective ground structure (DGS) is used. As microstrip patch antennas have narrow bandwidth, the slots are used to enhance bandwidth. The operating frequency is chosen as 2.4 GHz ISM band for inset-fed MPA. The proposed DGS offers stop-band at 2.4 GHz. Also, the DGS can change the wave properties by providing band stop filter or band-pass filter. Its (DGS) main principle is to distribute shield current in the ground plane, which affects input impedance and hence, the current flow of antenna and as a consequence the bandwidth gets enhanced. Return loss improves with due stop bands DGS as stop-band of MPA and DGS. Among several methods to improve the return loss, we use a two rectangular shaped DGS. The position of DGS has been optimized using trial and error method. HFSS has been used for simulation and analysis. The proposed design of MPA with DGS and multiple rectangular slots has achieved better results as the bandwidth has enhanced from 58 MHz to 223MHz, also VSWR lowered from 1.7584 to 1.2236, the S11 has enhanced from -11.2154 dB to -19.951 dB, the gain also increased from 0.37478 dB to 3.5883dB. Bandwidth is enhanced and the return loss is also reduced.