A CPW-fed defected substrate microstrip antenna is proposed. The proposed antenna shows wideband applications by choosing suitable defected crown shaped substrate. Defected substrate also reduces the size of an antenna. The radiating patch of proposed antenna is taken in the form of extended U-shape. The space around the radiator is utilized by extending the ground plane on both sides of radiator. Simulation of proposed antenna is done on Ansoft’s High Frequency Structure Simulator (HFSS v. 14). Measured results are in good agreement with simulated results. The prototype is taken with dimensions 36 mm × 42 mm × 1.6 mm that achieves good return loss, constant group delay, and good radiation characteristics within the entire operating band from 4.5 to 13.5 GHz (9.0 GHz) with 100% impedance bandwidth at 9.0 GHz centre frequency. Thus, the proposed antenna is applicable for C and X band applications.

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A coplanar waveguide- (CPW-) fed compact wideband defected structure shaped microstrip antenna is proposed for wireless applications. Defected structure is produced by cutting theUshape antenna in the form of two-sided T shape. The proposed antenna consists of two-sidedTshape strip as compared to usual monopole patch antenna for minimizing the height of the antenna. The large space around the radiator is fully utilized as the ground is on the same plane as of radiator. Microstrip line feed is used to excite the proposed antenna placed on an FR4 substrate (dielectric constantεr=4.4). The antenna is practically fabricated and simulated. Simulated results of the proposed antenna have been obtained by using Ansoft High-Frequency Structure Simulator (HFSS) software. These results are compared with measured results by using network analyzer. Measured result shows good agreement with the simulated results. It is observed that the proposed antenna shows a wideband from 2.96 GHz to 7.95 GHz with three bands atf1=3.23 GHz,f2=4.93 GHz, andf3=7.04 GHz.

A CPW – Fed octagonal ring shaped antenna for wideband operation is presented. The radiating patch of proposed octagonal ring antenna consists of symmetrical slot in place of conventional annular ring microstrip antenna. The ground plane consists of two rectangular slots, while the radiator and the ground plane are on same plane that utilizes the space available around the radiator. The proposed antenna is simulated through Ansoft’s High Frequency Structure Simulator (HFSS). Measured result shows balanced agreement with the simulated results. The prototype is taken with dimensions 47 mm × 47 mm × 1.6 mm that achieves good return loss, constant group delay and good radiation patterns over the entire operating bandwidth of 2.0 to 9.5 GHz (7.5 GHz). The proposed antenna achieves high impedance bandwidth of 130%. Thus, the proposed antenna is applicable for S and C band applications.

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