A MODIFIED BOW-TIE SLOTTED CIRCULAR PATCH ANTENNA

摘要

Title: A Modified Bow-Tie Slotted Circular Patch Antenna The present invention provides asymmetric modified Bow Tie (ABT) and symmetric modified bow-tie slotted patch antennas. The patch antenna provides a resonant mode at a desired frequency. The modified bow-tie slot is shaped by combining the portion of a trapezoid and a semi-ellipse arranged geometrically to ensure circular polarization. The invention proposes a circular patch antenna with different dimensions of 40 X 40 mm2 for asymmetric and symmetric slotted antennas. A feed port is provided on the bottom of the ground plane to feed the circular patch antenna through a feed line. ABT slotted circular patch offers 10 dB Return Loss (RL) bandwidth of 350MHz with CP, and 3dB AR bandwidth of 100MHz with a peak gain of 5dBi. SBT slotted patch provides 10dB bandwidth of 530MHz with CP, 3dB AR bandwidth of 100MHz with a peak gain of 5.1dBi. The proposed antennas are suitable for S-band applications. The scaled up symmetric bow tie SBT-CSSP (50mm X 50mm) version provides 10dB return loss (RL) bandwidth of 340MHz (2390MHz-2730MHz) with circular polarization (CP), 3dB AR bandwidth of 80MHz with a gain of 5dBi and the scaled down symmetric bow tie SBT-CSSP (30mm X 30mm) version provides 10dB return loss (RL) bandwidth of 710MHz (4800MHz-5510MHz) with circular polarization (CP), 3dB AR bandwidth of 180MHz with a gain of 5.25dBi. The scaled versions are suitable for IEEE 802.11a WLAN (2.4GHz), ISM (2.4-2.483GHz) and IEEE 802.11ac (5GHz) applications. The measured and simulation results are in close agreement. The small deviations in practical results when compared to simulation results are attributed to fabrication tolerances, which are not considered in the process of simulation.