Asymmetric and symmetric modified bow‐tie slotted circular patch antennas for circular polarization

Abstract

Modern communication systems employ wideband antennas with circular polarization (CP) radiation. In this work, asymmetric modified bow‐tie (ABT) and symmetric modified bow‐tie (SBT) slotted circularly polarized single‐point probe‐fed circular patch antennas with dimensions of 40 mm × 40 mm for wideband applications are proposed. A 10 dB RL bandwidth of 350 MHz with CP, 3 dB axial ratio (AR) bandwidth of 100 MHz, peak gain of 4.9 dBic, and 10 dB RL bandwidth of 530 MHz with CP, 3 dB AR bandwidth of 140 MHz, peak gain of 5 dBic are obtained for ABT and SBT slotted circular patch antennas, respectively. The proposed SBT slotted patch is scaled up and down to 50 mm × 50 mm and 30 mm × 30 mm, respectively. The proposed scaled‐up version offers 10 dB RL and 3 dB AR bandwidths of 340 MHz and 80 MHz, with a peak gain of 5 dBic. The scaled‐down version offers 10 dB RL and 3 dB AR bandwidths of 710 MHz and 180 MHz, with a peak gain of 5.25 dBic. These prototypes are suitable to work in IEEE 802.11a WLAN, ISM, and IEEE 802.11ac applications. The measured and simulated results are then discussed and compared.

Keywords

• AR bandwidth
• asymmetric slot
• circular polarization
• modified bow‐tie slot
• probe feed
• symmetric slot