Coplanar Waveguide-fed Circularly Polarized Antennas with Wideband Harmonic Suppression

• Main Authors: LIN, CHIH-HENG, 林志衡
• Other Authors: SIM, CHOW-YEN
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/u2gp8u

碩士 === 逢甲大學 === 電機工程學系 === 106 === This paper focuses on new type antennas of harmonic suppression with circular polarization. The π-shape resonator can be used to suppress the high-order frequency. They can be applied to wireless local area networks WLAN 5.8 GHz (5.725 GHz to 5.825 GHz) and DSRC 5.9 GHz (5.85 GHz to 5.925 GHz). A coplanar waveguide-fed circularly polarized antenna with harmonic suppression is initially proposed (proposed antenna 1). The antenna size is 30 mm× 30 mm× 0.762 mm. By adding two quadrant arc-shaped perturbed elements into the circular patch antenna, a circularly polarized (CP) band is excited from 5.85 GHz to 5.925 GHz. The π-shape resonator is loaded at the end of coplanar waveguide feed and coupled with the circularly polarized patch antenna. The measured 10-dB bandwidth and CP bandwidth were 660 MHz (5.67 GHz～6.33 GHz) and 75MHz (5.85 GHz～5.925 GHz), respectively. The measured maximum antenna gain and antenna efficiency were 5.5 dBic and 84.1%, respectively. The design of proposed antenna 2 is based on the architecture of proposed antenna 1. In order to increase the CP bandwidth without changing the structure of the resonator, a crescent slot is embedded into the ground plane. This design can increase the CP bandwidth to 5.72 GHz～5.88 GHz, which can cover the WLAN 5.8 GHz band (5.72 GHz～5.85 GHz). The measured 10-dB bandwidth was 850 MHz (5.7 GHz～6.55 GHz). The measured maximum antenna gain and antenna efficiency were 3.9 dBic and 81%, respectively.