Design of a Microstrip Monopole Slot Antenna With Unidirectional Radiation Characteristics

Author

Wang, Chien-Jen ; Sun, Te-Liang

Author_Institution

Dept. of Electr. Eng., Nat. Univ. of Tainan, Tainan, Taiwan

Volume

59

Issue

4

fYear

2011

fDate

4/1/2011 12:00:00 AM

Firstpage

1389

Lastpage

1393

Abstract

A design procedure for a wideband planar unidirectional antenna is presented based on the monopole slot antenna. Owing to the additional capacitance contributed by a stub-protruded feedline and two symmetrical stubs at the slot edge, the impedance-matching condition is improved; meanwhile, the resonance frequency of the monopole slot antenna is significantly shifted down, and an improvement in impedance bandwidth is achieved. By modifying the width of the ground plane, connecting one metallic finger at the upper right corner, and etching two asymmetrical slits in the ground plane as reflectors, the radiation directivity of the monopole slot antenna can be enhanced. The proposed antenna achieves a measured 97.4% bandwidth for S₁₁ <; -10 dB at the center frequency of 2.31 GHz, better than 10 dB front-to-back ratio.

Keywords

antenna feeds; antenna radiation patterns; broadband antennas; impedance matching; microstrip antennas; monopole antennas; slot antennas; frequency 2.31 GHz; impedance-matching condition; microstrip monopole slot antenna; radiation directivity; resonance frequency; stub-protruded feedline; symmetrical stubs; unidirectional radiation characteristics; wideband planar unidirectional antenna; Antenna measurements; Antenna radiation patterns; Bandwidth; Reflection; Reflector antennas; Slot antennas; Surface impedance; Corrugated grating structure; front-to-back ratio; monopole slot antenna; protruded stub;

fLanguage

English

Journal_Title

Antennas and Propagation, IEEE Transactions on

Publisher

ieee

ISSN

0018-926X

Type

jour

DOI

10.1109/TAP.2011.2109682

Filename

5704562