Ultra-wideband planar LPDA antenna with mode converter balun

Author

Mirzapour, M.I. ; Razavi, S.M.J. ; Armaki, Seyyed Hossein Mohseni

Author_Institution

Dept. of Electr. & Electron. Eng., Malek Ashtar Univ. of Technol., Tehran, Iran

Volume

50

Issue

12

fYear

2014

fDate

June 5 2014

Firstpage

848

Lastpage

850

Abstract

A new balun used for feeding a planar log-periodic dipole array antenna (PLPDA) is proposed. This balun, which is based on mode conversion, converts gradually the transmission mode from quasi-TEM (coaxial cable) to full TEM (balanced line), with an accessible excitation current property (ECP), which is not achievable in classical feeding techniques (infinite or self balun). To validate this approach, an ultra-wideband (UWB) PLPDA antenna was designed with these balun structures for operating in the L and S bands (1-4 GHz) and the results were compared in terms of reflection coefficient and radiation pattern. A PLPDA antenna with a mode converter balun was fabricated. Results show that the proposed balun is a low length (10 mm) frequency-independent (4.5 GHz based on |S₁₁| ≤ -10 dB) device useful for feeding the UWB PLPDA antenna. Moreover, antenna´s ECP can be modified, which is necessary for phase centre variation compensation.

Keywords

UHF antennas; antenna radiation patterns; baluns; coaxial cables; dipole antenna arrays; log periodic antennas; microwave antenna arrays; planar antenna arrays; ultra wideband antennas; PLPDA antenna; antenna radiation pattern; balanced line; coaxial cable; excitation current property; feeding technique; frequency 1 GHz to 4 GHz; frequency 4.5 GHz; full TEM; mode convertor balun; planar log-periodic dipole array antenna; quasi-TEM; reflection coefficient; ultrawideband planar LPDA antenna;

fLanguage

English

Journal_Title

Electronics Letters

Publisher

iet

ISSN

0013-5194

Type

jour

DOI

10.1049/el.2013.4027

Filename

6836711