Parameter Extraction of c- and π- modes for broadband balun using an asymmetric coupled line

Author

Saitou, A. ; Ishikawa, Ryo ; Honjo, Kazuhiko

Author_Institution

Univ. of Electro-Commun., Chofu, Japan

fYear

2012

fDate

4-7 Dec. 2012

Firstpage

22

Lastpage

24

Abstract

Miniature broadband 1:1 baluns for differential mode antennas are exhibited with an asymmetric broadside coupled line in an inhomogeneous medium. To design characteristics of a balun for both the in-band and the rejection band, c- and π-mode parameters for the coupled lines are extracted by both simulation and measurement. The rejection band of the broadband balun is shown to be caused by the c-mode transmission. With the extracted parameters, optimal line dimensions are obtained for 50 Ω single-mode input and differential-mode output port impedances. Measured fractional bandwidth is as wide as 178% for the 0.2-mm-wide broadside coupled line in a 1-mm-thick multi-layer FR-4 substrate.

Keywords

S-parameters; baluns; broadband antennas; electric impedance; printed circuits; π-mode parameters; asymmetric broadside coupled line; broadband balun; broadside coupled line; c-mode parameters; c-mode transmission; differential mode antennas; differential-mode output port impedances; fractional bandwidth measurement; inhomogeneous medium; multilayer FR-4 substrate; optimal line dimensions; parameter extraction; rejection band; resistance 50 ohm; single-mode input; size 0.2 mm; size 1 mm; Broadband antennas; Broadband communication; Impedance matching; Permittivity; Ports (Computers); Substrates; balun; coupled line; dual-band antenna; mixed-mode S-parameter; multi-layer PCBs;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Conference Proceedings (APMC), 2012 Asia-Pacific

Conference_Location

Kaohsiung

Print_ISBN

978-1-4577-1330-9

Electronic_ISBN

978-1-4577-1331-6

Type

conf

DOI

10.1109/APMC.2012.6421485

Filename

6421485