Tunable Sleeve Antenna Using Variable Capacitors

Kengo NISHIMOTO  Ryosuke UMENO  Toru FUKASAWA  Masataka OHTSUKA  Hiroaki MIYASHITA  Yoshihiko KONISHI 

Publication
B - Abstracts of IEICE TRANSACTIONS on Communications (Japanese Edition)  Vol.J93-B  No.9  pp.1322-1330
Publication Date: 2010/09/01
Online ISSN: 1881-0209
Print ISSN: 1344-4697
Type of Manuscript: PAPER
Category: 
Keyword: 
sleeve antennas,  variable capacitors,  band-tunable,  leakage current, 

Full Text(in Japanese): PDF(1.4MB)

Summary: 
Band-tunable small sleeve antenna using variable capacitors is proposed. In order to reduce the antenna's size when the broadband characteristic is required, variable capacitors C are put in shunt on the coplanar striplines composed by sleeve conductors and the ground conductor of a feeding line. CRB (Current Rejection Band: the band within which the leakage current on the ground conductor is suppressed) can be adjusted by changing C. Also, since CRB and the resonant frequency change to the same direction with a change in C, the impedance matching is easy to realize. Moreover, the antenna configuration using variable capacitance diodes is shown and investigated.