Information: Join today and make your research activities more affordable! Technical workshop participation fees and annual registration fees are available at member rates.
Notice: [Important] Announcement of Changes to Registration Fee Payment and Manuscript Upload Procedures for IEICE Technical Meetings[Type 1 Only]
IEICE Technical Committee Submission System
Conference Paper's Information		 Online Proceedings
[Sign in]
Tech. Rep. Archives
 Go Top Page Go Previous   [Japanese] / [English] 

Paper Abstract and Keywords
Presentation 2026-10-15 10:00
[Poster Presentation] An Investigation of Input Impedance Characteristics of Multipoint-Fed Circular Microstrip Antennas Using Z-Matrix
Haruto Yamaguchi, Keizo Cho (CIT), Masaya Tateno (Yokowo) AP2026-106
Abstract (in Japanese) (See Japanese page) 
(in English) Circular microstrip antennas (MSAs) are widely used in earth station antennas for mobile satellite communications. To ensure the symmetry of the radiation pattern, a dual-point differential feeding technique, in which feed ports are symmetrically placed with respect to the center of the MSA, has been proposed. While it is well known that impedance matching in a single feed MSA can be achieved by adjusting the feed position, the input impedance characteristics in a dual-feed configuration are altered due to mutual coupling between the feed ports. In this paper, we report the analytical results regarding the impact of this mutual coupling on the input impedance characteristics using Z-parameters. Through electromagnetic field analysis based on the
Method of Moments (MoM), single-port, dual-port, and four-port feeding models were constructed for a circular MSA operating at 2.3 GHz, and the variations of each parameter with respect to the feed position were evaluated. The analysis reveals that
whereas the reference single-port configuration achieves impedance matching near d/(D/2) = 0.614, the strong mutual coupling in the dual-port configuration causes the input impedance derived from ????11 to become inductive, thereby deteriorating the
matching characteristics. However, evaluations of the active input impedance under dual and four-point differential feeding, calculated using the Z-matrix, demonstrated that the effects of mutual coupling can be leveraged to achieve favorable resonance and impedance matching by locating the feed positions closer to the center compared to the single-feed configuration.
Keyword (in Japanese) (See Japanese page) 
(in English) Microstrip Antenna / differential feed / mutual coupling / input impedance / / / /  
Reference Info. IEICE Tech. Rep., vol. 126, no. 191, AP2026-106, pp. 12-13, Oct. 2026.
Paper # AP2026-106 
Date of Issue 2026-10-08 (AP) 
ISSN Online edition: ISSN 2432-6380
Copyright
and
reproduction		 All rights are reserved and no part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopy, recording, or any information storage and retrieval system, without permission in writing from the publisher. Notwithstanding, instructors are permitted to photocopy isolated articles for noncommercial classroom use without fee. (License No.: 10GA0019/12GB0052/13GB0056/17GB0034/18GB0034)
Notes on Review This article is a technical report without peer review, and its polished version will be published elsewhere.
Download PDF AP2026-106

Conference Information
Committee AP  
Conference Date 2026-10-14 - 2026-10-16 
Place (in Japanese) (See Japanese page) 
Place (in English) Hotel Épinard Nasu 
Topics (in Japanese) (See Japanese page) 
Topics (in English) Student Session, Antennas and Propagation 
Paper Information
Registration To AP 
Conference Code 2026-10-AP 
Language Japanese 
Title (in Japanese) (See Japanese page) 
Sub Title (in Japanese) (See Japanese page) 
Title (in English) An Investigation of Input Impedance Characteristics of Multipoint-Fed Circular Microstrip Antennas Using Z-Matrix 
Sub Title (in English)  
Keyword(1) Microstrip Antenna  
Keyword(2) differential feed  
Keyword(3) mutual coupling  
Keyword(4) input impedance  
Keyword(5)  
Keyword(6)  
Keyword(7)  
Keyword(8)  
1st Author's Name Haruto Yamaguchi  
1st Author's Affiliation Chiba Institute of Technology (CIT)
2nd Author's Name Keizo Cho  
2nd Author's Affiliation Chiba Institute of Technology (CIT)
3rd Author's Name Masaya Tateno  
3rd Author's Affiliation Yokowo, Co., Ltd (Yokowo)
4th Author's Name  
4th Author's Affiliation ()
5th Author's Name  
5th Author's Affiliation ()
6th Author's Name  
6th Author's Affiliation ()
7th Author's Name  
7th Author's Affiliation ()
8th Author's Name  
8th Author's Affiliation ()
9th Author's Name  
9th Author's Affiliation ()
10th Author's Name  
10th Author's Affiliation ()
11th Author's Name  
11th Author's Affiliation ()
12th Author's Name  
12th Author's Affiliation ()
13th Author's Name  
13th Author's Affiliation ()
14th Author's Name  
14th Author's Affiliation ()
15th Author's Name  
15th Author's Affiliation ()
16th Author's Name  
16th Author's Affiliation ()
17th Author's Name  
17th Author's Affiliation ()
18th Author's Name  
18th Author's Affiliation ()
19th Author's Name  
19th Author's Affiliation ()
20th Author's Name  
20th Author's Affiliation ()
21st Author's Name  
21st Author's Affiliation ()
22nd Author's Name  
22nd Author's Affiliation ()
23rd Author's Name  
23rd Author's Affiliation ()
24th Author's Name  
24th Author's Affiliation ()
25th Author's Name  
25th Author's Affiliation ()
26th Author's Name / /
26th Author's Affiliation ()
()
27th Author's Name / /
27th Author's Affiliation ()
()
28th Author's Name / /
28th Author's Affiliation ()
()
29th Author's Name / /
29th Author's Affiliation ()
()
30th Author's Name / /
30th Author's Affiliation ()
()
31st Author's Name / /
31st Author's Affiliation ()
()
32nd Author's Name / /
32nd Author's Affiliation ()
()
33rd Author's Name / /
33rd Author's Affiliation ()
()
34th Author's Name / /
34th Author's Affiliation ()
()
35th Author's Name / /
35th Author's Affiliation ()
()
36th Author's Name / /
36th Author's Affiliation ()
()
Speaker Author-1 
Date Time 2026-10-15 10:00:00 
Presentation Time 110 minutes 
Registration for AP 
Paper # AP2026-106 
Volume (vol) vol.126 
Number (no) no.191 
Page pp.12-13 
#Pages 2 
Date of Issue 2026-10-08 (AP) 

[Return to Top Page]

[Return to IEICE Web Page]

(Line Height for English Pages: 1)
The Institute of Electronics, Information and Communication Engineers (IEICE), Japan