Title: Laser-assisted manufacture for performance-optimized dielectrically loaded GPS antennas for mobile telephones
Authors : Leisten, Oliver
Fieret, Jim
Stassen Böhlen, Ines
Rumsby, Phil T.
McEvoy, Patrick
Vardaxoglou, Yiannis
Published in : Proceedings / SPIE
Proceedings: Photon Processing in Microelectronics and Photonics
Volume(Issue) : 4637
Pages : 397
Pages to: 404
Publisher / Ed. Institution : International society for optical engineering
Issue Date: 2002
License (according to publishing contract) : Licence according to publishing contract
Type of review: Not specified
Language : English
Subjects : Excimer laser; Nd:YAG laser; Trimming; Resist exposure
Subject (DDC) : 621.3: Electrical engineering and electronics
Abstract: The use of ceramic cores of high dielectric constant is an essential part of a strategy to miniaturize GPS antennas for mobile telephones. The core reduces the guide wavelength of the conducting structures on the antenna, thereby creating a need for high-resolution imaging to maintain very accurate dimensions. It is for this principal reason that a novel laser imaging technology has been developed using a positive electrophoretic photoresist and UV excimer laser mask imaging to produce the conducting features on the surface of the antenna. Furthermore, a significant process challenge in producing this type of antenna concerns the reproducibility of the right-hand circular polarization performance and the bandwidth over which this can be achieved - which becomes progressively smaller as antenna size is reduce. It is therefore a vital requirement that the antennas have the point to be tuned by a laser trimming process at an automatic RF testing station. A galvanometer controlled Nd:YAG laser spot is used to trim the conductive pattern on the top of the antenna following an RF measurement to characterize the resonant frequencies of the four helical conductors. Results demonstrate the laser imaging and trimming techniques ensure a high-speed method of guaranteeing the antenna performance. The technique is appropriate for other antenna types such as GSM, Bluetooth and Wireless LAN.
Departement: School of Engineering
Organisational Unit: Institute of Applied Mathematics and Physics (IAMP)
Publication type: Conference paper
DOI : 10.1117/12.470647
ISSN: 0277-786X
URI: https://digitalcollection.zhaw.ch/handle/11475/16449
Appears in Collections:Publikationen School of Engineering

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