Table of Contents
International Journal of Microwave Science and Technology
Volume 2010, Article ID 535307, 9 pages
http://dx.doi.org/10.1155/2010/535307
Research Article

Design and Comparison of 24 GHz Patch Antennas on Glass Substrates for Compact Wireless Sensor Nodes

1Berlin Institute of Technology, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
2Fraunhofer Institute for Reliability and Microintegration (IZM), Gustav-Meyer-Allee 25, 13355 Berlin, Germany

Received 9 September 2010; Revised 24 November 2010; Accepted 9 December 2010

Academic Editor: Chien-Jen Wang

Copyright © 2010 Florian Ohnimus et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Three patch antennas suitable for integration and operation in a compact 24 GHz wireless sensor node with radar and communication functions are designed, characterized, and compared. The antennas are manufactured on a low loss glass wafer using thin film (BCB/Cu) wafer level processing (WLP) technologies. This process is well suited for 3D stacking. The antennas are fed through a microstrip line underneath a ground plane coupling into the patch resonator through a slot aperture. Linear polarization (LP), dual mode (DM) operation, and circular polarization (CP) are achieved through the layout of the slot aperture and rectangular patch dimensions. Antenna gain values of ∼5.5 dBi are obtained in addition to the 10 dB impedance bandwidths of 900 MHz and 1.3 GHz as well as 500 MHz CP bandwidth with a 3 dB axial ratio for the LP, DM, and CP patch antennas, respectively.