Abstract
Antennas for hand-held portable equipment must be lightweight and compact. Microstrip patch antennas meet these requirements and, in addition, their manufacture using printed circuit technology allows easy integration with the transceiver's RF-circuitry. However, the main disadvantage with the low-profile microstrip patch antennas is their inherently narrow input bandwidth. Although, the input bandwidth may not be wide enough to cover all channels for a particular application, the bandwidth is usually perfectly adequate for a single channel requirement. For these applications frequency tunable antennas can be employed. Such antennas, using varactor diodes have been reported with operating bandwidths exceeding 20%. However, the antenna is a part of a system that will be operating in a time-varying environment. This environment may de-tune the feed-antenna match due to temperature changes or coupling and reflections from local objects. An adaptive feedback is introduced that is intended to optimise the feed-antenna match, and therefore act against any change in input impedance of the patch antenna. It is shown that the adaptive feedback gives a good match at any desired frequency inside the operating frequency range of the microstrip patch antenna, when the antenna is subjected to a local disturbance
Translated title of the contribution | Adaptive Feedback Frequency Tuning for Microstrip Patch Antennas |
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Original language | English |
Title of host publication | Unknown |
Publisher | Institution of Engineering and Technology (IET) |
Pages | 166 - 170 |
Volume | 1 |
ISBN (Print) | 085296377, 0852966377 |
DOIs | |
Publication status | Published - 4 Apr 1995 |
Event | 9th International Conference on Antennas and Propagation - Eindhoven, Netherlands Duration: 1 Apr 1995 → … |
Conference
Conference | 9th International Conference on Antennas and Propagation |
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Country/Territory | Netherlands |
City | Eindhoven |
Period | 1/04/95 → … |
Bibliographical note
Conference Proceedings/Title of Journal: IEE 9th Int. Conf. on Antennas & Propagation. Eindhoven, The Netherlands. AprilRose publication type: Conference contribution
Sponsorship: The authors are grateful to Hewlett Packard
Laboratories for funding this work.
Other identifier: Conference Publication No. 407
Keywords
- microstrip patch antennas
- adaptive feedback frequency tuning