| EPSRC Reference: |
GR/J42403/01 |
| Title: |
MICROSTRIP PATCH ANTENNAS OPERATING AT HIGHER ORDER MODES ON FERRITE SUBSTRATES |
| Principal Investigator: |
Langley, Professor RJ |
| Other Investigators: |
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| Researcher Co-Investigators: |
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| Project Partners: |
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| Department: |
Sch of Engineering & Digital Arts |
| Organisation: |
University of Kent |
| Scheme: |
Standard Research (Pre-FEC) |
| Starts: |
08 March 1994 |
Ends: |
07 October 1997 |
Value (£): |
153,071
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| EPSRC Research Topic Classifications: |
| RF & Microwave Technology |
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| Panel History: |
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Summary on Grant Application Form |
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To quantify the effects of varying the bias of a ferrite material acting as either a cover or substrate for ring type patch antennas. The rings are to be operated at higher order modes.To verify that biasing the ferrite changes the resonant frequency and direction of the radiation allowing beam steering of the pattern.To develop analysis and design procedures.To assess practical biasing circuits for the antennas.Progress:The initial phase of the project has concentrated on an experimental assessment of the properties of annular ring microstrip antennas printed on the Trans-Tech G-113 YIG ferrite material, with permittivity er=14.78, thickness 1.27 mm and a saturation magnetisation of 4pMs =1730 Gauss. Studies have concentrated on the fundamental TM11 mode and a higher order TM21 mode. Linear polarisation was obtained for each mode with the ferrite unbiased. On applying a dc magnetic field normal to the sub-strate the radiation patterns became circularly polarised for both modes using a single feed point. This is a considerable advantage since it significantly reduces the feed complexity for the higher order mode when compared with the four feeds required on dielectric substrates. Both left hand (LHCP) and right hand (RHCP) polarisation was generated, this being switchable by reversing the magnetic bias polarity. The resonant frequency can be tuned over a 15% range using a magnetic bias normal to the patch and ferrite. The measured bandwidths were about 1% for each mode, irrespective of polarisation. These did not appear to change with substrate bias. The gains and efficiency have yet to be determined. The next stage in the project is to examine whether the use of biased ferrites can change the beam direction and to write analysis software for design purposes.
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Key Findings |
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Potential use in non-academic contexts |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Impacts |
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| Description |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk |
| Summary |
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| Date Materialised |
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Sectors submitted by the Researcher |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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| Project URL: |
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| Further Information: |
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| Organisation Website: |
http://www.kent.ac.uk |