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# <a name="Cylindrical Patch Antenna v3 Des"></a> Cylindrical Patch Antenna v3 Design

[[Cylindrical_patch_antenna_design_package|CpaDesignv3/cpa_v3_design.zip]].  This package includes a spreadsheet to generate antenna designs based on desired parameters, as well as source files and PDFs for our board layouts.

Frequencies and Bandwidths
--------------------------

There's some confusion about the frequencies we're trying to design for. They are:

[[!table data="""
Frequency | Bandwidth | Description
2.41200 GHz | 30 MHz | Channel 1 of the IEEE 802.11b specification 
1.57542 GHz | 10 MHz | GPS L1
1.25325 GHz | 30 MHz | Amateur TV frequency
"""]]

Antenna Description
-------------------

After the [[results of our v2b tests were very positive|news/2004-07-27]], we decided to switch to the v3 design and just go for it.

The layers are now:

[[!table data="""
Layer|Material
1 (top) |   0.005&quot; thick FR4 PCB material with 1/2 Oz Copper (~ 0.0007&quot; thick), copper facing <em>down</em>
2       | ~ 0.005&quot; sprayed-on acrylic adhesive (3m # 77)
3       | 1/16&quot; UHMW polyethylene
4       | ~ 0.005&quot; acrylic adhesive (part of UHMW PE &quot;tape&quot; we purchased)
5 (bottom)| 0.005&quot; copper sheeting (purchased in a roll)
"""]]

... note that "top" means the top of the antenna, the surface that faces the airstream, and bottom is the side that touches the cylindrical aluminum moduldes.

I measured the the three v2b antennas at ~0.82", which (astoundingly) fits with the thicknesses we predicted.

Here's information on the [[Ultra High Molecular Weight Polyethylene tape|UhmwPeTape]] we're using for the dielectric.

Design and Construction
-----------------------

[[Here_are|CpaDesignv3/cpa_v3_design.zip]] the first revision of the v3 designs in a zip file, which includes the EAGLE v4.11 board layout files, PDFs of the layouts, and the Excel spreadsheet which created the cut-and-paste EAGLE scripts (note that Gnumeric and OpenOffice should have no trouble opening it up).

See our [[CPA_v3_construction_notes|CpaConstructionv3]] for info on actually building these beasts.

----
Attachments:

- [[cpa_v3_cam.zip]]