wiki/ CpaDesignv3

Cylindrical Patch Antenna v3 Design

Cylindrical patch antenna design package. 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:

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, we decided to switch to the v3 design and just go for it.

The layers are now:

Layer Material
1 (top) 0.005" thick FR4 PCB material with 1/2 Oz Copper (~ 0.0007" thick), copper facing down
2 ~ 0.005" sprayed-on acrylic adhesive (3m # 77)
3 1/16" UHMW polyethylene
4 ~ 0.005" acrylic adhesive (part of UHMW PE "tape" we purchased)
5 (bottom) 0.005" 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 we're using for the dielectric.

Design and Construction

Here are 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 for info on actually building these beasts.