Communications team meeting/workshop at PSBA
Andrew G., Glenn L., Dave C., Dan K., Nathan B.
Talked about routing the board that holds the copper components of the CPA.
Vacuum table to hold material in place.
- Can't get sharp edges because bit is round. Tapered bit will cause multi radii on the trace.
- 80 watt laser won't cut metal.
- Laser could cut a mask that could be used to expose etch resist, and we could do our own etch.
- If etch ourselves, edges are not precise, and pitted surface is common.
- Could peel away large portions of Cu to reduce routing work if chose that approach.
- Talked about alternate structures.
//117.4 ohm -> 58.7 ohm -- first level allows us to skip the first transformer. This was in the 5.8 GHz CPA as currently designed, but Andrew thinks that was an unintentional mistake. Seems like a good idea because it removes one bandwidth restricting transformer from the cascade.
Let's do it again at the second level since it is a tight fit, and it's hard to get the 5h separation of transmission line between the transformer. Let's see what that looks like. //58.7 ohm -> 29.35 ohm -- Yikes! Here's the problem; the width is 401 mils! That's fat!
Glenn drew up a quick sketch of what this would look like. Scanned and emailed? Andrew has original.
- Find out about PCB fab
PCB Fab Express in California. http://www.pcbfabexpress.com 1-408-522-1500 Can they do 4 X 18? - Yes but custom. Max size they do is 16 x 22 Sent email requesting quote for our 5.8 GHz antenna. Attached 5.8cpa.pdf file
13-Jun-2011 0930 PDT Have not seen quote yet. Call them. Pretty clumbsy customer service, however the quote was a rough number $1500 to $2000 for the first board.
- Looked up the quote Glenn got from Sunstone back in 10-Aug-2010
First board was $1194.00 + $180.00 non-Recurring tooling charge. Two boards $720.00 each; Three boards $450.00 each. The quote provided Silver plating. Without silver was $50.00 less. Contact: Linda Postlethwaite
- Look up UHMW
On our wiki http://psas.pdx.edu/UhmwPeTape/ Called Jenifer at Multicraft Plastics 503-288-5131
8 inch width, 50 foot roll 0.062 inch thick UHMW PE 0.005 inch acrylic with mylar film adhesive.
Product is still available, special order. Adhesive on one side is available; she's not sure if adhesive on both sides is available but will find out. She will call me back on Monday with price.
13-Jun-2011 0930 PDT Jenifer called back. Double side is available but a bad product. One side wants to delaminate; a heat process is used to apply, and one side gets messed up during the application. They don't want to quote since it is a bad product.
Single side is available. 8 inch x 50 ft. $205.00 + freight from Ohio. In stock, takes 4 days to ship out.
- Andrew working on Python program to compute CPA
http://en.wikipedia.org/wiki/Microstrip
http://en.wikipedia.org/wiki/Quarter-wave_impedance_transformer
http://www.microwaves101.com/encyclopedia/quarterwavexformer.cfm
http://www.microwaves101.com/encyclopedia/transformers_tapered.cfm