# How can I make a cheaper, more modern UHF RFID reader board?

I just began working on a new project that involves reading RFID tags, especiall UHF RFID tags. After doing some research on the available solutions, I came across the Cottonwood reader board. (here's the wiki: http://linksprite.com/wiki/index.php5?title=Cottonwood:_UHF_Long_distance_RFID_reader_module)

I found the schematic for the board and was shocked to see that:

1. The AS3992 costs $65 on digikey and seems to be older, and less available. 2. The coupler, RCP890A05, is so old that I can only find it on aliexpress. And it costs$8 or so.

I have done a few PCB design projects in eagle in the past few years, so I think I can lay out a design, but I'm looking for pointers that would help me reduce my cost to \$50 for the components on this board and strip it down to the bare minimum.

It looks like there is another chip on here that acts as a generic microcontroller. At this point I plan to use a different chip so I can use wifi/bluetooth with this device, so that part is basically eliminated.

So I guess this all boils down to, what I can switch out to reduce costs and make parts more available?

Cheers, David

• The directional coupler looks like it could be any generic part. The analog-front-end (the AS3992) will probably be the hardest part to replace. Also, if you haven't done RF PCB layout before, I'd suggest reading all the app-notes you can find, there's a lot of caveats and constraints to be aware of. Nov 19 '16 at 5:08