Replicating a microwave sensor

Hi all you technical geniuses! I am going to be using a series of microwave sensors hooked up to an arduino, and Parallax makes a great sensor for $30, but since I need a bunch of these I was thinking of using a wholesale sensor instead. Does anyone know what additional components I would need to hook up to use it in the same way? FYI I am just using it to detect motion, not to measure speed.

Parallax sensor:,ProductName

Wholesale sensor:


It looks like you might need to add a lot of extra components to use that sensor. Check out the manual in the Document Download section of the page you linked to for the wholesale sensor. They have an example schematic.


I’ve used the doppler radar module that that device is based on, available from ebay for $6.99: … 226wt_1064

That module outputs a doppler signal down in the microvolts range though, so it needs to be amplified to be sensed by an arduino. Looks like the Parallax device has piggybacked an amplifier on it so I guess that’s what you pay the $30 for.

The datasheet on the device is here, along with a schematic showing the suggested amplifier: … 1-V101.pdf

One advantage with designing your own amp though is you can set the bandwidth to whatever application you have in mind, for example, filter out high frequency (high velocity) signals if you want to concentrate on slower objects.