I'm considering building a short-distance direction finder to determine the relative position of two objects.
I want to be able to determine direction through other objects, which eliminates IR or ultrasonic detectors. This leaves RF.
Antenna design I've seen seems focused on long distances and on quality of signal. However, my goals are short range (less than 10m) and direction. I don't care what gets transmitted, just where it comes from.
I expect that one of the objects would have an omnidirectional beacon and the other object a directional antenna. An angle slot of 15 degrees would be acceptable. I can deal with multiple antennae.
There's various antenna configurations that look like they'd be sufficient for directionality. They are: Yagi-Uno, dish and HB9CV-Beam. However, I don't see how to shrink them, or which ones are suitable for shrinking to short distances and small receiver sizes.
I expect I'll have to build custom mechanical and electronics hardware, although off-the-shelf parts would make my life a lot easier.
Here are some specific questions:
- Which antenna configurations are suitable for shrinking?
- I think I need a very small wavelength, so would be looking in the 2Ghz range. Is that right?
- What power output should I be considering? Is this at all possible? Are there examples of this?
I have knowledge of electronics but am obviously new to antenna design. I appreciate any answers you might have.