DIY WiFi Helical Antenna impedance Problems Answered
First off, I live in the states, but I absolutely hate the imperial system of measurements. I will try to use the metric system as much as possible.
I have been attempting to follow hanzablast'sHelical WiFi Antenna, but have run into a few snags. I have most of the parts and have a few problems concerning it.
1. Instead of a Type N connector my USB card has a RP-SMA connector.
Do I have to do anything special (buy a special panel mount/ reverse the connections along the wire) because it has reverse polarity or does it not matter?
Edit: I feel foolish, Doing a quick wiki search on Reverse Polarity SMA I found out what it means. Turns out WiFi companies reverse the gender of the inner pin in their connectors. So either I have to find a RP-SMA panel mount jack, or buy a RP-SMA Male to N Male Adapter and a N Female Panel Mount. The latter of the two seems more efficient.
2. I understand that having too small of wire can have a detrimental effect on efficiency, but what about using a much larger wire (instead of AWG 16 gauge wire using AWG 4 gauge wire)?
Edit: Answered By NachoMahma
3. I am having trouble locating a SMA right angle 4-hole solder point panel jack mount other than in bulk buys. Does anyone know where to purchase one separately?
Edit: Answered By NachoMahma, but has become a null point.
4. I am having a problem with the impedance matching. I have seen several different ways to connect the antenna (142.68ohm impedance) to the SMA Jack (50ohm impedance). I've seen half and quarter circumference turns, quarter wavelengths turns, and triangularstripsofcopper. Which is best?
Edit: I did the math and read my friend's ARRL handbook. Supposedly, a 1/4 wavelength turn of a metal strip with an impedance of 84.463 ohm is what I need. Using TraceSim I figured that I can use part of the copper plate with a size of 12.79033mm in width, 30.775mm long (1/4 a 2.437GHz wavelength), and 0.406mm (.016") thickness placed 8.03mm (1/4 distance between coils) above the reflector plate will give me the exact impedance I need.