patch antenna with probe feeding
1. I am not quite sure what kind of connector and lauch pin I should use.
2. I also want to know if I need mount the patch antenna on a larger metal which acts as ground or just deposite a layer of metal on the bottome of the dielectric.
3. How can I fix the connector with the patch antenna.
also if someone have the practical materials about it, please send me by email. Thanks a lot!
my email box: wang.jia@neu.edu
Hi, there!
1. You should use a connector that gives you the require input impedance and this tends to be 50 ohm. So, look through your catalogue and find a connector for 50 ohm. In addition, the connector type is usually SMA type so that it is ready to be tested with a network analyser.
2. This depends how you want to manufacture your printed antenna. The usual method is via photo-etching or CNC milling. You buy a piece of dielectric material say Duroid 5870 (epsile ~ 2.2), it will have copper on both sides. One side will be untouched and is your ground plane for the patch. The other side you will either use photo-etching to create your patch pattern or use CNC milling to mill away the unwanted copper to form the patch pattern.
3. To fix the probe to the antenna. You must decide the location of the feeding point. This is usually at a distance between the center and the edge of the patch antenna. Drill a hole through the dielectric material with the diameter equal to the diameter of your pin. Slot your pin through to make sure the hole is a tight fit for the pin. Cut away any excess PTFE material (white) on the probe pin. Next turn to the ground plane and mill off a section of the copper at the pin location, this should be equal to the diameter of the PTFE material. The reason for doing this is to make sure the inner conductor does not get short out by the outer connector via the ground connection.
I hope this help.
Kind regards
Sassyboy
Sassyboy expressed very amply.