microstrip patch antenna impedance

[harry1984]

I designed microstrip patch antenna with 30 ohm impedance. Please tell me, where can I use this antenna? Is it necessary to keep it 50 ohm? If so then how can I use this antenna with 50 ohm transmission line and application? Please, its uregnt.

 

[nschutten]

50Ohm is the standard impedance for RF; hypothetically, you could use a different system impedance, e.g. if your RF PA has an output impedance if 30Ohms; but since measurement equipment, cables, etc. are all 50Ohms, it is probably advisable to target 50Ohms for your design as well.

You can adjust the location of the feedpoint of the patch antenna to tune it to 50Ohms (e.g. by using an inset in case of a fully planar structure, or by moving the coaxial feedpoint location in case of a coaxially fed patch antenna).