What is the dşfference of Characteristic Impedance and Input Impedance of a patch. I am designing a patch antenna, and to design its feeding geometry ı need to model a lambda/4 feed line between the patch and 50 ohm line.
So while I calculating the lambda/4 feed line width, I use chracteristic imp of the patch. Zf: sqrt (Za+50) formula.
But I dont understand characteristic imp and input impedance differance. input imp has imaginer part but characteristic imp does not. Can you explain me from a designer point of view please ?
As you will see, ı will calculate the lambda/4 feed line impedance with this generale formula;
Zline=sqrt(Zpatch*50)
So for Zpatch, it is written that characteristic impedance of the patch. Not the input impedance. I mixed up here. I can directly put a port and voltage source at the edge of the patch without feed lines and find the input impedance with an EM simulator. So ı should think the patch as a transmission line ?
So for Zpatch, it is written that characteristic impedance of the patch. Not the input impedance. I mixed up here. I can directly put a port and voltage source at the edge of the patch without feed lines and find the input impedance with an EM simulator. So ı should think the patch as a transmission line ?
You should think the patch as a load with impedance Zpatch and match it with the lambda/4 line. Your reasoning is right, you calculate Zline = sqrt(Zpatch*50) and design a line with a width that corresponds to that impedance, and you will see that the matching will occur.