Dipole antenna impedence matching at frequency other than resonant frequency

srijan.rio · June 30, 2016, 03:37

Hi all,

I have a confusion regarding impedance matching. Suppose I design a planar dipole antenna for 5 GHz and 50 ohm impedance.
Now if I want to use the same antenna at 1 GHz is it theoretically possible to match the input impedance of the same antenna @ 1 GHz and get good results in return loss and other parameters ?
Apologies if I am missing something obvious.

mprinkey · July 1, 2016, 11:12

This is not the forum to ask these questions. I doubt even the EM subforum here will be able to address your question. I suggest looking at general physics, EE, or RF engineering forums.

Having said this, I did some antenna work during my PhD program. Read up about impedence matching circuits. The standard antenna is designed to self-resonate at a given frequency. Adding a matching circuit between the signal source and the antenna allows you to set a co-resonance between the elements in the circuit and the antenna. And by adjusting capacitance and inductance, you can tune the total system to resonate at frequencies different than antenna's resonance. That said, there are always losses, because current is flying through non-radiating circuity and incurring ohmic losses rather than just driving radiation from the antenna.

Good luck.

June 30, 2016, 03:37	Dipole antenna impedence matching at frequency other than resonant frequency	#1
srijan.rio New Member srijan.rio Join Date: May 2016 Posts: 10 Rep Power: 10	Hi all, I have a confusion regarding impedance matching. Suppose I design a planar dipole antenna for 5 GHz and 50 ohm impedance. Now if I want to use the same antenna at 1 GHz is it theoretically possible to match the input impedance of the same antenna @ 1 GHz and get good results in return loss and other parameters ? Apologies if I am missing something obvious.

July 1, 2016, 11:12		#2
mprinkey Senior Member Michael Prinkey Join Date: Mar 2009 Location: Pittsburgh PA Posts: 363 Rep Power: 25	This is not the forum to ask these questions. I doubt even the EM subforum here will be able to address your question. I suggest looking at general physics, EE, or RF engineering forums. Having said this, I did some antenna work during my PhD program. Read up about impedence matching circuits. The standard antenna is designed to self-resonate at a given frequency. Adding a matching circuit between the signal source and the antenna allows you to set a co-resonance between the elements in the circuit and the antenna. And by adjusting capacitance and inductance, you can tune the total system to resonate at frequencies different than antenna's resonance. That said, there are always losses, because current is flying through non-radiating circuity and incurring ohmic losses rather than just driving radiation from the antenna. Good luck.