capcitive load

Hi all,

I have an antenna that is very small in size in relation to wavelength. The antenna's input impedance is purely capacitive. I am treating this antenna as some sort of coaxial probe. Now, my problem is to find a suitable matching network to connect this capacitive load to a broadband LNA (Interested freq range of operation is 1-3 GHz). Any suggestions on how to obtain maximum performance from the LNA when it is connected to a capacitive load will be very much appreciated.

Regards,
Element7k

Luckily for you, it is not a purely capacitive load. It has capacitance AND resistance, any you are still trying to get as much power into the resistance (radiation resistance) as possible. So either an LC match, microstrip match, or a transformer. It helps if you can resonate the capacitive part of the antenna with a series inductance.

http://www.ee.surrey.ac.uk/Personal/...es/radimp.html

Hi biff44,

thanks for the hint. Maybe you or somebody else will be maybe able to help with my matching problem if I attach my simulated s1p file of my structure. The S1P file ranges from 0-10 GHz. However, my interest to obtain a good match for 1-3 GHz only.

Just a sidenote...I was lucky to have been taught by Dr Jefferies :)

Thanks in advance.

Regards,
Element7k