Varactor Diode Tuning

Thread Starter

nana_asempa1

Joined Feb 1, 2020
14
I have designed a dualband bandpass filter with HFSS, but when I tune the varactor, the center frequency doesn't change. could there be any anything Ineed to do right please?thread.JPGthread.JPG
 

Thread Starter

nana_asempa1

Joined Feb 1, 2020
14
Or to put it another way, how can you have DC voltage across the diode if the circuit is open?
the path i only have a patch that is from the resistor to the ground. but the diode is fixed between the resistor and the resonator please. I really like your inputs, carry me on Sir, help me. I need to hand in my thesis
 

DickCappels

Joined Aug 21, 2008
6,185
Kjeldgaard has the main point. Progress in helping you will be more and more difficult if not impossible without a schematic. Anything we can read will be find.

How are you applying bias to the varactor?
 

Thread Starter

nana_asempa1

Joined Feb 1, 2020
14
Kjeldgaard has the main point. Progress in helping you will be more and more difficult if not impossible without a schematic. Anything we can read will be find.

How are you applying bias to the varactor?
ok, let me be humble and tell my problem. I don't actually know how to apply the bias to the varactor, I would be glad if I am helped on how to design the bias circuit. currently, I only removed the modeled resistor from the HFSS design and I was able to tune the frequencies, but I doubt if that will be correct for fabrication. please teach me hoe to do it. I would be very thankful
 
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