I am designing a Spiral antenna and to match Impedance with coaxial. I am taking the concept of quarter wavelength Transformer. But Not able to get good results in simulation itself. Can somebody please help?
The frequencies I am interested is 2.4 and 5.25 GHz
What are you doing to your coaxial line to alter its impedance in the quarter wave section? What impedances are you using/assuming? How are you sure that you have a quarter wave length of coax? What does the interface between your two coax cables look like?
There is too little information in your question to get a helpful answer.
Oh I am sorry, For the little information...
So, My spiral antenna is of impedance 180 ohms. To match the impedance of 180 ohms with 50 ohms coaxial. I am thinking of extending the arms of my spiral antenna of quarter wavelength (I assume) so that with the quarter wavenlength transformer concept , I can match 180 to 50 ohms, as much as possible.
Arms? I am envisioning inserting the quarter-wave transformer right where you feed the antenna with a coax. Not sure what "arms" you are talking about.
I presume your antenna has two arms. If so it will be a balanced antenna. To connect it to an unbalanced feed cable i.e. coax you will need a balance to unbalance transformer, a balun, as well as your quarter wave impedance matching section.
I wanted to try something else than Balun. That is why trying impedance transformer . Yes it has 2 arms. Can you please suggest something
You will need a structure that does what a balun does other wise you will excite radiating currents on the outside of the coaxial feeder and your antenna will be compromised.
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