Learning Forum

[reza94]

Hello,

I'm designing a patch antenna for RFID chip. The impedance of the RFID is 80-j420. Because the impedance is complex, HFSS calculation is wrong for realized gain as shown below:

Is there any setting in HFSS that we can correct the calculations? 

 

Thanks,

Reza

[DMARATHE]

Hi Reza,

Thanks for posting your query on the Ansys Learing Forum.

I will assue that your are designing the the RFID transponsder antenna. The impedance that you have mentioned, I will assume it as RFID chip impedance. This impedance is usually a complex quantity let say Zc  and let us consider antenna impedance as Za.  The voltage induced at the antenna terminal to get delivered to the chip requires, impedance matching between Za and Zc.

In such a scenario, the antenna impedance is a complex number. May I know, what impedance you are mentioning in your port setup while exciting the antena ?

Are you re-normalizing the port impedance to complex number (Za) ? Kindly provide these information. Thanks.

 

 

[reza94]

Thanks for your respond. I set the lumped port impedance to 80-j420 (Zc =80-j420) without renormalization. Also I tried to design the antenna to have the the impedance of  80+j420 = Za