ADS Clarification on Substrates

Hi

Currently, i'm doing a circular and slotted patch antenna for GPS purposes which consists of 1 patch layer but with 2 substrates ( FR4 and Foam). I have trouble getting the frequencies i want which is at 1.575 GHz and 2.4 GHz. Here are the following that i define at my layout layers ( using A2006) in other versions i think is called metallisation layers.

Air
------ STRIP cond
FR4
------
Foam
/////////GND//////////

The 2 substrates is not separated, they are together without any conductor in between. A 50 ohms coaxial probe is then feed at the patch. My height of the substrate for FR4 is 1.6mm and Foam is 3.5mm.

Questions i want to ask are:

- Are the substates layout layers define correctly as i have described? Will incorrectly define them cause a change of frequency?
- I was suppose to use a single feed mode port but whenever i simulate it, it will change to internal port. Will this effect the the frequecy i want as well?

Thank you for the kind attention

Regards

申明：网友回复良莠不齐，仅供参考。如需专业帮助，请学习易迪拓培训专家讲授的ADS视频培训课程。