microstrip antenna project

Dear all

I am communication engineer in Uk .. I'm working in the following project :
" Investigation of Adaptive Microwave Communication System Using Novel Planar Antennas ".

The type of antenna : rectangular microstrip antenna
Frequency : 5 GHz

The project has to achieve this type of antenna with some applications as follows :-

1- Switching in polarization between linear and circular.
2- To be active phased array antenna and that to steer the beam electrically by using the phase shifter (using PIN diodes).

I have to do a design according to satisfy these two applications to be in one antenna, and that to get a new adaptive antenna.

*The software for antenna design is ADS.

I have some difficulties in the design and also I do not know how to apply it (layout)very well by ADS.

Can you please tell me.. how can you help in my project?

Many thanks.. I am waiting for your reply.