Frequency Reconfigurable antenna design using fabric material (textile antenna)

I am designing frequency Re-configurable antenna in HFSS for switch in frequency between 2.45 GHz and 5.8 GHz using diode. This is micro-strip antenna. I am using substrate as fabric material as cotton, polyster, polycot, etc. I am facing some problem. please help me.

where do I get correct information about dielectric constant for various fabric material?
How to add new substrate material in HFSS?
How can I achieved frequency reconfigurability?
which will be good diode? (PIN/varactor)
how to fabricate antenna with diode?
how to do impedance matching for diode with antenna?
how to incorporate antenna with diode?
suggest me good books for reference.

I will first design rectangular patch antenna for 5.8GHz with Tx. line feeding. Then same antenna for 2.45GHz considering copper strip as diode and extra conducting part. is it correct way to do?

First You have to find the dielectric constant of cloth material from the below mentioned paper

http://ieeexplore.ieee.org/stamp/sta...number=5601775

You can go to materials and there is option for add new material, define the conductivity, loss tangent.

Your diode should be work at high frequencies, generally we prefer pin diode.