What substrate for high power, high gain panel antenna array?

Hello everyone,

I'm designing a printed high-power, high gain printed antenna array at appx. 1.7 GHz. I'm thinking an appropriately sized curtain quad or dipole array (backed with foam and a reflector) will work best to achieve >25 dBi of gain, but it needs to withstand 250W+ of CW input.

What material would be best suited for this application, and at what thickness? A curtain quad is only single-sided (i.e. no ground plane directly below), so I'm leaning towards 0.010" or 0.020" thick fiberglass (e.g. FR4). But, perhaps I'd be better off with the new RT durioid 6035HTC high-power laminate.

Any suggestions from folks that have designed high-power printed antenna arrays are welcome.

I didn't work at such high powers to suggest something for you, but you must take care in choosing a substrate at such powers.
Thermal conductivity & thickness of substrates play key role....
High dielectric substrates increase loss and inturn may dissipate more power resulting more heating of the substrate which substarte much handle....

The below article may be helpful to you..