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Dielectric material at ~GHz

Dielectric material at ~GHz

Dielectric material at ~GHz

(OP)
This forum has already been very helpful in refining my ideas. I have another question about an application involving high power em fields at between 1 to 2.5GHz:

What is the best dielectric to use at these frequencies? I'm thinking about a material to bind copper wire strands together (may even have to be superconductor). Possibly cooling pipes will also be included, but I'm keen that these are seperate from the field wires until I investigate the design further. Ideally the dielectric should have good mechanical properties, as well as no UHF heating (or shielding).

My first thought was epoxy-resin, since this allows me to position the wires first before setting. I'm willing to consider other plastics, but am keen to avoid expensive injection mold tooling. I have used Nylon in the past, since this can be machined. A friend has even suggested glass or carbon reinforced resin, since these are very robust for a given weight.

Does anyone have any ideas/suggestions?

Graham

RE: Dielectric material at ~GHz

What is a high power em field?

Are you trying to establish an electrical connection or provide insulation?

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RE: Dielectric material at ~GHz

(OP)
Apologies, I was being rather loose in my terminology. I meant to say for the purposes of insulation at high voltages and frequencies.

RE: Dielectric material at ~GHz

Well my immediate thought is stick insulator samples in a microwave oven, along with a glass of water, and heat on full power until the water gets hot. Then see which of the insulators is not as hot and that is the best one in terms of dissipation.

I have noticed definite differences between glasses used in the microwave and indeed you can buy special low loss glassware for use in microwave ovens.

RE: Dielectric material at ~GHz

(OP)
Yes that was my thought too, Logbook! Interesting about the glass, I'll look into that further.

RE: Dielectric material at ~GHz

(OP)
Thanks all for the feedback so far. This question has been moved to the Microwave engineering Forum, since it may need more specialist knowledge of material in microwave environments.

RE: Dielectric material at ~GHz

A safety warning was circulated around our works regarding heating water in microwave ovens. It seems that the water can become superheated to a temperature above boiling point but remain in a liquid state until disturbed by, for example, someone picking up the glass. The report stated that there had been some severe scalding injuries.

There are numerous weblinks if you Google the following words:

microwave oven water boiling explode

Hopefully this will save someone from a nasty surprise.


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