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Center frequency of microstrip filters/stubs, how much is temperature drift at 10GHz?

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Terminator3

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If somebody have experiense on this topic, i need some approximate numbers for cheap PTFE laminate.
For half-wave microstrip resonator, and quaterwave stub. What would be the worst-case change of center frequency for 0...60degC temperature sweep?
 

Terminator3 said:
If somebody have experiense on this topic, i need some approximate numbers for cheap PTFE laminate.
For half-wave microstrip resonator, and quaterwave stub. What would be the worst-case change of center frequency for 0...60degC temperature sweep?
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Depends on substrate as well as on filter structure. Must be determined by measurement on a real filter.

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The temperature changes force filter designers to use microstrip in low-quality filters. Cavity filters made of KOvar or with compensated resonators are better. Dielectric resonators can be designed as temperature-independent for the best filters.
 
Maybe you have some practical experience, how much it would be? few Mhz, hundred of Mhz, Ghz, etc?
 

That is not the difficult. First calculate your trace length/width variation with temperature, then you can check the filter freq response drift.
 
Copper metallic changings are almost negligible for these temperature range ( There may be some minor effects).Substrate specs. changings are more important.
You should check the variation of Er versus temperature for that substrate.
It may be few MHz, few tenths of MHz or maybe more..
Nobody says something without knowing your substrate.
 
You get correct answer once temperaure test is complete.
There is no rules to find this.
 
Er TK and mechanical expansion are the dominant effects. You can expect up to a few 10 ppm/K for PTFE substrate, resulting in a few MHz up to several 10 MHz frequency shift in a rough estimation. As said a measurement is preferable.
 
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