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Resistor value for RF

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Hi Everyone!

can i use general 10k 0603 ,10k resistor for directional coupler whose frequency is 433 MHz
circuit is shown in figure

Thanks 6 dB directional LC coupler.jpg
 

Yes, normal 0603 resistor can be used in RF up to some GHz; the lower the value the higher the frequency. However in the picture I can't see any 10k resistor.
 

Hi albbg!

Thanks for your help

actually ,my that was my mistake to write value of resistor...sorry for that !

can you please tell me ,can i use MLCC or ceramic capacitor in RF section for 433 MHz

thanks
 

Yes, you can use both MLCC (multi Layer Ceramic Capacitor) or "normal" ceramic capacitors.
 
At 433 MHz 0603 is definitely adequate for the job. Just any ordinary capacitor, Q-factor will likely be dominated by the inductors.

I used 0402 up to 8 GHz which is ok when designing carefully. You can even use it at much higher frequencies with some tricks.
 
hi !

first Thanks to you

but question is if we can use MLCC capacitor then why we prefer to use COG capacitor in RF section
 

i_engineer said:
hi !

first Thanks to you

but question is if we can use MLCC capacitor then why we prefer to use COG capacitor in RF section
Click to expand...

Common dielectric types: COG/NPO, X7R/X5R, Z5U, Y5V

COG and NPO dielectrics have the best performance vs. temperature (they don't change much). X7R/X5R's have more variation over temp but are decent in some cases (coupling caps, etc). The rest are just horrible when considering them for inside a filter structure, DO NOT use them for any RF design other than maybe bulk power filtering... but I don't even use them for that.

Here are some good links that will spell out the differences for you in detail.
www.syfer.com/category_docs/Ceramic_Dielectric_A.pdf
www.cde.com/catalogs/ceramperf.pdf
 
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