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How to calculate frequncy by LC?

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firecow

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Here is schematic that I dont really understand how it calculate the frequncy.
It is LNA for GPS RF. It should work with 1575MHZ.
11a.jpg
How C8 and L1 works? How to choose their value?
How c16 and L3 works?How to choose their value?
 

deepeshmishra said:
Go through the page https://en.wikipedia.org/wiki/LC_circuit
It will help you to understand behavior of LC.
Click to expand...

Yes, I knew it.
I just dont know how it calculate in this schematic

For C8 and L1 , it is Series LC circuit, right?
so f=1/(2∏√LC)=1/(2*3.14*√100*0.000000056)=1/(2*3.14*√0.0000056)=1/(2*3.14*0.002366)=1/0.0148=67.5hz
It doesnt match 1575MHz

Why is it 67.5Hz?
Or I calculated it wrong?
 

C11, L1 impedance matching antenna
C8 DC decoupling
C16 DC decoupling
L3 impedance matching or stability
 

From this picture, you can't calculate the working frequency of LNA. This picture only provides you a matching solution in PCB board. C11, L1 is the input L-type matching. C16,L3 is the output L-type matching. C8 blocks the DC current.
 

E Kafeman said:
C11, L1 impedance matching antenna
C8 DC decoupling
C16 DC decoupling
L3 impedance matching or stability
Click to expand...

Is there a formula to calculate impedance matching?
Is there a formula to calculate DC decoupling?

Thanks a lot.
 

Impedance matching you can use ADS tools.
DC decoupling is easy, Zc=1/(j 2 Pi f C)
 

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