Amplifier circuit modification help needed

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emax0198

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Based on the following attached MPS5179 amplifier circuit, I want to design the same circuit for 62MHz. The circuit shown was designed for 38MHz.

The input is 62MHz 15mVp-p and the desired output should be 500mVp-p and V+ = 4V.
What will the value of resistor next to V+ and L2. Will the L2 need to be fixed or variable. Does all the other values should remain same?
 

This resistor is for power supply filtering. It should have a value that does not drop much voltage while being higher impedance than the bypass capacitor at the left end of it.
 

What about L2 value?
 

you need to give a full schematic to let others think about for you
 

Here is the complete schematic. It is the application note AN980 from Motorola.
 

HI,

Would you please give me a larger pic? I cannot see it clearly. It is too small
 

The way I see it, L2 is just a choke.
If I am right, then the actual gain of the amplifier will depend only on the input impedance of the IC. Therefore, if the inductor can work at 62MHz, you can use it, without changing it. And the resistor can stay the same.
I think the circuit does not need any modification, provided the inductor works at 62MHz. Else, calculate its reactance at 38MHz and select one that will give you the same reactance at 62MHz.
 

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