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Measurements >> RF Measurements >> Input matching problem
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Message started by wccheng on Mar 11^th, 2004, 8:53am

Title: Input matching problem
Post by wccheng on Mar 11^th, 2004, 8:53am

Dear all,

I need to do the input matching of my cmos RF IC. I have some questions about the matching problem. I hope anyone could help me.

I will use the surface mount inductor and capacitor to do the input matching of my cmos RF IC at 1.9GHz(LO) and 1.8GHz(RF). What is the good procedure in order to match 50Ohms?

Let me tell yours about my tuning method first and give me some advice or share your experience to me.

Firstly, I will try to place randomly of the value of the inductor and the capacitor. Using network analyzer to see what is the value of the S11. Secondly, I will try to use smith chart to tune out that cap. and ind. in order to find out the originally S11 of the circuit. Thirdly, I will based on this calculated value and find out the requried cap. and ind. using smith chart. Fourthly, I will place this cap. and ind. to the input and measure it again by the network analyzer. Finially, I will try to fine tune it by changing different value of the ind. and cap. (the value of the ind. and cap. is just around the calculated one before).

Is I this procedure correct? Or, is any faster method to tune the input in 50Ohms?

Best Regards,

Charles CHENG ;D