50 ohm microstrip line

Thread Starter

Amir Sarikhan

Joined May 29, 2015
45
Hi all
I have a RF Ic. it has a pin need to connect to antenna by 50 ohm transmission line .
the pin width is about 0.5 mm
I want to use FR-4 0.8mm height.
but in this case the width of micro strip line need to be about 1.4mm
So how can I attach the pin to this line ?
 

Thread Starter

Amir Sarikhan

Joined May 29, 2015
45
Why do you need a tutorial? Do you know what a tapered line is? Do you know what the pad size is for your IC? Do you know what the width of your 50Ω tline is? If so, then you have everything that you need.
Yes I know all of them .
but the problem is that when I use a taper , is the impedance seen from the IC pad , 50 ohm ?
 

AnalogKid

Joined Aug 1, 2013
10,987
The fact that the output stage is designed to drive a 50 ohm load does not mean that its internal output impedance is 50 ohms. Also, no package pin has a true 50 ohm impedance. The pin, the chip bonding wire going to it, and the pcb trace leading away from it all are impedance discontinuities, and that's just the way life is. The key to a successful design is keeping those issues as close to the pin as possible. The farther away they are, the wider the reflections are.

ak
 
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