Why dont we do impedance matching in IC

[Julian18]

Hi, there
I am currently involved in a RF project, while the LNA input needs to be matched with some specified impedance, the mixer and other modules behind dont even bother about the matching issue. I just can not fully understand it. Can you guys here shed some light on this?

Thanks.

 

[kamalkiran.j]

the main reason we go for Impedance Matching is for the Maximum power transfer from one stage to the other ,, so to reduce the Attenuation during Propogation from one stage to the other and to maintain the signal levels at all points of the Design we Need Impedance Matching ..

Note: Power Gain is Equal to the Voltage Gain if there is a proper Impedance Matching , so thus from this Statement u can be clear why Impedance Matching is necessary in IC and that to RF IC..

 

[Alex_IC]

We need external IC matching due to power loss because of reflections. The signal wavelength is comparable with size of external devices.

We do not need internal IC power matching if we do not worry about maximum power transfer, we have no signal reflection inside IC (if chip size much smaller the signal wavelength), so there is no power loss due to reflections.

But if we need maximum power transfer inside IC - we need internal matching.

 

[khouly]

the LNA is the 1st stage in ur receiver , and it should be matched to external duplexer or the antenna so it need a matching circuit

the Mixer and other stages are almost on chip so the dimensions is very small , and the signals are voltage signals so they don't need matching

khouly

 

[fanshuo]

if you use a on chip balun or sth before the LNA to match tot he filter, you do not need the matching at LNA anymore

 

[jecyhale]

Hi, there
I am currently involved in a RF project, while the LNA input needs to be matched with some specified impedance, the mixer and other modules behind dont even bother about the matching issue. I just can not fully understand it. Can you guys here shed some light on this?

Thanks.

Usually we care of the voltage of each node in IC.
So impedance matching is not needed at all.