what is required Q-factor value of inductor in RF transreceiver

Hi


what is the minimum required Q-factor value of inductor in different circuits (LNA, VCO, Filter) of 2.4GHz RF transreceiver shown in figure.

hi
please study this tutorial from coilcraft

rocking_vlsi said:

Hi

what is the minimum required Q-factor value of inductor in different circuits (LNA, VCO, Filter) of 2.4GHz RF transreceiver shown in figure.

Click to expand...

To make the answer short, the Q of the various stages will be determined by the desired bandwidth of each circuit: Higher Q means (contributes to) narrower bandwidth. Usually the filters, if designed using discrete components, will comprised of 3 to 7 L and C components in Chebychev, Butterworth or even Elliptical (Caur) configuration.

However, many designs call for bandpass filters in the frontends of receivers, and many of these parameters are set in the filter products offered by vendors so the idea of 'required Q' is kind of set for you.

The tutorial offered by young.microwave.eng is a good place to start for info on individual inductors.

Chapter 4, pg 27 of this document gives some insight of how a modern receiver for WiMAX in this instance is designed:

**broken link removed**

Murata is one vendor of filters that might be used as bandpass filters (BPF) in the front end to filter out out-of-band RF energy; they have a wide product offering judging from their website:

**broken link removed**


Hope you find this info of some help in your project.

Jim

The unloaded Q should be as high as possible, always set by the current manufacturing techniques and materials. The loaded Q is set by the circuit conditions. For the minimum loss Ql should be low and Qu high and equals 1- (Qu-Ql) /Qu ~ Ql/Qu typically Qu = 100, Ql = 10-50
Frank