LC (negative gm)VCO amplitude

[rjshmadala]

negative gm

Hello guys,

i was confusing about the operationg regions of active crcuit used in the implementaion of negative resistance in a LC VCO. can u guys explain operating regions of transistors with respective to amplitude. i mean when they enter in to sat,triode,cut off,and for steady state in which regions they work.

Regards

 

[v_c]

lc vco amplitude

Please take a look at the following tutorial,

**broken link removed**

This tutorial describes the operation of a basic L.C
oscillator as used in RFIC circuits etc. The pertinent
design parameters are given together with their relevant
equations to allow basic ‘hand’ calculations before
simulation is attempted. The initial design consists
of a fixed frequency oscillator that is further
developed into a voltage controlled oscillator (VCO),
by the use of MOS devices configured as varactors.
Finally a worked example is given to highlight the
design steps required and CAD simulations are also
described.

Best regards,
v_c