how this increase Q factor?

[rezaee]

at first thanks in advance for your quick and good helps

This indicates that the series losses are dominant because -|Rq| acts as a series resistor.

-|Rq| acts as series with which element that has effect on Q?
is you mean -|Rq| series with Rseries ( as you named ) in equivalent passive circuit?
if your answer is yes , how -|Rq| is in series with Rseries?


it is logical now to realize the required negative resistance -|Rq| either by the cross-coupled pair only (without R1)

when I delet R1 and only add cross-coupled pair between source of M2 and gate of M1 , the simulation doesnt give me good result and circuit doesnt have good behavior, Conversely, when I add R1 in addition to cross-coupled pair.

 

[LvW]

when I delet R1 and only add cross-coupled pair between source of M2 and gate of M1 , the simulation doesnt give me good result and circuit doesnt have good behavior,

Yes, that's what I have expected, therefore try case (2) with R1 in series with -|Rn| and R1 variable (during simulation).

 

[dgnani]

No, it is not. Some information of the VALUES are interesting - for example, to know if the series or the parallel losses are dominant. This is necessary for explaining the effect of Q increase (as desired by you).

series is gds1/(gm1gm2) and parallel is 1/gm1 it seems that series has smaller value from the parallel losses.

Are you sure about Rn=-180 ohms for the cross-coupled pair?

I did S-parameter simulation in ADS and activate Z parameter and with simulation the cross-coupled pair I see the real part of Z(1,1) is -180

...special negative value? What value?

near -18ohm

since I have not seen this mentioned yet ans so you can double check your simulation, it is easy to derive that the cross coupled circuit provide a negative resistance of DC value
-2/gm
and a bandwidth of (by memory - if might be off by a factor of 2)
gm/Cgs
this is a fundamental difference between simulating with an active negative resistance and a lumped element