Help me with too much NF of a mixer

I have designed a mixer with 0.18um process. the frequence of LO is 2.45G, rf rfrequence is 2.448G, IF frequence is 2M, current of mixer is 4mA. simulating after the tutorial from http://www.ek.isy.liu.se/courses/tse...r_Tutorial.pdf , i got a nf of 19dB(ssb). nf is too big and unacceptable.

somebody here can help me? thanks!

u need to increase the gain , gm of the RF diff. pair

Some additional hints:
- NF versus LO swing?
- check your Noise summary to understand which parameter is limiting
-do not expect a much lower result.
I hope it can help.
Mazz