transistor stability

hello Friends

I am trying design wideband LNA and the transistor which I am using is unstable and when I am making it stable the transistor s-parameters are also chaning with stability.

Kindly suggest me your views and guide me if I am doing some thing wrong.

regards

You will find a good tutorial here:

http://www.odyseus.nildram.co.uk/RFM...heory_Page.htm

what do you mean by 'the transistor bocome unstable'?
Is it the current or what? 8O

u can use ads -s parameter-stability circle