Problem 1(a) B1 is always positive and K>1 beyond 68GHz. This suggests that the circuit is potentially unstable below 68 GHz and unconditionally stable above 68 GHz. At 20 GHz, the circuit is potentially unstable as K<1. So MAG is not defined at 20 GHz. We only have MSG (Maximum stable gain) defined. MSG = 17.759 dB. When the device is unconditionally stable, MSG=MAG. This value agrees well with the calculated value of 17.6 dB.