I am making a phase discriminator ADS.
I am using phasenoise modulator to add phase noise to my vco. Then using discriminator I should be observing the
phase noise at the output of mixer. The time delay should be set in order to have quadrature mixing. That is why
td * wo = pi/2
However, I cannot get a correct spectrum for output voltage of mixer.
The first figure is my phase noise in baseband after demodulation.
The second figure is the discriminated phase noise using a delay line and mixer (Vout of mixer).
Where do I make a mistake ?