Delay line phase noise discriminator

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 ?