


In the case
of phase modulation there are two nonzero components of the real and
imaginary parts of excitation.


The splitting
network multiplies the input signal by a constant and makes it as as argument
of Cosine in the real component and the Sine in the imaginary component.


This network
includes nonlinear elements.


Nevertheless,
for small signal analysis, the Cosine of small angle is approximately one,
and the Sine of small angle is approximately angle itself.


Thus for real
component we have a constant


And for
imaginary component – the input signal multiplied by constant.


This network
is linear and suitable for AC analysis, using phasor input VAC
