Hilbert Transform in C provides possibly strange results

1. Which of the following about Hilbert transform is not true?
2. What is the purpose of Hilbert transform?
3. Why is Hilbert transform non causal?
4. How complex signal is generated using Hilbert transform?

Which of the following about Hilbert transform is not true?

Hilbert transform does not change the magnitude spectrum of the signal.

What is the purpose of Hilbert transform?

The Hilbert transform facilitates the formation of the analytic signal. The analytic signal is useful in the area of communications, particularly in bandpass signal processing.

Why is Hilbert transform non causal?

Thus, the Hilbert transform is a non-causal linear time-invariant filter. degree phase shift at all positive frequencies, as indicated in (4.16). The use of the Hilbert transform to create an analytic signal from a real signal is one of its main applications.

How complex signal is generated using Hilbert transform?

When a real signal x(t) and its Hilbert transform y(t)=Htx are used to form a new complex signal z(t)=x(t)+jy(t) , the signal z(t) is the (complex) analytic signal corresponding to the real signal x(t) .