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It is implicit in this general definition of frequency stability that the stability of a given frequency decreases if anything except a perfect sine function is the signal wave shape. Phase noise is the term most widely used to describe the characteristic randomness of frequency stability.
How is phase noise measured in a spectrum analyzer?
Phase noise can be measured routinely with a modulation analyzer or a spectrum analyzer. Alternatively, a frequency stability analyzer can be employed to measure stability in the time domain or in the frequency domain.
Why is there phase noise in a beat tone?
It is only the phase noise difference that plays a role. Without it, the beat tone would simply contain no phase noise if the transmitted and received signals contained identical phase noise at the same time.
How does phase noise affect the FMCW radar?
Phase noise influences the radar performance in several ways. The FMCW radar transmits and receives simultaneously, so the transmit signal will therefore leak to the receiver directly via the antennas and feeds, and also via the substrate when the transmitter and receiver are integrated on an IC.
Are there physical restrictions on the derivative of a noiseless signal?
Physical restrictions impose a constraint on the maximum magnitude of the derivative of the noiseless, “artifactless” signal.
How to calculate the delay of a derivative?
Divide the derivative by dt, the time interval between consecutive samples, to set the correct units. dt = t(2)-t(1); vdrift = filter(d,drift)/dt; The filtered signal is delayed. Use grpdelay to determine that the delay is half the filter order.
What is the best way to compute the derivatives of noisy data?
Tuned the width of the Gaussian to emphasize the feature (s) I wanted to align. however, simpler approach is to do smoothing filter to alleviate the noise, then do the derivatives. What I do is to obtain a Fourier transform of noisy data, then apply Wiener filter (strongly depressing higher harmonics).