How do I show THD in Matlab?

Description. r = thd( x ) returns the total harmonic distortion (THD) in dBc of the real-valued sinusoidal signal x . The total harmonic distortion is determined from the fundamental frequency and the first five harmonics using a modified periodogram of the same length as the input signal.

How do you find signal distortion?

By using two precisely defined and highly linear tones, a signal/spectrum analyzer will be able to measure a device’s distortion products. If the total power of the two tones is well known, it’s possible to compare the power of the distortion products. Then a relationship can be developed between frequency and power.

How do you calculate total harmonic distortion from FFT in Matlab?

Calculate THD using fft

  1. %Use fft to find harmonics.
  2. harmonics = abs(real(fft(data))).^2;
  3. %Assume the fundamental frequency is the highest.
  4. fundamental_bin = min(find(harmonics==max(harmonics)));
  5. fundamental_power = harmonics(power_bin);
  6. %Find the sum of the rest of the harmonics.

How does Matlab calculate sinad?

r = sinad( x ) returns the signal to noise and distortion ratio (SINAD) in dBc of the real-valued sinusoidal signal x . The SINAD is determined using a modified periodogram of the same length as the input signal.

How do you measure THD?

Harmonic distortion may be measured by applying a spectrally clean sine wave voltage signal to the input of the amplifier under test (may require a band pass or low pass filter if the excitation RF source has high harmonic output content).

What is THD in Simulink?

Description. The THD block computes the total harmonic distortion (THD) of a periodic distorted signal. The signal can be a measured voltage or current. The THD is defined as the root mean square (RMS) value of the total harmonics of the signal, divided by the RMS value of its fundamental signal.

How is distortion measured?

Harmonic distortion may be measured by looking at the output spectrum on a spectrum analyzer and observing the values of the second, third, fourth, etc., harmonics with respect to the amplitude of the fundamental signal. The value is usually expressed as a ratio in %, ppm, dB, or dBc.

How can distortion factor be measured?

Measurement distortion factor A measuring instrument which can divide the distorted voltages into their spectral portions, is necessary for. A spectrum analyzer or FFT analyzer is very well suitable. They measure the amplitudes of the harmonious frequencies.

How does Matlab calculate SFDR?

r = sfdr( x ) returns the spurious free dynamic range (SFDR), r , in dB of the real sinusoidal signal, x . sfdr computes the power spectrum using a modified periodogram and a Kaiser window with β = 38.

How do you calculate signal to noise ratio in Matlab?

r = snr( xi , y ) returns the signal-to-noise ratio (SNR) in decibels of a signal, xi , by computing the ratio of its summed squared magnitude to that of the noise y : r = mag2db ( rssq ( xi (:))/ rssq ( y (:))) .

How do you calculate SINAD?

SINAD equals the RMS sum of THD + SNR. For the computed / entered SINAD, the corresponding RMS noise and the equivalent number of bits are shown in an output field at right.

What is SINAD in ADC?

ADC Signal-to-Noise Ratio and Distortion (SINAD) The Signal-to-Noise Ratio and Distortion (SINAD) is measured with a sinusoidal input near full-scale applied to the ADC.