Complex output after inverse FFT of a real signal

1. Why is FFT output complex?
2. What is complex conjugate of FFT?
3. What is the inverse FFT?
4. What are the outputs of FFT?

Why is FFT output complex?

Why does FFT produce complex numbers instead of real numbers? The reason FT result is a complex array is a complex exponential multiplier is involved in the coefficients calculation. The final result is therefore complex.

What is complex conjugate of FFT?

The complex conjugate of FFT(A) results from negating the imaginary part of FFT(A). The values of the elements in the power spectrum array are proportional to the magnitude squared of each frequency component making up the time-domain signal.

What is the inverse FFT?

Inverse FFT implements the inverse Fourier Transform for 2D images, supporting real- and complex-valued outputs. Given a 2D spectrum (frequency domain), it returns the image representation on the spatial domain. It is the exact inverse of FFT algorithm. Input as a magnitude spectrum. Output in spatial domain.

What are the outputs of FFT?

These frequencies actually represent the frequencies of the two sine waves which generated the signal. The output of the Fourier transform is nothing more than a frequency domain view of the original time domain signal.