Wideband frequency analyzer employing optical chirp transform

A wideband frequency analyzer comprising:

• an electrical signal mixer operable to mix an electrical input signal with an electrical chirp signal to output a chirped input signal;
• an electro-optic modulator operable to modulate the chirped input signal onto an optical carrier signal to output a chirped modulated optical signal;
• and
• an optical transversal filter operable to filter the chirped modulated optical signal to output an electrical output signal representing the amplitude of the Fourier transform of the input signal.

A method of performing spectral analysis of a wideband signal, said method comprising the steps of:

• modulating the wideband signal onto an optical carrier signal to generate a modulated optical signal;
• mixing the modulated optical signal with a chirp signal to generate a chirped modulated optical signal;
• and
• filtering the chirped modulated optical signal to generate an electrical output signal representative of the amplitude of the Fourier transform of the electrical input signal.

An optical transversal filter comprising:

• a tapped optical fiber delay line including a first end and a second end, wherein an optical signal to be filtered is receivable at said first end and is transmittable there through towards said second end;
• a plurality of taps spaced apart from one another along said optical fiber delay line between said first and second ends thereof, each said tap obtaining a sample of the optical signal after a period of delay corresponding to the location of said tap along said optical fiber delay line;
• and
• a plurality of optical detectors for receiving the delayed samples of the optical signal from said taps and converting the samples to electrical signals comprising an output signal of said filter.