Photonic image rejection RF mixer, a phased-array radio frequency receiver implementing the same and related methods of operation

A receiver comprising:

• a plurality of channels that are each coupled to an interference space, each channel comprising:
• an electro-optic modulator to modulate an RF electrical signal with an optical carrier signal to generate a corresponding modulated optical signal including the optical carrier signal and two sidebands that constitute a first upconverted optical signal and a second upconverted optical signal, respectively,
• a first optical waveguide configured to convey the first upconverted optical signal to the interference space;
• the interference space configured to receive the upconverted optical signals at a channel edge of the interference space to allow the upconverted optical signals to interfere with each other and form one or more optical beams at a beamspace edge of the interference space;
• a plurality of sensors, including a first sensor, arranged at the beamspace edge to capture an interference pattern at the beamspace edge including the one or more optical beams, the plurality of sensors each comprising a sensor having an image rejection mixer, each image rejection mixer comprising a star coupler forming a Fourier transform space (FTS), the star coupler comprising:
• a first input port configured to receive a corresponding optical beam of the interference pattern;
• a second input port configured to receive a local oscillator (LO) from a local oscillator (LO) source;
• and
• first and second pickups each configured to capture a corresponding combined signal of the received optical beam and the LO forming a beat frequency signal, wherein the beat frequency signals of the combined signals captured by the first and second pickups are formed at quadrature phase increments with respect to each other.

A method of performing an image rejection on received radio frequency (RF) beams, the method comprising:

• capturing a first RF beam with an antenna array comprising a plurality of antennas, each of the antennas generating a corresponding RF electrical signal;
• modulating each RF electrical signal with an optical carrier signal to generate a corresponding modulated optical signal including the optical carrier signal and two sidebands that constitute a first upconverted optical signal and a second upconverted optical signal, respectively;
• forming a first optical beam corresponding to the first RF beam at an output edge of an interference space including receiving at an input edge of the interference space at least the first upconverted optical signals;
• capturing the first optical beam at the output of the interference space;
• delivering the first optical beam and a local oscillator (LO) to a Fourier transform space (FTS);
• capturing by first and second pickups first and second composite optical signals, respectively, wherein the first and second composite optical signals each comprise a combination of the first optical beam and the LO that form a corresponding beat frequency signal, wherein the beat frequency signal of the first composite optical signal and the beat frequency signal of the second composite optical signal are formed at quadrature phase increments with respect to each other.