Systems and methods for millimeter and sub-millimeter wave imaging

A source of partially coherent radiation for illuminating a field of view, the source comprising:

• at least one non-movable diffuser destroying a spatial coherence of radiation being incident on the diffuser and directing the radiation towards a field of view, the diffuser including an array of independently controllable radiation scatterers;
• and
• at least one radiation emitting source being arranged to illuminate said diffuser with radiation;
• wherein each radiation scatterer comprises a static high-Q resonant scatterer exhibiting frequency resonance belonging to a particular frequency band and wherein the radiation emitting source comprises a radiation source that sweeps over the particular frequency band.

A millimeter wave system comprising:

• a source of radiation, the radiation comprising a set of independently controllable radiation components, each radiation component comprising a doublet that includes two spectral lines, and each radiation component being labeled by a given frequency shift between the two spectral lines;
• a receiver including an array of receiver elements disposed to receive the radiation emitted by the source, the receiver transforming the received radiation into an array of electrical signals;
• and
• a processing system coupled to receive the array of electrical signals and for decoding the array of electrical signals based on the labels of the radiation components.

A method for creating radiation that includes a polarized doublet, the method including:

• emitting radiation at a first s-mmw frequency;
• emitting radiation at a second s-mmw frequency, wherein the difference between the first s-mmw frequency and the second s-mmw frequency is much smaller than the average of the first s-mmw frequency and the second s-mmw frequency;
• controlling the difference between the first s-mmw frequency and the second s-mmw frequency;
• polarizing the radiation at the first s-mmw frequency into a first characteristic polarization;
• polarizing the radiation at the s-mmw frequency into a second characteristic polarization;
• combining the radiation at the first s-mmw frequency and the radiation at the second s-mmw frequency;
• and
• directing the combined radiation to a destination.

A method of creating radiation that includes a cross-polarized doublet, the method comprising:

• providing a voltage controlled oscillator operating at a first s-mmw frequency;
• directing energy of the oscillator to uniformly illuminate first and second sets of load-modulated point scatterers, the first set exhibiting a first polarization state and the second set exhibiting a second polarization state, wherein the first polarization state is orthogonal to the second polarization state;
• polarizing the oscillator in a third characteristic polarization state;
• positioning the first and second sets of point scatterers such that the first and second polarization state substantially differs from the third characteristic polarization state;
• modulating the load of the first scatterer with a first time varying signal;
• modulating the load of the second scatterer with a second time varying signal, wherein the ground harmonic of first time varying signal essentially differs from any harmonic of the second harmonic time varying signal;
• and
• scattering radiation from the first and second sets of point scatterers.

A millimeter wave transmitter-receiver apparatus for transmitting and receiving image or communication data comprising:

• a source of radiation, the radiation comprising a set of independently controllable radiation components, each radiation component comprising a doublet that includes two spectral lines, and each radiation component being labeled by a given frequency shift between the two spectral lines;
• a receiver including an array of receiver elements disposed to receive the radiation emitted by the source, the receiver transforming the received radiation into an array of electrical signals;
• and
• a processing system coupled to receive the array of electrical signals and for decoding the array of electrical signals based on the labels of the radiation components.

An s-mmw imaging system, comprising:

• a non-rotating diffuser destroying a spatial coherence of radiation incident on the diffuser and directing the radiation towards a field of view, wherein the radiation incident on the diffuser includes doublet spectral components and wherein the radiation incident on the diffuser is modulated by modulating a spectral shift between doublet spectral components;
• at least one radiation source disposed to illuminate the diffuser, the at least one radiation source generating radiation having a wavelength between about 0.1 mm and about 10 mm;
• a quasi-optical element disposed between the field of view and a multi-element receiver, the quasi-optical element directing radiation from the field of view toward an imaging plane;
• and
• said multi-element receiver disposed in the imaging plane, wherein particular ones of the receiver elements transform radiation into a set of electrical signals.