An antenna device includes a first antenna unit, a second antenna unit and a third antenna unit. An angle between the second antenna unit and the first antenna unit is substantially equal to 90 degrees. An angle between the third antenna unit and the first antenna unit is substantially equal to 90 degrees. The first antenna unit and the second antenna unit are configured to generate a signal having a first polarization when the third antenna unit is turned off. The third antenna unit and the second antenna unit are configured to generate a signal having a second polarization different from the first polarization when the third antenna unit is turned off. A method of generating polarized signals is also disclosed herein.

The invention relates to a source for a reflector antenna, comprising: a pseudo-cavity, a first sigma excitation device for exciting the pseudo-cavity in such a way as to generate a sum channel signal via a coaxial waveguide, a second excitation device for exciting the pseudo-cavity in such a way as to generate a difference channel signal, the second device comprising eight probes angularly distributed around a principal emission axis of the source, and a difference supply circuit for supplying the eight excitation probes according to the two modes TE.sub.21.

The invention relates to a source for a reflector antenna, comprising: a pseudo-cavity, a first sigma excitation device for exciting the pseudo-cavity in such a way as to generate a sum channel signal via a coaxial waveguide, a second excitation device for exciting the pseudo-cavity in such a way as to generate a difference channel signal, the second device comprising eight probes angularly distributed around a principal emission axis of the source, and a difference supply circuit for supplying the eight excitation probes according to the two modes TE.sub.21.

A first band radiating element for a multi-band antenna comprises at least one first band dipole that has a first dipole arm and a second dipole arm that each include one or more arm segments, and the number of the arm segments of the first dipole arm is greater than the number of the arm segments of the second dipole arm.

A first band radiating element for a multi-band antenna comprises at least one first band dipole that has a first dipole arm and a second dipole arm that each include one or more arm segments, and the number of the arm segments of the first dipole arm is greater than the number of the arm segments of the second dipole arm.

In certain embodiments, a two-dimensional antenna block has (at least) two different types of dual-band, dual-polarization patch antennas that support (at least) two different frequency bands in the same polarization direction, where each feed line in the antenna block supports only one frequency band. Quad-band antenna blocks, having three different types of patch antennas supporting three different frequency bands in a first polarization direction and a common frequency band in a second polarization direction, can be tiled to form larger, quad-band antenna arrays. A particular (4×4) antenna block has, in the first polarization direction, eight antennas supporting a first frequency band, four antennas supporting a second frequency band, and four antennas supporting a third frequency band, where all sixteen antennas support the common frequency band. In a PCB implementation, three IC chips are mounted onto the bottom of the PCB to support antenna block communication and/or imaging operations.

In certain embodiments, a two-dimensional antenna block has (at least) two different types of dual-band, dual-polarization patch antennas that support (at least) two different frequency bands in the same polarization direction, where each feed line in the antenna block supports only one frequency band. Quad-band antenna blocks, having three different types of patch antennas supporting three different frequency bands in a first polarization direction and a common frequency band in a second polarization direction, can be tiled to form larger, quad-band antenna arrays. A particular (4×4) antenna block has, in the first polarization direction, eight antennas supporting a first frequency band, four antennas supporting a second frequency band, and four antennas supporting a third frequency band, where all sixteen antennas support the common frequency band. In a PCB implementation, three IC chips are mounted onto the bottom of the PCB to support antenna block communication and/or imaging operations.

An apparatus and method for wavelength conversion of a signal, for example, a dual-polarization signal, is disclosed. The apparatus implements a single-loop counter-propagating wavelength conversion scheme which provides both up-conversion and down-conversion of the signal within the same loop. Nonlinear wavelength conversion devices in the loop provide both up-conversion and down-conversion of the polarization components of the signal within the loop depending on whether the polarization component travels through the nonlinear conversion device in a clockwise or a counter-clockwise direction. The wavelength-converted signal is available to be extracted from the wavelength-conversion loop. An all-optical wavelength-division multiplexing transponder based on the wavelength-conversion scheme is also disclosed.

An apparatus and method for wavelength conversion of a signal, for example, a dual-polarization signal, is disclosed. The apparatus implements a single-loop counter-propagating wavelength conversion scheme which provides both up-conversion and down-conversion of the signal within the same loop. Nonlinear wavelength conversion devices in the loop provide both up-conversion and down-conversion of the polarization components of the signal within the loop depending on whether the polarization component travels through the nonlinear conversion device in a clockwise or a counter-clockwise direction. The wavelength-converted signal is available to be extracted from the wavelength-conversion loop. An all-optical wavelength-division multiplexing transponder based on the wavelength-conversion scheme is also disclosed.

Aspects described herein relate to receiving, from a device, a first reference signal transmitted using a first set of antenna elements over a first polarization, receiving, from the device, a second reference signal transmitted using a second set of antenna elements over a second polarization, determining, based on the first reference signal and the second reference signal, an inter-polarization phase adjustment to be applied to signals transmitted from the first set of antenna elements or the second set of antenna elements, and transmitting, to the device, an indication of the inter-polarization phase adjustment.