The present description concerns a polarization cell (109) comprising a rectangular conductive plane having an off-centered opening, a terminal of application of an input signal located inside of the opening, a first switching element coupling the terminal to a first region of the conductive plane located in the vicinity of a first corner of the conductive plane and a second switching element coupling the terminal to a second region of the conductive plane located in the vicinity of a second corner of the conductive plane, the first and second corners being coupled by a same side of the conductive plane.

An isolator based on a waveguide-based artificial dielectric medium is scalable to a range of desired terahertz frequencies, has non-reciprocal transmission and provides low insertion loss and high isolation at various tunable terahertz frequencies, far exceeding the performance of other terahertz isolators, and rivaling that of commercial optical isolators based on the Faraday effect. This approach offers a promising new route for polarization control of free-space terahertz beams in various instrumentation applications. Artificial dielectrics are man-made media that mimic properties of naturally occurring dielectric media, or even manifest properties that cannot generally occur in nature. A simple and effective strategy implements a polarizing-beam-splitter and a quarter wave plate to form a highly effective isolator. Performance of the device is believed to exceed that of any other experimentally demonstrated method for isolation of back-reflections for terahertz beams.

In an exemplary embodiment, a phased array antenna comprises multiple subcircuits in communication with multiple radiating elements. The radio frequency signals are independently adjusted for both polarization control and beam steering. In a receive embodiment, multiple RF signals of various polarizations are received and combined into at least one receive beam output. In a transmit embodiment, at least one transmit beam input is divided and transmitted through multiple radiating elements, with the transmitted beams having various polarizations. In an exemplary embodiment, the phased array antenna provides multi-beam formation over multiple operating frequency bands. The wideband nature of the active components allows for operation over multiple frequency bands simultaneously.

Antenna arrays comprising planar combiner networks. An apparatus includes a first antenna component comprising a first multiplexer and a second antenna component comprising a second multiplexer. The apparatus is such that the first antenna component is located next to the second antenna component within an antenna array and the apparatus is disposed within a lattice spacing of the antenna array.

A transmitarray cell (105) comprises a first antenna element (105a) adapted to switching between two phase states, a second antenna element (105b) adapted to switching between two other phase states and between two circular polarization directions and a coupler (201) coupling the first antenna element to the second antenna element.

A two-port antenna system is proposed that uses a polarization-independent spatial power divider to align the beams from two orthogonally oriented dual-polarized feeds. This antenna system is compatible with fully polarimetric radar and provides high port isolation. It simultaneously provides a common aperture for transmit and receive to minimize radar parallax. The spatial power divider is designed using a combination of all-dielectric metamaterial techniques and the concept of miniaturized-element frequency selective surfaces, and is fabricated on a silicon wafer using standard microfabrication technology.

In an aspect, a polarization converter comprises a plurality of alternating high Dk layers and low Dk layers that alternate along an x-direction; wherein neighboring broad surfaces of the respective high Dk layers and low Dk layers are bonded together. In another aspect, a polarization converter can comprise a plurality of alternating high Dk layers and low Dk layers that alternate along a radial direction; wherein neighboring broad surfaces of the respective high Dk layers and low Dk layers are bonded together. The polarization converter is capable of converting an incoming electromagnetic wave to an outgoing electromagnetic wave having a different polarization.

An antenna array is provided that includes a plurality of radiating elements and one or more combiners. The plurality of radiating elements and the combiners are formed as a single indivisible metal element by use of additive manufacturing processes.

A multi-frequency folded lens antenna structure includes a stack, and the stack includes a polarization-dependent trans-reflector, a dielectric gap, and a multi-frequency twist-reflector; wherein the polarization-dependent trans-reflector is configured to transmit electromagnetic radiation of a first polarization incident from within the stack out of the stack and to reflect electromagnetic radiation of a second, different polarization incident within the stack towards the multi-frequency twist-reflector, and the multi-frequency twist-reflector is configured to selectively change a polarization of the reflected electromagnetic radiation from the second polarization to substantially the first polarization and to direct the electromagnetic radiation of substantially the first polarization, within the stack, towards the polarization-dependent trans-reflector for at least partial transmission out of the stack, wherein the multi-frequency twist-reflector is configured to selectively change the polarization for at least a first frequency band and for at least a second frequency band, non-contiguous to the first frequency band.

This elementary antenna includes a cavity delimited by front and rear faces and side walls, the front face being provided with first and second slots arranged in a cross, so that, when the cavity operates in a TE210 mode, a wave polarized perpendicularly to the first slot is emitted and when the cavity operates in a TE120 mode, a wave polarized perpendicularly to the second slot is emitted. This elementary antenna is characterized in that the rear face is brought to a reference electric potential, and in that the elementary antenna includes an excitation device, such as a metallized via, capable of exciting the front face through the cavity, the excitation device exciting the front face at a plurality of excitation points, distributed over the front face and presenting a common predefined impedance