An ultra-wideband linear-to-circular polarizer is disclosed. In accordance with embodiments of the invention, the polarizer includes a plurality of cascaded waveplates having biaxial permittivity or cascaded anisotropic sheet impedances. Each waveplate/sheet has a principal axis rotated at different angles relative to an adjacent waveplate/sheet about a z-axis of a 3-dimensional x, y, z coordinate system. Each waveplate is composed of a unit cell of an artificial anisotropic dielectric. Each sheet impedance is composed of an anisotropic metallic pattern. The polarizer further includes impedance matching layers disposed adjacent the cascaded waveplates/sheets.

A low-profile apparatus for transitioning circular polarized electromagnetic waves to linear polarized electromagnetic waves when moving in a first direction and transitioning linear polarized electromagnetic waves to circular polarized electromagnetic waves when moving in a second direction. The apparatus includes a substrate with an electrical path positioned within the substrate. A first antenna element attached to the substrate is capacitively coupled to the electrical path and a second antenna element attached to the substrate is capacitively coupled to the electrical path. The apparatus includes a ground plane and electromagnetic waves propagate along the electrical path in a transverse electromagnetic mode. The first antenna element may be positioned within an interior of a first waveguide and the second antenna element may be positioned within an interior of a second waveguide. The first waveguide may have a circular cross-section and the second waveguide may have a rectangular cross-section.

In a vital sign sensor of the present invention, an antenna assembly radiates an oscillation signal generated by a SIL oscillator to an object in a form of a wireless signal and receives a reflected signal from the object, and the reflected signal can have the SIL oscillator injection-locked. The wireless signal radiated from the antenna assembly is transmitted to a demodulator for demodulation such that the vital signs of the object can be obtained. Additionally, an isolator of the antenna assembly is provided to prevent the SIL oscillator from receiving a clutter reflected from the demodulator and an environment where the demodulator is placed. As a result, the clutter can't influence the vital sign detection of the object.

A variable inclination continuous transverse stub antenna includes a first conductive plate and a second conductive plate spaced relative to the first conductive plate. The first conductive plate includes a first surface partitioned into a first region and a second different region, a first group of CTS radiators on the first region, and a second group of CTS radiators on the second region. A spacing and a width in an E-field direction of the first group of radiators is different in respect to a spacing and width in the E-field direction of the second group of radiators. The second conductive plate includes a second surface parallel to the first surface, the second surface partitioned into a first parallel plate transmission line and a second different parallel plate transmission line, the first and second parallel plate transmission lines configured to receive or output a different radio frequency signals from one another.

A polarizing screen includes an arrangement of at least one, electrically conductive, polarizing cell, which at least one cell is frequency- and polarization-selective, for transforming the polarization of the electric component E of the transverse electromagnetic (TEM) wave, received with linear polarization, into an electromagnetic wave with circular polarization. The four lateral walls of each section of waveguide forming a polarizing cell are each open over their entire length due to a median continuous slot, parallel to the direction of propagation of the incident electromagnetic wave, so as to form four angled electrically conductive plates. Each polarizing cell includes electrically conductive interconnection rods which interconnect the lateral walls and the four angled plates so that they are partially or completely rigidly connected and which form one or more electrical discontinuities, which are arranged at the ends of or inside the section of waveguide forming the polarizing cell and form one or more inductive or capacitive loads, or one or more (LC) resonators equivalent to an inductor and a capacitor connected in parallel or in series. The longitudinally open slots of the lateral walls and the elementary electrical discontinuities of each polarizing cell include geometric shapes and dimensions which provide total transmission of the incident wave, which is associated with a phase anisotropy of +90 or 90 according to the components E.sub.V and E.sub.H.

A phase-controlled antenna array comprises at least four phase-controlled elements which are connected via a feed network. Each antenna element comprises a waveguide emitter with a signal output coupling or input coupling and a phase actuator which is rotatably attached in the waveguide emitter and contains a mounting and two polarizers, wherein each of the two polarizers can convert a circularly polarized signal into a linearly polarized signal. The antenna elements additionally comprise a connection element and a drive unit which is attached to a support and which is connected to the phase actuator via the connection element such that the drive unit can rotate the phrase actuator about an axis of the waveguide emitter. The antenna array additionally comprises a computing unit which is connected to the drive unit(s) of the phase-controlled antenna elements via control lines and which adjusts the rotation of each phase actuator.

A linear-to-circular polarizer includes a meanderline polarizer having a plurality of meanderline conductor patterns, and a gridline polarizer having a plurality of conductors arranged in a grid pattern. The gridline polarizer is spaced apart from the meanderline polarizer by a first prescribed distance and the gridline polarizer is spaced apart from a planar antenna aperture of a planar antenna by a second prescribed distance.

An ultra-wideband linear-to-circular polarizer is disclosed. In accordance with embodiments of the invention, the polarizer includes a plurality of cascaded waveplates having biaxial permittivity or cascaded anisotropic sheet impedances. Each waveplate/sheet has a principal axis rotated at different angles relative to an adjacent waveplate/sheet about a z-axis of a 3-dimensional x, y, z coordinate system. Each waveplate is composed of a unit cell of an artificial anisotropic dielectric. Each sheet impedance is composed of an anisotropic metallic pattern. The polarizer further includes impedance matching layers disposed adjacent the cascaded waveplates/sheets.

Systems and methods relating to patch antennas. A patch antenna has a substrate, a resonant metal plate at one side of the substrate, and a ground plane at the other opposite side of the substrate. Two feed pins are used to couple the antenna to other circuitry. The feed pins pass through the substrate and holes in at the ground plane. The feed pins are physically disconnected from both the resonant metal plate and the ground plane. The feed pins are capacitively coupled to the resonant metal plate to provide an electronic connection between other circuitry and the patch antenna.

The present invention provides a polarization control plate including n layers (n4) of overlapping admittance sheets (10-1 to 10-6) each of which includes a plurality of plane unit cells, in which an admittance of a first plane unit cell included in an admittance sheet in a layer a (1an) and an admittance of a second plane unit cell being included in an admittance sheet in a layer b (1bn and ba) and overlapping the first plane unit cell are different from each other, and an admittance of the plane unit cell in an x direction and an admittance of the plane unit cell in a y direction are different from each other.