Provided are examples of removable circularly polarized antenna fitment and methods of fabrication. In one aspect, a fitment comprises a plurality of conductive elements spaced radially around a central point contained with a housing. The elements may have an included angle of between 8 and 71 degrees from horizontal. The plurality of conducting elements may be straight, bent, or curved and may be comprised of between 3 and 12 conductors. The fitment may contain a housing which is removable from a linear antenna.

A system and method provide simultaneous dual polarization operation using a linearly-polarized planar antenna and a polarizer spaced apart from the linearly-polarized planar antenna, the polarizer including a first polarization state having primarily one of left-hand circular polarization (LHCP) or right-hand circular polarization (RHCP), and a third polarization state having linear polarization from which a combination of both LHCP and RHCP is simultaneously derived. The polarizer is placed in the first polarization state to at least one of transmit or receive a signal having primarily one of LHCP or RHCP, and the polarizer is placed in the third polarization state to simultaneously transmit and/or receive two different signals, where a first signal of the two different signals has primarily LHCP and a second signal of the two different signals has primarily RHCP.

A steerable beam antenna includes a feed line and first and second arrays of switchable scatterers along opposite sides of the feed line. The first array scatters an electromagnetic wave propagating through the feed line to form a first beam portion with a first polarization, and the second array scatters the propagating wave to form a second beam portion with a second polarization orthogonal to the first polarization. Each scatterer in the first and second arrays is switchable between a high state and a low state, the high state scatterers and the low-state scatterers in each of the first and second arrays defining a periodic pattern. The scatterers in the first and second arrays are switchable to shift the pattern of scatterers in one of the arrays relative to the pattern in the other array by a selectable period shift that yields a desired polarization for the beam.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for producing meander-line polarizers. In some implementations, a meander-line polarizer includes a dielectric substrate made of a polyester polymer material and meander-line arrays formed on a surface of the dielectric substrate. Each meander-line array includes a sequence of alternating perpendicular conductive traces that are formed the surface of the dielectric substrate by applying conductive ink to the surface of the dielectric substrate using a template that defines a location and dimensions of each conductive trace of each meander-line array.

A dual-mode polarizer for selectively switching between linear polarization and circular polarization includes a first meander-line polarizer, and a second meander-line polarizer spaced apart from the first meander-line polarizer to define a first gap therebetween. A first angular orientation between the first and second meander-line polarizers produces variably-oriented linear polarization of a signal passing through the first and second meander-line polarizers, and a second angular orientation between the first and second meander-line polarizers produces variably-oriented circular polarization of a signal passing through the first and second meander-line polarizers.

An apparatus and method for producing a low loss printed circuit board (PCB). The PCB includes an antenna patch, a ground plane, and a polarizer. The antenna patch consists of a plastic base having a first plurality of circuit patterns formed directly on its top surface. The ground plane is formed directly on a bottom surface of the plastic base used for the antenna patch, and contains one or more coupling circuit patterns. A polarizer spacer is provided on the antenna patch to provide separation from the polarizer. The polarizer also consists of a second plastic base having a second plurality of circuit patterns formed directly thereon.

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.

This disclosure relates generally to methods and systems for designing an optimal dual-band metamaterial polarization converter for refractive index sensing applications. Most of the existing techniques for designing the metamaterial-based polarization converters operating at very high frequency range limits the sensing performance and increases fabrication complexity. In the design of the optimal dual-band metamaterial polarization converter, first a circular split-ring resonator (SRR) as a unit cell is designed. Secondly, the two capacitive gaps of the top layer, are aligned at 180 degrees with respect to each other and at 45 degrees with respect to X-axis and Y-axis. Lastly, step-by-step tuning the one or more key design parameters of the SRR, is performed until an optimum frequency response is obtained, to obtain the optimal dual-band metamaterial polarization converter.

A waveguide antenna and a method for producing same is disclosed. In one embodiment, The waveguide-fed surface integrated antenna array comprises an aperture coupled waveguide (WG) antenna element with inclusive slot on a first metal layer, a first ground plane as part of a surface integrated waveguide (SIW) on a first metal layer, an embedded microstrip feed on a second metal layer, a second ground plane as part of a SIW with one or more apertures formed within the ground plane on a third metal layer, and a waveguide enclosing the antenna element on the first metal layer. The SIW is formed on the first and third metal layers of the composite RF board along with one or more shorting conductors electrically shorting the first and second ground planes.

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.