158 results about "Circularly polarized radiation" patented technology

The information signals are transferred to end users, customers, or service subscribers using at least two signal sources, generally satellites, and polarized radiation. Two polarization modes are employed, with the preferred modes being left-hand and right-hand circularly polarized radiation, although other polarization modes may be employed. The total number of channels can be divided among the polarization modes and transferred to end users either through the use of polarization switching in the receivers to selectively switch between the satellites, or by switching elements in the satellites (sources) to switch between polarization modes used for transmission.

A dual operational frequency slot antenna for receiving/transmitting wireless signals from a satellite or for receiving/transmitting wireless signals in an RFID system comprises two L-type slot antennas and a printed circuit feed line to receive and transmit circularly polarized radiation at dual operational frequencies.

An optical device for generating narrow-band circularly and elliptically polarized radiation, either by conversion from externally incident light or through thermal emission of heated objects. The optical device includes a metasurface comprised of unit cells, where each unit cell contains structural elements or features that break two mirror inversion symmetries of the unit cell and couple bright and dark resonances. In this manner, the optical device emits circularly polarized radiation that does not exhibit a preference for right-hand circularly polarized light or left-hand circularly polarized light incident upon it. As a result, multiple of such optical devices with different unit cell sizes, geometries and dimensions of the intra-cell elements may be implemented as a tag that thermally emits different states of circularly polarized radiation confined to multiple spectrally-narrow bands. Since the optical device can be fabricated in CMOS, the tag can be used for preventing/identifying tampering with genuine electronic components.

The invention relates to an efficient low-profile wide-axis ratio bandwidth large-scale circularly-polarized array antenna, in particular to a circularly-polarized array antenna composed of a metal floor with a coupling gap, a thin film printed with radiation patches and sequential rotating microstrip feed networks, a main feed network and a foam or hollow dielectric plate for supporting the thinfilm. Each four sequentially and rotarily-placed corner cut radiation metal patches and one sequential rotating microstrip feed network together form a sub array, coupling with the main feed network through the gap on the metal floor is carried out, sequential 90 DEG-difference equal-amplitude excitation of each sub array element is carried out, and thus, wide-axis ratio bandwidth circularly-polarized radiation is realized. Through increasing the stage number of the power divider and the number of sub arrays of the main feed network, a large-scale circularly-polarized array antenna can be constructed. In comparison with the existing circularly-polarized array antenna technology, the efficient low-profile wide-axis ratio bandwidth large-scale circularly-polarized array antenna has the advantages of wide axis ratio bandwidth, simple structure, high radiation efficiency, low profile, light weight, low cost and easy expansion to a large-scale array, and is especially suitable for mobile terminals and satellite terminals.

The invention discloses a substrate integrated ridge gap waveguide and a broadband circularly polarized leaky wave antenna. The substrate integrated ridge gap waveguide comprises an upper layer dielectric plate, upper layer peripheral metallized vias, an upper layer rectangular metal patch, two rectangular annular metal patches, a lower layer dielectric plate, lower layer peripheral metallized vias, a metal ridge, an electromagnetic band gap EBG structure, a metal ground, a feeding probe and a matching probe; the substrate integrate metal ridge is formed by two rows of metallized vias in the center of the low layer and a dumbbell-shaped metal patch; the electromagnetic band gap EBG structure is composed of periodic mushroom-shaped structural units arranged on both sides of a rectangular strip in the middle of the dumbbell-shaped metal patch, and is used for limiting electromagnetic wave leakage to two sides. The upper layer and lower layer dielectric plates are tightly bonded. The wideband circularly polarized leaky wave antenna is a slot array arranged on the upper surface of the upper rectangular metal patch, and circularly polarized radiation is realized. The invention maintainsthe wide band and frequency scanning characteristics of the leaky wave antenna, and realizes the characteristics of circular polarization and high gain flatness.

The invention discloses a low-profile omni-directional left-right-handed circularly polarized reconfigurable antenna which comprises a dielectric substrate, a circular radiation patch, N double-arc-arm radiation patches and 2N radio-frequency switch diodes, N+1 patch inductors, N bonding pads, a circular grounding plate, N short circuit columns, a coaxial feed probe and a direct-current power supply, wherein a circular seam is formed in the circular grounding plate and is divided into an inner patch and an outer patch; the upper surface circular radiation patch is connected with the N double-arc-shaped arm radiation patches through the 2N radio frequency switch diodes which are biased in opposite directions; one end of the direct-current power supply is connected with the N bonding pads onthe upper surface of the dielectric substrate, and the other end of the direct-current power supply is connected with the inner patch; and three short-circuit columns are arranged at equal intervalson the equiangular line of the double-arc-shaped arm patch and connected with the circular radiation patch, the medium substrate and the circular grounding plate. The reconfigurable antenna in the invention has the advantages of good omni-directional circularly polarized radiation performance, capability of realizing omni-directional left-right-handed circular polarization switching, low loss, lowprofile, easiness to machine and low cost.

Multipath reception by an antenna is reduced by mounting the antenna on a semi-transparent ground plane that has a controlled distribution of layer impedance over a central region and a peripheral region. The central region includes a continuous conductive segment on which the ground element of the antenna is disposed. The distribution of the layer impedance over the peripheral region is configured by multiple conductive segments electromagnetically coupled by lumped circuit elements. A semi-transparent ground plane can be fabricated by depositing a metal film on a dielectric substrate and etching grooves into the metal film to form a desired pattern of conductive segments. Lumped circuit elements can be fabricated as discrete devices, surface mount devices, and integrated circuit devices. Various semi-transparent ground planes can be configured for linearly-polarized and circularly-polarized radiation.

The invention discloses a ring-loaded microstrip patch antenna, comprising a reflecting plate (1), a lower patch (2), an intermediate patch (3) and a ring-loaded upper patch (4), wherein a short-circuit metal column (6) with a hole in the middle serves as a support among the three patches and the reflecting plate (1); a cover plate (5) is superposed on the upper patch (4); a feeder of the upper patch (4) passes through the hole in the middle of the short-circuit metal column (6), is connected with an impedance matching segment (12) on the cover plate (5) and then is fed onto the intermediate patch (3); a feeding port (8) of the intermediate patch (3) and a feeding port (9) of the lower patch (2) are connected with the circle center of the patches by lines to form included angles of 90 degrees to feed in circularly polarized radiation waves with equal signal amplitude and phase difference of 90 degrees; and the edge (11) of the upper patch (4) turns downwards to form a ring similar to the bottle cap. The edge of the upper patch turns downwards and the antenna utilizes the ring loading technology, thus increasing the gain of the upper patch and lowering the sidelobe and back lobe level.

A patch antenna includes a dielectric substrate having a body that extends a thickness from a first side to a second side that is opposite the first side. The body of the substrate includes thru openings that extend through the thickness of the body. A radiating patch is positioned on the first side of the body of the substrate. The radiating patch includes holes that are aligned with corresponding thru openings of the body of the substrate. A ground plane is positioned on the second side of the body of the substrate. At least three feed probes are electromagnetically coupled to the radiating patch such that the patch antenna is configured to generate a circularly polarized radiation pattern. Each feed probe includes a conductive path that extends within a corresponding thru opening of the body of the substrate from the second side of the body to the first side of the body. Each conductive path being exposed along the first side of the body via the holes of the radiating patch. The feed probes are positioned relative to the body of the substrate such that adjacent feed probes are spaced apart from each other along the body. The feed probes are configured to feed the radiating patch at at least three points with approximately equal power amplitude.

A patch antenna receives circularly polarized RF signals from a satellite. The antenna includes a radiating element. A plurality of feed lines feed the radiating element at a plurality of feed points. The feed points are spaced apart to generate a circularly polarized radiation beam solely in a higher order mode at a desired frequency. The antenna may include a plurality of parasitic structures. The feed point spacing and/or the parasitic structures tilt the radiating beam away from an axis perpendicular to the radiating element. Thus, the patch antenna provides excellent RF signal reception from satellites at low elevation angles.

An antenna system includes a ground plane including a first corner and a second corner that are positioned along a first common edge. A first antenna element is disposed at the first corner of the ground plane and includes a first slot. A second antenna element is disposed at the second corner of the ground plane and includes a second slot. The first antenna element and the second antenna element are fed with an electromagnetic signal and the electromagnetic signal at the first antenna element is approximately 90 degrees shifted from the signal at the second antenna element. The first antenna element and the second antenna element form an antenna structure, and the antenna structure transmits circularly polarized radiation.

An antenna assembly (700) includes a set of conformal shells (704, 706) housing a set of orthogonal dipoles (102, 104, 108, 110) that produce a circularly polarized radiation pattern. The dipoles (102, 104, 108, 110) are fed by a quadrature hybrid (118) and impedance matching circuit (114). The assembly (700) also includes a set of baluns (126, 128) to reduce VSWR.

A circularly polarized radiating element includes at least one excitation aperture for a wave that is linearly polarized with what is referred to as an excitation first polarization, a frequency selective surface and a metasurface comprising a two-dimensional and periodic array of metasurface cells, the excitation aperture opening onto the metasurface, the metasurface cells all being oriented identically with respect to the excitation polarization and configured to: reflect an incident wave having the excitation polarization in order to form a reflected wave polarized with the excitation polarization, and depolarize and reflect the incident wave in order to form a reflected wave polarized with the orthogonal polarization, having a phase difference substantially equal to ±90° with respect to the reflected wave polarized with the excitation polarization, and having an amplitude substantially equal to the amplitude of a wave radiated by the frequency selective surface, generated from the reflected wave polarized with the excitation polarization.

A method for approximating an influence of an optical system on the state of polarization of optical radiation comprises the steps of providing incoming optical radiation for the optical system in several incoming states of polarization, including at least one incoming state having circularly polarized radiation components; directing the incoming optical radiation onto the optical system; measuring at least one characteristic, including a phase distribution, of a resulting outgoing optical radiation emerging from the optical system with respect to each of the incoming states of polarization; and approximating the influence of the optical system on the state of polarization of optical radiation by evaluating the measured characteristics of the outgoing optical radiation.

The invention discloses a low-profile, bandwidth, circularly polarized cross-dipole antenna. The antenna comprises a cross-dipole radiator, two layers of dielectric substrates and an irregular reflector, wherein the cross-dipole radiator is composed of a ladder-like rectangular patch and a phase delay line respectively arranged on an upper surface and a lower surface of the upper dielectric substrate, and the phase delay line provides the phase difference at 90 DEG, thereby forming a circularly polarized radiation; the ladder-like rectangle patch can enable the antenna to produce the dual-band 3dB axial ration (AR) pass-band, and the introduction of the lower dielectric substrate can fuses two sections of AR pass-bands so as to greatly increase the AR bandwidth of the antenna; and the design of the irregular reflector enables the gain of the antenna to be well improved. The antenna disclosed by the invention creatively designs the ladder-like rectangle patch dipole, the antenna is simple in structure and free from using a complex feedback circuit, the height is only 0.13l0, 10dB impedance bandwidth achieves 66.9%, the 3dB AR bandwidth achieves 55.1%, and the average gain in the antenna pass-band is 10.4dBi.

The invention discloses a circularly polarized anti-metal tag antenna. The circularly polarized anti-metal tag antenna comprises a dielectric slab, and a circularly polarized radiation patch and a metal floor which are respectively etched at the top and the bottom of the dielectric slab through a light etching technology, wherein the circularly polarized radiation patch is a corner cutting rectangle micro strip patch, at least on cross-line-shaped groove which extends towards the center of the corner cutting rectangle micro strip patch is arranged on each edge of the corner cutting rectangle micro strip patch, at least one cross groove is formed in the surface of a portion surrounded by each two adjacent cross-line-shaped grooves and the corresponding edge of the circularly polarized radiation patch, a groove body is arranged at the center of the circularly polarized radiation patch, an impedance matching wire is arranged in the circularly polarized radiation patch, an impedance matching branch node is arranged at one end of each cross-line-shaped groove, close to the groove body, and the impedance matching wire is connected with the circularly polarized radiation patch through a chip, and connected with the metal floor through a metal short circuit pin. The circularly polarized anti-metal tag antenna has a good impedance characteristic and a circular polarization characteristic, is compact in structure, and simple and clear in design thought, and can be directly installed on an object of a metal structure for use.

A microstrip antenna for circularly polarized radiation including a substrate, a ground layer disposed on a first side of the substrate, a first radiating layer disposed on a second side of the substrate opposite the first side, one or more first electrically conductive pathways extending from the ground layer to the first radiating layer, wherein the one or more first electrically conductive pathways form a ring about an axis, one or more second electrically conductive pathways extending from the ground layer to the first radiating layer, wherein the one or more second electrically conductive pathways are disposed along a portion of a first line extending outwardly from the ring, and a feed conductor for connecting the antenna to a feed line.

Patch antennas for signals of global navigation satellite systems (GNSS) are described. A compact antenna system reduces directional diagram level in the rear hemisphere primarily for cross-polarized (left hand circularly-polarized) component. It can be used for reducing multipath reception. The antenna receives GNSS signals and includes a patch circularly-polarized radiator consisting of a radiating patch, a ground plane under it and a loop radiator coaxially located around the patch radiator. The loop radiator is excited by a separate power circuit or by a passive method where LHCP waves of MP and loop radiators in the rear hemisphere would be anti-phase added. A dual-band antenna system includes an active HF radiator, under which there is an active LF radiator under which there is a passive LF radiator, a loop HF radiator being coaxially located around the active HF radiator.

The invention discloses a wide-band circularly polarized high-gain antenna, which belongs to the technical field of circularly polarized antennas. Set a partial reflective surface; print the copper-clad surface on the lower surface of the lower dielectric substrate as a grounding plate, set a bottom plate under the grounding plate, print the feed network on the lower surface of the bottom plate, and print a circular pole on the lower dielectric substrate chemical radiation unit. The structure of the present invention is simpler, and the resonant cavity is formed by a part of the reflective surface and a ground plate parallel to the part of the reflective surface, and the gain of many array units can be significantly improved by using the resonance characteristics. At the same time, the structure between the circularly polarized radiation units Rotate 90 degrees in sequence to form broadband circular polarization; although the distance between the circularly polarized feed units of the present invention is much larger than the distance between conventional antenna array units, there is no grating lobe; it has good practicability.

The invention discloses a millimeter wave circularly polarized planar slot array antenna. The antenna comprises an antenna radiation layer, an antenna coupling layer, an antenna feed layer and an antenna receiving layer which are superposed together from top to bottom. The antenna radiation layer comprises multiple antenna units, each antenna unit is composed of a horn unit, a radiation slot and a radiation matching block, and one horn unit forms one horn subarray; the antenna feed layer comprises a feed slot, a feed waveguide and a feed matching block, and the feed slot, the feed waveguide and the feed matching block form a feed network together; and the antenna units of the antenna radiation layer have no polarization cover, and the horn subarrays are used for realizing the circularly polarized radiation. The millimeter wave circularly polarized planar slot array antenna has no polarization cover, and has the circularly polarized property, high gain property and perfect difference beam coverage performance; the coverage rate of the difference beam pairs and the beams is up to 100%; and compared with the prior art, the millimeter wave circularly polarized planar slot array antenna has the advantages that the difficulty in the electric fitting technology is reduced, the consistency of production is improved greatly, the workload of debugging in the later stage is avoided, the environmental suitability of the antenna is enhanced, and the production cost is lowered.

The invention provides a wide-angle circularly-polarized super surface antenna comprising a super surface structure and a half-wavelength dipole antenna placed at a certain height right above the super surface structure. The super surface structure is formed by periodically extending super surface units in the x and y directions according to a certain period respectively, and a super surface unit m*n gap-free arrangement structure is formed, wherein m and n are natural numbers greater than or equal to 2. Each super surface unit is composed of a dielectric substrate, a grounding plate arranged on one side of the dielectric substrate, and a double-arrow-shaped metal patch arranged on the other side of the dielectric substrate. According to the invention, circularly-polarized radiation wave can be generated in a space above the dipole antenna, and by changing the sizes of the super surface units and the dipole antenna and the vertical distance between the super surface units and the dipole antenna, the super surface antenna is enabled to work in different frequency bands. The wide-angle circularly-polarized super surface antenna of the invention has a series of advantages of simple structure, easy frequency adjustment, wide circular polarization angle, radar scattering cross section reduction, and the like.