85 results about "Free space wavelength" patented technology

An antenna array includes four closely spaced, linearly arranged antenna columns. At least two of the columns, e.g., the center two columns, are dual-polarized. Spacing between neighboring columns is about ½λ, where λ is the free space wavelength at the network carrier frequency. Each column includes a first vertical linear array of radiating elements or groups of elements (sub-arrays) connected to a port. The dual-polarized columns each further include a second linear array of radiating elements oriented at a different polarization than the first array. (For example, horizontal/vertical or slant 45°.) Array ports are connected with four RF feed cables using duplexers in such a way so as to provide two different antenna configurations for forward link and reverse link frequencies, namely, a four-column closely spaced beam-forming array at the forward link and a two-column dual-polarized array at the reverse link for 4-branch diversity reception.

DC inductive FSS technology is a printed slow wave structure usable for reduced size resonators in antenna and filter applications of wireless applications. It is a dispersive surface defined in terms of its parallel LC equivalent circuit that enhances the inductance and capacitance of the equivalent circuit to obtain a pole frequency as low as 300 MHz. The effective sheet impedance model has a resonant pole whose free-space wavelength can be greater than 10 times the FSS period. A conductor-backed DCL FSS can create a DC inductive artificial magnetic conductor (DCL AMC), high-impedance surface with resonant frequencies as low as 2 GHz. Lorentz poles introduced into the DCL FSS create multi-resonant DCL AMCs. Antennas fabricated from DCL FSS materials include single-band elements such as a bent-wire monopole on the DCL AMC and multi-band (dual and triple) shorted patches, similar to PIFAs with the patch/lid being a DCL FSS.

An interrogator with an antenna that allows information exchanges with multiple transponders in a shorter distance of communication, by securing an intensified and uniform electromagnetic energy concentrated on areas near antenna elements. The interrogator is furnished with a sleeve antenna that includes a monopole conductor of ¼ wavelength (free space wavelength) continuously connected to a core wire of a coaxial cable on one end thereof, and a feed point on the other end, in which the sleeve antenna is grounded at the feed point. The interrogator has a plurality of the transponders arrayed near the antenna, and a plurality of the antennas selected by RF signal selectors. The interrogator antenna allows movable body identification such as in a goods management system for identifying multiply arrayed goods.

An antenna device includes antennas, each of which includes antenna elements arranged in a longitudinal direction, arranged side by side in a transverse direction intersecting the longitudinal direction, wherein an interval between the antennas arranged side by side in the transverse direction is approximately 2λ. where λ is a free space wavelength corresponding to an operating frequency, and each of the antenna elements includes a horn formed therein.

The invention relates to a low-profile low-cross-polarization dual-polarized broadband antenna comprising a resonant cavity, an upper microstrip board, a lower microstrip board, four feed probes and a coaxial medium. A rectangular upper-layer copper foil paster is arranged at the middle of the top surface of the upper microstrip board; and a rectangular lower-layer copper foil paster is arranged at the middle of the bottom surface of the lower microstrip board. The four feed probes distributed in the resonant cavity uniformly enable the upper-layer copper foil paster to be transited to the bottom of the resonant cavity vertically in a feed mode and, together with the coaxial medium, form a coaxial radio-frequency connection port. And a 45-degree angle is formed between each side of the upper-layer copper foil paster and each side of the resonant cavity. The profile height of the dual-polarized broadband antenna is 0.1-0.15 lambda0, wherein the lambda0 expresses a free space wavelength of a central frequency point. Therefore, the antenna unit performance can be improved obviously and thus the work bandwidh reaches 60%. More than two low-profile low-cross-polarization dual-polarized broadband antennas are connected in parallel to form a low-profile low-cross-polarization dual-polarized broadband antenna array.

A wavelength division multiplexing/de-multiplexing optical assembly for high speed parallel long distance transmission, wherein, the output terminal of the laser group is provided with the silicon lens group, the optical adjusting plate group, the lower layer silicon lens array, the lower layer filter group, and the lower layer free space wavelength division multiplexer, the optical isolator, and the focusing lens arranged in turn; the output terminal of the focusing lens is coupled with an input optical fiber; an output optical fiber is coupled with the collimating lens; the output terminal of the collimating lens is coupled with a prism; the output terminal of the prism is provided with the upper layer free space wavelength division multiplexer, the upper layer filter group, the upper layer silicon lens array and the detector group arranged in turn. Thereby, multiplexing/de-multiplexing of optical signals is realized by use of filter groups.

An antenna device includes subarray antennas including antenna elements, feeding lines and feeding interfaces. At least one of the feeding lines includes a phase shifter which shifts phases of the signals feeding to corresponding antenna elements. The feeding lines feed signals to the antenna elements. Each feeding interface is connected to each of subarray antennas. The subarray antennas are arranged parallel to each other with an interval on a plane to be symmetrical about a central axis. The interval is less or equal than a free-space wavelength. The central axis is along with the center of two adjacent subarray antennas arranged at middle of the subarray antennas when the number of the subarray antennas is even. Moreover, the central axis is along with one subarray antenna arranged at the middle of the subarray antennas when the number of the subarray antennas is odd.

A waveguide slot array antenna apparatus having a polarized wave plane in an oblique direction of a tube axis of a waveguide with proper excitation distribution of an aperture part for electromagnetic wave radiation or incidence. The waveguide slot array antenna apparatus is characterized by having a waveguide slot array antenna composed of a rectangular antenna waveguide whose cross section orthogonal to a tube axis is rectangular, wherein the antenna waveguide has a power feeding port at one end side in the tube axis direction, while the other end side is short-circuited. At a first wide plane of a pair of wide planes in parallel with the tube axis on the antenna waveguide, a plurality of elongated and rectangular (excluding square) apertures for electromagnetic wave radiation or incidence are arranged at intervals of about lambda g/2 (lambdag is intra-tube wavelength) along the tube axis. Each of the apertures has the same specified angle relative to a center line in parallel with the tube axis of the first wide plane, and adjacent apertures are arranged alternately at opposite positions relative to the center line. Each of the apertures at one side relative to the center line of the first wide plane is longer in length than about lambda f/2 (lambda f is free-space wavelength), while each of the apertures at the other side is shorter than about lambda f/2.

The invention discloses a small all-metal slow wave device for a traveling wave tube or backward wave tube which works at a centimeter wave band or a millimeter wave band in the technical field of vacuum electronics. The small all-metal slow wave device comprises a cylindrical metallic wave conductor and annular sheet type metallic electric resonance pieces arranged inside the wave conductor at intervals, wherein the inner diameter of the cylindrical metallic wave conductor is not larger than one third of the free space wavelength of an electromagnetic wave working at a center frequency, an electron beam channel is formed in the middle of each annular sheet type metallic electric resonance piece, and two auricle-shaped through holes are symmetrically formed in the annular sheet body of each resonance piece. Due to the fact that the two auricle-shaped through holes generating electric resonance are symmetrically formed in the annular sheet body of each resonance piece, electromagnetism intercoupling is effectively eliminated, and only the electric resonance generated by electric dipoles exists. Taking a slow wave device working at the S waveband as an example, the cross section of the all-metal slow wave device is only 35%-50% that of a traditional coupled cavity traveling wave tube. Thus, the all-metal slow wave device has the advantages of being small in size, simple in structure, high in power capacity, output power and interaction efficiency, capable of being produced in an industrialized mode easily and the like.

The invention relates to a four-port multi-input-multi-output (MIMO) antenna with high isolation degree. The four-port MIMO antenna comprises a grounding metal plate (1), a dielectric substrate (2), four antenna radiation units (3), four 1/4 wavelength impedance converters (4), four 50-ohm microstrip lines (5) and four metal patches (6). The MIMO antenna is provided with four antenna units, the resonant frequency is 5.2GHz, and the nearest distance between adjacent two antenna units is only 4.75 millimeters and is about 0.082 times of wavelength of a free space corresponding to the resonant frequency; the MIMO antenna is compact in structure and small in size; and the coupling degree among the antenna units is below -19.5dB by a vertical polarization technology and a method of additionally arranging a coupling path on the premise of no increase on the antenna size, and the MIMO antenna is high in isolation degree and is expected to be widely applied to the technical field of wireless communication.

A rectangular conductor pattern is formed around a first waveguide on a multilayer dielectric substrate facing a metal substrate, with an end at about λ/4 away from a long side edge of the first waveguide, where λ is a free-space wavelength of a signal wave. A conductor opening is formed between the end of the conduction pattern and the long side edge of the first waveguide, with a length longer than a long side of the first waveguide and shorter than about λ. A closed-ended dielectric transmission path is formed in the multilayer dielectric substrate in the layer direction, with a length of about λg/4, where λg is an in-substrate effective wavelength of the signal wave.

An antenna device includes subarray antennas including antenna elements and feeding interfaces. Each feeding interface is connected to each of subarray antennas. The subarray antennas are arranged parallel to each other with an interval on a plane to be symmetrical about a central axis. The interval is less or equal than a free-space wavelength. The central axis is along with the center of two adjacent subarray antennas arranged at middle of the subarray antennas when the number of the subarray antennas is even. Moreover, the central axis is along with one subarray antenna arranged at the middle of the subarray antennas when the number of the subarray antennas is odd.

An optical apparatus that provides extraordinary light transmission through a sub-wavelength-sized light transmitting region of the apparatus includes a core region of dielectric material having a complex dielectric constant, ε₁, surrounded by a metallic cladding material having a complex dielectric constant, ε₂, wherein the core region has a maximum dimension, 2a, further wherein 2a is less than λ, where λ is the free-space wavelength of light incident on an input side of the apparatus, and further wherein |ε₁| is greater than 0.5|ε₂|, ε₁ has a positive real part, and ε₂ has a negative real part, whereby the incident light will be transmitted by and exit the apparatus from an output side with extraordinary transmission.

The invention discloses a surface plasmon lens integrated with a metal nano-cavity. The surface plasmon lens comprises a substrate, a gold film, a nano-seam circular ring and a metal nano-cavity, wherein the gold film is plated on the upper surface of the substrate; the nano-seam circular ring is positioned on the gold film, and passes through the gold film; the metal nano-cavity is a rectangular hollow groove, is positioned in the center of the nano-seam circular ring, and is etched in the gold film to a certain depth from the upper surface of the gold film without being etched completely. In the surface plasmon lens, a light field can be localized into a light spot which is 6.0*10<-3>lambda0<2> (lambda0 is the free space wavelength of incident light) under the condition of resonance of the metal nano-cavity, and the light intensity of a lens center is increased by 5,500 times than a cavity-free situation simultaneously. The use of radial polarized light in a light source is avoided, accurate alignment of a light beam center and the lens center is not required, the application range is larger, and the greater convenience is brought to use. Moreover, the surface plasmon lens is convenient to process, and is easy for high-quality preparation.