30 results about "Broadband antennas" patented technology

A low profile antenna system includes an artificial magnetic conductor comprising a frequency selective surface (FSS) having an effective sheet capacitance which is electronically variable to control resonant frequency of the AMC and the resonant frequency of an antenna element positioned adjacent to the FSS.

The fast switching multifunction antenna of the present invention is a variable length antenna that may be switched to provide the equivalent function of a broadband antenna. The variable length antenna quasi-continuously transmits or receives signals at a plurality of frequencies by changing the effective length of the antenna using a variety of switching mechanisms. The present invention may comprise a plurality of antenna segments, a plurality of selectively actuable switches for interconnecting the antenna segments, and a switching mechanism operably coupled to the plurality of selectively actuable switches for switching them at a switching rate that is greater than twice the highest frequency to be transmitted or received. The switching rate will be fast enough to allow the antenna to sample the highest frequency and all of the required lower frequencies within the desired frequency range without the loss of information at any frequency. However, the switching rate is slow enough to allow sampling of the frequency at each antenna length before the next antenna length is activated.

The invention utilizes small, narrow-band and frequency adaptable antennas to provide coverage to a wide range of wireless modes and frequency bands on a host wireless device. The antennas have narrow pass-band characteristics, require minimal space on the host device, and allow for smaller form factor. The frequency tunability further allows for a fewer number of antennas to be used. The operation of the antennas may also be adaptably relocated from unused modes to in-use modes to maximize performance. These features of the antennas result in cost and size reductions. In another aspect, the antennas may be broadband antennas.

A novel approach is disclosed that mitigates flare-end ringing induced distortion of impulse signals that are transmitted from an electromagnetic radiator. Conventional tapering suppresses energy in the return path by impedance loading the antenna element at the expense of reduced radiation efficiency. This disclosure presents a method that balances the trade-off between radiation efficiency and return path energy suppression while it simultaneously minimizes taper induced signal distortion effects on the front edge of the transmitted impulse. The balance between radiation efficiency, end-fire ringing, and impulse distortion is achieved by placing impedance loading at only at or near the second half of the antenna element. Recent disclosures show the advantage of determining the position of each band through mathematical calculation and by subsequently removing select bands near the feed point to move the reflected pulse away from the front-edge of the transmitted impulse. This disclosure will show that optimal placement of the first tapered band is substantially more critical. The reflection caused by this interface must reach the original impulse at a position that will minimally interfere with its front edge.

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 polarizing reflector for broadband antennas includes a flat dielectric substrate, a patch array layer formed by a bi-dimensionally periodic lattice of thin metallic patches along first and second perpendicular directions x, y, and a ground layer. All the patches have a same shape elongated along the second direction y and form electric dipoles when electrically excited along the second direction y. For each row the patches of the said row are interconnected by an elongated metallic strip oriented along the first direction x and having a width c. The geometry of the patch array, the thickness h and the dielectric permittivity ε_r of the substrate, and the width c of the elongated metallic strips are tuned so that the patch array including the elongated metallic strips induces a fundamental aperture mode and a complementary fundamental dipolar mode along two orthogonal TE and TM polarizations within a single operating frequency band or two separate operating frequency bands, and the differential phase between the two fundamental modes over the single or the first and second frequency bands being equal to ±90° or to an odd integer multiple of ±90°. The polarizing reflector can comprise also a curved substrate and a patch array layer formed by a bi-dimensionally lattice of metallic patches along first curvilinear rows and second curvilinear columns.

The invention provides a multi-band antenna free of a lumped parameter element for a high-screen ratio mobile terminal, and belongs to the technical field of broadband antennas for the mobile terminal. The multi-band antenna is characterized in that a monopole antenna of combining a drive branch and double-branch coupling ground branches is adopted; the multi-band antenna comprises an antenna main body, a dielectric plate, a microstrip feeder and a metal floor, wherein the antenna main body comprises the T-shaped drive branch and double-branch coupling parasitic ground branches; two 1/4 wavelength resonant modes are generated at a low band; full coverage of low-band LTE700, GSM850 and GSM900 and high-band DCS, PCS, UMTS, LTE2300 and LET2500 is achieved by combining a 3/4 wavelength mode of the drive branch and the 3/4 wavelength modes of long coupling parasitic ground branches and introducing a 1/4 wavelength resonant mode of the short coupling parasitic ground branch and tuning stubs; and the loss caused by the lumped parameter element is also omitted.

The present invention relates to connecting and impedance matching a balanced electrical signal, such as that received by an antenna, with an unbalanced transmission circuit, such as that delivered to an amplifier. A planar circuit board is described that delivers signals having opposite polarization collected by different antenna arms to a location for convenient connection to a twin-lead transmission line. Circuit topologies for the circuit board are described that provide relatively low loss and low cross-coupling. A tapered microstrip balun is also described that includes two conducting microstrips on opposing faces of a dielectric separator. Stepped or tapered microstrips at the balanced input port of the balun provide an impedance transforming section electrically connecting to a mode transducing section, in which one of the microstrips tapers outward to form a substantially wider strip. Appropriate choice of parameters is shown to lead to favorable performance in a compact balun.

The invention provides a radio frequency architecture of a broadband communication system. The radio frequency architecture is composed of a broadband transceiver, a broadband transmitting/receiving module and a broadband antenna, the broadband transmitting module mainly comprises a broadband power amplifier, band-pass filters of multiple frequency bands, a single-pole N-throw switch and the like.The receiving module comprises a broadband low-noise amplifier, band-pass filters of multiple frequency bands and a single-pole N-throw switch. According to the invention, it is achieved that the broadband communication system is capable of carrying out multi-frequency band receiving and transmitting and is simple in structure and relatively low in cost.

The invention relates to a miniature high-gain directional broadband antenna for a microwave detecting system. The antenna comprises a multilayer structured antenna. The multilayer structured antenna comprises three layers which are separated by a clearance, wherein a first layer is a directional layer, a second layer is a dielectric layer and a third layer is a reflecting layer. A metal patch is adhered on the front surface of the dielectric layer, and a grounding patch is adhered on the back surface of the dielectric layer. The miniature high-gain directional broadband antenna can effectively determine whether a foreign object exists in a detected object and determines position of the foreign object.

The invention discloses a multichannel small broadband receiver, which comprises a signal processor, a small broadband antenna group and a broadband radio frequency receiving front end group, whereinthe broadband radio frequency receiving front end group is positioned between the small broadband antenna group and the signal processor; the small broadband antennas in the small broadband antenna group are connected with the broadband radio frequency receiving front ends in the broadband radio frequency receiving front end group in a one-to-one correspondence manner; the small broadband antennagroup is used for receiving broadband microwave signals in a space; the broadband radio frequency receiving front end group amplifies, filters and down-mixes the broadband microwave signal into an intermediate frequency signal and sends the intermediate frequency signal to the signal processor; and the signal processor is used for carrying out analog-to-digital conversion on the intermediate frequency signal, converting the intermediate frequency signal into a digital signal and then carrying out digital signal processing. Under the condition that the function is not changed, the size of a conventional system can be greatly reduced.

A design for high-efficiency broadband antennas which includes a D-plate and an E-cylinder, electrically insulated from each other, the E-cylinder being above the D-plate, and both parts insulated from a ground plane. The E-cylinder and D-plate may be fed by distinct feed networks with adjustable impedance.

A broadband antenna applicable to a portable wireless electronic communication product, and especially suitable to be provided on the top or on two sides of a panel, it includes structurally a low-frequency antenna path, a high-frequency antenna path connected with the low-frequency antenna path, and a coaxial cable for feeding out a signal; the core line of the coaxial cable for signal transmission is connected with a signal feed-in point of the antenna, but a grounding line of the coaxial cable is not connected with the antenna to avoid making the coaxial cable a parasitic element of the antenna; the coaxial cable is arranged parallely to the low-frequency antenna path or the high-frequency antenna path, the grounding line of the coaxial cable is used to do perturbation against the transmission path of the antenna, thereby the antenna can get an effect of a broad bandwidth.

The present invention discloses a novel 3dB waveguide power divider and belongs to the microwave communication technical field. The 3dB waveguide power divider of the present invention comprises a T-shaped EH surface waveguide cavity, a stepped matching block and matching screws; two T-shaped standard rectangular waveguides are welded together so as to form the T-shaped EH surface waveguide cavity; the stepped matching block is located in the T-shaped EH surface waveguide cavity and includes three steps; and altogether 2 matching screws are adopted and are distributed at the inner wall of the T-shaped EH surface waveguide cavity in a mirror symmetry manner. The novel 3dB waveguide power divider of the invention is simple in structure and convenient to process. The standing waves of the ports of the novel 3dB waveguide power divider in frequency bands from 11.45GHz to 14.5GHz are smaller than 1.15; the phase and amplitude balance of the novel 3dB waveguide power divider are good; and the direction of the phase of the common port of the novel 3dB waveguide power divider is orthogonal to the directions of the electric fields of the two output ports of the novel 3dB waveguide power divider, and the directions of the electric fields of the two output ports of the novel 3dB waveguide power divider are identical. The novel 3dB waveguide power divider is suitable for being adopted as a power distribution or synthesis device of a broadband antenna and can be applied to conditions which have special requirements for the directions of the electric fields of ports.

Embodiments of the present invention relate to low-profile broadband antennas having an anisotropic traverse resonance condition. One important aspect of the invention is the incorporation of an anisotropic high index medium material, at least partially loaded within the cavity, which is configured to maintain a constant resonance frequency of the antenna. A low-profile cavity antenna may comprise: an aperture defining an opening to a cavity; an interior space defined by the cavity which is formed of a flat bottom wall defining a ground plane, and a pair of spaced-apart, lateral sidewalls extending away from the flat bottom wall in opposite directions toward the aperture; and an anisotropic high index medium material, at least partially loaded within the cavity, configured to maintain a constant resonance frequency of the antenna. The lateral sidewalls may extend from opposing sides of the flat bottom wall perpendicularly or with an outwardly taper.

The invention discloses a frequency selection surface unit, a frequency selection surface and a frequency selection method. The frequency selection surface unit comprises a first electromagnetic dipole antenna and a second electromagnetic dipole antenna, the first electromagnetic dipole antenna is arranged above the second electromagnetic dipole antenna, and the first electromagnetic dipole antenna and the second electromagnetic dipole antenna are connected in a back-to-back manner so as to form a tightly coupled antenna which is small in spacing and has dual polarization; the first electromagnetic dipole antenna comprises a first filtering antenna and a first metal column; the first filtering antenna is fixedly connected with the first metal column; the second electromagnetic dipole antenna comprises a second filtering antenna, a second metal column and a floor structure, and the second filtering antenna is fixedly connected with the second metal column; according to the invention, the first electromagnetic dipole antenna and the second electromagnetic dipole antenna are set as broadband antennas with filtering characteristics, and the filtering characteristics of the antennas are realized under the condition that the thickness of the antennas and an additional circuit structure are not increased, so that the frequency selective surface has the characteristics of low thickness, high selectivity and broadband.

Embodiments of present inventions relate to low-profile, tapered cavity broadband antennas. One important aspect of the invention (although not the only) is the incorporation of a tapered lateral sidewalls in the antenna cavity. More particularly, according to various embodiments, a low-profile, tapered cavity antenna may comprise: an aperture defining an opening to a cavity; and an interior space defined by the cavity which is formed of a flat bottom wall defining a ground plane, and a pair of spaced-apart, tapered lateral sidewalls extending away from the flat bottom wall in opposite directions toward the aperture. The tapered shape of the tapered lateral sidewalls are specifically configured to maintain a constant resonance frequency within the cavity. In some embodiments, an isotropic high index medium material is at least partially loaded within the tapered cavity. Also, antenna may include a single or two-input port.