115 results about "Front-to-back ratio" patented technology

A loop directive antenna having improved front-to-back ratio and gain for given input power levels assembly for a hand-held radio frequency transceiver, such as a cellular telephone or PCS device operating in the 800-900 or 1850-1990 MHz. frequency ranges, respectively, is provided by the present invention. The loop directive antenna assembly consists of a main loop antenna conductor disposed upon a dielectric element. The main loop antenna conductor and dielectric element are maintained a predetermined distance away from a ground plane, which may be the circuit board or other conductive element. The main loop antenna conductor may include a variety of feedpoint orientations to provide alternative polarizations of the transmitted signal. The ground plane may be a portion of the printed circuit board of the device, a conductive part of the device housing, the battery pack of the device, or a separate conductive panel.

The invention discloses an antenna. The antenna comprises a reflecting plate, and a plurality of single-polarity micro-strip vibrators arranged on the reflecting plate; each single-polarity micro-strip vibrator comprises a main PCB; two micro-strip radiating areas are symmetrically formed in the main PCB; each micro-strip radiating area comprises a micro-strip upper arc side and a micro-strip lower arc side which are closed to form a closed area; a plurality of independent micro-strip units with 1/2 wavelength are arranged in each micro-strip radiating area. The antenna shows outstanding communication electrical parameter performances between the frequency band from 800 to 950MHz; the front-to-back ratio of the minimum frequency point of single radiating unit is more than 31dB; the front-to-back ratio of the minimum frequency point of single radiating unit under 950MHz is 36dB; the low-frequency-point gain is more than 9.35dBi; the average gain in the band is more than 9.8dBi.

A band clamp for coupling a radome to a distal end of a reflector dish for improving the front to back ratio of a reflector antenna, is provided with an inward projecting proximal lip and an inward projecting distal lip. The distal lip is dimensioned with an inner diameter equal to or less than a reflector aperture of the reflector dish. The proximal lip may be provided with an inward bias dimensioned to engage the reflector dish in an interference fit and/or turnback region dimensioned to engage an outer surface of a signal area of the reflector dish in an interference fit. A variety of different configurations of protruding portions extending from the band clamp may be applied to further improve electrical performance.

A dual polarized variable beam tilt antenna (10) having a plurality of offset element trays (12) each supporting pairs of dipole elements (14) to orient the dipole element pattern boresight at a downtilt. The maximum squint level of the antenna is a consistent downtilt off of boresight and which is at the midpoint of the antenna tilt range. The antenna provides a high roll-off radiation pattern through the use of Yagi dipole elements configured in this arrangement, having a beam front-to-side ratio exceeding 20 dB, a horizontal beam front-to-back ratio exceeding 40 dB, and is operable over an expanded frequency range.

An ultra high frequency antenna includes a first plane, a second plane opposite to the first plane by a distance, a driven dipole, at least a parasitic element having an indentation, and a balun. The balun includes a coplanar strip line and a microstrip line which has a first strip, a second strip area parallel to the first strip, and a third strip perpendicular to the first and second strips. The coplanar strip line coupled to a truncated ground plane with two narrow slots. The present planer antenna features a compact size, wide impedance bandwidth, moderate gain, and excellent front-to-back ratio. This antenna is well suitable for the applications in RFID handheld readers.

A band clamp for coupling a radome to a distal end of a reflector dish for improving the front to back ratio of a reflector antenna, the band clamp provided with an inward projecting proximal lip and an inward projecting distal lip. The distal lip dimensioned with an inner diameter equal to or less than a reflector aperture of the reflector dish. The proximal lip provided with a turnback region dimensioned to engage an outer surface of a signal area of the reflector dish in an interference fit. A width of the band clamp may be dimensioned, for example, between 0.8 and 1.5 wavelengths of an operating frequency.

The invention discloses an integrated broadband dual polarized antenna, which comprises a radiator and a balanced feeding device, wherein the balanced feeding device is simultaneously formed into a supporting arm of an antenna oscillator; the radiator is a symmetric radiation array consisting of four radiation units; each radiation unit consists of two branches which are bilaterally symmetric and each branch is provided with hollow holes so as to form parallel current paths; the tail ends of the two branches are connected through a connecting arm so that the left and right branches of each radiation unit form a closed electromagnetic loop; the balanced feeding device comprises two pairs of U-shaped baluns which are mutually orthogonal and of which bottoms are connected; four supporting planes are formed at the top part of the balanced feeding device and are supported at the connecting parts of the radiation units respectively; and the balanced feeding device is integrated with the radiator. The integrated broadband dual polarized antenna is simple in structure, convenient in mounting, easy in feeding, good in consistency and easy to produce, and has the advantages of small horizontal wave beam width fluctuating with frequency, good cross polarization characteristic, high gain and high front-to-back ratio.

An oriented PIFA-type apparatus for reducing hearing aid radio frequency (RF) interference including a directional multi-band and/or single band antenna for use with PWDs such as digital cellphones is disclosed. The apparatus greatly reduces or eliminates the audio noise induced in hearing aids by the PWDs and allows operation of a hearing aid during PWD operation. In operation, the apparatus may be provided on the PWD side away from the user's head. The apparatus may be integrated into the PWB during its manufacture or provided as an after market assembly for a PWD that has a port for connection of an external antenna. The apparatus provides for improved front-to-back ratio as compared to antennas currently in use on PWD's, and therefore also reduces SAR (specific absorption rate), the level of RF energy received into the head by a PWD.

The invention discloses a low-profile small-scale dual-polarized base station antenna. The low-profile small-scale dual-polarized base station antenna comprises an antenna housing, a plurality of oscillator components, a power distribution plate, two inner side metal baffles and a reflection plate. The antenna housing covers the reflection plate, and the oscillator components, the power distribution plate and the inner side metal baffles are positioned inside the antenna housing. Two sides of the reflection plate are provided with vertical flanges, and the power distribution plate is positioned on the front or back surface of the reflection plate and fixedly connected with the reflection plate. Each oscillator component comprises a radiation plate and a supporting device, and each radiation plate is fixed to the power distribution plate through the corresponding supporting device. The two inner side metal baffles are symmetrical relative to the oscillator components and fixed to the reflection plate. The low-profile small-scale dual-polarized base station antenna has the advantages of ultra wideband, high gain, high efficiency, high cross polarization ratio, high front-to-back ratio, high isolation and the like.

The invention discloses a large-scale antenna field directional diagram measuring system and method for multi-rotor unmanned aerial vehicles. The system includes a multi-rotor unmanned aerial vehiclesubsystem, a signal source link subsystem, a receiving link subsystem and a data processing subsystem. A multi-rotor unmanned aerial vehicle is used to fly at near and far field areas of a to-be-measured antenna according to a set cruise mission; through remote real-time control on a signal source link module, an electromagnetic wave signal in the air can be swept and received in real time; and through the screening, error compensation and data fitting on a received level signal, final directional diagram information can be generated, and the maximum radiation direction, 3dB lobe width, sidelobe level, front-to-back ratios and corresponding position information can be given. On-the-spot directional diagram performance measuring of large-scale antennas under service status can be realized,so that accurate measured data can be provided for fault diagnosis; the system is convenient in operation, high in degree of automation and simple in dismounting; and single sortie flight can accomplish the testing of multifrequency directional diagrams.

The utility model discloses a dual-polarized slot coupling antenna which comprises a feed network and a radiation sticker, wherein the feed network comprises a substrate, wherein the lower surface of the substrate is completely covered by copper, so that a first copper-covered region is formed; the upper surface of the substrate comprises a second copper-covered region and two independent rectangular regions with the same structures; each rectangular region comprises an upper edge, a bottom edge and two side edges; copper sinking via holes which are uniformly arrayed are formed in the upper edge and the two side edges; a slot region and a feed end are arranged in a region surrounded by all the copper sinking via holes; the slot region is close to the center of the substrate; the slot region is positioned in a positive projection region of the radiation sticker on the substrate; the feed end is close to the bottom edge; the part below the feed end in the rectangular region is a blank region. The dual-polarized slot coupling antenna has the advantages that all the back part of the feed network is ground plane metal; a feed microstrip line is arranged on the upper surface of the feed network, so that the feed network cannot radiate the back surface, the front-to-back ratio cannot be affected, and the influence due to an antenna mounting environment can be avoided.

The invention provides a broadband coupled dual-polarized antenna vibrator, and belongs to the technical field of communication base station antenna manufacture. The broadband coupled dual-polarized antenna vibrator comprises a reflecting board, a medium substrate, a support seat and a feed sheet. A vibrator body is shaped by die-casting a metal and is of an I-shaped vibrator structure, wherein the medium substrate is arranged at the upper end of the I-shaped vibrator structure; a surface radiation structure is arranged at the upper end of the medium substrate; the support seat is arranged in the middle of the medium substrate; and the reflecting board is arranged at the lower end of the medium substrate. The manufacturing method for the broadband coupled dual-polarized antenna vibrator comprises the following steps: (1) preparing a die of each component of the vibrator body; (2) die-casting the die of each component prepared by the step (1) for moulding; and (3) assembling the components moulded by die-casting by the step (2) by welding and by bolts. The broadband coupled dual-polarized antenna vibrator has the advantages of gain, cross polarization ratio, front-to-back ratio, side-lobe energy ratio, dual polarization overlap ratio, simple structure, few constituent parts, and easy production and assembly.

The invention is based on a wideband electromagnetic dipole antenna based on an artificial magnetic conductor. The wideband electromagnetic dipole antenna comprises an electromagnetic dipole antenna and an artificial magnetic conductor (AMC) mounted together. The electric dipole of the electromagnetic dipole antenna is an electric dipole in an open fishtail shape and printed on an electric dipoledielectric plate. Magnetic dipoles are printed on two parallel magnetic dipole dielectric plates and have upper sides perpendicularly connected to the two arms of the electric dipole. A feed balun isprinted on a feed dielectric plate in parallel to the magnetic dipole dielectric plates and placed between the two magnetic dipole dielectric plates. The AMC consists of an AMC dielectric plate, and aperiodic circular metal patch and a grounding metal layer printed thereon, is parallel to the electric dipole, and is placed under the magnetic dipole dielectric plates. The AMC is equivalent to a perfect magnetic conductor (PMC), replaces the PEC reflector of a conventional antenna, and uses coaxial feed. The wideband electromagnetic dipole antenna based on the AMC is increased in the front-to-back ratio, has a stable directional diagram, and has a wide bandwidth, high gain and easy integration.

The invention relates to a high-anti-multipath high-precision measuring type antenna and communication equipment. The antenna comprises a central radiation unit assembly, a support assembly, a ground plate assembly, a half-opening round chamber assembly, a polarized isolation power dividing device and a wave-transmitting sealing antenna housing. The central radiation unit assembly is fixed on the top of the support assembly. The support assembly is fixed on the center of the ground plate assembly. The half-opening round chamber assembly is coaxially arranged in a way to abut on the back side of the ground plate assembly. The polarized isolation power dividing device is arranged on the back side central part of the ground plate assembly. The central radiation unit assembly is connected with the polarized isolation power dividing device through a coaxial supply line arranged inside the support assembly. The antenna is fully sealed inside the wave-transmitting sealing antenna housing. The antenna which achieves multi-frequency, broadband and stable radiation phase center characteristics further achieves a full-space single lobe pattern and has the advantages of high circular symmetry, high roll-off, high front-to-back ratio, and good wide angle circular polarization characteristics. Furthermore, the antenna has the characteristics of super strong anti-multipath performance, small size, lightness, high reliability, low cost, etc.

A slot-coupled microstrip antenna includes a first substrate, a second substrate, and a support base. The first substrate having a first surface and a second surface, in which a ground surface that is formed on the first surface, and a plurality of slots are formed on the ground surface. A feeding network is formed on the second surface. A plurality of antenna corresponding to the slots are formed on the second substrate disposed above the first surface. The support base having two fillisters at two side of the support base. The design of slot structure often has adverse influence on cross polarization and a front-to-back ratio of antenna radiation. The support base having two fillisters of the slot-coupled microstrip antenna can effectively inhibit the influence on the cross polarization and raise the front-to-back ratio from the slots.

An antenna system with at least one tunable dipole element with a length adjustable conductive member disposed therein that enables the antenna to be used over a wide range of frequencies. The element is made of two longitudinally aligned, hollow support arms made of non-conductive material. Disposed longitudinally inside each element is a length adjustable conductive member electrically connected at one end. In the preferred embodiment, each conductive member is stored on a spool that is selectively rotated to precisely extend the conductive member into the support arm. The support arms, which may be fixed or adjustable in length, are affixed at one end to a rigid housing. During use, the conductive members are adjusted in length to tune the element to a desired frequency. The antenna is especially advantageous when configured as a Yagi-style antenna that can be optimally tuned at a specific frequency for maximum gain, maximum front-to-back ratio, and to provide a desired feed point impedance at the driven element. The antenna can also function as a bi-directional antenna by adjusting the reflector element to function as a director. An electronic control system allows the length of the conductive members to be manually or automatically adjusted to a desired frequency.

A dual polarized variable beam tilt antenna having a superior Sector Power Ratio (SPR). The antenna may have slant 45 degree dipole radiating elements including directors, and may be disposed on a plurality of tilted element trays to orient an antenna boresight downtilt. The directors may be disposed above or about the respective dipole radiating elements. The antenna has a beam front-to-side ratio exceeding 20 dB, a horizontal beam front-to-back ratio exceeding 40 dB, a high-roll off, and is operable over an expanded frequency range.

Disclosed is a two-dimensional trench-oriented micro-strip patch antenna, which is characterized in that: firstly, the operating frequency f of the patch antenna is established; secondly, the metal plate material is selected and the thickness of the metal plate is h; thirdly, a micro-strip patch antenna is arranged in the central region of the metal plate and is fed with electricity by making use of the coaxial line; fourthly, N1 ring-shaped trenches are cyclically arrayed and distributed on the exit surface of the metal plate with a cycle of P1, a depth of d1 and a width of w1; finally, N2 traditional ring-shaped trenches are cyclically arrayed and distributed outside the trenches with a cycle of P2, a depth of d2 and a width of w2, and the manufacturing is finished; and the invention adopts a theory that the trench structure modulates the surface wave in order to improve the antenna radiation performance and a theory that the traditional trench structure inhibits the metal plate edge surface wave in order to reduce backward radiation, both of which are integrated and used in the micro-strip patch antenna, so as to improve the front to back ratio of antenna radiation energy and obtain significantly enhanced radiation gains, and meanwhile the antenna beam width can be substantially compressed.