416results about How to "Improve antenna efficiency" patented technology

An electromagnetic wave propagation resistivity borehole logging system comprising multiple groups of electromagnetic transmitter-receiver arrays operating at three frequencies. The borehole logging tool component of the system employs eight transmitters and four receivers. The transmitters and receivers are disposed axially and symmetrically along the major axis of the tool to form four group pairs. Each group pair consists of a transmitter-receiver groups axially and symmetrically on opposing sides of a reference point on the tool. Each, transmitter-receiver group consists of one transmitter assembly and two receiver assemblies. Each transmitter-receiver group is operated at two of three operating frequencies which are 100 kHz, 400 kHz and 2 MHz. Some of the transmitter and receiver assemblies are fabricated to yield azimuthally focused resistivity measurements, and to yield vertical and horizontal resistivity in anisotropic dipping beds. The system can be embodied as a logging-while-drilling system or as a wireline logging system.

Wireless communication device antenna matching circuit tuning responsive to power control signals, and, optionally, responsive to received signal quality indicators in a traffic channel. Systems and methods are provided that increase the antenna efficiency in either the transmit frequency or the receive frequency as needed, based on fading and environmental conditions, non-ideal antenna efficiency balance, mobile station forward versus reverse link usage and system forward versus reverse link usage. The antenna efficiency may be changed incrementally or may be optimized completely for the transmit frequency or the receive frequency. The re-balancing is accomplished by tuning the antenna matching circuit. One way to tune the antenna matching circuit is to apply a voltage to a ferro-electric capacitor in the matching circuit, thereby changing the capacitance of the ferro-electric capacitor, thereby changing the impedance of the antenna system.

Systems for determining a size, extent, and orientation of a hydraulic fracture of a reservoir, are provided. An exemplary system can include a plurality of RFID transponders modified to include an acoustic transmitter, and an RFID reader modified to include both an RF transmitter and a pair of acoustic receivers, to be deployed in a wellbore adjacent a hydraulic fracture. The system includes program product configured to receive acoustic return signal data to determine the three-dimensional location of each RFID transponder within the reservoir, to map the location of each RFID transponder, and to responsively determine the size, extent, and orientation can be determined.

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.

A mobile wireless terminal includes a housing, a cover removably attached to the housing, and an antenna device disposed inside the housing. The antenna device includes a first antenna element that is disposed inside the housing and serves as a feed element, a plate that provides a ground plane for the first antenna element, and a second antenna element that is formed on one surface of the cover so as to face the first antenna element with the cover being attached to the housing and capacitively couple to the first antenna element and that serves as a parasitic element.

A built-in antenna of a portable terminal and a method of forming the same are provided. The built-in antenna includes a first conductor having a specific length and used for a ground, a second conductor disposed with a specific distance in parallel to the first conductor to couple with the first conductor and used for power feeding, and a separating element disposed between the first conductor and the second conductor to separate the first and second conductors. Accordingly, the built-in antenna may exhibit a smooth radiation property even if a metal construction is used in a device and thus may implement robustness improvement of the device and make the device slim and have an attractive outer appearance. In addition, a method of improving antenna efficiency may prevent deterioration of the radiation property of the antenna radiator of the related art by using simple processing, and the metal construction may be used as a radiator.

The invention provides a mobile terminal, an antenna switching method and apparatus for the mobile terminal. The mobile terminal includes a terminal main body which includes an antenna unit and an antenna switching apparatus which is in electrical connection to the antenna unit. The terminal main body includes a plurality of placing states. The antenna unit includes a plurality of antenna modes, and each placing state corresponds to one antenna mode, and the antenna efficiency of the antenna modes which correspond to the placing states is higher than the antenna efficiency of other antenna modes. The antenna switching apparatus serves to detect the placing state of the terminal main body, and to control the antenna mode of an antenna unit to switch to an antenna mode corresponding to the placing state for signal transmission. According to the invention, the method, through detecting the placing state of the terminal main body and switching to a corresponding antenna mode, addresses the technical problems of poor antenna performances and poor signals of the mobile terminal caused by unreasonable antenna arrangement and complex switching algorithm of prior art.

The invention concerns generally the technological field of antenna arrangements in mobile stations. The invention also concerns a mobile station equipped with such an antenna arrangement. One idea of the present invention is providing a planar antenna in which the printed wired board (PWB) of the mobile station is used. The planar antenna has preferably an air gap between the radiator element (216) and the ground plate (218). In order to reduce the effects of the RF fields to other phone electronics there is a sheet of low reluctance material (245) for reducing the RF fields. The sheet of low reluctance material is so located that it covers an area of the printed wired board which is not covered by the radiator element or the ground plane of the planar antenna. The low reluctance material is preferably ferrite material, such as flexible ferrite sheet, and it may be attached to the display unit (208a, 208b) or on the PWB (234).

A compact and low-cost antenna device in which no interference occurs even when many antenna units corresponding to various systems are mounted close together in a small area, and a wireless communication apparatus including the antenna device. An antenna device includes plural antenna units mounted on a single dielectric base. A first antenna unit having a lowest fundamental frequency is disposed at a left end of a non-ground region, a second antenna unit having a highest fundamental frequency of the plurality of the antenna units is disposed at a right end of the non-ground region, and a third antenna unit having a fundamental frequency between those of the first antenna unit and the second antenna unit is disposed between the first and second antenna units. A current-density control coil is connected between a first radiation electrode and a power feeder of the first antenna unit, while a reactance circuit is disposed in the middle of the first radiation electrode. Notches may be disposed between the first radiation electrode and a second radiation electrode and between the first radiation electrode and a third radiation electrode.

Embodiments provide single-sided and multi-layered circular polarized, self-contained, compound loop antennas (circular polarized CPL). Embodiments of the CPL antennas produce circular polarized signals by using two electric field radiators physically oriented orthogonal to each other, and by ensuring that the two electric field radiators are positioned such that an electrical delay between the two electric field radiators results in the two electric field radiators emitting their respective electric fields out of phase. Ensuring the proper electrical delay between the two electric field radiators also maintains high efficiency of the antenna and it improves the axial ratio of the antenna.

A slotted NMR antenna cover for improved mechanical ruggedness during transmission and reception of NMR signals in a down hole environment during either MWD or wire line operations. A NMR slotted antenna cover is provided comprising an elongated tubular structure with longitudinal gaps or slots filled with a RF transmissive or non-conductive material. The slots can befilled at the slot ends with soft magnetic material to improve efficiency of the antenna. The slots are radial concave to reduce eddy currents induced by alternating magnetic flux entering and leaving the slots surrounding the antenna. In another embodiment, the antenna cover is RF transmissive on only a portion of the antenna, via slots or transmissive material, so that the antenna cover can be used to allow RF transmission from the antenna in a side looking or beam pattern restricted mode only.

The invention provides a printing boardband terminal antenna with smaller occupying space. The printing boardband terminal antenna comprises a first bent metal strip group and a second bent metal strip group; a gap is formed between the first bent metal strip group and the second bent metal strip group; a microstrip feed line is used for directly feeding electricity to the first bent metal strip group so as to excite a high-frequency current on the first bent metal strip group to form resonance; and a high-frequency current on the second bent metal strip group is excited by capacitive coupling of the gap between the first bent metal strip group and the second bent metal strip group to form resonance. According to the invention, the first bent metal strip group and the second bent metal strip group are not directly connected, a plurality of frequency points are matched according to the distributed parameter effect of the gap between the two metal strip groups, and therefore the bandwidth can be widened in a larger extent. Therefore, the size occupied by the antenna can be reduced; in addition, a dedicated matching circuit and a special substrate material are not required in the invention.

The invention discloses a Ku frequency band double-frequency dual-polarization micro-strip plane reflective array antenna. A plane medium substrate is provided with two kinds of frequency passive micro-strip resonance units, each kind of frequency units is arranged in equal rows and equal lines, the distance between every two rows is equal to that between every two lines, the distance is less than or equal to one half of the wavelength of the highest work frequency free space, and each second frequency unit is located at the center of every four first frequency units in a square array. The center of all the first frequency units is provided with a set of gaps, the center of all the second frequency units is provided with a set of gaps perpendicular to the gaps of the first frequency units, and polarization in the two perpendicular directions is formed. Each kind of frequency units is of loop line patch structures with at least two layers, and the size of a loop is determined according to the phase position needing compensation. According to the Ku frequency band double-frequency dual-polarization micro-strip plane reflective array antenna, the phase difference between a feed source and the space of each unit on the array surface is compensated by regulating the size of each micro-strip unit on the medium substrate, reflected waves achieve same-phase superposition in the special direction, pencil beams are formed, and the purpose of high gain is achieved.