Showing papers on "Feed line published in 2009"

Radio frequency network

Abstract: The present invention relates to radio frequency (RF) distribution systems for mobile communications. In particular, the present invention relates to a radio frequency network facilitating radio communication where the usual free space propagation of electromagnetic waves is hampered, undesired or impossible, for example in tunnels, mines, and buildings and in large complexes like exhibition grounds, shopping malls, and airports. The radio frequency network ( 1 ) comprises a distributed antenna system ( 2 ) having radiating elements, a wired distribution system ( 3 ) feeding the distributed antenna system ( 2 ), at least one antenna amplifier ( 5 ) between one end of the wired distribution system ( 3 ) and the distributed antenna system ( 2 ), at least one line amplifier ( 4 ) at the other end of the wired distribution system ( 3 ), and automatic self-leveling units included in the antenna and line amplifiers ( 4, 5 ).

Substrate-Integrated Waveguide Ku-Band Cavity-Backed 2 $\,\times\,$ 2 Microstrip Patch Array Antenna

Abstract: A Ku-band cavity-backed microstrip patch 2 x 2 antenna array has been implemented using the substrate-integrated waveguide (SIW) technology-a low-cost multilayer printed circuit board (PCB) process. Cavities are emulated using vias, and the patches are fed using microstrip lines that are centrally fed by a shielded coaxial probe feed line. Simple design guidelines for the cavity, patch, and substrate selection are presented. The array was fabricated, and its measured results agreed very well with theoretical predictions and indicated a relatively high efficiency and wide bandwidth of greater than 70% and 9%, respectively.

Two port frequency reconfigurable antenna for cognitive radios

Abstract: A two port frequency reconfigurable antenna for cognitive radios is presented. It is composed of a disc monopole with two ports that excite at opposite sides; one port is very wideband and consists of a coplanar feed line and the other port is tunable narrowband and consists of a microstrip feed line with defect slots in its ground plane. The slots act as a filter that suppresses frequencies outside the desired band, its operating frequency band can be tuned by varying the length of the slots. The two ports are decoupled by at least 10 dB through the considered frequency range. It is believed that the proposed antenna can be a good candidate for cognitive radios in generic small base stations where the narrowband port is used for operation and the wideband one is used for sensing the spectrum. For accuracy, it is important that the sensing (measurement of the interference noise) is made with the same polarisation as the operation and the proposed antenna achieves this by having the two collinear ports. To examine the presented approach, simulated and measured results are presented and good agreement is reported.

Antenna feed network for full duplex communication

Abstract: The present invention provides a wireless device for effecting two way wireless transmission, an antenna feed network, and a patch antenna. The wireless device includes an antenna assembly having two inputs accepting two feed signals shifted a feed signal phase difference apart. The antenna assembly receives a radiated signal and produces first and second received signals. First and second reflected feed signals are also produced at the two antenna inputs. A transmitter produces a transmission signal and a receiver receives the radiated signal while the transmission signal is transmitted by the antenna assembly. The antenna feed network interconnects the transmitter port, the receiver port, and the antenna assembly and produces the received signal while effecting substantial cancellation of the first and second reflected feed signals. Additionally, or alternatively, first and second transmission leakage signals at the received signal output substantially cancel each other.

Multiband handset antenna using slots on the ground plane: considerations to facilitate the integration of the feeding transmission line

Abstract: Technology and Intellectual Property Rights DepartmentFractusBarcelona, SpainS. KahngDepartment of Info. & Telecomm. Eng.University of IncheonIncheon, South KoreaAbstract—This research consists on a ground plane modificationusing slots of a PIFA (Planar Inverted F Antenna) handsetantenna with the objective to facilitate the integration of thefeeding transmission line which connects the antenna with the RF-module. Through this technique it is possible to obtain a multibandantenna while keeping the same antenna geometry, small volume

Compact millimeter wave packages with integrated antennas

Abstract: A radio-frequency integrated circuit chip package has at least one integrated antenna. The package includes at least one generally planar ground plane formed with at least one slot therein. A first substrate structure has an outer surface and an inner surface. The at least one generally planar ground plane is formed on the outer surface of the first substrate structure. At least one feed line is spaced inwardly from the ground plane and parallel thereto. The at least one feed line has an inner surface and an outer surface and is a transmission line formed on the inner surface of the first substrate structure with the outer surface of the at least one feed line adjacent the inner surface of the first substrate structure. At least one radio frequency chip is coupled to the feed line and the ground plane. A second substrate structure, spaced inwardly from the feed line, defines a chip-receiving cavity. The chip is located in the chip-receiving cavity. The inner surface of the at least one feed line borders the chip-receiving cavity. An antenna patch may be provided. Planar phased array embodiments, assemblies with motherboards and heat sinks, and fabrication techniques are also disclosed.

Parallel antennas for standard fit hearing assistance devices

Abstract: An embodiment of a hearing assistance device comprises a housing, a power source, a radio circuit, an antenna and a transmission line. The radio circuit is within the housing and electrically connected to the power source. The antenna has an aperture, and the radio circuit is at least substantially within the aperture. The transmission line electrically connects to the antenna to the radio circuit. Various antenna embodiments include a flex circuit antenna.

Antenna-aware method for transmitting packets in a wireless communication network

Abstract: A method for transmitting packets in a wireless communication network includes taking into consideration an antenna mode prior to transmission. The method includes determining a transmit antenna mode for a transmission between the node and at least one other node; when the transmit antenna mode is omni-directional, broadcasting a transmission schedule for the transmission omni-directionally; and when the transmit antenna is beamforming directional, broadcasting a transmission schedule for the transmission directionally on one or more transmitter beams. The method optionally can also take into consideration an antenna mode of a receive antenna between the node.

Method and apparatus for josephson distributed output amplifier

Abstract: The disclosure generally relates to a method and apparatus for providing high-speed, low signal power amplification. In an exemplary embodiment, the disclosure relates to a method for providing a wideband amplification of a signal by forming a first transmission line in parallel with a second transmission line, each of the first transmission line and the second transmission line having a plurality of superconducting transmission elements, each transmission line having a transmission line delay; interposing a plurality of amplification stages between the first transmission line and the second transmission line, each amplification stage having an resonant circuit with a resonant circuit delay; and substantially matching the resonant circuit delay for at least one of the plurality of amplification stages with the transmission line delay of at least one of the superconducting transmission lines.

Microwave system calibration apparatus, system and method of use

Abstract: A microwave system calibration apparatus including an antenna portion configured to deliver microwave energy to tissue, a transmission line portion configured to receive a microwave energy signal from a microwave source and to selectively deliver the microwave energy signal to the antenna portion and a switching mechanism connected between the antenna portion and the transmission line portion. The transmission line includes an inner conductor having a length, an outer conductor concentrically surrounding the inner conductor along the length and a dielectric material separating the inner and outer conductors. The inner conductor or the outer conductor of the transmission line portion is electrically connected to the antenna. The switching mechanism is configured to electrically disconnect the transmission line portion from the antenna portion in a first condition and further configured to connect the inner conductor to the outer conductor in a second condition.

Radio Channel Estimator

Abstract: Radio channel estimators are provided. In an exemplary embodiment, a radio channel estimator is provided for estimating a first radio channel to obtain a first estimate, the first radio channel being comprised in a multiple input multiple output (MIMO) radio channel extending between at least a first transmit antenna and a second transmit antenna and a receive antenna, the first radio channel extending between the first transmit antenna and the receive antenna. The estimator comprises a means for receiving a reference symbol transmitted by the second transmit antenna and a means for estimating a second radio channel based on the reference symbol, the second radio channel extending between the second transmit antenna and the receive antenna. The estimator further comprises a means for processing the estimate of the second radio channel based on a spatial property of the MIMO radio channel to obtain the first estimate.

Study of hybrid nonlinear transmission lines for high power RF generation

Abstract: In recent years there has been great interest in the study of nonlinear lumped element transmission lines for applications in high power RF generation. The line lumped elements account for the line dispersion while reverse varactor diodes or saturated inductors (used as nonlinear elements C & L, respectively) are responsible for the nonlinearity characteristics of the line. Both properties of the line (dispersion & nonlinearity) acting together allow the appearing of high frequency oscillations along the line and at its output, which can be used to feed a load antenna for RF generation. In view of that, there is a great prospect for building a very compact RF generator that can be applied in mobile platforms of defense systems or in satellite communications if the output oscillation frequency obtained is in excess of 1 GHz. Therefore, in this paper we will show through Spice simulations that in principle it would be possible to reach up to this frequency order by means of a hybrid line (i.e. using variable Ls and Cs at the same time).

Tunable metamaterial antenna structures

Abstract: Apparatus and techniques that provide tuning elements in antenna devices to tune frequencies of the antenna devices, including composite right and left handed (CRLH) metamaterial (MTM) antenna devices Examples of the tuning elements for CRLH MTM antenna devices include feed line tuning elements, cell patch tuning elements, meandered stub tuning elements, via line tuning elements, and via pad tuning elements tuning elements that formed near corresponding antenna elements such as the feed line, cell patch, meander stub, via line and via pad, respectively

Bidirectional High Gain Antenna for WLAN Applications

Abstract: —A bidirectional high gain four-element printed dipole array for WLAN (2.4/5.8GHz) applications is analyzed and successfully implemented in this paper. Each element used is a double-side printed dipole fed with a balance twin-lead transmission line. A wide-band balun is implemented for the dipole array. Both simulated and measured data are pretty matched. According to the measured results, the bandwidth with return loss less than −10 dB is about 280MHz (2250–2530MHz) and 510MHz (5470–5980MHz) in the two operating bands, the measured gain for 2.4GHz band is between 4.5 and 5.9 dB, and 6.1–8.9 dB for 5.8GHz respectively. Good shaped patterns have also been attained by tuning parameters of the dipole array.

Low Loss Broadband Planar Transmission Line To Waveguide Transition

Abstract: A transition for coupling a microwave signal between a transmission line formed on a planar dielectric substrate and a hollow waveguide may include a half-notch antenna formed on a portion of the dielectric substrate extending into an open end of the hollow waveguide.

Planar antenna and wireless communication apparatus

Abstract: A planar antenna disposed on a plate having a first surface and a second surface is provided. The planar antenna includes a metal layer, an antenna body, a stepped impedance device, a coupling device and a matching device. The metal layer is disposed on the first surface and has a slot line exposing the first surface. The antenna body, the stepped impedance device, the coupling device and the matching device are disposed on the second surface. The antenna body is corresponding to a surrounding of the metal layer except a feed end thereof, the stepped impedance device and the matching device are corresponding to the metal layer, and the coupling device is corresponding to the slot line. The matching device is coupled between the coupling device and the feed end. The stepped impedance device has a transmission zero in a radio frequency band operated by the antenna body.

Study of Microstrip Feed Line Patch Antenna

Abstract: This paper contains design microstrip patch antenna with feed line connector. The antenna is mainly intended to be used for reception of a signal transmitted from an unmanned aircraft, and can be used in many applications in communication systems such as satellite technology and military applications. A microstrip feed line patch antenna is designed for 2.5GHz center frequency have successfully been built. Measurement show that the half power beam width (HPBW) is 60 o with VSWR lower than 1.5, and return losses equal to -33.6dB at center frequency. Next, the results of microstrip feed line patch antenna is designed by using CAD (Microwave office 2000 version 3.22). Finally, the results obtained from the simulations are demonstrated.

A reconfigurable U-Koch microstrip antenna for wireless applications

Abstract: In this paper, a low-cost multiband printed-circuit-board (PCB) antenna that employs Koch fractal geometry and tunability is demonstrated. The antenna is fabricated on a 1.6mm-thick FR4- epoxy substrate with dimensions 4cm £ 4.5cm, is microstrip-line fed and has a partial ground plane ∞ushed with the feed line. The proposed antenna is simulated using the Finite-Element Method for three difierent switching cases and the return loss is measured for each case. It is shown that the antenna can cover the bands of several applications including 3G, WiFi, WiMAX as well as a portion of the UWB range. The radiation patterns are satisfactorily omnidirectional across the antenna's operation bands.

Antenna feed system

Abstract: A microwave system comprises an antenna, antenna feed, a radio transceiver, and appropriate cabling among the aforementioned. Cost, performance and reliability improvements are achieved with further integration of these elements and with design improvements in the antenna feed. One improvement is the integration of the radio transceiver with the antenna feed. This improvement has many benefits including the to elimination of RF cables and connectors. Another improvement, is the incorporation of parasitic radiators and sub-reflectors as part to of the antenna feed. The entire antenna, including the feed design is optimized with 3D finite element method (FEM) software and numerical optimization software. Another improvement is the utilization of the digital cable to power the integrated radio transceiver and a center fed parabolic reflector

X- through Q-band log-periodic antenna with monolithically integrated μ-coaxial impedance transformer/feeder

Abstract: An over two octaves wideband rectangular coaxial line fed log-periodic antenna is introduced. The feed line configuration consists of a three-step quarter-wave impedance transformer designed for matching 160 ? nominal antenna impedance to 50 ?. The transformer (feeder) is monolithically integrated with the antenna by a sequential surface micromachining process known as PolyStrata . Measurements and simulations have shown a VSWR < 2:1 from X- through Q-band.

Adjustable axial ratio of single-layer circularly polarised patch antenna for portable RFID reader

Abstract: A novel single-layer, proximity-fed technique for a slot-coupled circularly polarised square patch antenna operated in the ultra-high frequency band is presented. In the proposed design a pair of radiating square patches with a cross-slot and a microstrip feed line are both etched on the top of a microwave substrate, and a coupling arrow-shaped slot is etched on the bottom of this substrate. Simulated and measured results indicate that the proposed structure can achieve circular polarisation operation. Proper adjustment of the feed coupling gap distance between the patch and the feed line results in good impedance matching and circularly polarised radiation, and an impedance bandwidth (VSWR≤2) of about 3.74% and a 3 dB axial-ratio bandwidth of about 1.62% were obtained.

Scanning antenna with beam-forming waveguide structure

Abstract: A scanning antenna with an antenna element having an evanescent coupling portion includes a waveguide assembly including a transmission line, adjacent the coupling portion, through which an electromagnetic signal is transmitted, permitting evanescent coupling of the signal between the transmission line and the antenna element. First and second conductive waveguide plates, on opposite sides of the transmission line, define planes that are substantially parallel to the axis of the transmission line, each plate extending distally from a proximal end adjacent the antenna element, whereby the propagated signal forms a beam that is confined to the space between the plates and thus limited to a plane that is parallel to the planes defined by the plates. The signal coupled between the transmission line and the antenna element is preferably polarized so that its electric field component is in a plane parallel to the planes defined by the plates.

Compact slot antenna for 2.4 GHz/UWB with dual band‐notched characteristic

Abstract: A novel compact microstrip slot antenna for 2.4–2.5 GHz (WLAN) band and ultra-wideband is proposed and fabricated. Two single ring split resonators are etched in the feed line to obtain dual band-notched function in the 5 GHz WLAN band and ITU 8025–8400 MHz band, respectively. The entire antenna only occupies a volume of 33 mm × 35.5 mm × 1 mm. The proposed antenna is analyzed both numerically and experimentally. The measured results and simulated results reach good agreements. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 1859–1862, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24475

Motor circuit and electric power steering apparatus

Abstract: In a steering control unit, a U-phase feed line branches into paired branch feed lines, phase-open MOSFETs are provided in middle portions of the branch feed lines, phase-open MOSFETs are provided in middle portions of a V-phase feed line and a W-phase feed line, and the phase-open MOSFETs are arranged in such a manner that parasitic diodes are in the same orientation with respect to a motor. When an abnormality occurs, all the phase-open MOSFETs are turned off. Then, a closed circuit, which includes phase coils and through which electric currents flow, is no longer present.

Power divider having low pass filter based on rfid system

Abstract: A power divider including low pass filter based on RFID (Radio Frequency Identification) system is provided to implement the micro system by reducing the length of the transmission line by 1/2. The signal is input to an input port (P1). The inputted signal moves through an input terminal transmission line (12c). The low pass filters (12a, 12b) are connected to the input terminal transmission line. The low pass filter is arranged in both side of the input terminal transmission line symmetrically. The low pass filter removes the harmonic included within the signal passing through the input terminal transmission channel. The signal of the low pass filter is outputted through the output terminal transmission line (12e) to the output port (P2, P3). The isolation resistor (12d) is arranged between the low pass filters in the output terminal transmission line. The isolation resistor matches the impedance between the input port and the output port. The low pass filter comprises the feed line, the parallel coupled line and an open stud. The feed Line is connected to the input terminal transmission line and the output terminal transmission line. The parallel coupled line is connected to the feed line. The mutual inductance is generated between parallel to two lines. The feed line, the parallel coupled line and the open stud are the microstrip line. The feed line, the parallel coupled line and the open stud are formed in top of the one substrate.

Low cost electronically scanned array antenna

Abstract: An electronically scanned array (ESA) antenna includes a main line along which an electromagnetic traveling wave may propagate and a plurality of array elements distributed along the main line. Each of the plurality of array elements includes a branch line; an antenna radiator at one end of the branch line; an electronically controllable reflection phase shifter at the opposite end of the branch line; a directional coupler which couples energy between the main line and the branch line.

Antenna with integrated RF module

Abstract: An antenna assembly includes an antenna housing, an antenna located within the housing, a radio frequency (RF) module located within the housing and connected to the antenna, and a wire assembly operably associated with the module. The module includes a radio frequency device, such as a transmitter, receiver or transceiver, electrically connected to the antenna. The wire assembly includes electrical wires for providing external power to the module and conducting processed signals between the module and external circuitry. The proximal nature of the antenna and RF module reduces or eliminates induced power losses between the antenna and module, resulting in a very effective power transfer ratio. A conductive sleeve is located in the housing and surrounds the RF module. The conductive sleeve is electrically connected to the module to thereby provide a ground plane for the antenna and a shield against outside emissions. A spacer located between the sleeve and the mounting base together with a step between the sleeve and the wire assembly provide a choke effect for the RF energy.

A low-profile and broadband conical antenna

Abstract: A novel electric small conical antenna working on a very broad band, 0.47-6 GHz, with the height of only 60 mm, is presented. A capacitive ring on the top of the cone and three oblique shorted lines are used to expand the work band. By changing the width of the ring and the slope of the oblique line, the impedance of the antenna matches 50-ohm feed line commendably. Simulation and experiment results demonstrate that this antenna provides very broad band and low-profile characters, which exhibits a 12.8 : 1 impedance bandwidth with voltage standing wave ratio (VSWR) below 2 : 1 (the impedance bandwidth is 11.9 : 1 with the VSWR below 1.5 : 1) and with the height only 0.094 wavelength associated to the lowest frequency.

Communication device, mobile station, and communication control method

Abstract: Receiving quality in the receiving of signals from a plurality of transmission antennas is improved. A radio communication system including a communication apparatus (1) can transmit signals each including same data from a transmission antenna (2a) and a transmission antenna (3a) to a mobile station (4). The mobile station (4) measures a difference in receiving timing between the signal from the transmission antenna (2a) and the signal from the transmission antenna (3a). The communication apparatus (1) exercises control so as to change at least one of transmission timing of the signal from the transmission antenna (2a) and transmission timing of the signal from the transmission antenna (3a) according to the difference in receiving timing at the mobile station (4).