Showing papers on "Feed line published in 1998"

Steerable phased-array antenna having series feed network

Abstract: A phased-array antenna in accordance with illustrative embodiments of the present invention advantageously includes a plurality of radiating elements and a phase-shifter array integrated into a feed line of the antenna's series feed network. The phase-shifter array advantageously comprises a plurality of phase-shifting slabs each of which includes a phase-shifting member, advantageously comprised of a dielectric material. When placed in electromagnetic fields generated by signals propagating through different regions of a feed line, the phase-shifting members affect the phase of such signals. Each slab in the phase-shifter array also advantageously incorporates at least one impedance-matching member that decreases or eliminates an impedance mismatch between air-suspended and dielectric-loaded regions of the transmission line over the full phase-shifting range of the phase-shifting members. Since phased-array antennas in accordance with the illustrative embodiments are well impedance matched, relatively high-dielectric-constant materials may be used for the phase shifters. As such, the phase shifters provide a high differential phase shift that contributes to a large phase-shifting range and a large antenna beam steering range. In some embodiments, the present phased-array antennas are configured such that relatively little phase is required between adjacent radiating elements so that antenna bandwidth is relatively broad. The present phased-array antennas advantageously use Wilkinson power splitters and one impedance-matching member per phase shifter to reduce sensitivity to impedance mismatch from radiating elements while keeping phase between adjacent radiating elements quite small.

Compact antenna structures including baluns

Abstract: An antenna structure includes a center feed dipole antenna having first and second radiating sections that extend along a substrate from a center feed point. A feed section is electrically coupled to the center feed point. The feed section includes a radio frequency input line and a ground line extending along the substrate adjacent one another. A balun extends along the substrate between the first radiating section and the ground line. The first radiating section, the radio frequency input line, the ground line and the balun preferably extend along the substrate in parallel. A tuning shunt may also be provided across the balun for dual band operation. Accordingly, compact dual band antenna structures including baluns may be provided.

Microwave energy delivery system including high performance dual directional coupler for precisely measuring forward and reverse microwave power during thermal therapy

Abstract: A microwave energy delivery system for microwave thermal therapy includes an antenna and a transmission line connected to the antenna. A microwave generating source includes a generator connected to the transmission line and a dual directional coupler for detecting forward power delivered to the antenna and reverse power reflected from the antenna with low uncertainty.

Adaptive pre-emphasis technique

Abstract: A method and apparatus are described for adaptively pre-emphasizing signals transmitted over a stable but occasionally varying transmission medium such as a very-high-speed digital subscriber line (VDSL) signal, before it is transmitted by a transmitter (28), in order to compensate for frequency distortion that is introduced by the VDSL transmission line. At system start up, or whenever the parameters or configuration of the line are changed, the line termination transceiver at both ends of the transmission line exchange calibration signals to measure the attenuation-versus-frequency curves of the line in both directions. Thereafter, whenever the signal transmission band is to be changed in either direction, the transmitter (28) for that direction uses the measured attenuation curve for the line to calculate and design a set of filter coefficients for an adjustable pre-emphasis filter (38). The pre-emphasis filter (38) filters coefficient signal, attenuating most heavily those frequencies that are least attenuated by the transmission line, so that the net frequency response of the pre-emphasis filter (38) plus transmission line is flat, thereby eliminating frequency distortion.

The analysis of general axially symmetric antennas with a coaxial feed line by the method of lines

Abstract: The use of the method of lines in the analysis of various circular antennas-circular patch antennas and various forms of monopoles is proposed and substantiated. The antennas considered are fed by coaxial lines. Impedance/admittance transfer procedures are developed, which allow to calculate the antenna input impedance by a successive transfer from the aperture through the different sections. The described relations are also useful for other applications.

Vehicular use power feed apparatus

Abstract: A vehicular use power feed apparatus comprising a battery and a plurality of power distribution units connected in a loop via power feed lines. Each power distribution unit has a current monitoring circuit, a current amount determination circuit, and a current direction determination circuit, detects the direction of current and magnitude of current flowing through the power feed line, and thereby detects an occurrence of a short-circuit. A control unit exchanges information regarding occurrence of short-circuits with adjoining power distribution units via a multiplex signal transmission unit so as to pinpoint the trouble point. The control unit operates the relay switch circuits on the two sides to break the connection so as to isolate the trouble point in cooperation with the control unit of the adjoining power distribution unit. The other relay switch circuit is operated to establish a connection so as to establish a new power feed line.

Avalanche victim locating transceiving apparatus

Abstract: A rescue transceiver apparatus for transmitting a signal to and receiving a signal from another rescue transceiver apparatus is provided. The apparatus comprises a housing and a radio signal transmitter for the transmission of a radio signal in a transmitting mode with a first predetermined frequency with the radio signal transmitter being mounted within the housing. A receiver is provided for selectively receiving the first predetermined frequency from the radio signal transmitter in a receiving mode. The receiver comprises a first antenna mounted completely within the housing, a second antenna mounted completely within the housing with the second antenna being disposed substantially perpendicular to the first antenna, and a virtual third antenna mounted completely within the housing with the virtual third antenna being derived from phase information generated by the first antenna and the second antenna. The first antenna, the second antenna, and the third virtual third antenna provide three-dimensional vector analysis by the receiver of the predetermined frequency received from the radio transmitter. The apparatus further comprises a microcontroller for controlling the radio signal transmitter and the receiver.

Microwave antenna having wide angle scanning capability

Abstract: A planar array antenna having a switching matrix that couples an RF signal to two distributed ferrite scanning line feeds that feed a planar continuous transverse stub array antenna. The scanning line feeds couple RF energy to the antenna from opposite sides to form a total of four beams offset in space that each cover different angular scan sectors. The antenna has reduced complexity and lower design and production costs. The use of dual ferrite scanning line feeds, the switching matrix, and the continuous transverse stub antenna to obtain wide-angle scanning provides significantly improved performance. The present invention uses the two distributed ferrite scanning line feeds to obtain greater scan coverage at upper millimeter-wave frequencies, where realizable ferrite materials are less active and provide diminished scan capability. The scanning line feeds and planar array antenna may be designed so that the four scan sectors are contiguous, to increase the angular scan coverage of the antenna. The switching matrix is used to sequentially feed each of four RF ports, which effectively produces a single beam that scans over the four contiguous scan sectors.

Residential power cutback for splitterless DSL operation

Abstract: A digital subscriber line modem ( 30 ) capable of operating with multiple transmission line profiles depending on the current transmission line characteristics of a wire line pair ( 20 ) includes an interface ( 212, 292 ) to the wire line pair ( 20 ) and a signal converter ( 214, 290 ) with a terminal coupled to the interface. An on/off-hook detector( 300 ) drives an impedance analyzer function ( 304 ) that is able to measure transmission line parameters based on the current line characteristics of the wire line pair ( 20 ). A control logic block ( 310 ) performs the actions required to adapt to a new line conditions of the wire line pair ( 20 ) and rapidly adapt to the new on/off hook condition.

A compact shielded exposure system for the simultaneous long‐term UHF irradiation of forty small mammals: I. Electromagnetic and environmental design

Abstract: To carry out in vivo studies of the possible health effects of radiation from cellular telephone handsets, it is necessary to expose large numbers of small mammals at realistic power densities, modulations, and frequencies. Because even microwatt leakage could compromise the local cellular system, extreme care in shielding is required. Experimental logistics dictate, however, that the irradiated animals be easily accessed and that it be possible to irradiate them in small groups, while other groups are being loaded into or unloaded from the irradiators. This problem has been resolved by exposing the animals in aluminum-sheathed rectangular parallelepipeds, lined with microwave absorber and having doors that can be opened readily. Inside each of these microwave anechoic "chamberettes" is a vertical, four-element collinear array of dipole antennas; and around each antenna, 10 animal restrainers can be arranged like spokes on a wheel. The system has worked efficiently in studies of up to 480 rats. There is negligible coupling between antennas, and back reflection at an antenna's feed line is down 7-9 dB. Received CDMA power at the local base station is below the receiver's noise floor. Interior illumination reinforces the rats' diurnal rhythms, and the rats sleep during irradiation. Experimental logistics are excellent. In this paper, the irradiator design is presented.

Integrated radio and directional antenna system

Abstract: An integrated outdoor radio and directional antenna system provides a direct RF connection(s) on the signal path between a directional antenna and radio components to remove the lossy RF cable(s). Direct connections between the various components of the integrated radio and directional antenna system enable reduced cost and ease of manufacture. In certain embodiments, the integrated directional antenna and radio system provides a direct RF connection between the directional antenna and the radio, and a printed wiring board (PWB) -mounted connector provides a direct digital connection between the radio board(s) and a medium access control (MAC) board. An input/output (I/O) interface provides a digital network interface between the MAC unit and indoor processing circuitry. The digital network interface enables packets of digital information to pass between the indoor processing circuitry and the integrated directional antenna and radio system. An external connection is made between the digital network interface and indoor processing circuitry, such as a personal computer or digital network equipment, but the losses associated with such a digital connection are less significant due to the robustness associated with the processing of digital information in a digital packet data form. In other embodiments, the integrated antenna and radio system provides a direct RF connection between the antenna and RF signal circuitry, such as an RF matrix board which accommodates polar diversity for the antenna and includes a duplexer, RF switching for multiple radios, filtering and any other appropriate RF signal circuitry. A direct RF connection also exists between the RF signal circuitry and the radio components. A direct digital connection is provided between the radio board and the MAC board, and the I/O interface provides a digital network interface with the indoor processing circuitry. In yet other embodiments, all or some of the above components described for the integrated directional antenna and radio system are integrated onto a single printed circuit board and are directly connected together and to the directional antenna.

Feed line connecting circuit and optical transmission system

Abstract: In an optical transmission system of a double branching system configured to prevent a large current to power feeding lines when any trouble occurs in one or more of the power feeding lines, a branch station 34 connects to two branching units 36a, 36b. A power feeding line 40 connects a trunk station 30 to a feed line connecting terminal A of the branching unit 36a, a power feeding line 42 connects a feed line connecting terminal C of the branching unit 36a to the branch station 34. A power feeding line 44 connects the branch station 34 to a feed line connecting terminal C of the branching unit 36b, and a power feeding line 46 connects a feed line connecting terminal B of the branching unit 36b to a trunk station 32. A power feeding line 48 connects a feed line connecting terminal B of the branching unit 36a to a feed line connecting terminal A of the branching unit 36b. In the branching unit 36a, the feed line connecting terminals A and C are connected to each other, and a relay circuit 58a opens a switch 52a. In the branching unit 36b, the feed line connecting terminals C and B are connected to each other, and a relay circuit 58b opens a switch 52b.

Simplified stacked dipole antenna

Abstract: An antenna array is described in which a feed line that is formed by metalatterns on opposite sides of a circuit board has a plurality of pairs of adjoining quarter wave resonant sections formed by different widths of the patterns and dipoles respectively coupled to the junctions of the pairs of quarter wave sections. The proximity between dipole elements and the feed line is sufficiently close to enable a nearly symmetric azimuthal antenna beam pattern. Each dipole further uses capacitive compensation at its center to balance the capacitive loading with the closely spaced feed line.

Method and apparatus for increasing the bandwidth, and reducing the size, of the DC feed network for wideband RF amplifiers using selective placement of high dielectric constant material

Abstract: For use with RF circuitry in which a DC bias circuit provides bias voltage is provided to impedance-matched circuitry, a structure is provided, in which a dielectric member, having a high dielectric constant, is selectively placed adjacent to a bias feed line coupled between the DC bias circuit and the remainder of the circuitry, to maintain high RF impedance while reducing impedance at lower frequencies. The invention has particular applicability to RF amplifiers, to be used for amplifying modulated carriers, such as video signals made up of an RF carrier and a lower-frequency modulation. Where the carrier has a predetermined wavelength, the physical length of the bias feed line and the dielectric constant of the dielectric member are chosen such that an effective length of the bias feed line is a quarter of the wavelength of the carrier.

Antenna for communicating with low earth orbit satellite

Abstract: The object of the present invention is to provide an antenna for communicating with a low earth orbit (LEO) satellite which is small-sized and light and can track a LEO satellite at high speed at a small-sized earth station using a LEO satellite. The antenna according to the present invention uses two offset parabolic antenna-type reflectors and each primary feed is installed in the focal position of a paraboloid forming the reflector. The quantity of an offset of the offset parabolic antenna is selected so that antenna gain is maximum at the minimum operational elevation angle. Each primary feed is mechanically independent of the mobile reflector, is attached and fixed to a feed line. In the meantime, each reflector is turned based upon an azimuth axis and an elevation axis according to Az-EL mounting.

Microstrip type antenna device

Abstract: A conductive micro-strip line, a feeding line in contact with the micro-strip, and a radiation element connected to the feeding line are provided on a dielectric or semiconductor substrate, and a ground conductor is provided on the side of the substrate opposite to the micro-strip line to establish a diversification antenna and an array antenna. In accordance with another aspect, a plurality of antennas, each comprising a dielectric or semiconductor substrate, a conductive film provided on one side of the substrate for constituting a radiation element and a micro-strip line including a feeding line leading to the radiation element, and a ground conductor film provided on the other side of the substrate, are arranged. A coaxial feeding line leading to one of the antennas is provided along the ground plane, of another antenna, on which the ground conductor film is provided. This construction inhibits the influence of the coaxial feeding line on the radiation and impedance characteristics of another antenna.

Radio communication device antenna arrangements

Abstract: The present invention relates to antenna arrangements for radio communications devices including cordless phone handsets and base stations. The handset includes an antenna arrangement incorporating one or more batteries as part of a monopole structure. The base station includes an antenna arrangement incorporating a low voltage power supply cable. Both handset and base station may also optionally further incorporate an antenna structure located in the split line between their respective casing components.

Slot coupling type dielectric resonator antenna

Abstract: PROBLEM TO BE SOLVED: To provide the slot coupling type dielectric resonator antenna which has circular polarization characteristic of superior antenna efficiency, gain, and axis ratio over a wide band and is simple in radiation element shape and easily manufactured. SOLUTION: A radiation element 1 composed of a dielectric resonator, a ground conductor plate 3 having a cross slot 2 in asymmetrical structure in the center, a dielectric plate 4, an electric feeding circuit board 7 provided with a feed line 5 and a matching stub 6 are stacked in order, and the cross slot 2 excites the radiation element 1 by electromagnetically coupling the feeder line 5 with the radiation element 1. Furthermore, two slot parts of the cross slot are formed into an asymmetrical structure so as to enable circular polarization without deforming the element shape of the radiation element.

Double feed detection method for sheet material using ultrasonic wave

Abstract: PROBLEM TO BE SOLVED: To detect any double feed of sheet materials precisely by taking only ultrasonic waves passed through them on the receiving side as direct waves or as they are. SOLUTION: For double sheet feed detection where an ultrasonic transmitter 1 sends ultrasonic waves to an ultrasonic receiver 2, both disposed to hold therebetween a feed line for paper sheets P-1 and P-2, and the output waveform of the ultrasonic waves attenuated through the passage through the paper sheets P-1 and P-2 is compared with a preset reference value, the ultrasonic transmitter 1 sends such ultrasonic waves at the periods that include at least the times when direct waves passed through the paper sheets P-1 and P-2 direct to the ultrasonic receiver 2 have the peak. This enables the selection of direct waves necessary for a double feed determination without causing any disturbance such as reflected waves and those including stationary waves. COPYRIGHT: (C)2000,JPO

Over-voltage protection apparatus and vehicular direction indicating apparatus with over-voltage protection

Abstract: An over-voltage protection apparatus includes a power feed line. A load has a given low impedance. A current supplying device operates for supplying a current to the load via the power feed line. A load drive device operates for controlling the supply of the current to the load by the current supplying device. An over-voltage detecting device operates for detecting an over-voltage at the power feed line. A discharge command device operates for, when the over-voltage at the power feed line is detected by the over-voltage detecting device, controlling the load drive device to enable a discharge current to flow from the power feed line into the load and thereby to remove the over-voltage from the power feed line through discharge. A current detecting device operates for detecting the discharge current. A discharge continuing device operates for continuing the discharge and the flow of the discharge current from the power feed line in cases where the discharge current detected by the current detecting device exceeds a predetermined reference level.

Antenna coupling arrangement

Abstract: The present invention comprises an antenna coupling arrangement for connecting a portable communication device to a further signal transmission line. The portable communication device has an external radiative antenna. The coupling arrangement comprises a housing of generally rectilinear configuration having left and right sides, a lower side and a back side arranged to enclose a portable communication device. An antenna coupler is hingedly supported on the housing to pivotably mate with the external antenna of a portable communication device enclosed within the housing. The antenna coupler is connected to a transmission line for further connection to a further antenna or transmission line.

Broad-band microstrip antenna

Abstract: A broad-band microstrip antenna implemented using a dielectric base as its main body is disclosed. The base has two sides where the dual-mode resonator is located on the first side, while the grounded plane is located on the second side of the dielectric base. The dual-mode resonator has a high-frequency resonator and a low-frequency resonator, which are partially positioned in parallel. Due to the electric-magnetic effects, these two resonators are mutually coupled to significantly increase the operating bandwidth. In addition, there is a feed line on the first side of the dielectric base, which connects to the dual-mode resonator to provide signal transmission. In addition, there is a grounded mask in the antenna, which is located on the first side of the dielectric base, to provide sheltering for the feed line, and connect to the grounded plane to form a closed area to provide a more complete radiation field pattern.

Exposure system, manufacture of device, and cleaning method of optical device of exposure system

Abstract: PROBLEM TO BE SOLVED: To more easily and effectively prevent an optical device from being contaminated by organic molecules by a method wherein inert gas is supplied to an optical system closed space, and oxygen or clean air is fed. SOLUTION: Nitrogen gas as inert gas is supplied to the inner space 2j of a case 2g of an illuminating optical system 2, the inner spaces of lens tubes 2h and 2i, and spaces partitioned by lenses in a lens tube of a projection lens 5 respectively. Therefore, an inert gas feed device 8a is provided. The inert gas feed device 8a is connected to the above spaces through an inert gas feed line 8b and a solenoid valve 8c (open-close valve) provided to the line 8b respectively. An oxygen feed line 10b is joined to the inert gas feed line 8b, and an oxygen feed device 10a is connected to the oxygen feed line 10b through the intermediary of a solenoid valve 10c (open-close valve) provided to the oxygen feed line 10b. Oxygen-containing clean air may be mixed in place of pure oxygen.

Power supply circuit

Abstract: A power supply device of the present invention includes an electric double layer capacitor (2) connected to, eg, an HDD (Hard Disk Drive), CD-ROM (Compact Disk Read Only Memory) drive, floppy disk drive or similar motor-driven equipment (1), and another electric double layer capacitor (2) connected to, eg a pulse generating device (3) included in a radio transmitter The capacitors (2) each feed power when the load of the associated equipment sharply varies during operation of the equipment This makes it needless for a main power supply (5) to feed such power A laminate polymer battery (4) is connected to a low voltage IC (Integrated Circuit) (7) and feeds power thereto This also makes it needless for the main power (5) to feed power to the low voltage IC (7), and allows a short feed line to connect the laminate polymer battery (4) and IC (7) The short feed line reduces the transfer of noise to the IC (7) and therefore malfunction ascribable to noise

A substantially flat, aperture-coupled antenna element

Abstract: A substantially flat, aperture-coupled antenna element of the kind comprising a multilayer structure with a radiating patch (2) arranged on a dielectric layer (1), an electrically conductive ground plane layer (3) having a cross-shaped aperture (4) with two crossing slots (4a, 4b) being centered in relation to the patch, and a dielectric board provided with a feed network (6) for feeding microwave energy via feed elements (7, 8) and said cross-shaped aperture (4) to said patch so as to cause the latter to generate a dual polarized microwave beam propagating from the antenna element. The multilayer structure includes a single dielectric board (5) provided with a planar feed network (6) having a first feed element (7) with a pair of feed lines extending symmetrically on each side of the aperture centre (4c) and a second feed element (8) with a single feed line located unsymmetrically at one side of said aperture centre without crossing said first feed element, the two feed elements (8, 7) being oriented and dimensioned so as to excite each one of the slots (4a, 4b) separately from a respective microwave channel.

Device for transmission measurement with the aid of microwaves

Abstract: A system for transmission measurement with the aid of microwaves for the continuous determination of the concentration of a substance, the system being composed of: a transmission waveguide antenna for radiating microwave energy; a receiving waveguide a for receiving radiated microwave energy, each of the waveguides being provided with a window that is transparent to microwave radiation; and a signal processing circuit connected to the waveguides for supplying a microwave signal to the transmission waveguide antenna to cause the transmission waveguide antenna to radiate microwave energy via the window of the transmission waveguide antenna and for receiving from the receiving waveguide antenna a microwave signal created in the receiving waveguide antenna by microwave radiation received by the receiving waveguide antenna through the window in the receiving waveguide antenna.

Directional coupler, directionally coupling device, variable attenuator and transmission/reception equipment

Abstract: PROBLEM TO BE SOLVED: To vary a distribution ratio in the case of using as a distributor and to vary an attenuation amount in the case of using as an attenuator by relatively in parallel moving a first transmission line and a second transmission line and changing the confronted length of the first transmission line with the second transmission line. SOLUTION: A directional coupler 1 partially turns a first transmission line 2 and a second transmission line 3 into a confronted state and connects a terminal resistor 4 to one end of the first transmission line 2. The first transmission line 2 sandwiches a dielectric strip 2a between an upper sheet metal and a lower sheet metal 2b on a non-radioactive dielectric line. The second transmission line 3 sandwiches a dielectric strip 3a between an upper sheet metal and a lower sheet metal 3b on the non- radioactive dielectric line as well. The upper sheet metal and lower sheet metal 2b of the first transmission line 2 are independent of the upper sheet metal and lower sheet metal 3b of the second transmission line 3 and can be in parallel moved. The first transmission line 2 is moved parallel to the second transmission line 3 by a driving means 5 and a confronted length L is changed.

40 GHz parallel plate slot array fed by single-layer waveguide consisting of posts in a dielectric substrate

Abstract: A parallel plate slot array is an attractive candidate for a high-efficiency and mass-producible planar antenna for millimeter-wave applications since the transmission loss in a parallel plate waveguide is generally small in comparison with other feed lines such as a microstrip or a suspended line. The radiating part has a simple structure that consists of slots etched on the upper plate. There are various ways to feed a plane TEM wave in a parallel plate. Feed structures using a horn or a parabolic reflector are simple but need relatively large areas. We introduce a novel single-layer structure of a feed waveguide. Densely arrayed posts equivalently compose the waveguide walls. We make many through-holes in a metal-grounded dielectric substrate and metalizing them as posts. The structure is advantageous for fabricating planar antennas for millimeter-wave applications with low costs. In this paper, we make a 40-GHz model of the parallel plate slot array with the feed waveguide. We have confirmed the uniform dividing of the feed waveguide in amplitude and phase at 40.2 GHz. An antenna gain of 30.6 dBi with 29% efficiency is obtained.

Multilayer-transmission-line and electronic part using the same

Abstract: PROBLEM TO BE SOLVED: To provide a multilayer-transmission-line which suppresses the fluctuation of combined capacitance between upper and lower transmission lines and has desired characteristic impedance and to provide an electronic part using it SOLUTION: In this multilayer-transmission-line which successively laminates a transmission line conductor 6 and transmission line conductors 7 to 9 placed almost opposite to it through dielectric ceramic layers, the line width of the transmission line conductors 6 and 8 is constructed to mutually differ from the line width of the transmission line conductors 7 and 9 between opposite upper and lower transmission lines Thus, it is possible to absorb the stack deviation of the transmission line conductors to obtain a multilayer-transmission- line which suppresses the fluctuation of combined capacitance between the respective transmission lines and has desired characteristic impedance