Showing papers on "Feed line published in 2000"

Serially-fed phased array antennas with dielectric phase shifters

Abstract: A phased array antenna includes a plurality of radiating elements, a feed line assembly, a ground plane positioned between the plurality of radiating elements and the feed line assembly, with the ground plane having a plurality of openings positioned between the plurality of radiating elements and the feed line assembly, and a plurality of voltage tunable dielectric phase shifters coupled to the feed line assembly.

Microwave ablation instrument with a directional radiation pattern

Abstract: A medical instrument is disclosed The medical instrument includes a transmission line suitable for the transmission of electromagnetic energy and an antenna coupled to the transmission line The antenna is configured for generating an electromagnetic field sufficiently strong to cause tissue ablation The medical instrument further includes a reflector arranged to be electrically coupled to the transmission line The reflector is positioned laterally to a first side of the antenna and configured for redirecting a portion of the electromagnetic field to a second side of the antenna opposite the reflector, wherein a majority of the electromagnetic field is directed away from the second side of the antenna

Design and analysis of multisegment dielectric resonator antennas

Abstract: The multisegment dielectric resonator antenna (SDRA) has previously been developed to significantly enhance the coupling to a microstrip line. The MSDRA greatly facilitates the integration with a printed feed distribution network for use in a large array environment. The thickness and permittivity of the dielectric insert of the MSDRA can be adjusted to match the element impedance to that of the feed line. A detailed study of the effects of varying the dielectric insert parameters was carried out and useful guidelines are presented for the design of MSDRAs.

Feed structure for electromagnetic waveguides

Abstract: The present invention relates to feed structures for electromagnetic waveguides, cavities, antennas and other structures. A "feed structure" is an arrangement for electrical conductors used to transfer RF energy between any transmission lines and a waveguide. There are problems associated with designing and manufacturing conventional feeds. The present invention overcomes these problems by directly coupling an integrated circuit incorporating an RF circuit element to a waveguide, cavity, antenna or other structure. Coupling is achieved by an aperture formed in a ground plane of the integrated circuit and connected to a transmission line linked to the RF circuit element.

A low-profile conical beam loop antenna with an electromagnetically coupled feed system

Abstract: The radiation characteristics of a low-profile loop antenna are evaluated using the method of moments (MoM). The loop having a circumference of approximately two wavelengths is electromagnetically coupled to a bent Feed line and radiates a circularly polarized conical beam. The frequency bandwidth for a 3-dB axial ratio criterion is calculated to be approximately 0.5% for an antenna height of h=0.064 wavelengths. Over the same bandwidth, the input impedance is approximately 50 ohms and the gain is approximately 7 dB.

Yagi antenna coupled with a low noise amplifier on the same printed circuit board

Abstract: A Yagi antenna system consisting of a low noise amplifier (LNA) and a reflector co-located on the same printed circuit board (PCB) as the radiators and directors is disclosed. Furthermore, the balun cable is replaced by surface mount devices whose feed line is implemented in microstrip technology, all co-located on the same printed circuit board.

Antenna device and portable radio set

Abstract: An antenna in which first and second antenna elements are selected by a switching apparatus so that the first and the second antenna elements are connected to an unbalanced transmission line via a balancing-unbalancing transmission line or only the first antenna element is connected to the unbalanced transmission line The unbalanced transmission line supplies power via a balanced-to-unbalanced transformation apparatus to the first and the second antenna elements, so as to operate as an antenna, at which time, balanced-to-unbalanced transformation action of the balanced-to-unbalanced transformation apparatus prevents leakage current from flowing from the first or the second antenna element to the unbalanced transmission line and prevents a ground element on which the unbalanced transmission line is grounded from operating as an antenna This reduces deterioration of antenna characteristics in the vicinity of a human body, so that an antenna device and portable radio set which can sizably reduce deterioration of communication quality can be realized

A T-shaped microstrip-line-fed wide slot antenna

Abstract: We propose a simple feed structure for the wide rectangular slot antenna that can achieve a good impedance match over a wide frequency range. The feed structure is composed of a horizontal strip conductor connected at the end of the microstrip feed line. The proposed antenna is analyzed by using the finite difference time domain (FDTD) method. The measured result for the return loss of the antenna is also presented.

Mode conversion at GCPW-to-microstrip-line transitions

Abstract: Mode conversion at the transition between grounded coplanar waveguide (GCPW) and microstrip line is demonstrated. Experimental results show the effect of overmoding in a conductor-backed coplanar waveguide on the transition behavior. A simple micromachining solution is used to cancel the parasitic modes triggered by the transition in the GCPW feed line. This results in an insertion loss of 0.3 dB and a return loss better than -18 dB from 75 to 110 GHz. The transition can prove very useful for millimeter-wave packaging and interconnects.

Flat panel antenna

Abstract: A small size, flat panel, 1/6th wavelength antenna is provided. A flat copper-clad dielectric substrate (18) is processed on a first flat side to produce a copper triangular or pseudo triangular-shaped radiating element (16) having a linear copper feed line that extends from the triangle apex. The substrate (18) is also processed on its opposite flat side to produce a rectangular-shaped first copper ground plane element (13) that underlies at least a portion of the copper feed line (21), but does not underlie the copper radiating element (16). The first side of the substrate (18) may also be processed to produce a second copper ground plane element (14) that is out of physical engagement with both the copper feed line and the copper radiating element. The antenna ground plane element(s) may also function as the ground plane for another antenna, such as a GPS antenna.

Coplanar waveguide-fed circularly polarized microstrip antenna

Abstract: Design of a square microstrip antenna for obtaining circular polarization (CP) radiation using a coplanar waveguide (CPW) feed is presented. This CP design is achieved by insetting a slit to the boundary of the square microstrip patch, which makes possible the splitting of the dominant resonant mode into two near-degenerate orthogonal modes for CP radiation and introducing an inclined slot in the CPW feed line for coupling the electromagnetic (EM) energy of the CPW to the square patch. Good impedance matching for CP operation can be obtained by adjusting the inclined slot length and the tuning-stub length of the CPW feed line. Typical experimental results are presented and discussed.

Aperture coupled slot array antenna

Abstract: A planar, phased-array antenna (50) including a nonconductive substantially planar substrate and a transmission line (61) disposed on one surface is disclosed, a segment of the transmission line forming an arc of radius R centered on the antenna axis (51). A conductive layer on the other antenna surface includes two or more slotted openings (53, 55, 57, 59), each slotted opening having one end located within a distance R of the antenna axis, such that, when an electromagnetic signal is fed into one end of the transmission line, electromagnetic energy is sequentially coupled into the slotted openings, and a circularly-polarized signal is radiated from the antenna substantially in the direction of the antenna axis. An amplifier (71) or a connector may be electrically connected to one or both ends of the transmission line, or one end of the transmission line may be terminated in an impedance load (73) to form a leaky-wave antenna. The slotted openings may comprise either or both straight and curved segments, and may be of the same or unequal lengths. Curved slotted openings may be oriented clockwise or counter-clockwise to transmit or receive either left-handed or right-handed polarized signals.

Multi-frequency antenna feed

Abstract: A multi-frequency antenna feed for incorporation into a single unit which combines at least two waveguides to provide simultaneous reception and/or transmission of signals in at least two separate frequency bands is described. This is achieved by creating a waveguide system of at least two waveguides sharing the same central axis; a central conventional waveguide which also acts as a centre conductor for an outer coaxial waveguide and feeding the outer coaxial waveguide from a non-circular side feed, orthogonal to the waveguide axis, to set up a uniform field in the outer coaxial waveguide. The feeds are adjusted so that the phase centre for each frequency band is at the same point in the feed for the same dish. Various embodiments of the invention are described.

System and method for power line communication

Abstract: The present invention discloses a power line communication system and method for transmission of RF signals through an AC power line medium. The system includes a transmitter to transmit the RF signals through the AC power line medium and a receiver to receive the RF signals from the AC power line medium. The AC power line as a transmission medium is transparent to the circuits sending and receiving the RF signals.

Dual-frequency balun to decrease influence of RF feed cables in small antenna measurements

Abstract: A dual-frequency balun applied in connection with measurements of small dual-frequency antennas reduces parasitic currents on the surface of the RF feed cable, so that the influence of the RF measurement cable on the radiation pattern is minimised.

Base station of a communication network, preferably of a mobile telecommunication network

Abstract: The invention relates to a base station of a communication network which comprises a casing, a transmitting and receiving device housed in the casing, and an antenna connected to the transmitting and receiving device. The antenna is formed as a patch antenna which comprises at least one receiving antenna patch and at least one transmitting antenna patch spatially separated from the receiving antenna patch. The receiving and transmitting antenna patches are preferably attached to the outside of the casing of the base station. Two or more separate receiving antenna patches may be connected to a common receiving feed line for connection to a receiving circuit of the base station. Likewise, two or more separate transmitting antenna patches may be connected to a common transmitting feed line for connection to a transmission circuit of the base station.

Quadrifilar helix feed network

Abstract: A radio antenna system having a quadrifilar antenna having four helical arms and a method of feeding the arms. The antenna system comprises a first balun having a feed line and two feed points with 180° phase differential therebetween for feeding one opposite arm pair, and a second balun having a feed line and two feed points with 180° phase differential therebetween for feeding the other opposite arm pair. The two feed lines are combined in a single combiner, which provides a 90° phase differential between the feed lines.

Optimal reduction of the influence of RF feed cables in small antenna measurements

Abstract: A genetic algorithm is applied to optimize the size and location of a sleeve, which reduces parasitic currents on the surface of the feed cable of a mobile handset antenna, so that the influence of the RF cable on the radiation pattern is minimized. The pattern is calculated by the electric-field integral equation (EFIE) method in each iteration of the genetic algorithm. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 25: 194–196, 2000

Automatic gearbox for vehicle with hydrodynamic converter has oil cooler in oil line between main pressure valve and branch in lubricating oil line with controlled throughput bypass

Abstract: The gearbox has a converter safety element that restricts the oil pressure before the converter (1), an oil line (10) that branches off the oil feed line to the converter and contains a lubricating valve (20) and an oil cooler. The oil cooler (22) is arranged in an oil line (24) between the main pressure valve (16) and the branch (25) in the lubricating oil line (23) and has a bypass (26) whose throughput is controlled and/or regulated.

Transmitter and receiver communication apparatus with transmitter switch and receiver switch

Abstract: According to the invention, a transmitter antenna selector switch 109 or a receiver antenna selector switch 111 is respectively connected between the first antenna 101 a and the second antenna 101 b and the transmitter 103 or the receiver 105 . Transmission signals output from the transmitter 103 are supplied to either the first antenna 101 a or the second antenna 101 b in transmission, while reception signals are received from either the first antenna 101 a or the second antenna 101 b via the receiver antenna selector switch 111 in reception.

Method and apparatus for coupling strip transmission line to waveguide transmission line

Abstract: A strip transmission line to waveguide transmission line transition or impedance coupling is described. A strip transmission line is separated from a ground plane by a dielectric therebetween, and an aperture is formed through the ground plane and the wall of a waveguide transmission line on the other side of the ground plane (ground plane and wall may be the same piece). Each transmission line is terminated reactively, or at a port; for simple coupling across the transition, one end of each transmission line forms a reactive stub termination, such as an open circuit end. A waveguide channel waveguide walls and a waveguide base connected therebetween may be provided. The walls of such waveguide are coupled with the ground plane to provide a waveguide top for the waveguide transmission line. An aperture is located, preferably transverse to the microstrip transmission line, and passes through an opening in the ground plane and also through a coupled waveguide side, which may be separate or of a piece with the ground plane. The impedances of the transmission lines are adjusted to affect the coupling afforded by the aperture. Multiport impedance coupled transmission lines may be formed in this way.

Dielectric heating using inductive coupling

Abstract: A method and apparatus for heating or drying material by applying radio frequency (RF) power to a material in a resonant cavity; wherein an RF power source is inductively coupled to a resonant cavity formed by distributed inductance in resonance with the applicator and material where the magnetic field established by the feed line(s) induces a voltage on the applicator permitting feed line voltages delivering said RF power to the cavity to be lower than those that would normally be encountered for equivalent RF heating using direct coupling.

RF current injecting antenna device

Abstract: An apparatus for, and method of, replacing conventional antennas which transmit radio frequency energy from radio frequency transmitters. The invention provides for the use of any conductive surface as a transmitting antenna by taking advantage of the fact that any electrical conductor or surface that is 0.1 wavelengths or longer will radiate RF energy when injected with sufficient current. The RF current injecting antenna device, employing the principles of an instrument transformer, couples RF energy from a transmitter to a linear conductive element or a conductive surface. The useful frequency range that has been demonstrated for the device is 2 MHz to 1 GHz.

Method and apparatus for testing a signal line

Abstract: A transmission line for carrying digital signals is provided with auxiliary line drivers at the receiver end, which are used in combination with the data line driver at the transmitting end to apply a sequence of sets of test voltages onto the line. The voltage resulting at the receiver input is used to detect open signal conductors and/or shorts in the receiver.

Micro-strip antenna

Abstract: A micro-strip antenna includes a dielectric substrate, a radiation conductor disposed on one main face of the dielectric substrate, a ground conductor disposed on the opposite main face of the dielectric substrate, and at least one reactance compensation electrode disposed on a side face of the dielectric substrate and connected to the radiation conductor or the ground conductor. Through adjustment of the shape and length of the reactance compensation electrode, the input impedance of the micro-strip antenna is matched to a feed line. The reactance compensation electrode serves as a reactance compensation circuit element.

Transmission-line modelling of the cross-aperture-coupled circular polarised microstrip antenna

Abstract: A circular polarised antenna fed through a cross-aperture in a ground plane by means of a microstrip feed line is modelled, and an original analysis using a transmission-line method is presented. The field linkages from the feed to the slots and the slots to the antenna are modelled as voltage transformers, which are employed in the synthesis of the overall transmission-line model of the structure. This analysis allows for an efficient computational procedure to predict the input impedance of the structure. The application of a full wave simulation package and the experimental results obtained for the structure support the theory presented.

System for automatically adjusting receive path gain

Abstract: The present invention provides a system and method for automatically compensating for transmission line losses at a wireless base station antenna site. Transmission line losses are measured and the result of the measurement is used to adjust a variable gain amplifier which receives reception signals from the transmission line.

Method and system for autonomous two-way radio frequency communication

Abstract: A method and system for autonomous two-way RF communication between a launch vehicle and at least one receiving or tracking station. Detection circuitry continuously determines the identity of the optimum receiving or tracking station (ground, sea, airborne, or satellite) and selects the best launch vehicle transmission antenna to close the RF telemetry link. The method and system is designed to simultaneously transmit and receive RF signals. The antenna system includes a telemetry transmission link and an antenna selection link. Antenna selection link signals received by each antenna element on the launch vehicle are provided via RF couplers to a receiver for signal strength and modulation signal detection. The telemetry transmission link communicates with a receiving or tracking station by using a transmitter to drive one of two or more switched antennas mounted on the surface of the launch vehicle having the current higher signal strength.

Nonvolatile semiconductor memory and method of writing data therein

Abstract: PROBLEM TO BE SOLVED: To reduce the write time by applying an ideal voltage suited to write data to the channel of a memory cell to be written SOLUTION: In the write operation to an 8-valued NAND type flash memory, a drain side selected gate line DSG to a level Vcc to execute a multivalued parallel write, using a self boost After setting a selected bit line to a bit line voltage according to a write data, a word line voltage VWL is boosted in three steps According to the boost step of the word line voltage VWL, at specified timings, a bit line voltage feed line VBL3 for feeding a bit line voltage VB3 (=15 V) and a bit line voltage feed line VBL2 for feeding a bit line voltage VB2 (=15 V) are switched to the level Vcc one after the other to disconnect the channels of a memory cell from the bit lines Thus the channel voltage of a memory cell with a write data '110' and the channel voltage of a memory cell with a write data '10x' are boosted to specified write potentials by the capacitive coupling with word lines

DC-DC converter which supresses power supply noise in low power circuit

Abstract: A DC-DC converter facilitates preventing switching noises, caused by the switching of a main switching transistor and its driver, from affecting a control circuit adversely and securing stable operations of the converter. Specifically, the DC-DC converter includes a feed line LS 1 for the main circuit, a ground line LG 1 for the main circuit, a positive feed line LS 2 for the control circuit, a negative feed line LG 2 for the control circuit 3, an insulation resistance Rd 1 connected to the feed line LS 1 or to the feed line LS 2, (or) an insulation resistance Rd 2 connected to the ground line LG 1 or to the feed line LG 2, and, if necessary, a filter capacitor Cd connected in parallel to the control circuit 3.