Showing papers on "Feed line published in 2002"

Planar inverted-F antenna including a matching network having transmission line stubs and capacitor/inductor tank circuits

Abstract: A small multi-band planar inverted-F antenna (PIFA) includes a metal radiating element that is physically located above a metal ground plane element, and the space therebetween includes a frequency matching network having a microstrip transmission line that connects an antenna feed to a wireless communications device (WCD) feed. The impedance matching network may include a microstrip impedance transformer whose output provides a 50 ohm connection to the WCD. A number of microstrip stubs are connected to the microstrip transmission line. At least some of the microstrip stubs connect to the microstrip transmission line by way of a LC tank circuit. The LC tanks circuits are responsive to different ones of the multiple frequencies to which the PIFA is responsive, and in this manner the impedance matching network is dynamically reconfigured in accordance with the frequency band currently traversing the microstrip transmission line. The LC tanks circuits include discrete capacitors and inductors. A two-shot molding process is used to make a unitary plastic antenna assembly whose second-shot plastic surfaces are metallized in order to provide the antenna's metal elements, including the microstrip circuit pattern of the impedance matching network.

Apparatus and method for transmitting and receiving data using an antenna array in a mobile communication system

Abstract: A data transmitting/receiving apparatus and method using an antenna array in a mobile communication system. A Node B measures a transmission status of each transmission antenna, classifies transmission data according to priority, and transmits to a UE high-priority data through a transmission antenna at a relatively good transmission status and low-priority data through a transmission antenna at a relatively poor transmission status.

Coplanar-waveguide-fed slot-coupled rectangular dielectric resonator antenna

Abstract: A novel coupling scheme to a rectangular dielectric resonator antenna is proposed and investigated. In particular, coupling to the resonator is achieved through a narrow slot at the end of a coplanar waveguide (CPW). The objectives of this design are to maximize the coupling, match the dielectric resonator to the CPW feed line, achieve resonance at the desired frequency, obtain linear polarization with low cross polarization components, and minimize back radiation without using a back conductor. An approximate and quick design approach is given followed by more accurate design and analysis using commercial software. The antenna was fabricated and tested. Measurements match well with simulation results.

High speed system for embedding wire antennas in an array of smart cards

Abstract: A high speed system (1) for embedding antenna wire (136) within a non-conductive (eg plastic) sheet (30) on which electronic chips are mounted for manufacturing a plurality of smart cards (32), or the like The antenna wire (136) is installed in the non-conductive sheet (30) by an ultrasonic actuator (5) that is moved up and down relative to the sheet from one smart card to the next The movement of the actuator (5) relative to the sheet (5) is controlled by the interaction between a stationary voicecoil magnet (92) and a voicecoil (76) that is coupled to the ultrasonic actuator (5) and moveable with a slide assembly (7) Antenna wire (136) is fed to the ultrasonic actuator from an antenna wire dispensing spool (124) by way of an idler assembly (14) The idler assembly includes an encoder (150) which is responsive to an increase in tension in the antenna wire feed line Depending upon the output of the encoder (150), the speed and rotation of the wire dispensing spool (124) is controlled until the tension in the antenna wire feed line is eliminated

Method of determining the capacity of each transmitter antenna in a multiple input/multiple out/put (MIMO) wireless system

Abstract: The per antenna capacity of each of the transmitter antennas in a MIMO system are individually determined from measurable information at the receiver end. Specifically, the channel capacity for each individual transmitter antenna is calculated at the receiver end as a function of measurable channel coefficients (also known as channel state information), the measurable average signal-to-noise ratio, and the number of transmitter antennas. Once the per antenna capacity of each transmitter antenna is individually determined at the receiver end, the maximum transmission rate for each data stream transmitted by each transmitter antenna is determined from that individual capacity either at the receiver end and fed back to the transmitter end, or is determined at the transmitter end from the individual transmitter antenna capacities that are fed back by the receiver end to the transmitter end. A modulation scheme that supports each maximum transmission rate is then determined based on some defined criteria.

Multielement planar antenna

Abstract: A multielement planar antenna has a substrate, a plurality of antenna element pairs disposed on a first main surface of said substrate, each of the antenna element pairs including first and second antenna elements each made of a circuit conductor, a metal conductor disposed on a second main surface of the substrate, and a slot line defined in the metal conductor. Each of the antenna element pairs has a microstrip line interconnecting the first and second antenna elements. The slot line crosses the microstrip lines and is electromagnetically coupled to the microstrip lines for feeding the first and second antenna elements. The slot line is fed at its central area by a microstrip line or a coplanar line.

High-performance air-gap transmission lines and inductors for millimeter-wave applications

Abstract: The air-gap transmission lines and inductors are developed by new multilayer process. The developed transmission lines are air-gap coaxial line, air-gap strip line, air-gap coplanar waveguides (CPW), and air-gap buried microstrip line (BMSL). The air-gap transmission lines show very low signal loss and very high isolation performances. The transmission line loss of the coaxial line is less than 0.08 dB/mm up to 40 GHz. Those of the CPW, strip line and BMSL are about 0.07, 0.15, and 0.13 dB/mm, respectively. The isolation characteristics of the coaxial line and BMSL are measured. In case of the coaxial line with 2-mm coupling length and 60-μm distance between signal lines, the coupling is less than –52 dB up to 40 GHz. In case of the BMSL with the same conditions, the coupling is less than –43 dB. Therefore, the air-gap transmission line is very suitable structure for high performance and high-density RF application. Additionally, the air-gap inductors are monolithically fabricated using the same process of the transmission line. The fabricated inductors have very high quality factors, the maximum factor of 1.46-nH air-gap inductor is about 130. Using the developed multilayer process, we can realize various types of air-gap transmission lines (coaxial line, CPW, strip line and BMSL) and air-gap inductors simultaneously.

Radio transmission system and method, and transmitter apparatus and receiver apparatus used in the radio transmission system

Abstract: A radio transmission system is configured to, on the occasion of radio transmission of information between a transmitter and a receiver, perform the radio transmission of information using an orthogonal frequency and code division multiplexing transmission scheme of parallelly transmitting identical information by a plurality of sub-carriers. The radio transmission system has a spreading factor variable control transmitting device for parallelly converting information channel-coded at the transmitter, according to symbols transmitted simultaneously, and for spreading a sequence of parallelized symbols in at least one of a frequency direction and a time direction by a spreading code sequence of a designated spreading factor.

Portable radio terminal device

Abstract: A first and a second transmission antenna 2 and 3 are disposed in a lower and an upper part, respectively, of a housing 1. One of the two transmission antennas 2 and 3 is predetermined to be a normally used transmission antenna, in the neighborhood of which a sensor 8 is disposed. When the user's hand 4 covers the first transmission antenna 2, the control part 6 feeds out a control signal to the control part 6, whereupon an antenna select switch 7 automatically switches the first transmission antenna 2 over to the second transmission antenna 3.

Portable type radio equipment

Abstract: In a radio equipment of portable type, the impedance of an antenna is optimized by adjusting a matching circuit which has the adjustment function and is connected to an antenna, based on a reflection phase sent back from the antenna, outputted from a reflection phase detector, and a current supplied to a transmitter-receiver which generates a transmitting signal.

Smart antenna for portable devices

Abstract: A dynamically reconfigurable antenna system is disclosed which may be configured with low cost discrete analog components. Particularly, the antenna elements, phase shifters, and beam forming network of the current smart antenna system are configured from RF transmission lines, RF couplers and RF switches in a system which is able to dynamically reconfigure its beam forming signals to point in a direction of greatest signal strength. The smart antenna system may be configured on portable devices to accomplish greater signal reception and transmission when used in a wireless network.

Planar high-frequency antenna

Abstract: The present invention provides a planar antenna having a scalable multi-dipole structure for receiving, and transmitting high-frequency signals, including a plurality of opposing layers of conducting strips disposed upon either side of an insulating (dielectric) substrate. The dipoles are bifurcated between sides of a substrate on which the dipoles are disposed. A feed line is balanced to a co-axial cable and feeds one half of the bifurcated dipoles, and an independent feed line is connected to the other half of the bifurcated dipoles. Sets of the dipoles are arranged symmetrically around a center axis of the feed lines. The sets of dipoles are in series with other sets of dipoles. The antenna is ideally suited for operation in the 5.15-5.35 GHz RF band.

Dielectric antenna for high frequency wireless communication apparatus

Abstract: A dielectric antenna is provided for a high frequency wireless communication apparatus. The antenna includes a dielectric substrate and a conductive meander line layer formed on the dielectric substrate. A conductive feed line layer, having a greater line width than the width of the meander line layer, is also formed on the dielectric substrate. A conductive taper layer connects the conductive meander line layer to the conductive feed line layer. An edge of the conductive taper layer slants at an angle from an adjacent edge of the conductive feed line layer in a direction toward the conductive meander line layer.

Multi band built-in antenna

Abstract: A planar inverted F antenna (PIFA) includes a feed pin supplying a current, a feed line having one end electrically coupled to one end of the feed pin and having a predetermined resonance length, a coupling pin coupled to the other end of the feed line, and a radiating patch formed on a plane spaced-apart from the feed line by a predetermined distance to induce the current supplied through the other end of the coupling pin, and a slot having one end starting at a portion of an edge and the other end disposed in an inside portion of the radiating patch, and a shorting pin having one end coupled to the radiating patch and the other end coupled to a ground. The PIFA becomes smaller by using an electrical resonance length of the feed line, a shape of the feed line, and the open stub and the matching pad, improves the flexibility of the antenna design, and obtains a wider frequency band.

On the equivalent circuit of a receiving antenna

Abstract: The equivalent circuit of a receiving antenna consists of a current generator and two admittances: one for the load, and one for the antenna. The short-circuit current, I/sub g/ - receiving property - may be expressed in terms of the transmitting properties of the antenna. The article gives a derivation for the value of I/sub g/. It is assumed, to simplify matters, that the antenna is located in free space, and that its feeding line is a monomode waveguide (a coaxial cable, for example). The extension to multimode lines, or to spatial regions containing linear media (possibly anisotropic, and/or non-reciprocal) is fairly straightforward.

Controlled power source for underground line location

Abstract: A transmitter for a line locator system that controls the electrical current, voltage or power applied to the target line is disclosed. Control of the electrical output of the transmitter can be achieved passively or by means of a feedback control system. A transmitter connected directly to a line can include an operator control and monitoring of current being supplied to a line to be located. Some transmitters include a current regulating circuit that controls current supplied to a line. In some transmitters, feedback controllers and feedback loops are used to regulate output current, voltage or power. Some control loops are based on monitoring currents in circuits; some control loops monitor power output from an inductive mode transmitter antenna. An inductively coupled transmitter with power output control is also disclosed.

Tunable patch antenna for wireless communication terminals

Abstract: A radio antenna comprising a tuning component, such as a transmission line, coupled to the radiating element for providing a frequency shift from the resonant frequency, and an adjustment mechanism for adjusting the frequency shift by effectively changing the length of the transmission line. The adjustment mechanism comprises one or more extension lines, and a switching mechanism, which can be closed to couple one or more of the extension lines to the transmission line. The tuning component can also be one or more lumped reactive elements.

Miniature multi-element antenna for wireless communications

Abstract: We present a novel broad-band miniature antenna and employ it in a multi-element geometry with diversity capabilities for wireless communications. This antenna (diameter < 0.2 /spl lambda/ and thickness < 0.06 /spl lambda/) consists of two stacked circular patches that create two cylindrical slots resonating at two slightly different frequencies, fed by a strategically positioned coaxial probe. An extensive parametric study and results for a prototype working at 5.2 GHz are presented. A multi-element geometry with two or four of such elements follows. Microelectromechanical system (MEMS)-based switches located within its geometry can not only change the working frequency of the design, but also activate a particular radiation beam depending on their specific location (resonant slot-aperture or feed line). Simulation results of a four-element antenna with dimensions 0.8 /spl lambda/ /spl times/ 0.8 /spl lambda/ /spl times/ 0.06 /spl lambda/ and a frequency band operation from 5 to 6 GHz are presented and compared to an experimental prototype. Circuit and radiation characteristics are discussed in terms of reconfigurability and diversity capabilities.

Microstrip phase shifter

Abstract: A phase shifter adjusts the phase between two segments of an RF feed line that are fed with the phase shifter. Specifically, the phase shifter adjusts the phase between two signals in RF feed line segments by changing the electrical path lengths that RF energy travels down in each respective RF feed line. The phase shifter includes a coupling arm, a key, a spring, and a support architecture that fastens the phase shifter to a substantially planar surface. The support architecture is rotated manually or with a machine such as a motor. The coupling arm can include a coupling ring, a wiper element, a support trace, and a dielectric spacer. The phase shifting system is a relatively compact structure having a predetermined value of capacitance maintained between a coupling ring disposed on the coupling arm and a coupling ring disposed on a planar surface.

Dual-band inverted-F antenna

Abstract: A dual-band inverted-F antenna comprises a first surface and a second surface opposite to each other; a ground surface formed on the second surface of substrate; a first radiating microstrip formed on the first surface of substrate; a second radiating microstrip formed on the first surface of substrate; a feed line formed on the first surface of substrate, in which the feed line is connected to the portion in between the first radiating microstrip and the second radiating microstrip for feeding signal; a connection line formed on the first surface of substrate for connecting both the first radiating microstrip and the second radiating microstrip; and a common metal short-circuit rod used to ground the short-circuit of the first radiating microstrip and the second radiating microstrip. As the dual-band inverted-F antenna of the invention can be operated in dual frequency bands and can be produced by using circuit substrate, it has very high commercial application value.

Active signal conditioning circuitry for well logging and monitoring while drilling nuclear magnetic resonance spectrometers

Abstract: NMR transmitter/receiver antenna (20) active signal conditioning circuit that enables receiver antenna circuit protection from high voltage RF transmitter pulses, provides energy dumping for the entire antenna in successive stages (35,32,34) and eliminates retuning during sweeping of the antenna frequency.

Dual-polarized, stub-tuned proximity-fed stacked patch antenna

Abstract: A dual-polarized, stub-tuned, proximity-fed, stacked patch antenna includes a ground plane layer and a dielectric substrate overlying the ground plane layer. An active patch antenna element is disposed on the dielectric substrate. A parasitic patch antenna element is supported in spaced relation to the active patch antenna element. Dual feed lines are spaced from and field-coupled to the active patch antenna element. Each feed line has a tuning stub for producing a distributed antenna resonance. The dual feed lines are configured to provide dual polarization and minimize coupling between the feed lines. The feed lines are positioned substantially orthogonal to each other to provide orthogonal linear polarizations. Each feed line includes a feed line tip that extends towards the center of the active patch antenna element and spaced from each other to minimize tip-to-tip coupling. Each feed line tip includes a 90 degree bend.

Wideband conical spiral antenna

Abstract: A spiral antenna having a horizontal member that terminates wires for conducting and radiating signals provides increased efficiency over the HF transmission range in a smaller size construction. A load having a parallel RLC circuit is provided at about the center of the horizontal member. The wires are provided in an elliptical pattern with the spacing between wires provided arithmetically. The wires are further configured symmetrically around a vertical support member. A balun transformer is also provided for impedance matching with a feed line.

Double-folded monopole antenna using parallel line or coaxial cable

Abstract: It has been shown that loading a certain reactance component at the feeding point of an antenna is useful in reducing antenna size. When a parallel transmission line with a short-circuited end is loaded onto a monopole antenna, we can obtain a small antenna called a parallel line loaded monopole antenna. However, a small antenna usually has low input resistance and low actual gain. The approach outlined is to increase the actual gain of the small loading antenna and utilise knowledge of a folded monopole antenna, which has a very high impedance value. A small folded monopole antenna called the double folded monopole antenna (DFMA) with high resistance and high actual gain can then be realised. An explanation of the operational principles of the DFMA is provided and the characteristics of small antenna design discussed. A coaxial cable is also used as the loading element for the loading antenna. It is proposed that a coaxial cable DFMA can be realised by replacing the parallel transmission line loading with coaxial cable transmission line loading. The advantage of the coaxial cable DFMA is that it has a small cross-sectional area, since the coaxial cable loading is embedded within the cylindrical antenna element. The results of actual testing of the coaxial cable DFMA are presented. All other results are provided by computer simulation using the method of moments, since the results are assumed to be similar to those recorded from practical experimentation.

Integrated segmented and interdigitated broadside- and edge-coupled transmission lines

Abstract: A combination edge- and broadside-coupled transmission line element formed in an integrated circuit chip, using semiconductor processes, in a stack of metal layers separated by dielectric layers. Each of the metal layers includes a number of transmission lines. Interconnects between the transmission lines are formed at predetermined locations, each interconnect electrically connecting together a group of the transmission lines to form a conductor. The efficiency of the coupling between the lines in the different conductor is increased by positioning the lines such that both edge- and broadside-coupling is realized. For example, at least one of the transmission lines in one of the conductors is positioned either above or below a transmission line in the other conductor to achieve broadside-coupling and laterally adjacent to another transmission line in the other conductor to achieve edge-coupling. In a preferred embodiment each of the lines in one of the conductor is edge- and broadside-coupled to lines in the other conductor. The transmission line element may contain two, three or more conductors, and each conductor may contain two, three or more transmission lines. The transmission line element can be used, for example, to fabricate various types of balanced and unbalanced transformers.

High efficiency antennas of reduced size on dielectric substrate

Abstract: An antenna formed on a dielectric substrate including at least a first and second dielectric substrate region. One or more antenna-radiating element is formed on the first region of the dielectric substrate and defines a conductive path. Feed circuitry for the antenna can be formed on the second region of the dielectric substrate. The feed circuitry can comprise a balun, an impedance transformer, and/or a feed line. The dielectric substrate in the first region can preferably have a first relative permeability and/or first permittivity different from a second relative permeability and/or a second permittivity of the dielectric substrate of the second region.

Circuit protecting against electrostatic discharge

Abstract: A quarter wavelength transmission line is provided between a signal transmission line for transmitting a high frequency signal and a ground node. The quarter wavelength transmission line has a length equal to a quarter of an effective wavelength of an operation frequency of a semiconductor device. A surge absorbing element is connected between the quarter wavelength transmission line and an internal circuit. The signal transmission line is coupled to the internal circuit through a capacitor. A clamp circuit is provided between a power supply line and a ground line. The clamp circuit clamps the voltage difference between the power supply line and the ground line to a prescribed voltage level or less. A high frequency semiconductor device is thus implemented which is capable of preventing breakdown of an internal circuit element due to an electrostatic discharge phenomenon (ESD) without degrading high frequency characteristics.

The RF transmission systems handbook

Abstract: Applications of RF Technology Electromagnetic Spectrum Amplitude Modulation Frequency Modulation Pulse Modulation Digital Modulation High-Power Vacuum Devices Microwave Vacuum Devices Bipolar Junction and Junction Field-Effect Transistors Metal-Oxide Semiconductor Field-Effect Transistors Solid-State Amplifiers Coaxial Transmission Lines Waveguides RF Combiner and Diplexer Systems Radio Wave Propagation Antenna Principles Practical Antenna Systems Preventing RF System Failures Troubleshooting RF Equipment RF Voltage and Power Measurement Spectrum Analysis Testing Coaxial Transmission Line The Smith Chart Tower Construction and Maintenance Safety Issues for RF Systems Index

Broad-band U-slot patch antenna with a proximity-coupled double /spl Pi/-shaped feed line for arrays

Abstract: The paper considers the design of a broad-band U-slot patch antenna using a new proximity-coupled double /spl Pi/-shaped feed line. The new feed is an improvement upon a /spl Pi/-shaped feed line and allows the elements to be spaced closely in two-dimensional (2D) arrays. The bandwidth of a single element is shown to be 21.5% for a return loss better than 10 dB.

RF AGC amplifier system for satellite/terrestrial radio receiver

Abstract: Saturation of an RF front end in a radio receiver is prevented when receiving a desired radio broadcast signal via an antenna in the presence of a strong, undesired radio broadcast signal within a passband of the RF front end. An antenna signal from the antenna is coupled to the RF front end, thereby generating an amplified signal. The radio receiver demodulates the desired radio broadcast signal in response to the amplified signal, thereby generating a demodulated signal. A signal-to-noise quality parameter of the demodulated signal is determined. The antenna signal is attenuated prior to coupling it to the RF front end by an attenuation determined in response to the signal-to-noise quality parameter.