Showing papers on "Feed line published in 2005"

System for obtaining vehicular information

Abstract: System for obtaining information about a vehicle or a component therein includes sensors arranged to generate and transmit a signal upon receipt and detection of a radio frequency (RF) signal and a multi-element, switchable directional antenna array. Each antenna element is directed toward a respective sensor and transmitter RF signals toward that sensor and receive return signals therefrom. A control mechanism controls transmission of the RF signals from the antenna elements, e.g., causes the antenna elements to be alternately switched on in order to sequentially transmit the RF signals and receive the return signals from the sensors or cause the antenna elements to transmit the RF signals simultaneously and space the return signals from the sensors via a delay line in circuitry from each antenna element such that each return signal is spaced in time in a known manner without requiring switching of the antenna elements.

Stacked multi-resonator antenna

Abstract: An antenna structure comprising a ground plane, a feed line and at least one resonator element that is embedded in a dielectric substrate and which is meandering in shape such that it includes at least two adjacent resonator segments. As a result, the resonator element resonates in two separate frequency bands. A second resonator element is preferably provided, the second resonator element being dimensioned to resonate in a frequency band located on one side of a third operating frequency band, the feed line and ground plane being arranged to cause a resonance in a frequency band located on the other side of the third operating frequency band. During use, the combined effect of the resonance of the second resonator element and of the feed line and ground plane is to cause the antenna structure to resonate in the third operating frequency band.

An improved design of microstrip patch antennas using photonic bandgap structure

Abstract: Microstrip antennas inherently have a high input impedance at resonant frequency. This may not be convenient for some applications. For active integrated antennas, moreover, the radiated power of microstrip antennas needs to be very low at harmonic frequencies. The main goals of this study are impedance matching and harmonic suppression of microstrip antennas. In order to meet these requirements, two one-dimensional (1-D) photonic bandgap (PBG) structures, namely, the defected ground structure (DGS) and the compact microstrip resonant cell (CMRC), are applied to the feed line of microstrip antennas. The characteristic impedance of the microstrip line is controlled by the additional effective inductance of the PBG structure. Without any matching circuits, microstrip antennas can be easily fed by a simple 50 /spl Omega/ microstrip line with a PBG structure at the operating frequency. Additionally, the second harmonic of the proposed antennas is properly suppressed compared to a conventional antenna. Measured results indicate that the two PBG structures are quite effective for harmonic suppression. Therefore, the proposed antennas are suitable for active integrated antennas.

Rotation-independent helical antenna

Abstract: A helical antenna having a central axis defined between a base end and a distal end comprises a helical conductor wound about the central axis and having a feed line disposed at the base end and along the central axis, and may also include an elongated dielectric core about which the electrical conductor is wound.

Antenna using inductively coupled feeding method, RFID tag using the same and antenna impedance matching method thereof

Abstract: Provided are an antenna using an inductively coupled feeding method, a Radio Frequency Identification (RFID) tag thereof, and an antenna impedance matching method thereof. The antenna includes a resonator for determining a resonance frequency of the antenna and a feeder for providing an RF signal to an element connected to the antenna. An RFID tag includes an antenna which receives an RF signal from the RFID reader, an RF front-end which rectifies and detects the RF signal, and a signal processor which is connected to the RF front-end. Particularly, the antenna includes a resonator for determining a resonance frequency of an antenna and a feeder for providing the RF signal to the RF front-end, wherein mutual inductive coupling between the resonator and the feeder is performed.

RF front-end apparatus in a TDD wireless communication system

Abstract: A transmitting apparatus in a TDD wireless communication system is provided. In the transmitting apparatus, a circulator transmits a signal received from a power amplifier to an antenna feed line and transmits a signal received from the antenna feed line to a quarter-wave transmission line. The quarter-wave transmission line is installed in a reception path, for reception isolation in a transmission mode. An RF switch shorts the load of the quarter-wave transmission line to the ground or connects the load of the quarter-wave transmission line to an LNA according to a control signal. The LNA low-noise-amplifies a signal received from the RF switch.

Design of resonant small antenna using composite right/left-handed transmission line

Abstract: The paper presents the design of an electrically small antenna employing a composite right/left-handed (CRLH) transmission line. The physical size and operating frequency of the antenna depend on the unit cell size and equivalent transmission line model parameters. Therefore, the small antenna is realized by miniaturizing the unit cell and increasing the shunt inductance and series capacitance. A four unit cell resonant antenna is designed and tested at 1.06 GHz. The length, width and height of the proposed antenna are (1/19)/spl lambda//sub 0/, (1/23)/spl lambda//sub 0/, and (1/83)/spl lambda//sub 0/, respectively.

Microstrip antenna and high frequency sensor using microstrip antenna

Abstract: A microstrip antenna has feed element 102 and parasitic elements 104, 106 on the front surface of substrate 1. Microwave electrical power is applied to feed element 102. Parasitic elements 104, 106 are connected via through hole type leads passsing through substrate 1, to switches upon the rear surface of substrate 1, respectively. By actuating the switches individually, parasitic elements 104, 106 are individually switched between a grounded state and a float state. The direction of the radio beam emitted from the microstrip antenna is varied by selecting which of parasitic elements 104, 106 is grounded and floated. A microwave signal source connects to feed element 102 via an feed line 108 very much shorter than the wavelength, accordingly the transmission losses being low and the efficiency being excellent.

Antenna and RFID tag mounting the same

Abstract: The RFID tag of the present invention includes the tag antenna, and the LSI chip being connected in parallel with the tag antenna. The tag antenna includes a feeder terminal to which the LSI chip is connected, a loop antenna connected to the feeder terminal, and a bypass conductive line bypassing the loop of the loop antenna. Further, the line width of the bypass conductive line is structured thicker than the line width of the loop antenna.

Method and apparatus for wirelessly coupling a source signal to a radio frequency receiver

Abstract: A digital audio system (20) can include a receiver (24) coupled to an RF modulator (30), a source signal modulated by the RF modulator to provide a modulated signal, and an external antenna (32) for receiving the source signal and for transmitting the modulated signal. The receiver can be a satellite radio receiver or any digital source such as an FM radio or MP3 player for example. The system can further include a coupling network (26) coupled between the receiver and the external antenna and between the RF modulator and the external antenna. The system can further include an internal antenna (34) coupled to the RF' modulator for radiating the modulated signal via a second path. The digital audio system can be a satellite digital audio radio system for a vehicle (31) with the external antenna placed outside the vehicle and the internal antenna placed inside the vehicle.

A planar antenna in LTCC for single-package ultrawide-band radio

Abstract: This correspondence presents a planar antenna in low-temperature cofired ceramic technology for a single-package solution of ultrawide-band (UWB) radio. The antenna has an elliptical radiator fed through a microstrip line. The radiator and the microstrip line share the same ground plane with the other UWB radio circuitry. The experiments have been conducted. Results show that the prototype antenna has achieved bandwidth of 110.9%, gain from -1.34 to 5.43 dBi, broad patterns, and relatively constant group delay at frequencies from 3 to 10.6 GHz. Furthermore, it is also found that the normalized antenna radiated power spectrum density basically conforms to the FCCs regulation on the emission limit of indoor UWB systems.

The designing, manufacturing, and testing of a dual-band feed system for the Parkes radio telescope

Abstract: This paper presents the designing, manufacturing, and testing of a dual-band feed system for the Parkes radio telescope (Australia). The feed system consists of a coaxial horn and associated feed components to operate in the 648-712 MHz and 2.6-3.6 GHz frequency bands. The manufacturing of such a feed system was challenging, and we present the innovative solutions that were devised to fabricate the different parts of the feed system. Preliminary measurements indicate that the overall system, feed and reflector, is working to operational expectations, and valuable scientific results have already been obtained using the simultaneous dual-frequency capability.

Air-core microwave ablation antennas

Abstract: A method and device delivers microwave power to an antenna through a coaxial cable utilizing air or other gases as its dielectric core. The cable includes supports made of low-loss materials to keep the inner conductor centered in the cable, and defining spaces therebetween for the air or gas. Channels in the supports allow the air or gas to circulate in the cable. The gas may be chilled or cooled to provide an addition level of heat dissipation. The device enables delivery of large amounts of power to tissue without undue heating of the feed cable or peripheral tissues, and without increasing the diameter of the feeding cable or antenna, keeping the antenna safe for percutaneous use.

Process and device for the radio transmission of signals generated near the body

Abstract: A process and a device for the radio transmission of signals generated near the body via an array of at least two antennas arranged in different positions near the body. At least one antenna, which will act as the transmitting antenna, is selected before or during the transmission.

A broadband printed bow-tie antenna with a simplified balanced feed

Abstract: A broadband printed bow-tie antenna with a simplified balanced feeding network and modified tapering is presented. Microstrip and parallel-strip transmission lines printed on the substrate with high dielectric permittivity realize the proposed feeding network. The ground-plane transition between the microstrip line and the parallel-strip line is exponentially tapered so as to reduce the reflection losses and produce a balanced feed for the antenna. This printed bow-tie antenna achieves a 68% measured bandwidth and a stable radiation pattern within the X-band. Commercial FEM software is used for optimization of the bow-tie antenna and the simulation results agree very well with the experiment. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 534–536, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21221

Passive self-switching dual band array antenna

Abstract: A dual band antenna array comprises a pair of coplanar antenna elements, the first antenna element excitable at a frequency within a first frequency band, the second antenna element excitable at a frequency within a second frequency band. A single transmission feed line in a second plane has an input for receiving a signal, the feed line dividing at a branch point into a first line segment for communicatively coupling the first antenna element with the input at a first feed point, and a second line segment for communicatively coupling the second antenna element with the input at a second feed point. The first and second line segments have lengths adapted for impedance matching at the first and second frequency bands, respectively, relative to the feed line input, to selectively allow energy transmission in one of the first and second line segments while reflecting energy in the other line segment according to the input signal frequency, whereby the activated antenna elements are passively switched based on the input signal frequency.

Dual-layer planar antenna

Abstract: An antenna for receiving an RF signal from a satellite is preferably integrated with a window of a vehicle. The window preferably includes a first nonconductive pane and a second nonconductive pane laminated together with a PVB adhesive layer. A first conductive layer is disposed on one of the surfaces of the nonconductive panes and a second conductive layer is disposed on another of the surfaces of the nonconductive panes. The second conductive layer includes a main slot extending thereinto. The main slot defines a feed line region and ground plane regions. The second conductive layer also includes stub slots extending into the ground plane regions for antenna impedance matching and providing the antenna with a circular polarization.

Radio frequency antenna system and high-speed digital data link to reduce electromagnetic interference for wireless communications

Abstract: A radio frequency antenna system and high-speed digital data link are disclosed to, among other things, reduce electromagnetic interference (“EMI”) at relatively high data rates while reducing the manufacturing complexities associated with conventional data links. In one embodiment, a radio frequency (“RF”) antenna system includes an antenna and an RF radio coupled to the antenna for receiving wireless RF signals. In particular, the RF radio is configured to digitize RF signals at a fixed data rate to form digitized data signals and to apply the digitized data signals at a variable data rate to a high-speed digital link. The variable data rate distributes the signal energy of the digitized data signals over one or more bands of frequencies, thereby beneficially altering an EMI spectral profile describing emissions that develop as the digitized data signals are transported through a channel.

Design of Microstrip Antenna for WLAN

Abstract: This study presents theoretical investigation and simulation of Input Impedance behavior of nearlysquare single fed aperture coupled microstrip patch antenna that can satisfy the narrowband WLANapplications with 2.4 GHz band with 80 MHZ bandwidth. For maximum coupling the patch should be centeredover the slot, moving the patch relative to the slot in the H-plane direction has little effect, while moving thepatch relative to the slot in the E-plane (resonant) direction will decrease the coupling level, also for maximumcoupling, the feed line should be positioned at right angles to the center of the slot. Skewing the feed line fromthe slot will reduce the coupling, as will positioning the feed line towards the edge of the slot. Position of thefeed line in different places relative to patch also was presented. Key words: Microstrip antenna, WLAN, input impedance INTRODUCTION Mathematical modeling of the basic microstripradiator was initially carried out by the application f otransmission-line analogies to simple rectangular patchfed at the center of radiating wall. The radiation pattern ofa circular patch was analyzed and measurements reportedby Carver

Air-filled square coaxial transmission line and its use in microwave filters

Abstract: A suspended coaxial transmission line with an air propagation medium is presented. The transmission line is made only of metal, thereby avoiding dielectric and radiation losses. Short-circuit stubs suspend the centre conductor of the coaxial structure which is used in the design of two dual-mode narrowband microwave filters. Stacked layers of copper sheets are used to form the square coaxial transmission line, which has low loss and low dispersion.

Silicon integrated antenna developments up to 80 GHz for millimeter wave wireless links

Abstract: Today, SiGe HBT cut-off frequencies are higher than 230 GHz (P. Chevalier, et al., 2004) and this increase allows new millimeter wave (MMW) applications on silicon such as 60 GHz WLAN and 77 GHz automotive radar. One of the success keys is then the passive integration. This study focuses on a 52 GHz silicon integrated antenna and related feeding transmission line (TL) topics. Double slot antenna integrated in a standard BiCMOS process and 40 GHz coplanar patch antenna (2.3 dB gain @ 40 GHz) with a coplanar waveguide (CPW) feed line are depicted and characterized. Integrated TL achieved on standard STMicroelectronics (ST) BiCMOS, CMOS and silicon on insulator (SOI) technologies are described, performances are given (<0.7 dB/mm losses @ 80 GHz for SOI CPW). A full modeling has been developed up to 80 GHz with new approach for CPW on silicon technology due to passivation layer

Antenna isolation using grounded microwave elements

Abstract: This invention describes a method for improving antenna isolation in an electronic communication device using grounded RF microwave elements and patterns (structures). According to embodiments of the present invention, the RF microwave element can be implemented as a short-circuited section of a quarter-wavelength long transmission line (such as a stripline), or the RF microwave element can contain a metallic coupler and two thin striplines with different lengths, or the RF microwave element can be implemented using a balun concept.

Earphone cable antenna device, connection cable, and broadcast receiving apparatus

Abstract: PROBLEM TO BE SOLVED: To provide an earphone cable antenna device, a connection cable and a broadcast receiving apparatus for UHF bands, wherein provision of an earphone cable antenna that is resistant to affection by a human body being close to the antenna can achieve a stable antenna performance that is less dependent on the usage status. SOLUTION: An insertion connector part 6 is inserted into an earphone connector part 8 connected to the circuitry within a lower case 2, whereby at least one of signal lines 4 is connected to a broadcast receiving circuit 9 via an audio signal line 10. The signal line 4 is also connected to a high frequency cutoff circuit 7 that is spaced by 3/4λ of operational frequency from the insertion connector part 6 to cut off the high frequency currents of UHF bands. The high frequency cutoff circuit 7 is further connected to an earphone 3 via the signal line 4. An earphone cable antenna element 5 is arranged in parallel with the signal line 4 and is equivalent to a L1=3/4λ length at the operational frequency. An antenna signal is inputted to the broadcast receiving circuit 9 via a matching circuit 12. COPYRIGHT: (C)2006,JPO&NCIPI

Improving antenna isolation using grounded microwave elements

Abstract: This invention describes a method for improving antenna isolation in an electronic communication device using grounded RF microwave elements and patterns (structures). According to embodiments of the present invention, the RF microwave element can be implemented as a short-circuited section of a quarter-wavelength long transmission line (such as a stripline), or the RF microwave element can contain a metallic coupler and two thin striplines with different lengths, or the RF microwave element can be implemented using a balun concept.

Receiving apparatus and receiving method, and program

Abstract: A receiving apparatus according to the present invention includes an obtaining unit operable to obtain the reception level of a first radio wave received via one antenna of first and second antennas, and a transmission rate representing the transmission speed of the first radio wave, the transmission rate being included in the first radio wave and being set by a transmitting apparatus transmitting the first radio wave; a storing unit operable to store, for each of a plurality of transmission rates, a range of signal reception levels in which a packet error rate is substantially 0%; a determining unit operable to determine whether to switch from the one antenna to another antenna based on the reception level of the first radio wave and a first range of reception levels stored in the storing unit which correspond to the transmission rate of the first radio wave; and a controlling unit operable to control switching of the antennas when the determining unit determines to switch from the one antenna to the another antenna so as to receive via the another antenna a second radio wave of a packet different from the packet of the first radio wave.

Cavity-backed slot antenna array for the repeater system of a satellite digital multimedia broadcasting service

Abstract: For the repeater system of the satellite digital multimedia broadcasting (DMB) service (2630/spl sim/2655 MHz) requiring a high-gain antenna and enough isolation between antennas, a cavity-backed slot antenna array (CBSAA) fed by a single waveguide is proposed to suppress side lobe level (SLL) and to increase front-to-back ratio (FBR). The SLL and FBR are enhanced with an optimized magnitude ratio of the electric field at each slot and an additional vertical reflector. The measured SLLs in the H- and E-planes are under -33.24 and -35.78 dB, respectively. An FBR over 37.84 dB and a peak gain over 17 dBi are measured. The proposed CBSAA consists of 2 /spl times/ 4 slot elements backed by a single cavity and has the characteristics of high power handling capability, high radiation efficiency, low feed line loss, and simple feed network.

Antenna structure having patch elements

Abstract: In an antenna structure having a plurality of serially fed patch elements, at least one of the patch elements has a slot coupling to the continuation of the feed line for influencing the radiation of this patch element.

Wireless telephone antenna diversity system and method

Abstract: A system and method are provided for diversifying radiated electromagnetic communications in a wireless communication device having a plurality of embedded antennas. The method comprises sensing conducted electromagnetic transmission line signals communicated by the antennas, selecting between the antennas in response to sensing the transmission line signals, and modifying antenna electrical performance characteristics in response to sensing the transmission line signals. In some aspects sensing transmission line signals includes sensing transmission line signal power levels. For example, the power levels of the radiated signals conducted on the transmission lines can be sensed or the transmission line signal power levels of transmitted signals reflected by the antennas are sensed.

Multi-frequency antenna

Abstract: The utility model discloses a multi-frequency antenna which is used for electronic equipment, comprising a vertical insulated basal plate, a first, second and third pairs of dipole oscillators which are mutually parallel and are symmetrically arranged on the insulated basal plate, a capacitor and a feed line. The first, second and third pairs of dipole oscillators are respectively coupled with the feed line to form the first, second and third dipole antennas. The capacitor is used for improving impedance matching of the multi-frequency antenna. The multi-frequency antenna of the utility model has multi-frequency and wideband operation characteristic.

Transmitter for tire condition monitoring apparatus and antenna for the transmitter

Abstract: A transmitter for a tire condition monitoring apparatus includes a circuit board, circuit components mounted on a main surface of the circuit board, and a transmission antenna that transmits a transmission signal as radio waves. The transmission antenna includes a loop shaped transmission conductor that transmits radio waves. The transmission conductor has a loop plane that is substantially perpendicular to the main surface of the circuit board. When the transmitter is attached to the wheel, the loop plane is substantially perpendicular to a portion of the circumferential surface of the wheel that faces the transmitter. As a result, when the transmitter is attached to the wheel, the radio wave transmission efficiency is effectively prevented from being reduced.