Showing papers on "Feed line published in 2008"

Lumped Element Kinetic Inductance Detectors

Abstract: Kinetic Inductance Detectors (KIDs) provide a promising solution to the problem of producing large format arrays of ultra sensitive detectors for astronomy. Traditionally KIDs have been constructed from superconducting quarter-wave resonant elements capacitively coupled to a co-planar feed line [1]. Photon detection is achieved by measuring the change in quasi-particle density caused by the splitting of Cooper pairs in the superconducting resonant element. This change in quasi-particle density alters the kinetic inductance, and hence the resonant frequency of the resonant element. This arrangement requires the quasi-particles generated by photon absorption to be concentrated at positions of high current density in the resonator. This is usually achieved through antenna coupling or quasi-particle trapping. For these detectors to work at wavelengths shorter than around 500 μm where antenna coupling can introduce a significant loss of efficiency, then a direct absorption method needs to be considered. One solution to this problem is the Lumped Element KID (LEKID), which shows no current variation along its length and can be arranged into a photon absorbing area coupled to free space and therefore requiring no antennas or quasi-particle trapping. This paper outlines the relevant microwave theory of a LEKID, along with theoretical and measured performance for these devices.

Planar Ultrawideband Antennas With Multiple Notched Bands Based on Etched Slots on the Patch and/or Split Ring Resonators on the Feed Line

Abstract: Three types of ultrawideband (UWB) antennas with triple notched bands are proposed and investigated for UWB communication applications. The proposed antennas consist of a planar circular patch monopole UWB antenna and multiple etched slots on the patch and/or split ring resonators (SRRs) coupled to the feed line. Good agreement is achieved between the simulated and measured results. These techniques are significant for designing UWB antennas with multiple narrow frequency notched bands or for designing multiband antennas.

Transmission Line Sensor

Abstract: A system and method in which an overhead high voltage transmission line sensor system is able to measure one or more of temperature, current, and line sag for a conductor within a high voltage transmission line system. The sensor system may be able to clamp to a transmission conductor or splice, harvest power from the transmission line, and/or transmit data corresponding to measurements of current, temperature, and line sag.

Wideband Circularly Polarized Antenna With L-Shaped Slot

Abstract: A wideband circularly polarized (CP) L-slot antenna single fed by L-shaped feed line is designed. Wideband CP is obtained by truncating one of the corners of the antenna element. This arrangement introduces orthogonal components with quadrature phase difference to excite circularly polarized wave. A bandwidth of 46.5% (2.18-3.5 GHz) is achieved with an dB and dB. Good agreement between measured and computed results is achieved. Moreover, parametric study results are presented.

Development of Ultrawideband Antenna With Multiple Band-Notched Characteristics Using Half Mode Substrate Integrated Waveguide Cavity Technology

Abstract: Investigations on planar ultrawideband (UWB) antenna with multiple band-notched characteristics based on half mode substrate integrated waveguide technology are presented. The proposed antenna consists of a planar UWB monopole antenna and a half mode substrate integrated waveguide cavity which can generate multiple stopbands by proper arrangement. Planar antennas with dual, triple and quadruple notched bands are designed and implemented. The notched frequencies and their bandwidths can be adjusted according to specification by altering the cavity and feed line independently. These antennas are fabricated with two-layer printed circuit board (PCB) process. Sharp and high band rejection, narrow frequency notches are achieved, which are in good agreement with the simulated results. This technique is suitable for designing wideband antenna with multiple frequency notches or for creating multiband antennas.

Circularly-Polarized Wide Slot Antenna Loaded With a Parasitic Patch

Abstract: A design is described of a broadband circularly-polarized (CP) slot antenna. A conventional annular-ring slot antenna is first analyzed, and it is found that two adjacent CP modes can be simultaneously excited through the proximity coupling of an L-shaped feed line. By tuning the dimensions of this L-shaped feed line, the two CP modes can be coupled together and a broad CP bandwidth is thus formed. The design method is also valid when the inner circular patch of the annular-ring slot antenna is vertically raised from the ground plane. In this case, the original band-limited ring slot antenna is converted into a wide-band structure that is composed of a circular wide slot and a parasitic patch, and consequently the CP bandwidth is further enhanced. For the patch-loaded wide slot antenna, its key parameters are investigated to show how to couple the two CP modes and achieve impedance matching. The effects of the distance between the parasitic patch and wide slot on the CP bandwidth and antenna gain are also presented and discussed in details.

Compact structure of UHF band RFID tag antenna mountable on metallic objects

Abstract: A new type of a compact tag antenna, which can be effectively mounted on metallic objects, is proposed for UHF band RFID systems. The proposed antenna consists of a simple microstrip path and feed line, and it is fabricated on a very thin (1.6 mm) subtrate compared with previous works. The impedance of the proposed antenna can be easily adjusted to match the various impedance values of tag chips by simply changing the length of the feed line only. The antenna is analyzed by simulations by Ansoft HFSS software, and the measured results based on backscattering method are provided. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 232–234, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23031

Beam-Scanning Performance of Leaky-Wave Slot-Array Antenna on Variable Stub-Loaded Left-Handed Waveguide

Abstract: Metamaterial is an artificial material in which the effective phase constant can be controlled by the internal physical periodic structure of the transmission line. Effective phase constant is designed to be of any value, which may be small, large, approximately zero, or negative, attained by changing the dimensions of the periodic structure. Miniaturization of the antenna and wide design flexibility of radiation patterns can be expected from the use of metamaterials. In this work, we developed a leaky-wave slot-array antenna on a variable stub-loaded left-handed waveguide. The radiation pattern of the fabricated antenna was measured and the characteristics of the left-handed transmission line were observed. Moreover, performance of beam-scanning by changing the length of the stubs on the waveguide was confirmed experimentally.

Synthesis of transmission line models for metamaterial slabs at optical frequencies

Abstract: We study the scattering parameters of typical transmission line resonant circuits and their corresponding nonlocal effective material parameters at optical frequencies using transmission line theory. We find that each circuit has specific features in terms of nonlocal permittivity and permeability and can be utilized to quantitatively synthesize transmission line circuit models for metamaterial slabs. As application examples, we construct circuit models for cut wires, cut-wire pairs, metallic meshes, and mesh pairs. Moreover, we calculate local material parameters in a simple way using fitted impedance parameters together with a transmission line homogenization procedure. Using transmission line (TL) models, we show how the material parameters can be optimized in actual metamaterials. The physical dependence of circuit parameters on structure geometries validates our TL model further.

Spatial focusing characteristics of time reversal uwb pulse transmission with different antenna arrays

Abstract: Spatial focusing characteristics of time reversal (TR) electromagnetic waves are studied in this paper. Different antenna arrays are used as a TR mirror and their elements are arranged in one and two dimensions in the horizontal plane. The focused energy density around initial source location is investigated in non-line-ofsight (NLOS) and line-of-sight (LOS) cases, respectively. The results demonstrated that, roughly speaking, under the case of fixed space between two adjacent elements, the more the number of the array elements, the stronger the focused average energy density. However, in the case of fixed TR mirror array aperture, some abnormal phenomena are observed when additional elements are inset into the initial one.

Apparatus method and computer program for configurable radio-frequency front end filtering

Abstract: A radio use case is determined for concurrently operating radios of a multi-radio device and/or transmitter and receiver of a FDD radio. A local memory is accessed with the determined use case to find a high and/or a low frequency cutoff for the concurrent operation radio or transmitter/receiver. Control signals are applied to impose the high and/or the low frequency cutoff to a pair of frequency adjustable diplexers that are in series with one another in one of a transmit branch or a receive branch of a duplexer circuit that is disposed between the radio and an antenna. Then, a receive signal is passed through the antenna and the receive branch of the duplexer circuit to the radio or receiver of the FDD radio, or a transmit signal is passed from the respective radio or transmitter of the FDD radio through the transmit branch of the duplexer circuit to the antenna.

Probing the Feed Line Parameters in Vivaldi Notch Antennas

Abstract: Some new parameters in Vivaldi Notch antennas are debated over in this paper. They can be availed for the bandwidth application amelioration. The aforementioned limiting factors comprise two parameters for the radial stub dislocation, one parameter for the stub opening angle, and one parameter for the stub’s offset angle. The aforementioned parameters are rectified by means of the optimization algorithm to accomplish a better frequency application. The results obtained in this article will eventually be collated with those of the other similar antennas. The best achieved bandwidth in this article is 17.1 GHz.

A Patch array antenna for 60 GHz package applications

Abstract: This paper has presented array feed line structures that are suitable for mmWave applications where microstrip lines do not function very well. Since CPS and CWP lines are used, the feed line loss is reduced tremendously so large arrays are possible for mmWave applications. Although the corporate-fed patch array is presented here, the feed line structures can be used for slot arrays or a combination of series and corporate-fed patch arrays. Since air-bridges are used in the feed line structures, thin-film technologies are preferred manufacturing choice of these arrays.

Radio frequency (rf) integrated circuit (ic) packages with integrated aperture-coupled patch antenna(s)

Abstract: A radio-frequency integrated circuit chip package with at least one integrated aperture-coupled patch antenna includes at least one generally planar patch and at least one generally planar ground plane spaced inwardly from the generally planar patch and substantially parallel thereto. The ground plane is formed with at least one coupling aperture slot therein. The slot is substantially opposed to the patch. Also included are at least one feed line spaced inwardly from the ground plane and substantially parallel thereto, at least one radio frequency chip spaced inwardly from the feed line and coupled to the feed line and the ground plane, and a first substrate layer spaced inwardly from the feed line. The first substrate layer is formed with a chip-receiving cavity. The chip is located in the chip-receiving cavity.

Transmission line microwave apparatus including at least one non-reciprocal transmission line part between two parts

Abstract: A transmission line microwave apparatus includes at least one nonreciprocal transmission line part, which includes a series branch circuit equivalently including a capacitive element and a shunt branch circuit equivalently including an inductive element. The nonreciprocal transmission line part has gyrotropic characteristic by being magnetized in a magnetization direction different from the propagation direction of a microwave, and has an asymmetric structure to a plane formed by the propagation direction and the magnetization direction. The nonreciprocal transmission line part has a propagation constant and an operating frequency set in a dispersion curve that represents a relation between the propagation constant and the operating frequency so that the propagation constant in the forward direction and the propagation constant in the backward direction have nonreciprocal phase characteristics different from each other. A microwave transmission line is constituted by cascade-connecting at least one non-reciprocal transmission line part between first and second ports.

Radio antenna assembly and apparatus for controlling transmission and reception of rf signals

Abstract: An apparatus includes an antenna for transmitting RF radiation and being structured to enable the distribution of RF energy emitted therefrom to be varied in the vertical plane. The apparatus comprises a generator for generating an RF signal and to pass the signal to the antenna, and a controller arranged to control the distribution of RF energy emitted from the antenna in the vertical plane in response to positional information about an object.

Antenna, and radio-frequency identification tag

Abstract: An antenna connected to a circuit portion and configured to effect transmission and reception of information by radio communication, the antenna including a driven meander line portion which has a feed section connected to the circuit portion and which is a line conductor formed in a meandering pattern, and a parasitic meander line portion which does not have a feed section connected to the circuit portion and which is a line conductor formed in a meandering pattern and positioned relative to the driven meander line portion, so as to influence an input impedance of the driven meander line portion. Also disclosed is a radio-frequency identification tag including the antenna.

The effect of conductor line to meander line antenna design

Abstract: In this paper, the meander line antenna (MLA) have been designed to operate at 2.4-GHz for WLAN application. Two different designs of meander line antenna are investigated, without conductor line and with conductor line. Microwave Office software is used for simulation designed process. The antenna is fabricated on a double-sided FR-4 printed circuit board using an etching technique. Then the design has been tested with the Advantest Network Analyzer. The comparison between simulation and measurement results for the return loss and radiation patterns were presented. A bandwidth of 152 MHz and return loss of -37.7 dB were obtained at frequency 2.4 GHz. The gain is comparable to microstrip yagi antenna.

Method of transmitting data to a receiver

Abstract: A method of transmitting data to a receiver, wherein the data is transmitted using a plurality of sub-carriers, is provided. The method provided includes determining, for each sub-carrier and for each of a plurality of combinations of the sub-carrier and an antenna of a plurality of antennas to be used for transmitting the data, a transmission characteristic of a transmission of the sub-carrier using the antenna; and selecting, for each sub-carrier, an antenna of the plurality of antennas to be used for the transmission of the sub-carrier based on the transmission characteristic of the transmission of the sub-carrier between the antenna and the receiver.

Mobile wireless communications device with reduced harmonics resulting from metal shield coupling

Abstract: A mobile wireless communications device includes a housing, antenna, and circuit board carried by the housing and having radio frequency (RF) circuitry operative with the antenna for receiving and transmitting RF signals through the antenna. A power amplifier is connected within a transmission line for amplifying RF signals to be transmitted over the transmission line to the antenna. An antenna switch is connected to the antenna and RF circuitry. An RF shield surrounds the power amplifier and antenna switch and isolates the power amplifier and antenna switch from the antenna and RF circuitry. A low pass filter is connected to the power amplifier and antenna switch for reducing any RF coupling of voltage standing waves of upper harmonic frequencies from the power amplifier into the antenna switch through the RF shield while maintaining transmission of signals through the transmission line at a desired fundamental frequency.

A compact multiple bands notched UWB antenna by loading SIR and SRR on the feed line

Abstract: In this paper, a new compact circular monopole ultrawide band (UWB) antenna with multiple narrow bands notched is proposed, designed and fabricated with a standard printed circuit board (PCB) process, which is implemented by loading a stepped impedance resonator (SIR) and a split ring resonator (SRR) on the feed line. Good agreement between simulations and measurements is achieved, which shows the antenna is a promising candidate for UWB applications.

Slot coupled microstrip antenna for ultra wideband applications in c and x bands

Abstract: This paper presents an aperture coupled microstrip antenna with a rectangular patch which is located on top of two slots on the ground plane. The patch and slots are separated by an air gap and a material with low dielectric constant. There is a 50 Ω feed line which is divided into two 100 Ω feed lines by a two way microstrip power divider under the ground plane. Using a parametric study on the effect of the position and dimensions of the feed line the impedance bandwidth of the antenna (VSWR < 2) is increased to 7.9 GHz (86%) centered at 9.25 GHz and the gain of the structure is more than 7 dB from 5.4 GHz to 8.8 GHz (48%).

Design of a circular microstrip antenna

Abstract: A circular microstrip antenna is designed in order to obtain the required parameter responses from 2.4 GHz-2.5 GHz by using GENESYS software based on the method of cavity model due of simplicity and easier to analyze. This circular patch is fed by microstrip line and RT Duroid 5870 is used with the specified information include the dielectric constant of substrate (isinr = 2.33) the resonant frequency (fr = 2.45GHz) and substrate height (h=0.5 mm). The circular microstrip antenna exhibits appropriate required parameters depend on the feed point position, size of the circular patch and length of the microstrip line. A prototype of a circular microstrip antenna has been built and tested by Vector Network Analyzer. The agreement between the measured and simulated results is slightly differ caused by several factors that would be discussed in result part.

Antenna system for remote control automotive application

Abstract: An antenna system for remote control applications including a communications module, a printed circuit board including an antenna assembly disposed thereon, and a radio frequency cable having a first connection end and a second connection end. The first connection end may be coupled to the communications module and the second connection end may be coupled to the printed circuit board. The second connection end includes a center conductor for communicating signals and a coaxial shield encircling the center conductor. A portion of the center conductor may extend from the coaxial shield and have a substantially 90 degree bend above a connection point of the printed circuit board and center conductor.

Design of a compact CPW-fed UHF RFID tag antenna for metallic objects

Abstract: A compact CPW-fed UHF RFID tag antenna for metallic objects is proposed. It is less sensitive to the size of metallic objects and has a low profile and a long reading distance. The antenna consists of shorting walls, CPW feed line, a tag IC, and a radiating patch with Ishaped slits. The overall dimensions of the antenna are 55 mm × 26 mm ×2.2 mm. The tag IC has an input impedance of 43 - j800 Ω at 915 MHz. When the antenna is mounted on 200 mm × 200 mm, 400 mm × 400 mm, and 600 mm × 600 mm planar metallic plates, the maximum reading distances are 5.1, 5, and 4.5 m, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1439–1443, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23378

Antenna device and wireless communication equipment using the same

Abstract: An object of the present invention is to obtain high radiation efficiency by strengthening electromagnetic coupling in an antenna device that supplies a radiation current by the electromagnetic coupling. An antenna device includes a substrate 110 and a conductor pattern that includes a radiation conductor 121, a feed conductor 122, and a coupling conductor 123 formed on the substrate 110. Both the feed conductor 122 and the coupling conductor 123 are formed on a side surface 115 of the substrate 110. One end 122 a of the feed conductor 122 is connected to a feed line, and other end 122 b is connected to a ground pattern. A coupling portion 122 b of the feed conductor 122 is substantially U-shaped, and the coupling conductor 123 is electromagnetically coupled to the coupling portion 122 b of the feed conductor 122. Because the feed conductor 122 is gently curved, an electric filed concentration can hardly occur. The length of the feed conductor 122 can be increased, and thus it is possible to obtain a strong electromagnetic coupling with the coupling conductor 123.

Headset antenna and connector for the same

Abstract: A headset antenna and a connector for the same are provided. The headset antenna includes an audio signal line, an antenna and a high impedance element in specified application frequency ranges. The audio signal line is adapted for transmitting an audio signal and the antenna is adapted for receiving an RF signal. The high impedance element is disposed on a transmission path of the audio signal and generates a high impedance at a specified frequency band of the RF signal, so that the audio signal line is equivalent to an open circuit and the antenna obtains a better receiving capability.

Dual-band Capacitive Feed Antenna for Nonlinear Junction Detection Device

Abstract: The paper presents an antenna design for use in a nonlinear junction detection device. To achieve wide bandwidth a capacitive feed technique is used in which small probe feed elements are coupled to the radiating patch. In order to minimize the overall antenna size both receiving and transmitting antenna elements have been integrated into one dual-band structure having two separate excitation ports. High isolation between ports is achieved to avoid direct interferences between a transmitter and a receiver. Results of theoretical analysis are presented agree well with the experimental ones.

Elevator cabin position detection system and method of determining a position of an elevator cabin in an elevator shaft

Abstract: Elevator cabin position detection system (10) comprising an activation device (1) mounted on an elevator cabin (100), a sensor stripe (20) mounted on a sidewall of an elevator shaft and control electronics (21). The activation device (1), preferable a light emitting device, activates a portion of the sensor stripe (20) which comprises a feed line (25), a resistor line (24) and sensors (23) positioned between these. The sensors (23), preferable optical sensors, when activated by the activation device (1), conduct electricity to create electrical connection between the feed line (25) and resistor line (24) and thus modify the resulting resistance between an end (A) of the resistor line and an end (B) of the feed line. The control electronics (21) determines the exact position of the elevator cabin (100) based on the resulting resistance between the end (A) of the resistor line and the end (B) of the feed line.

Transmission Line Structure for Power Line Communication and Power Line Switch Used Therein

Abstract: A power line switch apparatus is provided for use in a power line communication system that transmits a signal through a power line that feeds a power supply current. In the power line switch apparatus, a switch section is inserted in the power line to make or break connection of the power line. A power line filter is connected in series to the switch section and inserted in the power line, the power line filter being used to pass the power supply current and to cut off the signal of the power line communication system. A by-pass circuit is connected in parallel with the series connection of the switch section and the power line filter, the by-pass circuit including a by-pass filter for cutting off the power supply current and passing the signal of the power line communication system.