Showing papers on "Stub (electronics) published in 2005"
TL;DR: In this paper, the authors investigated the behavior of self-consolidating concrete (SCC) filled hollow structural steel (HSS) stub columns subjected to an axial load.
422 citations
TL;DR: In this paper, an ultra-wideband (UWB) microstrip filter with a frac-tional bandwidth (FBW) of more than 100% is designed and demon-strated.
Abstract: An ultra-wideband (UWB) microstrip filter with a frac- tional bandwidth (FBW) of more than 100% is designed and demon- strated. This UWB microstrip-filter design is based on a circuit model for an optimum short-circuited stub transmission-line filter whose unit Figure 4 Reflection coefficient of the ultra-thin absorber: (a) simulated reflection coefficient; (b) measured reflection coefficient; (c) comparison of magnitude; (d) comparison of phase
137 citations
Patent•
28 Mar 2005TL;DR: In this article, a high frequency resonator circuit and method of fabrication is described which has a resonant frequency independent of physical resonator dimensions, and operates in a zero-eth-order mode on a composite right/left-handed (CRLH) transmission line (TL).
Abstract: A high frequency resonator circuit and method of fabrication is described which has a resonant frequency independent of physical resonator dimensions. The resonator operates in a zeroeth-order mode on a composite right/left-handed (CRLH) transmission line (TL). The LH wave properties of the CRLH-TL contributing anti-parallel phase and group velocities. In one variation, the unit cells are formed from microstrip techniques, preferably creating alternating interdigitated capacitors and stub inductors. The resonant wavelength of the resonator is dependent on the electrical characteristics of the unit cells and not the physical size of the resonator in relation to the desired resonant wavelength. The resonator is created with at least 1.5 unit cells and the Q of the resonator is substantially independent of the number of unit cells utilized. The resonator circuit is particularly well suited for reducing resonator size, and allows resonators of various wavelengths to be fabricated within a fixed board area.
92 citations
TL;DR: In this article, a compact printed ultra wideband (UWB, 3.1-10.6 GHz) circular-slot antenna with a notched frequency band at 5 GHz is presented.
Abstract: A compact printed ultra-wideband (UWB, 3.1–10.6 GHz) circular-slot antenna with a notched frequency band at 5 GHz is presented. The antenna is a uniplanar structure and occupies a compact area of 25 × 26 mm2 only (the side length is less than 27% of the lower edge frequency at 3.1 GHz). The antenna has a U-slotted circular stub embedded inside the circular slot. By choosing the length of the U-slot cut in the circular stub to be about a half-wavelength of the desired notched frequency, band-notched UWB operation is obtained. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 45: 128–130, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20746
86 citations
TL;DR: In this paper, a miniaturized dual-mode ring bandpass filter at 1.45 GHz with a bandwidth of 6% was demonstrated, which was achieved by loading the peripheral of the ring with the butterfly radial stub structure.
Abstract: A miniaturized dual-mode ring bandpass filter at 1.45 GHz with a bandwidth of 6% is demonstrated. The perturbation of the dual modes is realized by a pair of local ground defects. The miniaturization is achieved by loading the peripheral of the ring with the butterfly radial stub structure. A 41% loading factor has been achieved using this method. The simulated and measured results are in good agreement.
61 citations
TL;DR: In this paper, a radio frequency (RF) microelectromechanical system (MEMS) single-stub impedance tuner has been developed based on combining the loaded line technique with the singlestub topology to obtain wide impedance coverage.
Abstract: A novel radio-frequency (RF) microelectromechanical system (MEMS) single-stub impedance tuner has been developed. The design is based on combining the loaded line technique with the single-stub topology to obtain wide impedance coverage with high |/spl Gamma//sub MAX/|. The tuner consist of ten switched MEMS capacitors producing 1024(2/sup 10/) different impedances. The design has been optimized for noise parameter and load-pull measurements of active devices and shows excellent measured impedance coverage over the 20-50 GHz frequency range.
58 citations
07 Nov 2005
TL;DR: In this article, an equivalent-circuit model for composite right/left-handed coplanar waveguide (CPW) was proposed, which includes the series interdigital capacitor and shunt meandering stub inductor in symmetric configuration.
Abstract: This study proposes an equivalent-circuit model for the composite right/left-handed (CRLH) coplanar waveguide (CPW) comprising the series interdigital capacitor and shunt meandering short-circuited stub inductor in symmetric configuration. The new technique for extracting the equivalent-circuit elements of the CRLH CPW, which include inductances, capacitances, and resistances to represent the left-handed, right-handed, and lossy characteristics, is developed based on the effective medium concept. The applications to the compact resonators and filters are presented to emphasize the unique features of the CRLH CPW. A novel CRLH CPW resonator with a 0/spl deg/ effective electrical length at resonance is proposed, which gives a 49.1% size reduction when compared with the conventional half-wavelength resonator at 5 GHz. Based on the zeroth-order CRLH CPW resonators, an inductively coupled two-pole bandpass filter with 5.4% 3-dB bandwidth and 2.7-dB insertion loss at 5 GHz is implemented, and it is 51.4% more compact than the conventional structure. A good agreement among the results of the full-wave simulation, equivalent-circuit model, published data, and measurement demonstrates the effectiveness of the proposed modeling technique. To suppress the higher order harmonic spurious passbands, the electromagnetic-bandgap CPW structures are incorporated into the proposed CRLH CPW filter.
57 citations
TL;DR: In this article, an aperture-coupled hemispherical dielectric resonator antenna (DRA) with a parasitic patch is studied rigorously using the Green's function approach, integral equations for the unknown patch and slot currents are formulated and solved using the method of moments.
Abstract: The aperture-coupled hemispherical dielectric resonator antenna (DRA) with a parasitic patch is studied rigorously. Using the Green's function approach, integral equations for the unknown patch and slot currents are formulated and solved using the method of moments. The theory is utilized to design a circularly polarized (CP) DRA and a wide-band linearly polarized (LP) DRA. In the former, the CP frequency and axial ratio (AR) can easily be controlled by the patch location and patch size, respectively, with the impedance matched by varying the slot length and microstrip stub length. It is important that the AR will not be affected when the input impedance is tuned, and the CP design is therefore greatly facilitated. For the wide-band LP antenna, a maximum bandwidth of 22% can be obtained, which is much wider than the previous bandwidth of 7.5% with no parasitic patches. Finally, the frequency-tuning characteristics of the proposed antenna are discussed. Since the parasitic patch can be applied to any DRAs, the method will find applications in practical DRA designs.
55 citations
TL;DR: In this paper, a small, lightweight, and low-cost ultra wideband (UWB) antenna that exhibits a notch characteristic in the 5 GHz WLAN band (5.15-5.825 GHz) using a planar half-circle shape patch, a two-step matching stub, a coplanar waveguide (CPW)-type feed, and a hat-shaped slot.
Abstract: In this paper, we propose a small, lightweight, and low-cost ultra-wideband (UWB) antenna that exhibits a notch characteristic in the 5-GHz WLAN band (5.15–5.825 GHz) using a planar half-circle shape patch, a two-step matching stub, a coplanar waveguide (CPW)-type feed, and a hat-shaped slot. The notch frequency of the proposed antenna can be adjusted by controlling the slot length. The measured results are in reasonably good agreement with the simulated results. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 9–11, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21065
52 citations
TL;DR: In this article, the transmission properties of phononic crystal waveguides with grafted stub resonators were measured, and the effects of propagation waveguide modes with localized stub resonances were interpreted as the interaction of propagating waveguide mode with localized resonances.
Abstract: The transmission properties of phononic crystal waveguides with grafted stub resonators were measured. The phononic crystal consists of a two-dimensional periodical array of steel rods immersed in water. Waveguides for acoustic waves are created by removing a line defect and stubs are formed by removing rods from the sidewalls of the waveguide. Depending on the stub geometry, definite wavelengths are reflected from the stub creating a one-dimensional bandgap within the waveguide transmission spectrum, the bandwidth of which can be controlled by arranging a proper sequence of stubs. These effects are interpreted as the interaction of propagating waveguide modes with localized stub resonances.
51 citations
TL;DR: To address the continuing demand for low-cost, light-weight and high-performance antennas, and multiband antenna arrays for wireless communications, a new design of the continuous transverse stub (CTS) antenna technology is developed based on a coplanar waveguide (CPW) feed.
Abstract: To address the continuing demand for low-cost, light-weight and high-performance antennas, and multiband antenna arrays for wireless communications, we developed a new design of the continuous transverse stub (CTS) antenna technology. The design is based on a coplanar waveguide (CPW) feed which combines the advantages of the planar designs originally developed by Hughes Aircraft and the newer 50 /spl Omega/ coaxial version recently developed by our group . To examine the feasibility of the approach, a one-element CPW-CTS antenna is designed and a prototype is built in the frequency range of 5.2-5.6 GHz. S-Parameters and radiation pattern results shows good agreement between the simulation results and the experimental data.
Patent•
20 Oct 2005
TL;DR: In this paper, a via stub is used to route electrical interconnects between layers of printed circuit boards to minimize distortion and increase bandwidth, and one or more terminating elements can be attached to the unterminated end of the via stub section.
Abstract: Vias are used in multilayer printed circuit boards to route electrical interconnects between layers. Some via constructions embodiments result in the formation of a via-stub section. Via stub sections can distort signals passing through the interconnect and decrease the usable bandwidth of the interconnect. To minimize distortion and increase bandwidth, one or more terminating elements can be attached to the unterminated end of the via-stub section. The impedance terminating element may include, by way of non-limiting example, one or more resistors, capacitors, and/or inductors between the via stub and a ground layer. The impedance terminating element may be formed internally to the PCB or mounted to the PCB surface.
Patent•
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TL;DR: A multi-band antenna can be defined as a unitary radiating element having a feed element and a ground port as discussed by the authors, which can function in 6 bands and can be independently tunable in a majority of the 6 bands.
Abstract: A multi-band antenna ( 10 ) includes one or more a loop portions ( 12 ) substantially defining operation in frequency ranges covering between approximately 800 MegaHertz and approximately 1.0 GigaHertz and between approximately 1.8 GigaHertz and approximately 2.0 GigaHertz, a surface plate portion ( 14 ) having a length ( 15 ) substantially defining operation in a frequency range between approximately 1.7 GigaHertz and approximately 1.9 GigaHertz, and a slot ( 16 ) within the surface plate portion having a length ( 17 ) substantially defining operation in a frequency range between 5 and 6 Gigahertz (WLAN). The antenna can further include a resonant stub ( 18 ) having a length ( 19 ) substantially defining operation in a frequency range of approximately 2.4 Gigahertz. The antenna can be a unitary radiating element having a feed element ( 9 ) and a ground port ( 7 ). Operationally, the antenna can function in 6 bands and can be independently tunable in a majority of the 6 bands.
17 Jun 2005
TL;DR: In this paper, the first W-band integrated impedance tuner is presented, which is based on double and triple-stub topologies and employs 11 switched MEMS capacitors producing 2048 (2 11 ) different impedances.
Abstract: Reconfigurable integrated impedance tuners have been developed for W-Band on-wafer noise parameter and loadpull measurement applications. The impedance tuners are based on double and triple-stub topologies and employ 11 switched MEMS capacitors producing 2048 (2 11 ) different impedances. Measured ${\left\vert\Gamma_{MAX} \right\vert}$ for the double-stub tuner is 0.92 and 0.82 at 75 and 100 GHz from 110 measurements out of 2048 possible impedances, and 0.92 and 0.83 for the triple-stub tuner. To our knowledge, this represents the first W-band integrated impedance tuner to date.
Patent•
NEC1
TL;DR: In this article, a composite via structure in a multilayer printed circuit board (PCB) and also compact and shielded filters formed by the use of composite via structures as building blocks are provided.
Abstract: A composite via structure in a multilayer printed circuit board (PCB) and also compact and shielded filters formed by the use of composite via structures as building blocks are provided. The composite via structure consists of two functional parts. The first functional part is designed to form an interconnected circuit with low return and leakage losses between the first pad disposed at the one side of the PCB and the special pad serving for a connection to a planar transmission line. The second functional part of the composite via structure serves to form a shielded open- or short-circuited resonant length (stub) extended in the vertical direction from the special pad to the second pad disposed at the opposite side of the PCB.
07 Nov 2005
TL;DR: This paper describes impact avalanche transit time (IMPATT) diodes fabricated in 0.18-/spl mu/m standard complementary metal-oxide-semiconductor technology to enable operation at 77 GHz to find application in automotive and communication systems.
Abstract: This paper describes impact avalanche transit time (IMPATT) diodes fabricated in 0.18-/spl mu/m standard complementary metal-oxide-semiconductor technology to enable operation at 77 GHz. The lateral IMPATT diodes are integrated with a microstrip patch antenna, modified to provide impedance matching and widen the tuning range. The antenna dimensions and the impedance matching are designed using the high-frequency electromagnetic field solver Sonnet. The output spectrum has no visible spurious components. The transmitted power is -62 dBm at 76 GHz. The measured frequency is within 1.3% of the simulated value. It is hoped that this device will find application in automotive and communication systems.
12 Jun 2005
TL;DR: In this article, a class-F power amplifier at 2.4GHz using a novel harmonic tuner based on a composite right/left handed (CRLH) transmission line (TL) is proposed and experimentally tested.
Abstract: A class-F power amplifier at 2.4GHz using a novel harmonic tuner based on a composite right/left handed (CRLH) transmission line (TL) is proposed and experimentally tested. Two structures are presented. One structure uses one open CRLH-TL stub to suppress 2nd, 3rd harmonics and the fundamental frequency is matched to 50/spl Omega/. The other structure uses two open CRLH-TL stubs in order to suppress 2nd, 3rd, 4th harmonics and the fundamental frequency is matched to specific impedance. The structure proposed is used to design a class-F power amplifier. A maximum drain efficiency of 64% is obtained.
TL;DR: Simulation results show that the adaptive and the proposed hybrid systems have nearly the same performance accuracy, with the hybrid system offering faster tracking time, improved computational efficiency, and a possible reduction in the implementation cost.
Abstract: In this letter, we investigate and compare the performance of a newly proposed hybrid smart antenna system with the fully adaptive and switched beam smart antenna arrays. Simulation results show that the adaptive and the proposed hybrid systems have nearly the same performance accuracy, with the hybrid system offering faster tracking time, improved computational efficiency, and a possible reduction in the implementation cost. The comparative study also included measured radiation pattern from a recently developed coplanar waveguide continuous transverse stub (CPW-CTS) antenna.
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21 Feb 2005
TL;DR: In this paper, a combination of a stub resonance-based, impedance transformation boosting scheme and a ladder boosting scheme is proposed to overcome the drawback of conventional RFID tag devices having a short communication range, and expand the communication range to several times or more that in the conventional scheme.
Abstract: The present invention aims to overcome the drawback with conventional RFID tag devices having a short communication range, and expand the communication range to several times or more that in the conventional scheme. The conventional scheme is based on equilibrium feeding/equilibrium modulation (a two-terminal circuit for antenna operation), whereas the present invention is based on disequilibrium feeding/equilibrium modulation (a three-terminal circuit for antenna operation). The conventional scheme is based on simple rectification of received RF signals, whereas the present invention employs a circuit based on a combination of a stub resonance-based, impedance transformation boosting scheme and a ladder boosting scheme. The conventional scheme is based on ASK or BPSK modulation, whereas the present invention is based on passive modulation, but can employ a QPSK modulation circuit.
TL;DR: In this paper, a single-layer circular-slot antenna, fed by a microstrip ending with a rectangular stub, is presented for wireless ultra-wideband (UWB) communications.
Abstract: We present a single-layer circular-slot antenna, fed by a microstrip ending with a rectangular stub, which is suitable for wireless ultra-wideband (UWB) communications. The antenna is fully characterized in terms of impedance bandwidth, phase linearity, gain, and radiation pattern. The time-domain pulse response versus azimuth and elevation is also studied numerically. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 465–470, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20669
TL;DR: In this paper, a planar single-layer rectangular-slot antenna, fed by a microstrip ending in a fork-shaped tuning stub, was proposed for wireless ultra-wideband (UWB) communications.
Abstract: This paper describes a planar single-layer rectangular-slot antenna, fed by a microstrip ending in a fork-shaped tuning stub, for wireless ultra-wideband (UWB) communications. The realized prototype exhibits a stable bidirectional gain pattern in the 3.1–10.6-GHz UWB. Moreover, the antenna is “nondispersive” and minimizes the distortion of the transmitted pulsed signals at different azimuth and elevation angles. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 315–319, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20975
12 Jun 2005
TL;DR: In this article, a dual-mode microstrip triangular patch resonator is used to achieve a 1.9:1 tunable passband ratio with a fixed center frequency of 10 GHz.
Abstract: A reconfigurable bandpass filter is demonstrated using a dual-mode microstrip triangular patch resonator. The proposed circuit uses a single switch to control its fractional bandwidth while keeping a fixed center frequency of 10 GHz. The switching mechanism is accomplished by a p-i-n diode that connects and isolates a tuning stub from the rest of the circuit. The on and off state of the diode effectively controls the resonance frequencies of the two poles, produced by the dual-mode behavior of the resonator. The filter achieves a measured 1.9:1 tunable passband ratio. The circuit presented here represents the first single switch bandwidth reconfigurable filter that requires no size compensation to maintain a fixed center frequency.
TL;DR: In this paper, a printed elliptical slot antenna fed by tapered microstrip line with U-shaped tuning stub is proposed for ultra-wideband (UWB) applications, and the design parameters for achieving optimal performance are investigated.
Abstract: A printed elliptical slot antenna fed by tapered microstrip line with U-shaped tuning stub is proposed for ultra-wideband (UWB) applications in this paper. The design parameters for achieving optimal performance are investigated. The operation and characteristics of the proposed antenna are also analyzed. Good agreement is obtained between the simulation and the experiment. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 140–143, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21104
TL;DR: In this article, a slot antenna with a fan-shaped microstrip feed with a straight stub is introduced, and the effect of the fan feed on the impedance characteristics is investigated theoretically and experimentally.
Abstract: A novel slot antenna of large bandwidth and small size, which is fed by a fan-shaped microstrip feed with a straight stub, is introduced. The effect of the fan feed on the impedance characteristics is investigated theoretically and experimentally. Good agreement between the theoretical and experimental results is obtained. Its measured VSWR ≤ 2 bandwidth reaches approximately 114%, covering 1.55–5.66 GHz. The measured standing-wave ratio curves and radiation patterns of the antenna at f = 2 GHz and at f = 5 GHz are both presented. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 46: 275–278, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20964
04 Dec 2005
TL;DR: Based on the detailed analysis, a varactor-tuned hairpin bandpass filter using a tapped open stub is designed, in which the tuning bandwidth reaches 15 % of the center frequency at 2 GHz.
Abstract: In this paper, a varactor-tuned hairpin bandpass filter using a tapped open stub is studied In this configuration the filter's center frequency as well as the bandwidth can be controlled The tapped open stub introduces the attenuation pole which can be located near the passband by adjusting the stub length Varactors loaded at the end of hairpin resonator and the tapped open stub enable us to control the center frequency with constant bandwidth as well as to have a large tuning bandwidth Based on the detailed analysis, the varactor-tuned hairpin bandpass filter is designed, in which the tuning bandwidth reaches 15 % of the center frequency at 2 GHz
03 Apr 2005
TL;DR: In this article, the authors describe and illustrate recent wideband, dual-polarized and phased-array developments of the CTS array applied to fixed and mobile terrestrial and satellite-based broadband access applications at both microwave and millimeter-wave frequencies.
Abstract: The continuous transverse stub (CTS) array represents a unique class of array antenna that exploits the low-loss, low-dispersion, dimensional robustness, and design flexibility of an open parallel-plate structure as both its transmission-line and radiator basis. Relative advantages of this array type include unusually high aperture efficiencies; precision sidelobe control; benign active impedance dependence on both frequency and scan angle; and inherently low cost This paper describes and illustrate recent wideband, dual-polarized and phased-array developments of the CTS array applied to fixed and mobile terrestrial- and satellite-based broadband access applications at both microwave and millimeter-wave frequencies.
TL;DR: In this paper, an improved design of the U-shaped stub rectangular slot antenna with a tuning pad for enhancing the impedance bandwidth is proposed, by properly tuning the physical size of the copper pad, a wide impedance bandwidth can be achieved for UWB applications.
Abstract: An improved design of the U-shaped stub rectangular slot antenna with a tuning pad for enhancing the impedance bandwidth is proposed. By properly tuning the physical size of the copper pad, a wide impedance bandwidth of the antenna can be achieved for UWB applications. For 10 dB return loss, a impedance bandwidth of the antenna is covered from 2.3 to 12 GHz (135.7%). A gain variation from 2 to 6.82 dBi is obtained.
Patent•
04 Jul 2005TL;DR: In this article, a multi-band internal antenna of a symmetry structure having stub, in which a size of the internal antenna can be reduced by stacking loop antennas, a broadband characteristic can be obtained in a high frequency band by connecting the stub to a top patch of the antenna, and a reduced SAR and an omni-directional radiation pattern is obtained by configuring an antenna patch in a symmetric structure.
Abstract: Provided is a multi-band internal antenna of a symmetry structure having stub, in which a size of the internal antenna can be reduced by stacking loop antennas, a broadband characteristic can be obtained in a high frequency band by connecting the stub to a top patch of the antenna, and a reduced SAR and an omni-directional radiation pattern can be obtained by configuring an antenna patch in a symmetry structure. The multi-band internal antenna includes: a top patch disposed in an upper portion of the antenna, the top patch being formed in a loop shape of which one end is opened; a stub connected to the top patch to expand a bandwidth of a high frequency band in an operating frequency of the antenna; a bottom patch connected to a ground part through a feeder part and a shorting part, the bottom patch being formed in a loop shape of which one end and another end are opened; a connecting part connecting the top patch to the bottom patch to transmit a signal from the bottom patch to the top patch; an intermediate part formed between the top patch and the bottom patch to a predetermined thickness; the feeder part for feeding power to the bottom patch; and the shorting part for grounding the bottom patch. The multi- band internal antenna is used in wireless communication fields.
TL;DR: In this article, an improved filter design of a dual-mode double-ring resonator with radial stub for ultra-wideband (UWB) applications is presented, where two radial stubs are added to the outer ring in order to construct the band-pass filter.
Abstract: An improved filter design of a dual-mode double-ring resonator with radial stub for ultra-wideband (UWB) applications is presented in this paper. Based on the double-ring resonator and adjusted voltage/current couplings, two radial stubs are added to the outer ring in order to construct the band-pass filter. The dual-mode double-ring resonator exhibits wideband responses, and the radial stubs enhance the bandwidth of the operating-frequency band. Thus, an alternative approach to improve the bandwidth of the conventional dual-mode double-ring resonator, is presented. The experimental and simulation results are given and discussed. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 44: 219–222, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20593
12 Jun 2005
TL;DR: In this paper, a fully integrated transmitter at 77GHz is presented in a 0.18/spl mu/m standard CMOS technology that consists of a lateral IMPATT diode and a microstrip patch antenna.
Abstract: In this paper, a fully integrated transmitter at 77GHz is presented in a 0.18/spl mu/m standard CMOS technology. The system consists of a lateral IMPATT diode and a microstrip patch antenna. The antenna impedance seen by the IMPATT diode is optimized using the high frequency electromagnetic (EM) field solver, Sonnet, which is matched to the measured impedance of the diode. The transmitted power had an offset frequency of -0.13% from the simulation results.