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Showing papers on "Stub (electronics) published in 2010"


Journal ArticleDOI
TL;DR: An improved analytical model describing transmittance of a metal-dielectric-metal (MDM) waveguide coupled to an arbitrary number of stubs is presented and it is shown that certain phase-matching conditions must be satisfied to provide opt al filtering characteristics for such waveguides.
Abstract: We present an improved analytical model describing transmittance of a metal-dielectric-metal (MDM) waveguide coupled to an arbitrary number of stubs. The model is built on the well-known analogy between MDM waveguides and microwave transmission lines. This analogy allows one to establish equivalent networks for different MDM-waveguide geometries and to calculate their optical transmission spectra using standard analytical tools of transmission-line theory. A substantial advantage of our model compared to earlier works is that it precisely incorporates the dissipation of surface plasmon polaritons resulting from ohmic losses inside any metal at optical frequencies. We derive analytical expressions for transmittance of MDM waveguides coupled to single and double stubs as well as to N identical stubs with a periodic arrangement. We show that certain phase-matching conditions must be satisfied to provide optimal filtering characteristics for such waveguides. To check the accuracy of our model, its results are compared with numerical data obtained from the full-blown finite-difference time-domain simulations. Close agreement between the two suggests that our analytical model is suitable for rapid design optimization of MDM-waveguide-based compact photonic devices.

199 citations


Journal ArticleDOI
Kuo-Sheng Chin1, Ken-Min Lin1, Yen-Hsiu Wei1, Tzu-Hao Tseng1, Yu-Jie Yang1 
TL;DR: In this article, a step-impedance-stub line for a dual-band branch-line coupler design with improved design flexibility is presented. But the complexity of the circuit is not addressed.
Abstract: This study constructs stepped-impedance-stub lines for a dual-band branch-line coupler design with improved design flexibility. The proposed structure demonstrates dual-band performance and a compact size due to additional stepped-impedance stubs to branches. The developed synthesis method has two degrees of freedom which can be exploited to miniaturize circuit size and/or replace impractical impedances with more realizable ones. Observations also show the advantage of a wide-range realizable frequency ratio of dual bands. The current work fabricates three experimental dual-band branch-line couplers, including a two-section coupler, and achieves a size reduction up to 21.7%, compared with conventional structures. The measured results validate good dual-band performance at 2.4/5.8 GHz with enhanced bandwidths up to 21% and 12%, respectively. This research also successfully applies the proposed circuit to synthesize a dual-band rat-race coupler.

154 citations


Journal ArticleDOI
TL;DR: In this paper, an ultra wideband bandpass filter using stub-loaded resonator (SISLR) is presented, which has the advantage of providing more degrees of freedom to adjust the resonant frequencies and two transmission zeros can be created at both lower and upper sides of the passband.
Abstract: In this letter, an ultra-wideband (UWB) bandpass filter (BPF) using stepped-impedance stub-loaded resonator (SISLR) is presented. Characterized by theoretical analysis, the proposed SISLR is found to have the advantage of providing more degrees of freedom to adjust the resonant frequencies. Besides, two transmission zeros can be created at both lower and upper sides of the passband. Benefiting from these features, a UWB BPF is then investigated by incorporating this SISLR and two aperture-backed interdigital coupled-lines. Finally, this filter is built and tested. The simulated and measured results are in good agreement with each other, showing good wideband filtering performance with sharp rejection skirts outside the passband.

128 citations


Journal ArticleDOI
TL;DR: In this paper, a planar circular slot antenna for UWB communications is presented, and the integration on this antenna of a notch filter, to reduce the possible interferences with the 5 GHz WLAN communications, has been discussed in detail.
Abstract: —The study of a planar circular slot antenna for Ultrawideband (UWB) communications is presented. The integration on this antenna of a notch filter, to reduce the possible interferences with the 5GHz WLAN communications, has been discussed in detail. Four different structures, achieved by etching a suitable pattern on the antenna circular stub, have been considered, and their features have been compared. The antenna with symmetrical and inverted-L cuts shows the best performance, and it has been therefore realized and fully characterized. It shows very good matching features over the UWB band, and notable rejection of the 5 GHz WLAN band.

128 citations


01 Jan 2010
TL;DR: In this article, a tri-band filter with three pass-bands centered at 2.45, 3.5, and 5.25 GHz is proposed, where the DGS resonator on the lower plane constructs the first passband, and the SLR on the upper plane forms the second and third passbands, in which a DGS loop is properly used to pro- videdethecoupling betweenthe SLRs.
Abstract: Atri-bandbandpassfilterusingstubloadedresonator (SLR) and defected ground structure (DGS) resonator is proposed in this letter. The DGS resonator on the lower plane constructs the first pass-band, and the SLR on the upper plane forms the second and third pass-bands, in which a DGS loop is properly used to pro- videthecouplingbetweentheSLRs.Thethreepass-bandsarecom- bined together with a common T-shaped feed line, and a reason- able tuning method is adopted to tune the three pass-bands with smooth responses. A compact tri-band filter with three pass-bands centered at 2.45, 3.5, and 5.25 GHz is designed and fabricated. The measurement results agree well with the full-wave electromagnetic designed responses. Index Terms—Defected ground structure (DGS) resonator, stub- loaded resonator (SLR), tri-band filter, T-shaped feed line.

127 citations


Journal ArticleDOI
TL;DR: A tri-band bandpass filter using stub loaded resonator (SLR) and defected ground structure (DGS) resonator is proposed in this article, where the DGS resonator on the lower plane constructs the first pass-band and the SLR on the upper plane forms the second and third pass-bands, in which a DGS loop is properly used to provide the coupling between the SLRs.
Abstract: A tri-band bandpass filter using stub loaded resonator (SLR) and defected ground structure (DGS) resonator is proposed in this letter. The DGS resonator on the lower plane constructs the first pass-band, and the SLR on the upper plane forms the second and third pass-bands, in which a DGS loop is properly used to provide the coupling between the SLRs. The three pass-bands are combined together with a common T-shaped feed line, and a reasonable tuning method is adopted to tune the three pass-bands with smooth responses. A compact tri-band filter with three pass-bands centered at 2.45, 3.5, and 5.25 GHz is designed and fabricated. The measurement results agree well with the full-wave electromagnetic designed responses.

121 citations


Journal ArticleDOI
TL;DR: In this paper, the possibility of using an active internal matching element in several types of metamaterial-inspired, electrically small antennas to overcome their inherent narrow bandwidths is demonstrated.
Abstract: The possibility of using an active internal matching element in several types of metamaterial-inspired, electrically small antennas (ESAs) to overcome their inherent narrow bandwidths is demonstrated. Beginning with the Z antenna, which is frequency tunable through its internal lumped element inductor, a circuit model is developed to determine an internal matching network, i.e., a frequency dependent inductor, which leads to the desired enhanced bandwidth performance. An analytical relation between the resonant frequency and the inductor value is determined via curve fitting of the associated HFSS simulation results. With this inductance-frequency relation defining the inductor values, a broad bandwidth, electrically small Z antenna is established. This internal matching network paradigm is then confirmed by applying it to the electrically small stub and canopy antennas. An electrically small canopy antenna with k? = 0.0467 that has over a 10% bandwidth is finally demonstrated. The potential implementation of the required frequency dependent inductor is also explored with a well-defined active negative impedance converter circuit that reproduces the requisite inductance-frequency relations.

113 citations


Journal ArticleDOI
TL;DR: In this paper, a balanced dual-band band-pass filter (BPF) using four coupled bi-section halfwavelength (?/2) stepped-impedance resonators (SIRs) is presented.
Abstract: A new fourth-order balanced dual-band band-pass filter (BPF) designed using four coupled bi-section half-wavelength (?/2) stepped-impedance resonators (SIRs) is presented. To obtain the required differential-mode (DM) operation with suppressed common-mode (CM) transmission, the SIRs were designed to have the same odd-mode, but different even-mode, resonant frequencies. For that purpose, the two inner SIRs were loaded at the center with T-shaped open stubs of different dimensions so that their even-mode resonant frequencies are shifted away from those of the outer SIRs and that their odd-mode ones remain almost intact. For the fabricated prototype BPF, the measured minimum DM insertion losses for the first and second bands are 2.4 and 2.82 dB, respectively, whereas the measured CM insertion loss is larger than 25 dB in 1-7 GHz.

113 citations


Journal ArticleDOI
TL;DR: In this article, a four-element high-gain circularly polarized microstrip antenna array operating in the Ka-band is proposed, and the sequentially rotated series-parallel stub technique is employed in constructing the feed network to allow symmetrical positioning of microstrip patch elements, resulting in good axial ratio of polarization.
Abstract: In this letter, a four-element high-gain circularly polarized microstrip antenna array operating in the Ka -band is proposed. The sequentially rotated series-parallel stub technique is employed in constructing the feed network to allow symmetrical positioning of microstrip patch elements, resulting in good axial ratio of polarization. In addition, an L-shaped matching branch is used to offer good impedance matching and spatial flexibility for positioning patch elements. Both simulation and measurement results are presented. They agree with each other well and demonstrate much better 3-dB axial-ratio bandwidth and return loss than the single patch antenna.

93 citations


Journal ArticleDOI
TL;DR: In this paper, a folded stepped impedance resonator (SIR), modifled by adding an inner quasi-lumped SIR stub, is used as a basis block for a new implementation of dual-band bandpass fllters.
Abstract: In this paper, a folded stepped impedance resonator (SIR), modifled by adding an inner quasi-lumped SIR stub, is used as a basis block for a new implementation of dual-band bandpass fllters. The main advantage of the proposed fllter is to make it possible to independently control the electrical features of the flrst and second bands. The behavior of the flrst band basically depends on the geometry of the outer folded SIR. The second band, however, is strongly in∞uenced by the presence of the inner stub. Additional design ∞exibility is achieved by allowing the inner stub to be located at an arbitrary position along the high impedance line section of the main SIR. The position of the tapped input and output lines can be

87 citations


Journal ArticleDOI
TL;DR: In this paper, a microstrip-fed broadband circularly polarised (CP) monopole antenna with broad impedance bandwidth and wide axial ratio bandwidth (AR-BW) was studied.
Abstract: A microstrip-fed broadband circularly polarised (CP) monopole antenna was studied A broad impedance bandwidth and wide axial ratio bandwidth (AR-BW) could be achieved simultaneously This antenna used a conventional monopole architecture, except for its deforming ground plane and asymmetric-feed approach The asymmetric-feed was used to provide an orthogonal component distinct from its original linear polarisation In addition, by embedding a slit and a stub on the ground plane, this antenna could generate CP wave radiation and achieve a broad impedance bandwidth According to the measurement results, the impedance bandwidth was 656 GHz for a 10 dB return loss, which covered a range of 232 888 GHz The AR-BW was 12 GHz for a 3 dB AR, which covered a range of 32 44 GHz

Journal ArticleDOI
TL;DR: An open stub feed planar patch antenna for UHF RFID tag mountable on metallic objects has planar structure which can decrease the manufacturing cost of the tags and makes the impedance of the patch antenna be tuned in a large scale for conjugate impedance matching.
Abstract: An open stub feed planar patch antenna is proposed for UHF RFID tag mountable on metallic objects. Compared to conventional short stub feed patch antenna used for UHF RFID tag, the open stub feed patch antenna has planar structure which can decrease the manufacturing cost of the tags. Moreover, the open stub feed makes the impedance of the patch antenna be tuned in a large scale for conjugate impedance matching. Modeling and simulation results are presented which are in good agreement with the measurement data. Finally, differences between the open stub feed patch antenna and the short stub feed patch antenna for UHF RFID tag are discussed.

Journal ArticleDOI
Hong-Wei Deng1, Yong-Jiu Zhao1, Lu Zhang1, Xue-Shun Zhang1, Si-Ping Gao1 
TL;DR: In this article, a novel quintuple-mode stub-loaded resonator and ultrawideband (UWB) bandpass filter (BPF) are proposed, which can generate two odd modes and three even modes in the desired band.
Abstract: A novel compact quintuple-mode stub-loaded resonator and ultrawideband (UWB) bandpass filter (BPF) are proposed in this letter. The proposed resonator can generate two odd modes and three even modes in the desired band. The odd-mode resonance frequencies are exclusively correlated to the modified triple-mode resonator; even-mode resonance frequencies can be flexibly controlled by the impedance-stepped open and short stub at its central plane, whereas the odd-mode ones are fixed. The open stubs in pairs at two sides of the low-impedance line are mainly applied to adjust the high resonant modes (fm4, fm5) into desired passband. The short stub can generate two transmission zeros near the lower and upper cutoff frequencies, leading to high rejection skirt. A quintuple-mode UWB filter is simulated, fabricated, and measured. The EM simulated and measured results are presented, and an excellent agreement is obtained.

Journal ArticleDOI
TL;DR: It is shown that light can be coupled efficiently from a conventional MDM waveguide to the plasmonic waveguide system, which supports a subwavelength broadband slow-light guided mode with a tunable slowdown factor at a given wavelength.
Abstract: We introduce a plasmonic waveguide system, which supports a subwavelength broadband slow-light guided mode with a tunable slowdown factor at a given wavelength. The system consists of a metal-dielectric-metal (MDM) waveguide side-coupled to a periodic array of MDM stub resonators. The slowdown factor at a given wavelength can be tuned by adjusting the geometrical parameters of the system. In addition, there is a trade-off between the slowdown factor and the propagation length of the supported optical mode. Finally, we show that light can be coupled efficiently from a conventional MDM waveguide to the plasmonic waveguide system.

Journal ArticleDOI
TL;DR: In this article, a defected ground structure (DGS) is proposed in the design of a proximity coupled antenna for its miniaturization and two artiflcial cells are added on the feed line to reduce the protrudent stub length.
Abstract: A new defected ground structure (DGS) is flrstly proposed in this paper, which has better slow-wave efiect than that of cross or dumbbell one. Using the model of transmission line, its equivalent parameters are extracted. With good omni-directional properties, the proposed DGS is then used in the design of a proximity coupled antenna for its miniaturization. The size of the developed antenna is about 68% smaller than that of the conventional one. Further, two artiflcial cells are added on the feed line to reduce the protrudent stub length from 26.9mm to 18.94mm. With the utility of the DGS and artiflcial cells, the size of proximity coupled antenna is reduced signiflcantly. By introducing a PIN diode at the end of feed line, the antenna is switchable in both x- and y-direction linear polarizations. Such miniaturization in antenna size has little negative efiect on its cross polarization, with both simulated and experimental results presented for comparison.

Journal ArticleDOI
TL;DR: In this article, a total of 250 experimental tests of axially loaded circular concrete-filled steel tube (CFT) stub columns, published in the literature was summarized and four new empirical models for predicting the axial capacity of circular CFT stub columns are proposed.

Journal ArticleDOI
TL;DR: In this article, a novel compact ultra-wideband (UWB) band-pass fllter (BPF) based on surface-coupled structure is proposed.
Abstract: A novel compact ultra-wideband (UWB) band-pass fllter (BPF) based on surface-coupled structure is proposed. The surface- coupled structures and Y-shaped shorted stub resonator are adopted as quasi-lumped circuit elements to achieve UWB pass-band. To avoid the interference of the wireless local area network (WLAN) at 5.25 and 5.775GHz, two difierent quarter-wavelength lines are arranged on the ground of UWB BPF to generate dual narrow stop bands. Being developed from the quasi-lumped elements, the proposed UWB BPFs have very compact size. The fabricated UWB BPFs have the advantages of low insertion loss, good selectivity and ∞at group delay. Good agreement between equivalent circuit modeled, simulated and measured responses of these fllters is demonstrated.

Journal ArticleDOI
TL;DR: In this article, the authors studied the behavior of inclined, tapered and straight-tapered-straight (STS) concrete-filled steel tubular (CFST) stub columns.

Journal ArticleDOI
TL;DR: In this paper, a single-layer microstrip antenna for ultrawideband (UWB) applications, in which an array of rectangular microstrip patches was arranged in the log-periodic way and proximity-coupled to the microstrip feeding line, is presented.
Abstract: A single-layer microstrip antenna for ultrawideband (UWB) applications, in which an array of rectangular microstrip patches was arranged in the log-periodic way and proximity-coupled to the microstrip feeding line, is presented. In order to reduce the number of microstrip patches in the UWB log-periodic arrays, a large scale factor k = 1.1 was firstly reported and proved to be highly effective. Furthermore, instead of using an absorbing terminal loading, a novel loss-free compensating stub was proposed. Detailed parameters study was also presented for better understanding of the proposed antennas. The impedance bandwidth (measured VSWR < 2.5) of an example antenna with only 11 elements is from 2.26-6.85 GHz with a ratio of about 3.03:1. Both numerical and experimental results show that the proposed antenna has stable directional radiation patterns, very low-profile and low fabrication cost, which are suitable for various broadband applications.

Patent
12 Jul 2010
TL;DR: In this article, a system, device and method that can control the rates of seed dispensation and fertilizer application as a function of forward speed as well as across all rows is presented.
Abstract: The invention provides a system, device and method that can control the rates of seed dispensation and fertilizer application as a function of forward speed as well as across all rows. Thus, the system and control device allow control of each individual row unit, whereby dispensation and application are effected, by a central controller which controls a plurality of pulse width modulation valves, each of which controls a hydraulic motor with an integrated rpm reduction and which drives a stub drive shaft which rotates at the proper speed in order to provide the desired seed and fertilizer metering. Each of the stub drive shafts may rotate at completely different speeds and/or may be shut down while the remaining stub drive shafts rotate at the desired speed. The integrated rpm reduction within each hydraulic motor allows very fine rotational control of the dispensation and application rates.

Journal ArticleDOI
TL;DR: A new design method of single‐stub impedance matching networks is presented and the proposed impedance matching scheme is successfully applied to the design of a stubbed dual‐band T‐junction power divider.
Abstract: A new design method of single-stub impedance matching networks is presented for the dual-band application. The dual-band operating conditions are analyzed in detail and the design equations are derived in concise form for different locations and termination types of the stub line. The proposed impedance matching scheme is successfully applied to the design of a stubbed dual-band T-junction power divider. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1359–1362, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25201

Proceedings ArticleDOI
01 Nov 2010
TL;DR: In this article, a dual-band bandpass filter using both an open stub-loaded resonator (OSLR) and a short stubloaded resonators (SSLR) is presented.
Abstract: A dual-band bandpass filter using both an open stub-loaded resonator (OSLR) and a short stub-loaded resonator (SSLR) is presented. The use of SSLR has the advantage that a transmission zero can be flexibly controlled by tuning the length of the short stub, which can be employed as a new but convenient way to create transmission zeros in front of passbands in filter design. By further introducing a two-order planar transversal filter structure using the OSLR as well as the source-load coupling, a dual-band filter is implemented with four transmission zeros and exhibits high skirt selectivity based on the simulated result. Two passbands with center frequencies of 2.45 GHz and 3.5 GHz are achieved with compact size of about 0.18λ × 0.12λ at 2.45 GHz.

Patent
05 Jan 2010
TL;DR: In this article, a fiber optic union includes a split sleeve with an interior channel and a fiber stub centrally located within the interior channel, which makes direct optical contact with the cable end faces to enable efficient optical transmission between interconnected cables while providing a low loss, low back reflection adiabatic transition between the waveguide cores of the two cables.
Abstract: Devices to enhance the reliability of optical networks and to reduce the cost of repair are disclosed in this invention. In particular, compact and inexpensive fiber optic union adapters with built-in protective isolation prevent the transfer of damage from one connectorized fiber optic cable to another. The fiber optic union includes a split sleeve with an interior channel and a fiber stub centrally located within the interior channel. The fiber stub makes direct optical contact with the cable endfaces to enable efficient optical transmission between interconnected cables while providing a low loss, low back reflection adiabatic transition between the waveguide cores of the two cables.

Journal ArticleDOI
TL;DR: In this paper, a broadband microstrip bandpass filter using a stub-loaded resonator is proposed, which consists of a half-wave resonator and a shunt open-circuited stub.
Abstract: A broadband microstrip bandpass filter using a stub-loaded resonator is proposed. The basic block of the proposed filter is a triple-mode resonator that consists of a half-wave resonator and a shunt open-circuited stub. A parameter study of how to control the frequencies of the three modes is presented. Two bandpass filters using the proposed resonator have been designed, fabricated and tested to validate the design concept. Design guidelines and a comparison with previous work are also included. For the first bandpass filter, from 1.75 to 3.25 GHz, the measured return loss is greater than 16 dB and the measured insertion loss is less than 0.9 dB. The maximum group delay variation is 0.6 ns. Furthermore, there are two transmission zeros at 1.3 and 3.8 GHz for a better cut-off response. For the second one, from 1.6 to 3.7 GHz, the measured return loss is greater than 14 dB and the measured insertion loss is less than 1 dB. The maximum group delay variation is 0.6 ns, and there are two transmission zeros at 1.36 and 4.03 GHz.

Journal ArticleDOI
TL;DR: In this article, the authors presented an internal mobile phone antenna with three wide operating bands of at least 698-960, 1710-2690, and 5150-5825 MHz for the 11-band long-term evolution (LTE)/ wireless wide area network (WWAN)/wideband local area networks (WLAN) operation.
Abstract: This work presents an internal mobile phone antenna occupying a small board space of 600 mm2 on the system circuit board and providing three wide operating bands of at least 698–960, 1710–2690, and 5150–5825 MHz for the 11-band long term evolution (LTE)/ wireless wide area network (WWAN)/wideband local area network (WLAN) operationThis includes three LTE bands of LTE700/2300/2500, five WWAN bands of GSM850/900/1800/1900/UMTS, and three WLAN 24/52/58 GHz bands The antenna is a coupled-fed shorted monopole, with a wide feeding strip in the coupling feed, a long shorting strip closely coupled to the shorted monopole, and a tuning stub connected to the shorting strip The antenna's three wide operating bands are achieved and controlled by tuning the width of the feeding strip, the gap between the shorting strip and the shorted monopole, and the dimensions of the tuning stub Operating principle of the proposed antenna is described in detail in this article Results of the fabricated antenna are presented and discussed The specific absorption rate results of the antenna with the presence of the user's head and hand are also studied © 2010 Wiley Periodicals, Inc Microwave Opt Technol Lett 52:2603–2608, 2010; View this article online at wileyonlinelibrarycom DOI 101002/mop25526

Journal ArticleDOI
TL;DR: The applicability of Gaussian process (GP) regression as modeling tool within a genetic algorithm (GA) antenna optimization scheme is demonstrated and is shown to be an efficient alternative to artificial neural networks when many accurate and fast estimates of antenna performance parameters are required.
Abstract: The applicability of Gaussian process (GP) regression as modeling tool within a genetic algorithm (GA) antenna optimization scheme is demonstrated. GP regression has recently been shown to be an efficient alternative to artificial neural networks (ANNs) when many accurate and fast estimates of antenna performance parameters, usually only obtainable from computationally intensive full-wave analyses, are required. GP regression has the important advantage that far fewer free parameters need to be determined; it furthermore is not subject to the implementation issues associated with neural nets. By using genetic algorithm optimization, two kinds of CPW-fed slot antennas were designed to operate within pre-specified frequency bands: an ultrawide-band (UWB) slot antenna with U-shaped tuning stub, and a dual-band slot loop antenna with separate T-shaped and insert tuning stubs. In both cases, the associated modeling problems were challenging, involving highly nonlinear mappings of several tunable geometry varia...

Journal ArticleDOI
TL;DR: In this article, a planar Wilkinson power divider using π-equivalent shunt-stub-based artificial transmission lines (SSB ATLs) was designed and experimentally verified.
Abstract: A compact planar Wilkinson power divider using π-equivalent shunt-stub-based artificial transmission lines (SSB ATLs) has been designed and experimentally verified. Instead of using conventional quarter-wave microstrips, the π-equivalent SSB ATLs realised by a series high-impedance microstrips and two sets of branch-type stubs are employed to implement a compact power divider. The developed power divider occupies only 14.7% of the circuit size of a conventional one. The measured results of the developed power divider are in good agreement with simulated results.

Journal ArticleDOI
TL;DR: In this article, the axial compressive behavior of stub concrete-filled columns with elliptical stainless steel and carbon steel hollow sections was analyzed using the finite element method developed via ABAQUS/Standard solver.
Abstract: This paper presents the axial compressive behaviour of stub concrete-filled columns with elliptical stainless steel and carbon steel hollow sections. The finite element method developed via ABAQUS/Standard solver was used to carry out the simulations. The accuracy of the FE modelling and the proposed confined concrete stress-strain model were verified against experimental results. A parametric study on stub concrete-filled columns with various elliptical hollow sections made with stainless steel and carbon steel was conducted. The comparisons and analyses presented in this paper outline the effect of hollow sectional configurations to the axial compressive behaviour of elliptical concrete-filled steel tubular columns, especially the merits of using stainless steel hollow sections is highlighted.

Journal ArticleDOI
TL;DR: In this article, a modified UWB power divider formed by implementing one delta stub on each branch is proposed, which makes branch line shorter and stub's size smaller than those of other works based on UWB using radial stub.
Abstract: A modified UWB power divider formed by implementing one delta stub on each branch is proposed. Delta stub is used as a substitution of radial stub that can present wideband characteristic. The proposed structure makes branch line shorter and stub’s size smaller than those of similar works based on UWB power divider using radial stub. It also achieves a compact size of 18 mm by 13 mm. The simulation and measurement results of the developed divider are presented and shown good agreement in the UWB range.

Patent
27 Jan 2010
TL;DR: In this paper, the RF matching pads allow the manufacture of circuit boards having RF interconnects without the need to perform any back drill and back fill operation to remove stub portions of the RF Interconnects in the multilayer circuit board assembly.
Abstract: A multilayer circuit board assembly includes one or more radio frequency (RF) interconnects between different circuit layers on different circuit boards which make up the circuit board assembly. The RF interconnects can include one or more RF matching pads which provide a mechanism for matching impedance characteristics of RF stubs to provide the RF interconnects having desired insertion loss and impedance characteristics over a desired RF operating frequency band. The RF matching pads allow the manufacture of circuit boards having RF interconnects without the need to perform any back drill and back fill operation to remove stub portions of the RF interconnects in the multilayer circuit board assembly.