Stub (electronics)

About: Stub (electronics) is a research topic. Over the lifetime, 8172 publications have been published within this topic receiving 75018 citations.

Study of a compact ring monopole UWB antenna with band‐notched characteristic

Abstract: In this article, a printed ring shaped monopole ultra-wideband antenna with band-notched feature is presented and investigated. To get the band-notched characteristic, a quarter wavelength tuning stub is embedded into the ring radiator. The measured results show that the proposed antenna meets the requirement of wide working bandwidth of 3.1–10.6 GHz with VSWR < 2, while avoiding the interference with the wireless local area network band (5.150–5.825 GHz). The transfer function (amplitude of S21/group delay) and time domain characteristic (fidelity/power spectrum density) are also studied in this article. The proposed antenna has a compact size, good radiation characteristics, ultrawide bandwidth, and good time-domain behaviors to satisfy the requirement of the current wireless communications systems. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:2387–2392, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27067

Compact High-Isolation LTCC Diplexer Using Common Stub-Loaded Resonator With Controllable Frequencies and Bandwidths

Abstract: In this paper, a low-temperature co-fired ceramic (LTCC) diplexer is presented with compact size and high isolation By using the common stub-loaded resonator shared by two channel filters, combining and matching networks are eliminated and only three resonators are used to design the two second-order channel filters, resulting in simple structure and miniaturized size A novel transmission path is utilized to not only realize the higher channel filter but also prevent the signal at the lower frequency band And a specific coupling region is selected to simultaneously realize the coupling strength required by lower channel filter and a transmission zero at higher-band frequency In this way, each channel filter can generate a transmission zero at the passband frequency of the other channel filter, resulting in high isolation Moreover, the bandwidths and center frequencies of the two channel filters can be individually controlled due to the design flexibility of the multilayer LTCC structure For demonstration, a diplexer operating at 35 and 55 GHz is fabricated The core circuit has the compact size of 19 mm $\times17$ mm $\times2$ mm or $0054~\lambda _{g} \times 0048 \lambda _{g} \times 0057~\lambda _{g}$ Within the 3-dB passbands of the lower and higher channel filters, the measured isolation levels are better than 40 and 45 dB, respectively

Impedance matching device

Abstract: In an impedance matching device having at least two stubs serially provided to a main coaxial tube so as to be separated from each other with a predetermined interval in a tube axial direction, each stub is composed of a variable capacity capacitor to be jointed to an inner conductor of the main coaxial tube, an electrically conductive capacitor cover to be jointed to an outer conductor of the main coaxial tube so as to cover a surrounding of the variable capacity capacitor, and a drive motor arranged on an outside of the capacitor cover so as to drive a movable side electrode of the variable capacity capacitor. The movable side electrode of the variable capacity capacitor is driven directly by the drive motor so that the impedance matching device is made to be compact and response of impedance matching to a fluctuation of a load impedance such as a behavior of a plasma load is improved, and the life is lengthened and degrees of freedom of installation is widened.

Analytical behavior of concrete-filled aluminum tubular stub columns under axial compression

Abstract: This paper presents finite element investigations on the structural behaviors of circular concrete-filled aluminum tubular (CFAT) stub columns under axial compression. The finite element models are developed by considering the nonlinearities of concrete and aluminum materials and the interactions between the two components. The predicted ultimate strengths, load-axial strain relationships and failure modes are compared to those from collected experimental data. Full range analysis on the load-deformation N-e are conducted, where the investigations on the multi-axial stress conditions of the aluminum tube and the interaction stress between the aluminum tube and concrete core are included. The verified finite element models are used to carry out a series of parametric studies on key material and geometric properties. The ductility index DI and strain at ultimate strength escy are studied. Equations to determine escy for circular CFAT stub columns are proposed. The applicability of the existing design method for CFST to CFAT stub columns is investigated.

Compact ultrawideband MIMO dielectric resonator antennas with WLAN band rejection

Abstract: A new compact configuration of ultrawideband (UWB) multiple-input-multiple-output (MIMO) dielectric resonator antennas (DRAs) with wireless local area network (WLAN) band rejection is proposed The antenna arrangement consists of two identical inserted rectangular DRAs excited by two microstrip feeds, with an overall compact size of 29 × 29 × 5 mm3 To enhance isolation and improve impedance bandwidth, a stub connected to the ground is added to the bottom plane of the substrate Further, to reduce interferences with WLAN systems, two L-shaped parasitic strips connected to the dielectric resonators are added to create a band rejection between 498 and 608 GHz The measurement results demonstrate that the proposed DRAs achieve satisfactory MIMO UWB performance, with an impedance bandwidth of around 106% excluding a rejection band for WLAN, low mutual coupling and a low envelope correlation coefficient across the whole desired frequency band