We present results of experimental and theoretical investigations of electron transport through stub-shaped waveguides or electron stub tuners (ESTs) in the ballistic regime. Measurements of the conductance G as a function of voltages, applied to different gates Vi (i =bottom, top, and side) of the device, show oscillations in the region of the first quantized plateau which we attribute to refl...

In this article, a novel compact triple-band monopole antenna for WLAN/WiMAX applications is proposed. The proposed antenna is designed on an FR-4 substrate with thickness of 0.8mm, relative permittivity of 4.4 and loss tangent of 0.02. It consists of a square ring, an open ended stub, and an inverted T-shaped stub. Three bands covering 2.3–2.76, 3.387–3.73, and 4.97–6.28 GHz are achieved, whic...

The design and analysis of an ultra wideband aperture antenna with dual-band-notched characteristics are presented. The proposed antenna consists of a circular ring exciting stub on the front side and a circular slot on the back ground plane. By utilizing a parasitic strip and a T-shaped stub on the antenna structure, two notched bands of 850 MHz (3.5-4.35 GHz) and 900 MHz (5.05-5.95 GHz) are a...

A compact printed wide-slot (PWS) antenna is proposed for UWB applications. The proposed UWB-PWS antenna basically consists of a stepped microstrip feed-line with a rectangular patch stub and a rectangular wide-slot element at the aperture. Additional parasitic split-ring elements are placed along the patch stub to achieve notch-band characteristics. As the proposed antenna in absence of the ri...

We redefine an address, which is location information within the Internet, as a locator, and propose a HANA protocol, which hierarchically and automatically allocates and assigns locators to network equipments. From the Internet core to stub networks, HANA can reduce manual configurations of network equipments related to locators as possible, and then can reduce network management costs. Even i...

A wideband high-gain circularly polarized (CP) shaped dielectric horn-lens antenna (SDHLA) operating in the frequency band between 6.7 and 18.2 GHz [fractional impedance bandwidth (FIBW) of 92.4%] with a 3-dB axial-ratio range from 8.1 to 16.3 (FARBW) 67.2%], is presented. The antenna, composed suitably horn, integrated super-ellipsoidal-axicon lens made out stacked thin disks, mounted on print...

Formal verification has been successfully applied to provide strong correctness guarantees of software systems, but its application to large code bases remains an open challenge. The technique of component-based software development, traditionally employed for engineering benefit, also aids reasoning about such systems. While there exist compositional verification techniques that leverage the s...

Wired equivalent security is difficult to provide in ad hoc networks due to high dynamics, wireless link vulnerability, and requirement of complete decentralization. Especially mutual authentication among nodes in a self-organized mode of ad hoc network, where a single definition of trust is hard to build, is very difficult. This leads to several loopholes in previously established security arc...

Dr Jeffrey Wigand is delivering an anti-smoking message to children and young people. He talked to Ben Jones about his work.

We report on low-noise heterodyne mixing with NbN/A1N/NbN tunnel junctions in the submillimeter-wave region for the first time. The receiver consists of the quasi-optical NbN SIS mixer with an integrated tuning circuit in which a radial short stub tuner is incorporated to resonate out the junction capacitance for RF matching and a balanced IF circuit for broadband IF matching. The prepared NbN ...