This paper presents a microwave reflectometer using self-mixing oscillator antennas. A unique characteristic of the proposed reflectometer is its simple structure without a circulator and a directional coupler. Each self-mixing oscillator antenna utilizes a Gunn diode as an active device and a rectangular waveguide as a resonator and a radiator. The determination of dielectric properties of mat...

-Dual frequency operation of antennas has become a necessity for many applications in wireless communication systems such as GPS, GSM services operating at two different frequency bands and services of PCS and IMT-2000 applications. Although there are various techniques to achieve dual-band operation from various types of microstrip antennas, there is no efficient design tool that has been inco...

This study demonstrates superposing several eddy current distributions enables one to size defects much deeper than the depth of penetration from eddy current signals. A probe developed in an earlier study of the authors is utilized for the demonstration. The probe consists of four large exciters and one detector; the uniqueness of the probe is to realize an eddy current distribution that does ...

Hot-wire measurements have been made in the boundary layer, the separated region, and the near wake for flow past an NACA 4412 airfoil at mad mum lift. The Reynolds number based on chord was about 1,500,000. Special care was taken to achieve a two-dimensional mean flow. The main instrumentation was a flying hot wire; that is, a hot-wire probe mounted on the end of a rotating arm. The probe velo...

This paper presents an objective speech quality measure which is based on loudness patterns using the equivalent rectangular bandwidth (ERB) scale. The proposed measure, called the loudness pattern distortion (LPD), is computed from the differences between the loudness patterns of the original and processed speech. The LPD measure takes into account the transmission through the outer and middle...

Excellent progress in the development of Submillimeter-wave SIS and HEBmixers has been demonstrated in recent years. At frequencies below 800 GHz these mixers are typically implemented using waveguide techniques, while above 800 GHz quasi-optical (open structure) methods are often used. The choice of waveguide offers several advantages over quasi-optical techniques, such as the use of broadband...

The aerodynamic noise of a thin rigid annulus (referred to as the ring here) placed in the mixing layer of a subsonic circular jet is investigated in the paper, both theoretically and experimentally. From the experimental point of view, the jet–ring configuration is understood as an axisymmetric alternative to more usual ones involving a rectangular aerofoil held between parallel side plates, d...

An effective procedure to correct known 3D probe positioning errors affecting the near-field–far-field transformation (NF–FF) with non-conventional plane rectangular scanning, named planar wide-mesh scanning (PWMS), is developed in this paper. It relies on non-redundant sampling representations of electromagnetic fields and related optimal interpolation (OSI) expansions has been devised when a ...

scanning hall probe microscopy (shpm) is a scanning probe microscopy technique developed to observe and image magnetic fields locally. this method is based on application of the hall effect, supplied by a micro hall probe attached to the end of cantilever as a sensor.  shpm provides direct quantitative information on the magnetic state of a material and can also image magnetic induction under a...

We present a brief historical overview of the classical theory of a radiating point charge, described by the Lorentz-Dirac equation. A recent development is the discovery of tunnelling of a charge through a potential barrier, in a completely classical context. Also, a concrete example is discussed of the existence of several physically acceptable solutions for a range of initial data. We end by...