Tunable frequency selective surface with a shorted ring slot

In order to realize the tunable performance of a frequency selective surface （FSS）, a new unit cell is designed in this paper by properly adding two metal shorts to the ring slot. Based on the spectral-domain method, the frequency responses of the FSS structure with two shorts per slot ring are analysed for both the horizontal and the vertical polarizations at the normal incidence. It is demonstrated that the presence of the metal shorts does not affect the resonant frequency of the horizontally polarized wave but doubles the resonant frequency of the vertically polarized wave. Therefore based on the analysis of the novel transmission properties, a new approach to adjusting the resonant frequency by rotating the FSS screen 90° is presented in this paper.

Spin Hall effect of a light beam in anisotropic metamaterials

We theoretically investigate a switchable spin Hall effect of light （SHEL） in reflection for three specific dispersion relations at an air-anisotropic metamaterial interface. The displacements of horizontal and vertical polarization compo- nents vary with the incident angle at different dispersion relations. The transverse displacements can be obtained with the relevant metamaterial whose refractive index can be arbitrarily tailed. The results of the SHEL in the metamaterial provide a new way for manipulating the transverse displacements of a specific polarization component.

New Metrics for the Detection of Suicide Bombers

An experimental field study was conducted at the University of California at Santa Cruz USA to determine if radar cross section signals were different between a person without wearing any wires and a person wearing both a suicide vest and wires with （without） loops in the wires. The data was collected using the GunnPlexer Doppler radar at 12.5 GHz at various safe distances using various subjects both without any wires and wearing a suicide vest with detonation wires and with detonation wires and loops. The raw data was separated in its horizontal and vertical polarization signals （HH and VV）. The analysis of these two HH and VV polarization signals from the data allowed several promising metrics to be created. These metrics were individually tested in a Monte Carlo simulation which is in order to determine the probability of detection of a would-be suicide bomber. The results of the Monte Carlo simulation showed that the metrics yielded a probability of successful detection of slightly over 98% and a false positive rate of just less than 2 %. This research and its result are encouraging and suggest further testing to insure that suicide bombers can be found prior to their detonation of their bombs at a safe range.

Influence of aircraft surface distribution on electromagnetic scattering characteristics

In this paper,two typical stealth aircraft concepts（wing fuselage blended and flyingwing） were designed.Then three gradually changed surface distribution models with the same planform for each concept were created.Based on the multilevel fast multipole algorithm（MLFMA）,the vertical polarization transmitting/vertical polarization receiving（VV） and horizontal polarization transmitting/horizontal polarization receiving（HH） radar cross section（RCS） characteristics were simulated with five frequencies between 0.1 and 1.0 GHz.The influences and mechanisms of aircraft surface distribution on electromagnetic scattering characteristics were investigated.The results show that for the wing fuselage blended concept,the W RCS of this frequency range is higher than the HH RCS in most cases,while it is just the opposite for the flying-wing concept.As for the two aircraft concepts,the RCS levels of HH and W both decrease with the frequency increasing,but the HH RCS has a faster downward trend.The surface distribution has little influence on HH RCS characteristics.On the contrary,it has a significant impact on W RCS characteristics,and the amplitude of the VV RCS increases with the surface thickness.