We consider the scattering of H-polarized eigenwaves a planar dielectric waveguide by coplanar system graphene strips in THz range. The are placed along centreline waveguide. Our treatment is based on singular integral equations with Nystrom-type discretization algorithm. Dependences characteristics, near and far fields, studied. Frequency scanning radiation patterns presented. Maximum radiated...

A design problem of uniform linear antenna arrays for maximal side lobe level reduction with the constraint of a fixed beam width is dealt with. This problem is modelled as a simple optimization problem. The method of tabu search is used to determine an optimum a set of weights of antenna element that provide a radiation pattern with maximal side lobe level reduction with the constraint of a fi...

A 77 GHz microstrip antenna array with a small surface providing high side and grating lobe suppression is presented. This may serve as a starting point for 77 GHz automotive radar applications. Multiple Wilkinson dividers guarantee both impedance matching at the input port (TX) as well as low return loss for the incoming (RX) signal. Phase shifting is done by adjusting the level of the Wilkins...

OBJECTIVES To assess patterns of postictal cerebral blood flow in the mesial temporal lobe by coregistration of postictal 99mTc-HMPAO SPECT with MRI in patients with confirmed mesial temporal lobe epilepsy. METHODS Ten postictal and interictal 99mTc-HMPAO SPECT scans were coregistered with MRI in 10 patients with confirmed mesial temporal lobe epilepsy. Volumetric tracings of the hippocampus ...

Capacity is one fundamental problem in wireless Ad hoc networks. Deploying directional antennas to wireless networks can reduce interference among concurrent transmissions and increase spatial reuse, while the technology of multi-channel can separate concurrent transmissions. Therefore, combining these two technologies into one wireless network is capable of great improvement on the network cap...

The spectral width of a nonlinear converter is usually thought to be inversely proportional to the length of the nonlinear crystal. We present a method to overcome this limitation using the concept of super-oscillations, thus creating an arbitrarily narrow converter. A “super-narrow” frequency doubler was fabricated by appropriate modulation of its quadratic nonlinear coefficient, showing spect...

The paper presents a new closed-form expression for the fractional Fourier transform of generalized Triangular and Welch window functions. Fractional Fourier Transform (FrFT) is a parameterized transform having an adjustable transform parameter which makes it more flexible and superior over ordinary Fourier transform in several applications. It is an important tool used in signal processing for...

The error reduction of the non-parametric amplitude estimation of the periodic signals with the three-point interpolated discrete Fourier transform (DFT) using cosine windows is presented. The paper analyzes and compares the systematic bias errors and the noise error behavior of the amplitude estimation changing the order of Rife-Vincent windows class I (RV1), which are designed for maximizatio...