To simulate earthquake ground motion, we combine a multiple-point stochastic earthquake fault model and a suite of Green functions. Conceptually, our source model generalizes the classic one of Haskell (1966). At any time instant, slip occurs over a narrow strip that sweeps the fault area at a (spatially variable) velocity. This behavior defines seismic signals at lower frequencies (LF), and pr...

Dolph-Chebychev arrays are known to exhibit the best compromise between sidelobe level and directivity. However, they place a constraint on the null locations. Any attempt to impose nulls or get them deeper will impact the directivity/sidelobe level trade-off. In this work, null placement in Dolph-Chebychev arrays through element position perturbation is carried out based on Taguchi method whil...

This paper gives an analysis of operation of a self-phased array under conditions of multipath propagation (either reflections or jamming signals). A general method for the calculation of directivity of such an array has been proposed. Influence of reflections by way of the pilot signal channel as well as by way of the primary signal channel is taken into account. Some limitations of the approa...

A measurement system is presented that allows large aperture measurements with a high angular resolution and that is still compact and thus convenient for portable use. Theoretical considerations show that a cardioid microphone characteristic is desireable to achieve a low amplification of sensor noise throughout the audio frequency range. The directivity of real cardioid microphones, however, ...

In these research paper two designs such as rectangular microstrip antenna and concentric equilateral triangular microstrip antenna are presented. The resonant frequency of this antenna is 8 GHz suitable for wireless applications. The antenna is fed by microstrip feeding technique. Design of an antenna using ADS (Advanced Design System), based on MoM (Method of Moments) has been used to analyze...

A method for the joint localization and orientation estimation of a directional sound source using distributed microphones is presented. By modeling the signal attenuation due to the microphone directivity, the source directivity, and the source-microphone distance, a multi-dimensional search over all possible sound source locations and orientations is performed. This sound source scene reconst...

This paper increases directivity and gain of Small Planar Dipole Antenna (SPDA) by using Symmetrical Pyramidal Block (SPB) which operates in X band at 11 GHz. The SPB consists four sides; each of which is metamaterial with Epsilon Negative Medium (ENG) and Epsilon Near-Zero (ENZ). The results simulated using the High Frequency Structure Simulator (HFSS) show that the SPB is capable of enhancing...

This paper is a review of amateur-built high-directivity wire antennas, for wireless local area network (WLAN), operating at 2.4-GHz frequency range. Those antennas can be deployed for range extension and interference reduction, for example. Covered in this review are a biquad antenna with reflector, Yagi-Uda antenna, and helical antenna. The distinctive feature of these antennas is their ease ...

This paper introduces a novel variation of the vee dipole antenna consisting of two coplanar vee dipoles with a common feed point. It is referred to as a double-vee dipole. Radiation characteristics of the double-vee dipole antenna are investigated numerically and experimentally. It is shown that the double-vee dipole can provide significantly higher directivity and lower sidelobes and back rad...