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...

A new type of highly-directional ultrasonic range sensor is designed, fabricated, and tested in this paper. To improve directivity, the parametric acoustic array, a nonlinear effect of media between two intensive waves, is applied to an ultrasonic range sensor. Additionally, a new type of the stepped-plate transducer is applied for generating high amplitude waves consisting of two frequencies. ...

A novel design of patch antenna is presented with double U slot structure on patch with ground irregularities. As a result tri-band response is achieved with gain reaching 0.785 to 3.75dB respectively and directivity of 5.5 to 5.6dBi. Coaxial cable is mounted with patch as medium of power. The antenna has shown minimum mismatch loss with 0 to 5% with high bandwidth response of 37 to 1200MHZ. Th...

We show that the enhanced directivity phenomenon for light passing through a subwavelength aperture in a silver film with corrugations on the exit face, is due to a leaky wave that decays exponentially from the aperture. We show quantitatively that the field along the interface of the silver film is dominated by the leaky wave, and that the radiation of the leaky wave, supported by the periodic...

Side lobe and directivity of antenna array is main problem in radar and communication field. This paper describes linear antenna array radiation pattern in adaptive beam forming using genetic algorithm. Unlike Simple GA (SGA), Genetic Algorithm is an iterative stochastic optimizer that works on the population values based on the fitness value. This improves the performance of the maximum reduct...