This paper reports progress in on-going studies to validate UT modeling of nozzle inner radius examinations. In a previous paper [1] it was shown that geometric modeling and raytracing in the Windows-based software WARay3D predicts the geometry and location of search units needed to detect known defects in a nozzle mock-up. The present paper describes the addition of beam forming [2] and flaw r...

designing FIR fan filters suitable for the multibeam forming network of the wideband beamspace adaptive array. Characteristics were approximated through the combination of spectral transformation and the window method so that those beam patterns that included the sidelobe characteristics of the resulting fan filters were virtually frequency independent. Using the fan filters designed by the pro...

An efficient method based on the hybrid model with breeding and subpopulations, between genetic algorithm and a modified particle swarm optimizer for the linear antenna arrays pattern synthesis with prescribed nulls in the interference direction and multi-lobe beam forming by the complex weights of each array element is presented. In general, the pattern synthesis technique that generates a des...

Automatic speech recognition in real world situations often requires the use of microphones distant from speaker’s mouth. One or several microphones are placed in the surroundings to capture many versions of the original signal. Recognition with a single far field microphone yields considerably poorer performance than with person-mounted devices (headset, lapel), with the main causes being reve...

studied when the receiver is connected to a GAS-1 CRPA mounted on a C-12J aircraft. The signals received by the seven elements of the CRPA are fed to antenna electronics (AE) where the signals are combined based on null steering or beam forming/null steering. AE based on space-only processing, 7-tap STAP, as well as 128-bin SFAP is considered. It is shown that platform generated multipath has v...

In Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing system using beamforming improve the receive Signal to Noise Ratio. In the transmission signals after beam forming the Peak-to-Average Power Ratio (PAPR) is a major issue in Orthogonal Frequency Division Multiplexing systems, High Peak to Average Power Ratio is complicated to design the power amplifier and also increas...

A coherent optical beam forming network principle using phase-locked semiconductor lasers as sources is presented. For this scheme the spectral purity of the intermediate frequency derived from mixing the signals from two semiconductor lasers is considered and the relationship between the linewidths of the lasers in a satellite transmitter and the phase error at the detector of a microwave diff...

This paper proposes two novel beam-forming methodologies, which employ passive RF devices to enhance received signal through a passive, scattering based beam forming. Currently available backscattering systems, e.g. the radio frequency identification (RFID), suffer from a poor communication in an environment with multiple passive devices. The intermediate antennas create severe scattering envir...

We propose a diagnostic technique to detect instability waves in a round jet using a conical microphone array. The detection algorithm is analogous to the beam-forming technique, which is used with a far-field microphone array to localize noise sources. By replacing the reference solutions used in the conventional beam-forming with eigenfunctions from a linear stability analysis, the amplitude ...

Advanced satellite communications system needs large-scale satellite-borne antenna with a function of beam steering and/or multiple spot beams to cover wide service area with high antenna gain. Although phased array antenna is very useful for the feed for the large reflector to satisfy the requirements above, it generally causes increase in the equipment weight, feed loss, and complexity in bea...