We describe and demonstrate an electro-optic technique to simultaneously downconvert and demodulate vector-modulated millimeter-wave signals. The system uses electro-optic phase modulation and optical filtering to perform harmonic downconversion of the RF signal to an intermediate frequency (IF) or to baseband. We demonstrate downconversion of RF signals between 7 and 70-GHz to IFs below 20-GHz...

We demonstrate a Single-Mode (SM) Large-Mode-Area (LMA) ytterbium-doped PCF rod fiber laser with stable and close to diffraction limited beam quality with 110W output power. Distributed-Mode-Filtering (DMF) elements integrated in the cladding of the rod fiber provide a robust spatial mode with a Mode-Field-Diameter (MFD) of 59μm. We further demonstrate high pulse energy Second-Harmonic-Generati...

Increasing application of non-linear loads cause power quality issues in power system. Even though the distributed generation helps to meet the increase in power demand, they enhance the power quality problem of grid. They need power electronic interface and produce fluctuating power output hence give rise to voltage fluctuations, voltage sags, swells, harmonic distortion etc. This paper discus...

The problem of estimating time-varying harmonic components of a signal measured in noise is considered. The approach used is via state estimation. Two methods are proposed, one involving poleplacement of a state observer, the other using quadratic optimization techniques. The result is the development of a new class of filters, akin to recursive frequency-sampling filters, for inclusion in a pa...

This paper is concerned with the acoustical analysis on sub-harmonic of glottal source in Mandarin tones. The methods used in this research are: 1) extracting glottal source of tones by inverse filtering; 2) analyzing subharmonic and spectrum tilt by FTT; 3) simulating the double peak pulse by 4 functions and describing the natures of them in both time and frequency domains. There are 3 conclus...

Power supply systems in telecommunication applications employ several parallel-connected ac-to-dc and dc-to-dc power converters. Such a system offers modularity, redundancy, and is easily scalable to higher power levels. Such parallel-connected systems normally consist of several single-phase powerfactor-correction (PFC) stages connected to the same input utility. In this paper, a modular singl...

An adaptive digital filtering system is developed for low-frequency audio transducers to reduce nonlinear transducer responses in an effort to eliminate audible harmonic distortion. A Spectrum PC/C5X digital signal processing (DSP) board is used to implement the filtering algorithm , and a piezoelectric accelerometer is used to measure the transducer's movement. The filter is based on the least...

We demonstrate generation of two synchronized picosecond pulses at different wavelengths near 778 nm by frequency doubling of a femtosecond pulse. We use nonlinear frequency filtering with quasi-phase-matching gratings, which allow us to obtain second-harmonic spectral intensities that are higher than the spectral intensities of the pump.

An algorithm for selecting the optimal sampling frequency of continuous signals based on the information optimality of the time series of samples is proposed. The effectiveness of the algorithm is shown on the example of solving the problem of determining the relative time delay of signals in multichannel transmission based on an algorithm of digital filtering of harmonic filling.

The main aim of the paper is to present the analytical solution of the Belavkin quantum filtering equation for damped harmonic oscillator being initially in the squeezed coherent state for diffusion observation with complex white noise. The comparison of the a priori and a posteriori mean value of the optical quadrature operators and the photon number operator is given.