Showing papers on "Bessel filter published in 2008"
TL;DR: Two Matlab programs are provided to compute integrals of the form ∫ 0 ∞ e − c x x m ∏ i = 1 k J ν i ( a i x ) d x and ∫0 ∞ x m r 2 + x 2 ∏i =1 k Jη i (a i x) with the Bessel function of the first kind and (real) orderν i .
28 citations
TL;DR: In this paper, higher order numerical quadratures for the integration of systems containing Bessel functions are presented. But they are based on a truncation of the asymptotic series and extend an approach in the work of Levin.
26 citations
TL;DR: In this paper, binary optical elements (BOE) are designed for generating Bessel beams at mm- and sub mm- wavelengths, which combine a GA for global optimization with a two-dimensional finite-difference time-domain (2-D FDTD) method for rigorous electromagnetic computation.
Abstract: In this paper, binary optical elements (BOE’s) are designed for generating Bessel beams at mm- and sub mm- wavelengths. The design tool is to combine a genetic algorithm (GA) for global optimization with a two-dimension finite-difference time-domain (2-D FDTD) method for rigorous electromagnetic computation. The design process for converting a normally incident Gaussian beam into a Bessel beam is described in detail. Numerical results demonstrate that the designed BOE’s can not only successfully produce arbitrary order Bessel beams, but also have higher diffraction efficiencies when compared with amplitude holograms.
22 citations
TL;DR: In this article, the authors extended the Bessel functions from the real number field to the complex number field and defined a new type of Bessel function, called the phased Bessel Function.
Abstract: In the study of photon-state transitions, we found a natural extension of the first kind of Bessel functions that extends both the range and domain of the Bessel functions from the real number field to the complex number field. We term the extended Bessel functions as phased Bessel functions. This extension is completely different from the traditional “analytical extension”. The new complex Bessel functions satisfy addition, subtraction, and recurrence theorems in a complex range and a complex domain. These theorems provide short cuts in calculations. The single-phased Bessel functions are generalized to multiple-phased Bessel functions to describe various photon-state transitions.PACS Nos.: 02.30.Gp, 32.80.Rm, 42.50.Hz
17 citations
17 Nov 2008
TL;DR: It is shown that even though Bessel filters pass more adjacent channel interference, they result in a significantly lower Bit Error Rate (BER) and insertion loss than the other filter types.
Abstract: This paper investigates the Bit Error Rates (BER) obtained using different filter types for RF front ends for WCDMA-UMTS mobile radio systems. Most Base Stations use Chebychev or Cauer-Chebychev filters. This paper compares the use of Bessel, Butterworth and Chebychev filters for use as single channel filters in a WCDMA-UMTS radio system. It is shown that even though Bessel filters pass more adjacent channel interference, they result in a significantly lower Bit Error Rate (BER) and insertion loss than the other filter types.
13 citations
TL;DR: In this article, the authors extended the analytic treatment of Bessel functions of large order and/or argument and examined uniform asymptotic Bessel function expansions and showed their accuracy and range of validity.
Abstract: In this work, we extend the analytic treatment of Bessel functions of large order and/or argument. We examine uniform asymptotic Bessel function expansions and show their accuracy and range of validity. Such situations arise in a variety of applications, particularly the Fourier transform (FT) of the gravitational wave (GW) signal from a pulsar, global parameter space correlations of a coherent matched filtering search for continuous GWs from isolated neutron stars and tomographic reconstruction of GW LISA sources. The uniform expansion we consider here is found to be valid in the entire range of the argument.
8 citations
Proceedings Article•
01 Sep 2008
TL;DR: In this paper, a self-adjusting time delay estimator operating in the discrete time domain on a sinusoidal signal is presented based on an original concept of Hilbert transform filter aggregated with a fractional delay filter.
Abstract: In the paper a novel solution of a self-adjusting time delay estimator operating in the discrete time domain on a sinusoidal signal is presented. The proposed solution is based on an original concept of Hilbert transform filter aggregated with a fractional delay filter. The aim is to substitute a series connection of a pair of filters: the Hilbert transform filter and the filter of adjustable fractional delay, by a compound one-stage filter in order to reduce the numerical load of processing. The performance as well as the numerical complexity of our self-adjusting time delay estimator is analysed and illustrated by the results of its operation in presence of noise.
2 citations
TL;DR: In this article, an analog of the Whittaker-Kotel-nikov-Shannon theorem on the basis of the harmonic Fourier-Bessel analysis was obtained, where generalized Bessel translations are used instead of the usual translations.
Abstract: In this paper, we obtain an analog of the Whittaker-Kotel’nikov-Shannon theorem on the basis of the harmonic Fourier-Bessel analysis. We construct a new interpolation formula for a class of entire functions of exponential type in which generalized Bessel translations are used instead of the usual translations.
2 citations
07 Feb 2008
TL;DR: In this paper, a gain clamping approach is used to flatten the gain of erbium doped fiber amplifier (EDFA), so that it could be used for long haul wave length division multiplexing (WDM) communication system to maximize the transmission distance.
Abstract: In this paper a gain clamping approach is used to flatten the gain of erbium doped fiber amplifier (EDFA), so that it could be used for long haul wave length division multiplexing (WDM) communication system to maximize the transmission distance. The gain clamping is done through filters like Multi-stage Lorentzian filter, Super Gaussian filter, Bessel filter, and Raised cosine filter with bandwidth of 500 GHz at center frequency 193.41 THz. It has been inferred from the simulation results that first order notch type super Gaussian filter is most appropriate for the transmission of 16 times 40 Gb/s WDM optical DPSK data with channel spacing 200 GHz, over 518 km. The quality factor obtained for all the channels is above 15 dB.
2 citations
01 Dec 2008
TL;DR: It is shown that even though Bessel filters pass more adjacent channel interference, they result in a significantly lower BER and insertion loss than the other filter types, even for amplifiers with moderate distortion levels.
Abstract: This paper investigates the bit error rates (BER) obtained using different filter types and the effect of amplifier distortion for RF front ends for WCDMA-UMTS mobile radio systems. Most Base Stations use Chebychev or Cauer-Chebychev filters. This paper compares the use of Bessel, Butterworth and Chebychev filters for use as single channel filters in a WCDMA-UMTS radio system. It is shown that even though Bessel filters pass more adjacent channel interference, they result in a significantly lower BER and insertion loss than the other filter types, even for amplifiers with moderate distortion levels.
1 citations
TL;DR: In this paper, a method for fast computation of the Bessel transform of a function of a certain type was proposed, which relies on the approximation of the original function by a linear combination of exponentials with prespecified exponents.
Abstract: We consider the direct problem of aeroelectrosounding for a layered medium. The specific feature of this problem is that its solution is representable as a Bessel transform of a function ƒ of a certain type. We have developed and implemented a method for fast computation of the Bessel transform of such functions. The method relies on the approximation of ƒ by a linear combination of exponentials with prespecified exponents. The Bessel transform of the original function ƒ is computed analytically as the Bessel transform of the approximating linear combination. Numerical computations have been carried out.
08 Dec 2008
TL;DR: In this article, the second-order Bessel function is used to simulate the delay of microwave transistors and the simulation times are comparable with those obtained without the delay model, and the proposed model does not create spurious oscillations that are typical for any LC approximation.
Abstract: At present, most of simulation programs can characterize gate delays of microwave transistors. However, the delay is mostly approximated by means of a first-order differential equation only. In the paper, a more accurate way is suggested which is based on an appropriate second-order Bessel function. The delay model is implemented to a slightly but efficiently modified classic MESFET model. The proposed model does not create spurious oscillations that are typical for any LC approximations, and the simulation times are comparable with those obtained without the delay model. Properties of the implementation of the second-order Bessel function are demonstrated by an analysis of a tunable distributed microwave oscillator.
Journal Article•
TL;DR: The article introduced one kind using the MATLAB signal processing toolbox (Signal Processing Toolbox) the fast effective design the conventional analogue filter design method which is composed by the software.
Abstract: The traditional analogue filter design process is complex,the computation work load is big,the filter characteristic adjustment difficulty,has affected its application.The article introduced one kind using the MATLAB signal processing toolbox (Signal Processing Toolbox) the fast effective design the conventional analogue filter design method which is composed by the software.Using the MATLAB design filter,may contrast the design request and the filter characteristic adjustment parameter as necessary,direct-viewing simple,enormous reduced the work load,is advantageous optimization which designs in the filter.
TL;DR: In this article, for Bessel polynomials, the authors obtained asymptotics uniform on compact sets inside some domain and uniform on subsets of some curves, respectively.
Abstract: In this paper, for Bessel polynomials, we obtain asymptotics uniform on compact sets inside some domain and uniform on compact subsets of some curves.
TL;DR: In this article, the Riccati-Bessel functions are derived by eliminating the factors responsible for the inverse radius and inverse square radius laws of wave power per unit area of wavefront.
Abstract: Intrinsic waveforms associated with cylindrical and spherical Bessel functions are obtained by eliminating the factors responsible for the inverse radius and inverse square radius laws of wave power per unit area of wavefront. The resulting expressions are Riccati–Bessel functions for both cases and these can be written in terms of amplitude and phase functions of order v and wave variable z. When z is real, it is shown that a spatial phase angle of the intrinsic wave can be defined and this, together with its amplitude function, is systematically investigated for a range of fixed orders and varying z. The derivatives of Riccati–Bessel functions are also examined. All the component functions exhibit different behaviour in the near field depending on the order being less than, equal to or greater than 1/2. Plots of the phase angle can be used to display the locations of the zeros of the general Riccati–Bessel functions and lead to new relations concerning the ordering of the real zeros of Bessel functions and the occurrence of multiple zeros when the argument of the Bessel function is fixed.