Showing papers on "Bessel filter published in 1979"

Synthesis of monotonic passband sharp cutoff filters with constant group delay response

Abstract: A new technique is developed for determining nonminimumphase filter functions that can meet stringent specifications for both the attenuation and group delay characteristics. The organization of a computer program for automatic computation of these transfer functions according to any prescribed specifications is described. As revealed by comparison with some other known approximation techniques, the method proposed is very effective, especially when the delay equalization to within a prescribed error is not required over the entire passband.

Group Delay Estimation with Wideband Signals

Abstract: A new formula for the group delay of a network is derived. The formula is not restricted to narrow-band signals and is valid up to quite large bandwidths. A simple and very sensitive technique for group delay measurement, based on this new relation, is described.

Transitional rational filters

Abstract: Transitional rational XY filters (TRXY) with rational transfer functions are considered having characteristics that vary smoothly from those of filter X to those of filter Y as certain parameters are varied continuously. The X and Y filters are chosen as various combinations of the ultraspherical rational filter, the generalized Bessel rational filter and the inverse Chebyshev filter.

Fourier‐Bessel series solution for potential and intensity field of open electron optical systems with rotational symmetry, in terms of I0 Bessel functions

Abstract: A Fourier‐Bessel series representation in terms of I0 Bessel functions is given for the potential distribution in certain open Einzel‐ or immersion‐type electrostatic configurations with rotational symmetry described by φ (A,z) =F (z), 0

Computation of bessel functions of complex argument using their zeros

Abstract: A method for calculating values of Bessel functions of the first kind Jv (z) is described, which requires only a knowledge of their zeros in order to evaluate a simple analytic formula. A simple error formula is derived and its behaviour as a function of z and v are described. Numerical examples of the error involved in approximating Jv (z) for and v=0,1 are given.

A maximally flat group delay recursive digital filter with improved passband magnitude response

Abstract: A technique is proposed for the design of a recursive digital filter with maximally flat responses in both magnitude and group delay. In comparison to the previous designs [1]-[3], the magnitude and group delay always show smooth responses no matter what the difference is in the polynomial degrees of the numerator and denominator.

Filters with variable order and virtually independent time delay

Abstract: An all-pole filter and a filter with a rational transfer function are considered, both of which are generalizations of the Bessel filter. It is shown that by properly selecting the generalizing parameters, the time delay in each case is, for low frequencies, very nearly independent of the order of the filter. It is possible, also, to select the parameters so that a nearly constant time delay is maintained for low frequencies while the filter order is varied to obtain a number of amplitude responses.

Filter coefficients of high-pass and band-elimination recursive digital filters with a maximally flat group delay

Abstract: The design technique for a recursive digital filter with a maximally flat group delay at an arbitrary specified frequency is known. It is shown here that, for certain cases, the filter coefficients for high-pass and band-elimination recursive digital filters with a maximally flat group delay can be expressed in closed forms.

Correction to "Comments on 'In Impedance of Coaxial Line to Circular Waveguide Feed'" (Letters)

Abstract: In the above correspondence the expression of the Hankel asymptotic approximation for Bessel functions on page 284, should read without the subscripts "np" in the argument x of the Bessel functions as: