Accession Number : AD0015392


Title :   SOLUTION OF THE APPROXIMATION PROBLEM OF NETWORK SYNTHESIS WITH AN ANALOG COMPUTER


Corporate Author : POLYTECHNIC INST OF BROOKLYN NY MICROWAVE RESEARCH INST


Personal Author(s) : Lehr, Stanley


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/015392.pdf


Report Date : 18 Jun 1953


Pagination or Media Count : 40


Abstract : An electrostatic analog computer was built which is capable of approximating to the real or imaginary part as well as to the amplitude of the required function. The approximating function is described in terms of its pole and zero locations and a multiplicative constant. The poles and zeros are moved around in the conducting medium until the desired immittance is obtained. The method is one of trial and error, but the amount of computational work is greatly reduced as compared to that normally encountered in the analytical approach to the approximation problem. The perturbation technique, as well as the proper use of the logarithmic transformation, simplifies the approach. The continuous scan feature of the analog makes it possible to observe immediately changes in the approximation, and solutions are obtainable in a short time. The approach from the real part leads to realizable driving-point functions, while economization reduces the number of elements. Small adjustments in the positions of the critical points effected substantial improvements. Approximations were carried out to the transcendental function arising from the input admittance of a shortened transmission line. The synthesized networks gave smaller deviations than known expansions of partial fractions, and the analog gave networks with fewer elements.


Descriptors :   *RADIO EQUIPMENT , *ANALOG COMPUTERS , *CIRCUIT ANALYSIS , REDUCTION , PERTURBATIONS , LOGARITHM FUNCTIONS , ELECTROSTATICS , CONTINUOUS PROCESSING , TRANSFORMATIONS , MULTIPLICATION FACTOR , ADMITTANCE , TRANSMISSION LINES , TRANSCENDENTAL FUNCTIONS , COMPUTATIONS , SYNTHESIS


Subject Categories : Radio Communications
      Computer Programming and Software
      Electricity and Magnetism


Distribution Statement : APPROVED FOR PUBLIC RELEASE