Antenna Theory by Numeric Field Calculations

Computation of the current distribution and the input impedance of linear antennas and collinear antenna system by rigorous numeric methods. Corresponding formulae derived by extensive analytic calculations are implemented in FORTRAN program packages called GALNEC 1.1, GALNEC 2 and GALNEC 3. The method is based on the electric field integral equation, which is solved by the method of moments and Galerkin's method. End caps are hemispheres joined smoothly to the cylindrical main body. Basis and weight functions are trigonometric subdomain functions. Matrix elements are evaluated rigorously. The main object is to obtain accurate results for some simple test cases with which other codes may be compared for checks. Numeric design of an annular ring antenna fed by a directional coupler to emit circularly polarized waves.