INFINITE PLANAR AND COLLINEAR ARRAYS OF CYLINDRICAL ANTENNAS

The active impedance and current distribution on a cylindrical antenna in a uniform, infinite, planar or collinear array are examined. A Fourier series for the antenna current is derived by relating the electric field variation in the gaps between adjacent collinear elements to the current. The electric field in the gaps is expanded in a series of Chebyshev polynomials whose coefficients are found by solving the set of algebraic equations obtained by enforcing at a number of points the boundary condition that the current vanish in the gaps between the ends of adjacent elements. The analysis is suitable for any combination of element length and scan angle, provided that the distance between the ends of adjacent collinear elements is comparable to or less than the element length. Results are compared with those based upon sinusoidally distributed currents and discrepancies are noted for arrays with closely spaced collinear elements and for wide H-plane scan angles of planar arrays.