Design of a 5:1 bandwidth stripline notch array from FDTD analysis

A 5:1 bandwidth stripline notch array antenna is designed from parametric investigations of flare and feed dimensions. The finite-difference time-domain (FDTD) method is employed to perform the parametric studies. Both linear and planar single-polarization arrays are considered with half-wavelength element spacing at the highest frequency. The linear array elements depend upon E-plane element mutual coupling to achieve wideband behavior. Edge elements, which cannot benefit from full E-plane coupling, are shown to maintain good transmit performance with the application of amplitude tapering. The planar array is shown to have a scanability (active VSWR <2) averaging 51/spl deg/ off broadside in the E-plane and exceeding 60/spl deg/ in the H-plane. As an infinite planar array, the antenna is predicted to have a bandwidth exceeding 7:1 on broadside. Measurements are in good agreement with the computations.