Frequency performance enhancement of resonant slotted waveguide arrays through the use of wideband radiators or subarraying

Resonant arrays of waveguide slots suffer from severe bandwidth limitations, which are caused by the frequency dependence of the slot properties, and by the shift in the positions of the standing-wave peak relative to the slot positions. In this paper, the effects of the use of wideband radiators and subarrays are assessed by means of two representative examples. Results indicate that the potential advantage presented by the utilization of wideband slot radiators is limited while employing subarraying in the design of planar arrays is the most effective way of improving the bandwidth. (C) 1999 John Wiley & Sons, Inc.