Tapered slot antenna array with parallel plate waveguides

Tapered slot antennas (TSA) are adequately applicable to wideband phased array antennas due to their ultra wide bandwidths. However, a significant degradation of VSWR performance is observed when a smaller aperture is adopted to suppress grating lobes for the phased array. To overcome the difficulty, a new tapered slot antenna is proposed; tapered slot antenna with a parallel plate waveguide (PPTSA). The PPTSA is capable of providing the ultra-wide bandwidth characteristics even when the width of the aperture is less than a half wavelength at the lowest operating frequency. Major performances of a single PPTSA was presented through numerical simulations and experiments in the previous report. In this paper array performances of PPTSA is investigated. A new configuration to suppress ripples from the ground plane is proposed by introducing cut-off waveguides close to the PPTSA. Measured and calculated data for VSWR and radiation pattern are also presented.