High-gain tapered monopulse antenna based on octuple excitation method in diffusion bonding technology at W-band

The authors present the design, fabrication and testing of a W-band monopulse antenna. This antenna consists of three main building blocks: an array with 48 x 48 slots, a tapered corporate-feed network and a comparator. The comparator has four input ports to generate sum and difference patterns in orthogonal cardinal planes for monopulse operation. A novel octuple excitation is adopted for the corporate network to achieve a side lobe level lower than -20 dB for the sum patterns and simultaneously reduce drastically the manufacturing complexity. Diffusion bonding technology is used for fabrication. Twenty-four etched copper sheets with a thickness of 0.2 mm are stacked to realise the prototype. The total size of the antenna is 40.76x40.76x1.51 lambda 03 $40.76\times 40.76\times 1.51{\lambda }_{0}<^>{3}$, with lambda 0 being the wavelength at the centre frequency (94 GHz). The antenna presents an isolation better than 12 dB among the input ports in the 84-100 GHz band. The realised measured gain is 40.7 dBi at 94 GHz. The measured 3-dB gain bandwidth is 17.4%. The difference patterns at 94.0 GHz present null depths of -24.0, -18.0, -17.5, and -17.4 dB, in the E-, H-, 45 degrees-, and 135 degrees-planes, respectively. The authors present the design, fabrication and testing of a highly directive antenna at W-band for MPT. Diffusion bonding is used to integrate a wideband planar monopulse comparator with a novel corporate feeding network (CFN) used to feed a 48 x 48 slot antenna array. The measured realised gain is more than 35 dBi across the full frequency band. image