Best Paper Award

  In this paper, a two-dimensional monopulse circuit and a 16x16-element corporate-feed slot array antenna are integrated into one body by a plate-laminating waveguide structure and diffusion bonding in the 71-86 GHz band. The monopulse circuit creates sum and difference patterns and the arrival direction of the signal is estimated by the output difference between these two patterns. It is important to achieve deep null as much as possible at the boresite in the difference pattern. In this paper, the monoopulse circuit is realized by a cascade of two-stage magic T. The structural symmetry of the magic T guarantees balanced outputs at any frequency. In the slot array antenna, the full corporate-feed gives wideband characteristics by feeding all the elements in equal amplitude and phase irrespective of frequency. Low-loss electrical contact is achieved by laminating several metal plates with different waveguide structures and bonding with mechanical pressure and high temperature in a vacuum. The diffusion bonding of laminating plates is one method to make a complicated hollow-waveguide multi-layer structure simply in the millimeter-wave band. High antenna efficiency is achieved by using no dielectric and minimizing conductor loss because of large waveguide height not to excite higher modes. These advantages such as deep null, wideband and high antenna efficiency are demonstrated by the design, the fabrication and the measurement. Multiplexing transmission is possible by facing two sets of antennas to each other in the non-far region based on the orthogonality of field in the rectangular coordinate system. High data rate transmission can be expected due to the wideband characteristic of the antenna.
  As stated above, this paper proposes one low-loss integration of a beam-switching circuit and a slot array antenna in the millimeter-wave band by the diffusion bonding of laminating plates and the effectiveness of the design is also confirmed through measurements. Accordingly, this paper deserves the IEICE Best Paper Award.