Fixed frequency slotted waveguide beam reconfigurable antenna for mmWave application

Summary form only given. Millimeter wave antennas are of recent interest due to their commercial applications for high data-rate links. However, at mm-waves, losses are of major concern. To mitigate losses, slotted waveguide antennas have been proposed due to their small power loss and low cost. For airborne transceivers, such antennas typically perform beam steering via frequency scan. However, beam steering using frequency variation is not suitable here since the beam direction is not fixed across the signal bandwidth, causing data rate variations.In this paper we propose a simple and low cost antenna configuration that employs slotted waveguide aperture in single layer slotted waveguide configuration. Scanning is performed at a fixed frequency, by modifying the propagation constant. To modify propagation constant (β) within the waveguide, corrugations are added to the backplane of the slotted aperture. Real time variation of β is then achieved by moving the corrugations up and down. For precise and repeatable corrugation movement; piezo motors are proposed. An optimization study of corrugation width (w), periodicity (d) and height (h) will be presented. Leakage losses are of course expected due to gap between sliding corrugations and the backplane wall. These losses can be minimized by optimizing various corrugation parameters. Fabrication issues and approaches will also be discussed at the presentation. To achieve the broadest possible bandwidth, dispersion in waveguides should be minimized. To this end, ridge gap waveguides have been demonstrated to show dispersion-less quasi TEM-like propagation. Such ridge waveguides also make excellent choice for high frequency application because of fabrication ease. A study exploring waveguides for beam scanning slotted antennas will be presented.