Low-Cost Ball-Pen Gap Waveguide With Nearly Zero Friction for Sliding Movements

This letter presents a novel easy-to-manufacture ball-pen gap waveguide (GW) by utilizing commercial low-cost ball pens to have mechanical reconfigurability. The proposed ball-pen GW consists of a perforated bottom metal plate with ball pens’ tips inserted and a flat top plate. Compared with the other noncontact GWs with bed-of-pins structures obtained by milling, the realization of the new ball-pen GW requires only drilling holes on the bottom plate for inserting ball-pen tips to obtain the electromagnetic bandgap property, making it low cost. The more important advantage of the ball-pen GW is to make use of the balls of the ball-pen tips to realize smooth low-friction sliding movements for the mechanical reconfiguration. For the sake of verification, a double 90° bend of the ball-pen GW has been designed, manufactured, and measured. Both simulated and measured results demonstrate its excellent transmission performance and the movable property.