Conical and Broadside Beam Switching Micromachined Antenna at 26GHz

A pattern switchable micromachined antenna operating at 26 GHz is proposed. The antenna consists of a microstrip circular patch and a ring antenna placed concentrically. The antenna can switch between conical and broadside radiation patterns by exciting TM21 mode of the ring and TM11 mode of the circular patch, respectively. The ring is excited by two ports and the patch is excited parasitically. Two different techniques are proposed to switch between these patterns. In the first approach in phase and out of phase feeding of the antenna is employed whereas in the second approach both ports are fed in phase and the beam control is achieved by inserting two slots to the ring. The absence or presence of the slot can be controlled by placing a switch at the center of each slot. Hence, switches control pattern selection in this configuration.