RF MEMS 스위치를 이용한 재구성 슬롯 안테나의 설계

Abstract

This paper presents reconfigurable slot antenna using a voltage-controlled MEMS switches. The slot antenna operates at its nominal frequency as determinedly the slot length. The tuning of the operating frequency is realized by varying the electrical length of the antenna, which is controlled by MEMS switches, which have different actuation voltages.

Three-pairs of MEMS switches are symmetrically placed in slot. When the MEMS switch is in the ON-state, they essentially behave as equivalent short circuits reducing the length of the slot. On the other hand, when the MEMS switch is in the OFF-state(bias voltage=0V), the length of the slot remains unchanged. As a result, different resonant frequencies are shown at each switch state. The length and the width of the slot are 5.6mm and 200㎛, respectively.

Until now, many researchers have reported the development of MEMS switches for operation at RF and microwave frequencies. A actuation voltage of MEMS switches can be determined by switch geometry and air-gap height between a movable plate and a bottom plate. This paper using Cantilever MEMS switch. A width and a thickness of the cantilever are 100㎛ and 1㎛, respectively. The length of the cantilever is different at the position of switch 240㎛, 320㎛, 400㎛ in the slot in order to be able to actuate each switch at different DC voltage.

The process used in this work was very simple, reproducible, controllable, and compatible with CMOS fabrication process. The fabricated RF switch showed an applicability other RF systems.