MEMS-SWITCHED RECONFIGURABLE MULTI-BAND ANTENNA : DESIGN AND MODELING

Reconfigurable multi-band antennas are attractive for many military and commercial applications where it is desirable to have a single antenna that can be dynamically reconfigured to transmit and/or receive on multiple frequency bands. Such common-aperture antennas find applications in space-based radar, unmanned aerial vehicles (UAVs), communication satellites, electronic intelligence aircraft and many other communications and sensing applications. The reconfigurable antenna can be envisioned as an array of microstrip patch elements that are resonant at the highest operation frequency fmax, that can be connected together using switches to form groups of elements that are resonant at several lower frequencies fmax/? i, where ? i, i= 1,2,...,N are scale factors related to the element groupings. It is easy to envision that an array that can be reconfigured to operate over a relative bandwidth of 100:1 would require hundreds and perhaps thousands of switches. Hence, a critical component of the reconfigurable antenna is the switches or relays used to interconnect the patch elements. Moreover, the efficiency (insertion loss) and effectiveness (isolation) of the switches will dictate the overall performance of the reconfigurable antenna array. One type of switch that has received a lot of attention recently as a candidate for reconfigurable antennas is the microelectromechanical system (MEMS) switch. In this paper, we present design and modeling details for a prototype reconfigurable muli-band antenna using MEMS switches. A general adaptive reconfigurable (GARF) feed methodology is employed to allow various antenna configurations to have independent feed structures, and hence be tuned independently. We present computer simulations and measurement results for a small reconfigurable patch module (RPM) that may be used as a building block for a larger array in a tile architecture.