1. Frequency Reconfigurable Slotted Patch Antenna for Mobile Applications using MEMS Cantilever Switch
Sruthi Dinesh1, Dr.Aanandan C.K.1
Department of Electronics, Cochin University of Science and Technology, Kochi, Kerala
Introduction: The study presents the design and simulation of a frequency reconfigurable antenna which can support several mobile application frequencies in one platform by switching MEMS cantilever switches on and off.
Results:
Figure 3. S11 for switches in off state
S11:-30.5 db at 1.8 GHz (GSM frequency)
: db at 5.4 GHz (Wifi frequency)
Figure 1. Frequency reconfigurable antenna with cantilever switches
Computational Methods: Used the MEMS module of COMSOL MultiPhysics.
Vpi :pull-in voltage, k: spring constant of movable plate, €0:permittivity of free space, A: beam area, d0: distance between movable and fixed plates .
Figure 4. S11 for switches in on state
S11:-12 db at 2.4 GHz (Wifi frequency)
: -21 db at 3.26 GHz (WiMaX frequency)
: db at 5.6 GHz (Wifi frequency)
Figure 2. Simulated cantilever beam in COMSOL
Cantilever beam dimensions:
Length: 300 µm, width:20 µm, thickness: 200 nm, air gap: 2 µm, pull-in voltage: 6.1 V
Conclusions: Pull-in voltage of cantilever of designed dimensions could be obtained from COMSOL simulation. Frequencies for different mobile applications can be attained by integrating cantilever switch of low insertion loss and high isolation with the antenna structure.
References:
Greg H.Huff and Jennifer T.Bernhard, Integration of Packaged RF MEMS Switches with Radiation Pattern Reconfigurable Square Spiral Microstrip Antennas, IEEE Transactions on Antennas and Propagation, Vol.54, No.2, page
Figure 3. Displacement of cantilever tip as a function of applied voltage.