SAW filters with reconfigurable transition bands

Abstract

A surface acoustic wave (SAW) filter with a reconfigurable upper transition band is presented. This is achieved through the reuse of SAW resonators by incorporating single pole double throw (SPDT) GaAs switches. The reconfigurable filter with two states is demonstrated around the 700 MHz frequency range currently allocated to LTE bands. The EM simulation results are obtained from a 3D EM model built in Ansys HFSS. Fabricated SAW dies and GaAs switch dies are assembled in a 7×9×1.4 mm 3 SMP package. Measured results agree well with the EM simulations. In the first state the center frequency is 687.8 MHz and the BW is 2.4%. In the second state the center frequency is 691.1 MHz and the BW is 3.4%. The shift in the upper transition band is 0.95%. © 2012 IEEE.