INV-14097
There is increasing demand for highly reconfigurable radio frequency (RF) systems capable of operating in the severely crowded and rapidly changing modern commercial and military spectral environment, at a reduced overall component count and with a reduced development cost compared to conventional multi-band radios. In this context, the implementation of high quality factor (Q) micro acoustic resonators with monolithically integrated switching and frequency reconfiguration functionalities will dramatically reduce loss associated with the filtering element. This enables new radio architectures with enhanced spectrum coverage and overcomes the lack of such high performance and intrinsically reconfigurable components.
High Q MEMS resonant devices enable the implementation of low insertion loss filters in a very small form factor. Different MEMS resonator technologies based on electrostatic or piezoelectric transduction have been investigated. Nevertheless, the current filtering solutions based on AlN micro acoustic resonant devices cannot be dynamically reconfigured to operate at different frequencies, orders, and bandwidths.
This invention presents the concept that integration of phase change material switches with piezoelectric MEMS resonators can introduce reconfigurability and programmability to these MEMS devices. This integration of the phase change material technology and the piezoelectric MEMS resonator designs can be accomplished simply and includes one additional mask step during the fabrication process to add ON/OFF switching capability and capacitive tuning to the MEMS resonators. With several additional steps and some design alterations, the piezoelectric MEMS resonators are monolithically integrated with the phase change material to create resonator designs and filter architectures that provide frequency programming, capacitive tuning, and ON/OFF switching for individual resonators, sections of filter banks, or entire filter banks.
This new technology addresses the demand for highly reconfigurable radio frequency (RF) systems, capable of operating in the severely crowded and rapidly changing modern commercial and military spectral environment, at a reduced overall component count and with a reduced development cost compared to conventional multi-band radios.
The inclusion of the phase change material in the fabrication of piezoelectric MEMS resonators requires a deposition sputtering technique with RF source or DC source with pulse. The phase change material is then be patterned on the MEMS devices using lithography and liftoff techniques. An insulation layer is required to contain and protect the phase change material.