SYSTEMS AND METHODS OF OPERATION OF CAPACITIVE RADIO FREQUENCY MICRO-ELECTROMECHANICAL SWITCHES

• Main Authors: DE WILD, Nico Maris Adriaan, SHULEPOV, Sergei, LOEBL, Hans-Peter, BUDZELAAR, Franciscus Paulus Maria, TIMMERMANS, Petrus Henricus Maria, DIRKSEN, Peter
• Format: Patent
• Language: English; French; German
• Published: 30.10.2019
• Subjects: FOR PERFORMING MECHANICAL WORK IN GENERAL; GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL; METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICALVIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY; PERFORMING OPERATIONS; TRANSPORTING

Disclosed are systems and methods of operation for capacitive radio frequency micro-electromechanical switches, such as CMUT cells for use in an ultrasound system. An RFMEMS may include substrate, a first electrode connected to the substrate, a membrane and a second electrode connected to the membrane.In some examples, there is a dielectric stack between the first and second electrodes. The dielectric stack design minimizes drift in the membrane collapse voltage. In other examples, a voltage supply coupled to an ultrasonic array compressing the CMUT cells is adapted to provide a sequence of voltage profiles to the electrodes of the CMUT cell, wherein each profile includes a bias voltage and a stimulus voltage, and wherein a polarity of each subsequent voltage profile in the sequence is opposite to the polarity of the preceding profile. In another example, there is a capacitance sensing circuit provided, which is arranged to determine a drift voltage of the CMUT cell.