A semiconductor transistor structure with increased mobility in the channel zone and a method of its fabrication are described. The transceiver also includes a wake-up detector for selectively waking up the microcontroller connected to the transceiver, and one or more switches operable to put the transceiver in a first mode of operation. An aggregation frame makes more efficient use of the wireless communication resources. Portions of the dielectric layer are removed such that the dielectric layer becomes perforated and a portion of the conductive bond pad is exposed. The cryogenically cooled RF coil structure comprises a sealed structure constructed of non-conducting material and adapted for containing a cooling substance and at least one RF coil disposed integrally in contact with the sealed structure such that sealed structure and integrally disposed RF coil are disposed about an object to be imaged.