An arrangement of coaxial windings is provided. The arrangement includes primary and secondary windings as air-core pulse transformers having insulation and winding arrangement for efficient energy transfer to the secondary winding. The secondary winding is wound with a central metallic core to include a coaxial transmission line with it and is configured to deliver a rectangular pulse across its terminals. The arrangement also includes a coaxial feeding arrangement for the primary winding with a central coaxial terminal connecting to one end of an adjustable primary closing switch electrode so as to have variable voltage feed input corresponding to its load requirement.

A device may include a substrate and an oscillation circuit integrated with the substrate. The oscillation circuit may include a field-emission-based vacuum transistor. The oscillation circuit may also include a capacitive transducer. An oscillation frequency of the oscillation circuit may be indicative of a magnitude of a temperature, a pressure, or a vibration at the capacitive transducer.

A device may include a substrate and an oscillation circuit integrated with the substrate. The oscillation circuit may include a field-emission-based vacuum transistor. The oscillation circuit may also include a capacitive transducer. An oscillation frequency of the oscillation circuit may be indicative of a magnitude of a temperature, a pressure, or a vibration at the capacitive transducer.