Abstract: An antenna assembly for use with a level measurement device for measuring the level of a material held in a container is provided. The antenna assembly includes an upper section for coupling to the level measurement device, and an antenna for transmitting energy pulses emitted by the level measurement device and receiving energy pulses reflected by the material in the container. A transducer module is disposed between the upper section and the antenna. A controller is operably connected to the transducer module, the transducer module being responsive to control signals of the controller for activating the transducer module such that the transducer module, when activated by the controller, vibrates the antenna to dislodge or remove material adhering to the antenna.

Abstract: A capacitive pump circuit suitable for use in loop powered level measurement and time of flight ranging systems. The capacitive pump circuit comprises an input buffer, a level shifter and an output stage. The input buffer receives a clocking signal which is also coupled to the input of the output stage through the level shifter. The output from the input buffer is switched by the output stage to charge a capacitor and generate a voltage output which has the opposite polarity of the voltage supply rail. According to another aspect, a capacitive voltage doubler circuit is provided which is also suitable for use in loop powered level measurement and time of flight ranging systems.