Patent ID: 7372397

Claim:
A radar level gauge using microwaves for measuring a level of a surface of a product in a container, comprising: a microwave unit for transmitting microwaves towards the surface and receiving microwaves reflected by the surface, processing circuitry connected to said microwave unit and arranged to determine said level based on a relation between transmitted and received microwaves, an interface for connecting said radar level gauge externally thereof, and power management circuitry arranged to provide operating power to said microwave unit and said processing circuitry, said power management circuitry including: a temporary energy store, first converting means for converting a drive voltage from said interface to an intermediate voltage, lower than an operating voltage required by said processing circuitry, means for providing said temporary energy store with said intermediate voltage, in order to charge said energy store, and second converting means, for converting an output voltage from said temporary energy store up to said operating voltage.