Fmcw radar level gauge with enhanced timing control
AssigneeRosemount Tank Radar AB
InventorMikael Kleman
Life of this patent
Estimating the term…
Abstract
A radar level gauge system controllable between a measurement state and a signal processing state. In the measurement state a first timing signal circuit is enabled, a microwave signal source generates a transmit signal with a time-varying frequency being related to first timing signals from the first timing signal generating circuitry, and a sampler samples a mixer signal at sampling times related to the first timing signals. in the signal processing state, the first timing signal circuit is disabled, and a signal processor determines the filling level based on the sampled values of the mixer signal using second timing signals from a second timing signal generating circuit.
Claims17
A radar level gauge system for determining a filling level of a product in a tank, said radar level gauge system comprising:
- a microwave signal source controllable to generate an electromagnetic transmit signal with a time-varying frequency;
- a propagation device connected to said microwave signal source and arranged to propagate said electromagnetic transmit signal towards a surface of said product in the tank, and to propagate an electromagnetic surface echo signal resulting from reflection of said transmit signal at said surface back from said surface;
- a mixer connected to said microwave signal source and to said propagating device and configured to mix said transmit signal and said surface echo signal to form a mixer signal;
- sampling circuitry connected to said mixer for sampling said mixer signal to provide sampled values of the mixer signal;
- first timing signal generating circuitry connected to said microwave signal source and to said sampling circuitry for providing first timing signals to said microwave signal source and to said sampling circuitry;
- signal processing circuitry for determining said filling level based on said sampled values of the mixer signal;
- second timing signal generating circuitry connected to said signal processing circuitry for providing second timing signals to said signal processing circuitry;
- and
- measurement control circuitry for controlling the radar level gauge system between a measurement state in which said first timing signal generating circuitry is enabled and a signal processing state in which said first timing signal generating circuitry is disabled, wherein:
- in said measurement state, said measurement control circuitry:
- controls said microwave signal source to generate said transmit signal with said time-varying frequency being related to said first timing signals from said first timing signal generating circuitry;
- and
- controls said sampling circuitry to sample said mixer signal at sampling times related to said first timing signals from said first timing signal generating circuitry;
- and
- in said signal processing state, said measurement control circuitry:
- controls said signal processing circuitry to determine said filling level based on said sampled values of the mixer signal using said second timing signals from said second timing signal generating circuitry.
A method of determining a filling level of a product in a tank using a radar level gauge system comprising a microwave signal source;
- a propagation device connected to said microwave signal source;
- a mixer connected to said microwave signal source and to said propagating device;
- sampling circuitry connected to said mixer;
- first timing signal generating circuitry connected to said microwave signal source and to said sampling circuitry;
- signal processing circuitry;
- second timing signal generating circuitry connected to said signal processing circuitry;
- and measurement control circuitry, said method comprising the steps of:
- enabling, by said measurement control circuitry, said first timing signal generator;
- providing, by said first timing signal generator, first timing signals to said microwave signal source and to said sampling circuitry;
- generating, by said microwave signal source, an electromagnetic transmit signal with a time-varying frequency being related to said first timing signals from said first timing signal generator;
- propagating, by said propagation device, said electromagnetic transmit signal towards a surface of said product in the tank;
- propagate, by said propagation device, an electromagnetic surface echo signal resulting from reflection of said transmit signal at said surface back from said surface;
- mixing, by said mixer, said transmit signal and said surface echo signal to form a mixer signal;
- sampling, by said sampling circuitry, said mixer signal to provide sampled values of the mixer signal at sampling times related to said first timing signals from said first timing signal generating circuitry;
- disabling, by said measurement control circuitry, said first timing signal generating circuitry;
- providing, by said second timing signal generator, second timing signals to said signal processing circuitry;
- and
- determining, by said signal processing circuitry, said filling level based on said sampled values of the mixer signal using said second timing signals from said second timing signal generating circuitry.
101-116. (canceled)
Dependencies are inferred from the claim text.