Low power radar level transmitter having reduced ground loop errors

A low power radar level transmitter having reduced ground loop errors, the transmitter comprising:

• a termination electrically couplable to a reference voltage and extendable into a process product;
• a low power microwave transceiver electrically coupled to the termination, the transceiver being adapted to generate a microwave signal with the termination and receive a reflected microwave signal from the process product;
• a level calculator electrically coupled to the microwave transceiver;
• a loop communicator electrically coupled to the level calculator and electrically couplable to a two-wire process control loop;
• a power supply electrically coupled to the level calculator, the loop communicator, and the microwave transceiver and electrically couplable to the two-wire process control loop;
• a first bandpass filter coupling the microwave transceiver to the termination;
• and
• a second bandpass filter coupling the microwave transceiver to the reference voltage.

A method of calculating a height of a process product with a low power radar level transmitter, the method comprising;

• a generating a microwave signal;
• passing the microwave signal through a low frequency isolator to inhibit direct current flow;
• receiving a microwave signal reflected from the process product;
• and
• calculating the height of the process product based upon the received, reflected microwave signal.

A low power radar level transmitter having reduced ground loop errors, the transmitter comprising:

• means for guiding microwave signals, the guiding means couplable to earth ground;
• means for generating a microwave signal along the guiding means and receiving a reflected microwave signal indicative of process product height;
• means for calculating process product height based upon the reflected microwave signal;
• means for transmitting information related to the process product height over a two-wire process control loop;
• means for receiving power from the loop to power the transmitter;
• and
• means for passing microwave signals between the generating means and the guiding means, and blocking substantially all other signals.