System, controller, and method for determining conductance of an object
First Claim
1. A system for determining a conductance of an object, the system comprising:
- a sensor configured to emit an electromagnetic field when an excitation signal is received, wherein the electromagnetic field interacts with the object when the object is positioned within the electromagnetic field;
a signal processing circuit coupled to the sensor and configured to;
provide an adjustable capacitance to the sensor to adjust a phase angle of a current flowing through the sensor;
generate a voltage measurement representative of a voltage across the sensor; and
generate a current measurement representative of the current flowing through the sensor; and
a controller coupled to the signal processing circuit, the controller configured to;
adjust the adjustable capacitance to drive the sensor to a non-resonant state;
calculate an admittance of the sensor based on;
the voltage measurement when the sensor is in the non-resonant state; and
the current measurement when the sensor is in the non-resonant state; and
determine a conductance of the object based on the calculated admittance of the sensor.
2 Assignments
0 Petitions
Accused Products
Abstract
A system for determining a conductance of an object includes a sensor configured to emit an electromagnetic field when an excitation signal is received, wherein the electromagnetic field interacts with the object when the object is positioned within the electromagnetic field. A signal processing circuit is coupled to the sensor and configured to provide an adjustable capacitance to the sensor to adjust a phase angle of a current flowing through the sensor, to generate a voltage measurement representative of a voltage across the sensor, and to generate a current measurement representative of the current flowing through the sensor. A controller is coupled to the signal processing circuit and configured to calculate an admittance of the sensor based on the voltage measurement and the current measurement, and to determine a conductance of the object based on the calculated admittance of the sensor.
-
Citations
22 Claims
-
1. A system for determining a conductance of an object, the system comprising:
-
a sensor configured to emit an electromagnetic field when an excitation signal is received, wherein the electromagnetic field interacts with the object when the object is positioned within the electromagnetic field; a signal processing circuit coupled to the sensor and configured to; provide an adjustable capacitance to the sensor to adjust a phase angle of a current flowing through the sensor; generate a voltage measurement representative of a voltage across the sensor; and generate a current measurement representative of the current flowing through the sensor; and a controller coupled to the signal processing circuit, the controller configured to; adjust the adjustable capacitance to drive the sensor to a non-resonant state; calculate an admittance of the sensor based on; the voltage measurement when the sensor is in the non-resonant state; and the current measurement when the sensor is in the non-resonant state; and determine a conductance of the object based on the calculated admittance of the sensor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method of determining a conductance of an object comprising:
-
emitting an electromagnetic field from a sensor towards an object such that the electromagnetic field interacts with the object; adjusting a phase angle of a current flowing through the sensor to drive the sensor to a non-resonant state using a processor to adjust an adjustable capacitive element coupled to the sensor; generating a voltage measurement representative of a voltage across the sensor; generating a current measurement representative of the current flowing through the sensor; calculating an admittance of the sensor based on; the voltage measurement when the sensor is in the non-resonant state; and the current measurement when the sensor is in the non-resonant state; and determining a conductance of the object based on the calculated admittance of the sensor. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18)
-
-
19. A controller for determining a conductance of an object, the controller comprising:
-
a processor; and a memory device coupled to the processor and configured to store a plurality of program modules comprising; a phase angle calculator module executable by the processor to; receive a current measurement representative of a current flowing through a sensor when the sensor is in a non-resonant state; receive a voltage measurement representative of a voltage across the sensor when the sensor is in the non-resonant state; and calculate a phase angle of the current flowing through the sensor based on the current measurement and the voltage measurement; an impedance calculator module executable by the processor to; receive the current measurement; receive the voltage measurement; and calculate an impedance of the sensor based on the current measurement and the voltage measurement; an admittance calculator module executable by the processor to calculate an admittance of the sensor based on; the calculated phase angle when the sensor is in the non-resonant state; and the calculated impedance when the sensor is in the non-resonant state; and a conductance calculator module executable by the processor to determine a conductance of the object based on the calculated admittance of the sensor. - View Dependent Claims (20, 21, 22)
-
Specification