Impedance measurement apparatus
AssigneeAdvantest Corporation
InventorsYuki ENDO, Yasuo FURUKAWA, Tomoaki UEDA
Life of this patent
Estimating the term…
Abstract
A measurement auxiliary circuit is configured to form a resonance circuit together with a detection target. An ATAC is coupled with the resonance circuit. A signal generator applies an AC probe signal VS to the resonance circuit. After the impedance measurement apparatus enters a stable state, an impedance detection unit measures a voltage at at least one node and/or a current that flows through at least one current path. The impedance detection unit detects the impedance of the detection target based on the measurement value.
Claims14
An impedance measurement apparatus configured to measure an impedance of a detection target, the impedance measurement apparatus comprising:
- a measurement auxiliary circuit configured to form a resonance circuit together with the detection target;
- an automatic tuning assist circuit coupled with the resonance circuit, and comprising (i) a first terminal and a second terminal, (ii) N (N represents an integer) auxiliary capacitors, (iii) a plurality of switches, each of which is arranged between two terminals from among the first terminal, the second terminal, and terminals of the N auxiliary capacitors, and (iv) a controller configured to respectively switch each of the plurality of switches;
- a signal generator configured to apply an AC probe signal to the resonance circuit;
- and
- an impedance detection unit configured to measure a voltage at least one node and/or a current that flows through at least one current path after the impedance measurement apparatus enters a stable state, and to detect the impedance of the detection target based on the measurement value.
An impedance measurement apparatus configured to measure an impedance of a detection target, the impedance measurement apparatus comprising:
- a measurement auxiliary circuit configured to form a resonance circuit together with the detection target;
- an automatic tuning assist circuit coupled with the resonance circuit, and comprising (i) N (N represents an integer) auxiliary capacitors, (ii) a plurality of switches configured to charge and discharge the N auxiliary capacitors using a current that flows through the resonance circuit, (iii) a controller configured to respectively switch on and off each of the plurality of switches so as to generate a capacitor voltage across both ends of each of the N auxiliary capacitors, and to apply an auxiliary voltage to the resonance circuit according to the capacitor voltages generated across the N auxiliary capacitors;
- a signal generator configured to apply an AC probe signal to the resonance circuit;
- and
- an impedance detection unit configured to measure a voltage at least one node as well as or otherwise a current that flows through at least one current path after the impedance measurement apparatus enters a stable state, and to detect the impedance of the detection target based on the measurement value.
An impedance measurement apparatus configured to measure an impedance of a detection target, the impedance measurement apparatus comprising:
- a measurement auxiliary circuit configured to form a resonance circuit together with the detection target;
- an automatic tuning assist circuit coupled with the resonance circuit, configured to inject a correction current into, or otherwise draw a correction current from, the resonance circuit, and comprising (i) a first terminal and a second terminal, (ii) N (N represents an integer) auxiliary coils, (iii) a plurality of switches arranged between two terminals from among the first terminal, the second terminal, and terminals of the N auxiliary coils, and (iv) a controller configured to respectively switch on and off each of the plurality of switches;
- a signal generator configured to apply an AC probe signal to the resonance circuit;
- and
- an impedance detection unit configured to measure a voltage at at least one node as well as or otherwise a current that flows through at least one current path after the impedance measurement apparatus enters a stable state, and to detect the impedance of the detection target based on the measurement value.
An impedance measurement apparatus configured to measure an impedance of a detection target, the impedance measurement apparatus comprising:
- a measurement auxiliary circuit configured to form a resonance circuit together with the detection target;
- an automatic tuning assist circuit comprising an auxiliary coil, and configured to alternately switch between (1) a first state in which the auxiliary coil is coupled with the resonance circuit such that a correction current that corresponds to a current that flows through the auxiliary coil is injected into, or otherwise is drawn from, the resonance circuit, and (2) a second state in which the auxiliary coil is disconnected from the resonance circuit such that the current that flows through the auxiliary coil flows through a current path that is independent of the resonance circuit;
- a signal generator configured to apply an AC probe signal to the resonance circuit;
- and
- an impedance detection unit configured to measure a voltage at least one node as well as or otherwise a current that flows through at least one current path after the impedance measurement apparatus enters a stable state, and to detect the impedance of the detection target based on the measurement value.
Dependencies are inferred from the claim text.