Device and a method for adjusting electrical impedance based on contact action

Patent metadata

Field	Value
Publication number	US-10084424-B2
Application number	US-201515533121-A
Country	US
Kind code	B2
Filing date	May 18, 2015
Priority date	May 18, 2015
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

A device and associated method for adjusting electrical impedance based on contact action are disclosed. The device includes a drive unit (1), a contact unit (2), a monitoring unit (3), and a control unit (4). The monitoring unit (3) measures an impedance signal of an electromagnetic functional material (7) in an alternating-current circuit, and transfers the impedance signal to the control unit (4). In response to the impedance signal measured by the monitoring unit (3), the control unit (4) controls the drive unit (1) to apply a mechanical load on the contact unit (2), which causes the contact unit (2) to contact the electromagnetic functional material (7). The value of a contact load is adjusted, so as to adjust the electrical impedance of the electromagnetic functional material (7), thereby achieving the objective of adjusting the impedance matching in the alternating-current circuit in real time.

First claim

What is claimed is:

1. A device for adjusting electrical impedance based on contact action, comprising:
a drive unit;
a contact unit configured to contact an electromagnetic functional material to be adjusted, wherein the drive unit is fixedly connected to the contact unit;
a monitoring unit configured to measure an impedance signal of the electromagnetic function material; and
a control unit electrically connected to the drive unit and configured to receive the impedance signal from the monitoring unit, wherein in response to the impedance signal, the control unit is configured to control the drive unit to apply a mechanical load on the contact unit to cause the contact unit contact the electromagnetic functional material, wherein the control unit is configured to adjust a value of a contact load so as to adjust an electrical impedance of the electromagnetic functional material.

2. The device of claim 1 , wherein the drive unit comprises a piezoelectric actuator, wherein the piezoelectric actuator is fixedly connected to the contact unit.

3. The device of claim 2 , wherein the drive unit comprises a lead zirconate titanate ceramics piezoelectric actuator or a lead magnesium niobate-lead titanate single crystal piezoelectric actuator.

4. The device of claim 1 , wherein the contact unit comprises a conductive indenter having a spherical or frustum-shaped tip with a size in nano-scale or micro-scale.

5. The device of claim 4 , wherein the monitoring unit comprises an impedance measuring apparatus electrically connected respectively to the conductive indenter and a bottom electrode on the electromagnetic functional material.

6. The device of claim 5 , wherein the monitoring unit further comprises a precision displacement sensor configured to measure a displacement of the contact unit.

7. The device of claim 6 , wherein the precision displacement sensor comprises a capacitive displacement sensor,
wherein the capacitive displacement sensor comprises a capacitive sensor head formed by an upper capacitor plate and a lower capacitor plate,
wherein the electric impedance adjusting device further comprises a main structure,
wherein the upper capacitor plate and the lower capacitor plate are respectively fixed on the main structure and an end of the drive unit.

8. A method for adjusting electrical impedance based on contact action to adjust impedance matching in an alternating-current circuit in real time, comprising the steps of:
1) under the control of a control unit, applying a mechanical load on a contact unit by a drive unit to cause the contact unit to contact an electromagnetic functional material to be adjusted;
2) monitoring an impedance signal of the electromagnetic functional material in real time by a monitoring unit; and
3) in response to the impedance signal measured by the monitoring unit, adjusting the mechanical load of the drive unit by the control unit, varying a value of a contact load on the electromagnetic functional material applied by the contact unit, and adjusting an electrical impedance of the electromagnetic functional material.

9. The method of claim 8 , wherein the electromagnetic functional material comprises a layered electromagnetic composite material, the method further comprising:
adjusting an electrical impedance of the layered electromagnetic composite material.

10. The method of claim 9 , wherein an amplitude of the electrical impedance of the layered electromagnetic composite material is adjusted according to the following equation:



Z
⁡

(
f
)





Z
0

⁡

(
f
)



=

1
+

h
⁡

(
f
)

*

h
⁡

(
f
)

(
1
)

where h(f) represents a contact displacement of the mechanical load on the material at AC frequency f, |Z(f)| represents a corresponding amplitude of the electrical impedance, |Z 0 (f)| and h(f)* are respectively an impedance amplitude parameter and a contact displacement parameter, which are related to a thickness of the layered electromagnetic composite material and the AC frequency, wherein in step 3) the value of the contact load is controlled to reach a predetermined contact displacement.

Assignees

• Univ Beijing
• Univ Jilin

Inventors

• Fang Daining
• Zhou Hao
• Pei Yongmao
• Li Faxin
• Zhao Hongwei
• Fu Ji

Classifications

• H03H7/38 Primary

  Impedance-matching networks · CPC title

• G01R27/02

  Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant (by measuring phase angle only G01R25/00) · CPC title

• H01L41/042

  Electricity · mapped topic

• H03H7/40

  Automatic matching of load impedance to source impedance · CPC title

• H01L41/1876

  Electricity · mapped topic