Proximity sensing using EHF signals

• US 9,322,904 B2
• Filed: 06/15/2012
• Issued: 04/26/2016
• Est. Priority Date: 06/15/2011
• Status: Active Grant

• Current Assignee: Molex LLC (KOCH Industries Incorporated)
• Original Assignee: Keyssa, Inc.
• Inventors: McCormack, Gary D., Kyles, Ian A.
• Primary Examiner(s): MILLER, DANIEL R
• Application Number:
  US13/524,956
• Publication Number:
  US 20120319496A1
• Time in Patent Office: 1,411 Days
• Field of Search: 307/104, 324637-646, 455/41.1, 455/41.2
• US Class Current: 1/1
• CPC Class Codes: G01S 13/04 Systems determining presence of a target based on relative movement of target G01S13/56
• CPC Class Codes: G01S 13/08 Systems for measuring distance only indirect measurement G01S13/46
• CPC Class Codes: H01L 2224/48227 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/49111 the connectors connecting two common bonding areas, e.g. Litz or braid wires
• CPC Class Codes: H01L 2224/49113 the connectors connecting different bonding areas on the semiconductor or solid-state body to a common bonding area outside the body, e.g. converging wires
• CPC Class Codes: H01L 2224/49171 Fan-out arrangements
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: H01L 2924/30111 matching
• CPC Class Codes: H04B 5/00 Near-field transmission systems, e.g. inductive or capacitive transmission systems
• CPC Class Codes: H04B 5/70 specially adapted for specific purposes
• CPC Class Codes: H04B 5/75 for isolation purposes

Abstract

A system for sensing proximity using EHF signals may include a communication circuit configured to transmit via a transducer an EM signal at an EHF frequency, and a proximity sensing circuit configured to sense a nearby transducer field-modifying object by detecting characteristics of a signal within the communication circuit. A system for determining distance using EHF signals may include a detecting circuit coupled to a transmitting communication circuit and a receiving communication circuit, both communication circuits being mounted on a first surface. The transmitting communication circuit may transmit a signal toward a second surface, and the receiving communication circuit may receive a signal relayed from the second surface. The detecting circuit may determine distance between the first surface and a second surface based on propagation characteristics of the signals.

Claims

1. A system comprising:

a first amplifier for amplifying an output signal having an EHF frequency;

a transducer operatively coupled to the first amplifier for converting the amplified output signal into an electromagnetic signal having the EHF frequency; and

a proximity-sensing circuit, responsive to a reference and a composite signal conducted between the first amplifier and the transducer, for sensing the proximity of a transducer field-modifying device proximate to the transducer, the composite signal including the amplified output signal and any electromagnetic received signal received by the transducer and induced by the field-modifying device, wherein the reference is representative of a characteristic of the composite signal when the transducer field-modifying device is in a reference position, wherein the proximity-sensing circuit compares an amplitude of the reference signal with an amplitude of the composite signal, the proximity-sensing circuit comprising a reference circuit having a second amplifier and a terminating impedance coupled to an output of the amplifier, with the terminating impedance being equivalent to an impedance of the transducer when the transducer field-modifying device is in the reference position, the reference circuit generating the reference signal between the second amplifier and the terminating impedance.

2. The system of claim 1, wherein the proximity-sensing circuit includes a cancellation circuit that cancels the amplified output signal from the composite signal.

3. The system of claim 2, wherein the system further includes an impedance circuit coupling the first amplifier with the transducer, and the cancellation circuit has first and second resistive voltage dividers connected in parallel with the impedance circuit, the resistive voltage dividers producing relative voltages that cancel an amplified output signal but do not cancel the received signal, with the received signal being detected on the resistive voltage dividers.

4. The system of claim 3, wherein the impedance circuit includes a transformer having a coupling factor and the voltage dividers include a first resistor connected to a first conductor coupling the first amplifier to the transformer and a second resistor connected to a second conductor coupling the transformer to the transducer, the ratio of a resistance of the second resistor to the sum of resistances of the first and second resistors is proportional to the coupling factor of the transformer.

5. The system of claim 3, wherein the impedance circuit includes an in-line resistor and the voltage dividers include a first resistor connected between the in-line resistor and the first amplifier and a second resistor connected between the in-line resistor and the transducer, and the ratio of a resistance of the second resistor to the sum of resistances of the first and second resistors is proportional to the ratio of an impedance of the transducer to the sum of impedances of the transducer and the in-line resistor.

6. The system of claim 1, wherein the reference is representative of a frequency of the amplified output signal when the transducer field-modifying device is in the reference position, the proximity-sensing circuit detecting the frequency of the composite signal and producing the indicator signal indicative of when there is a change in the frequency of the composite signal.

7. The system of claim 6, wherein the reference signal is a clock signal representative of the frequency of the amplified output signal when the transducer field-modifying device is in the reference position, the proximity-sensing circuit including a dual counter responsive to a frequency signal representative of the frequency of the composite signal and the reference signal, the proximity-sensing circuit producing the indicator signal indicative of a change in the frequency of the composite signal relative to the frequency of the amplified output signal when the transducer field-modifying device is in the reference position.

8. A method comprising:

amplifying by a first amplifier an output signal having an EHF frequency;

converting by a transducer the amplified output signal into an electromagnetic signal having the EHF frequency;

sensing in response to a reference and a composite signal conducted between the first amplifier and the transducer the proximity of a transducer field-modifying device proximate to the transducer, the composite signal including the amplified output signal and any electromagnetic received signal received by the transducer and induced by the field-modifying device, wherein the reference is representative of a characteristic of the composite signal when the transducer field-modifying device is in a reference position;

comparing an amplitude of the reference signal with an amplitude of the composite signal;

amplifying the output signal by a second amplifier; and

outputting, as the reference signal, the output signal amplified by the second amplifier to a terminating impedance that is equivalent to an impedance of the transducer when the transducer field-modifying device is in the reference position.

13. The method of claim 8, where the reference is representative of a frequency of the amplified output signal when the transducer field-modifying device is in the reference position, and wherein generating an indicator signal includes detecting a frequency of the composite signal and producing the indicator signal indicative of when there is a change in the frequency of the composite signal.

14. The method of claim 13, further comprising producing the reference signal as a clock signal representative of the frequency of the amplified output signal when the transducer field-modifying device is in the reference position, and wherein detecting a frequency of the composite signal includes counting the cycles of the composite signal and producing the indicator signal indicative of a change in the frequency of the composite signal relative to the frequency of the amplified output signal when the transducer field-modifying device is in the reference position.

9. The method of 8, further comprising producing a signal representative of a received signal by canceling the amplified output signal from the composite signal.

10. The method of claim 9, wherein canceling the amplified output signal from the composite signal includes applying a voltage divider across an impedance circuit coupling the first amplifier with the transducer, the resistive voltage dividers producing relative voltages that cancel the amplified output signal but do not cancel the received signal, and producing a signal representative of a received signal includes detecting the received signal on the resistive voltage dividers.

11. The method of claim 10, wherein the impedance circuit includes a transformer having a coupling factor, and wherein applying a voltage divider includes connecting a first resistor to a first conductor coupling the first amplifier to the transformer and connecting a second resistor to a second conductor coupling the transformer to the transducer, with the ratio of a resistance of the second resistor to the sum of resistances of the first and second resistors being proportional to the coupling factor of the transformer.

12. The method of claim 10, where the impedance circuit includes an in-line resistor and wherein applying a voltage divider includes connecting a first resistor between the in-line resistor and the first amplifier and connecting a second resistor between the in-line resistor and the transducer, with the ratio of a resistance of the second resistor to the sum of resistances of the first and second resistors being proportional to the ratio of an impedance of the transducer to the sum of impedances of the transducer and the in-line resistor.