Cross-talk compensation for gradiometer probes

Patent metadata

Field	Value
Publication number	US-2022011401-A1
Application number	US-202117369280-A
Country	US
Kind code	A1
Filing date	Jul 7, 2021
Priority date	Jul 7, 2020
Publication date	Jan 13, 2022
Grant date	—

Abstract

A system/device, such as a gradiometer probe for detecting RF signals, or for example for explosive detection, has the shape of the coils in its adjustment mechanism that minimizes the cross-talk between the receiver probe (Rx) and the transmitting antenna (Tx) in such a way as to minimize (or reduce) the areas where the distance between the coils during the adjustment is the smallest. Moving coils along the plain of the coils is one mechanism of achieving it. Having the coils of different shapes, e.g., circular receiver and oval transmitter coils, is another. Many shapes are possible, including circular, oval, elliptical, and polygonal, to give a few examples. In some embodiments both of these methods/approaches are combined in a single device.

First claim

1 . A device comprising:
a transmitter antenna; and a receiver antenna that at least partially overlaps the transmitter antenna, configured to reduce cross talk; wherein at least one of the antennas is a differential antenna; and wherein the antennas are adjustable by movement of one of the antennas relative to the other of the antennas in a direction of adjustment that is parallel to or in a plane of one or both of the antennas.

2 . The device of claim 1 , wherein the antennas have different shapes.

3 . The device of claim 1 , wherein one of the antennas is circular.

4 . The device of claim 1 , wherein one of the antennas is oval.

5 . The device of claim 1 , wherein the antennas are non-axisymmetric.

6 . The device of claim 1 , wherein the device includes an adjuster that is capable of adjusting position of the antennas relative to one another.

7 . The device of claim 6 , wherein the adjustment mechanism provides structural stiffening.

8 . The device of claim 6 , wherein the adjuster includes an adjustment mechanism.

9 . The device of claim 1 , further comprising a cross-talk tuner operatively coupled to at least one of the antennas.

10 . The device of claim 1 , wherein the differential antenna is a multi-loop antenna.

11 . The device of claim 10 , wherein multiple loops of the multi-loop antenna are connected in series.

12 . The device of claim 1 , wherein the device includes one or more spacers to maintain spacing between the antennas.

13 . The device of claim 1 , wherein the device includes a lock for locking the antennas in a positional relationship relative to one another.

14 . The device of claim 1 , wherein the device is a handheld device.

15 . The device of claim 1 , wherein the device is a table top device.

16 . The device of claim 1 , wherein the device is an explosive detection device.

17 . A method of reducing cross talk in an antenna system, the method comprising:
adjusting relatively positioning of a transmit antenna and a receive antenna, with the adjusting includes relative movement of the antennas in a direction of adjustment that is parallel to or in a plane of one or both of the antennas; and monitoring energy coupling between the antennas at multiple relative positions between the antennas.

18 . The method of claim 17 , wherein the antennas are planar, and planes of the antenna are maintained at a fixed distance from each other.

19 . The method of claim 17 , wherein the antennas are locked in place relative to one another at a position of minimum energy coupling.

Assignees

• Raytheon Co

Inventors

• Dolgin Benjamin
• Fraundorfer Joseph J
• Lavedas Thomas G

Classifications

• G01S13/887

  for detection of concealed objects, e.g. contraband or weapons · CPC title

• G01R33/441

  Nuclear Quadrupole Resonance [NQR] Spectroscopy and Imaging · CPC title

• G01R33/3657

  Decoupling of multiple RF coils wherein the multiple RF coils do not have the same function in MR, e.g. decoupling of a transmission coil from a receive coil · CPC title

• G01R33/34007

  Manufacture of RF coils, e.g. using printed circuit board technology; additional hardware for providing mechanical support to the RF coil assembly or to part thereof, e.g. a support for moving the coil assembly relative to the remainder of the MR system · CPC title

• G01N24/084

  Detection of potentially hazardous samples, e.g. toxic samples, explosives, drugs, firearms, weapons · CPC title