Cancellation of an electric field component of a magnetic field generated by artificially structured electromagnetic unit cells

Patent metadata

Field	Value
Publication number	US-2016018495-A1
Application number	US-201414334450-A
Country	US
Kind code	A1
Filing date	Jul 17, 2014
Priority date	Jul 17, 2014
Publication date	Jan 21, 2016
Grant date	—

Abstract

Described embodiments include a system, apparatus, and method. An apparatus includes an assemblage of artificially structured electromagnetic unit cells. The assemblage of artificially structured electromagnetic unit cells includes a first artificially structured electromagnetic unit cell configured to transform incident radiofrequency electromagnetic waves into a radiofrequency magnetic field B perpendicular to the plane of the assemblage. The assemblage of artificially structured electromagnetic unit cells includes a second artificially structured electromagnetic unit cell configured to transform the incident radiofrequency electromagnetic waves into an electric field E counteracting a non-vanishing electric field component generated by the first artificially structured electromagnetic unit cell.

First claim

What is claimed is:

1 . An apparatus comprising:
an assemblage of artificially structured electromagnetic unit cells, the assemblage of artificially structured electromagnetic unit cells including (i) a first artificially structured electromagnetic unit cell configured to transform incident radiofrequency electromagnetic waves into a radiofrequency magnetic field B perpendicular to a plane of the assemblage and (ii) a second artificially structured electromagnetic unit cell configured to transform the incident radiofrequency electromagnetic waves into an electric field E counteracting a non-vanishing electric field component generated by the first artificially structured electromagnetic unit cell.

2 . The apparatus of claim 1 , wherein the assemblage includes planar assemblage.

3 . The apparatus of claim 1 , wherein the assemblage includes an arcuate assemblage

4 . The apparatus of claim 1 , wherein the assemblage includes planar array of at least two assemblages of artificially structured electromagnetic unit cells.

5 . The apparatus of claim 1 , wherein the first artificially structured electromagnetic unit cell and the second artificially structured electromagnetic unit cell are respectively configured to produce a selected E/(Bc) ratio in the radiofrequency magnetic field B perpendicular to the plane of the assemblage.

6 . The apparatus of claim 5 , wherein the first artificially structured electromagnetic unit cell and the second artificially structured electromagnetic unit cell are respectively configured to produce a selected minimized E/(Bc) ratio in the radiofrequency magnetic field B perpendicular to the plane of the assemblage.

7 . The apparatus of claim 1 , wherein the counteracting electric field E includes an offsetting electric field E.

8 . The apparatus of claim 1 , wherein the counteracting electric field E includes an electric field E at least partially cancelling a non-vanishing electric field component generated by the first artificially structured electromagnetic unit cell.

9 . The apparatus of claim 1 , wherein the non-vanishing electric field includes a non-vanishing electric field component generated by electric dipole or multipole moments by the first artificially structured electromagnetic unit cell.

10 . The apparatus of claim 1 , wherein the second artificially structured electromagnetic unit cell includes a one-dimensional or two-dimensional split ring resonator unit cell optimized for high electric field intensity.

11 . The apparatus of claim 1 , wherein each assemblage includes two first artificially structured electromagnetic unit cells, and one second artificially structured electromagnetic unit cell.

12 . The apparatus of claim 1 , wherein each assemblage includes two first artificially structured electromagnetic unit cells arranged in a first row, and two second artificially structured electromagnetic unit cell arranged in a second row.

13 . The apparatus of claim 1 , wherein each assemblage includes two first artificially structured electromagnetic unit cells arranged on a first diagonal, and two second artificially structured electromagnetic unit cell arranged on a second diagonal orthogonal to the first diagonal.

14 . The apparatus of claim 1 , wherein the first artificially structured electromagnetic unit cell is configured to transform incident radiofrequency electromagnetic waves into a radiofrequency magnetic field B having a first component perpendicular to the plane of the planar assemblage and a second component orthogonal to the plane of the planar assemblage.

15 . The apparatus of claim 1 , wherein the first artificially structured electromagnetic unit cell is configured to transform incident radiofrequency electromagnetic waves into a radiofrequency magnetic field B having components in all three mutually orthogonal directions.

16 . The apparatus of claim 1 , wherein the first artificially structured electromagnetic unit cell includes a pair of artificially structured electromagnetic unit cells, a first cell of the pair configured to transform incident radiofrequency electromagnetic waves into a radiofrequency magnetic field B perpendicular to the plane of the planar assemblage, and a second cell of the pair configured to transform incident radiofrequency electromagnetic waves into a radiofrequency magnetic field B orthogonal to the plane of the planar assemblage.

17 . The apparatus of claim 1 , wherein the first artificially structured electromagnetic unit cell includes a trio of artificially structured electromagnetic unit cells configured to transform incident radiofrequency electromagnetic waves into a radiofrequency magnetic field B having components in all three mutually orthogonal directions.

18 . The apparatus of claim 1 , wherein the assemblage of artificially structured electromagnetic unit cells includes (i) a first layer of artificially structured electromagnetic unit cells configured to transform incident radiofrequency electromagnetic waves into a radiofrequency magnetic field B perpendicular to the plane of the planar assemblage and (ii) a second layer artificially structured electromagnetic unit cells configured to transform the incident pulse of radiofrequency electromagnetic waves into an electric field E counteracting a non-vanishing electric field component generated by the first layer of artificially structured electromagnetic unit cells.

19 . The apparatus of claim 1 , further comprising:
a radiofrequency electromagnetic wave conducting structure configured to distribute the radiofrequency electromagnetic waves as incident radiofrequency electromagnetic waves to the planar assemblage of artificially structured electromagnetic unit cells.

20 . An apparatus comprising:
a radiofrequency electromagnetic wave conducting structure configured to distribute radiofrequency electromagnetic waves as incident radiofrequency electromagnetic waves to each assemblage of at least two planar assemblages of artificially structured electromagnetic unit cells; the at least two assemblages of artificially structured electromagnetic unit cells, each assemblage of the at least two assemblage of artificially structured electromagnetic unit cells including (i) a first artificially structured electromagnetic unit cell configured to transform the incident radiofrequency electromagnetic waves into a radiofrequency magnetic field B perpendicular to a plane of the assemblage and (ii) a second artificially structured electromagnetic unit cell configured to transform the incident radiofrequency electromagnetic waves into an electric field E counteracting a non-vanishing electric field component generated by the first artificially structured electromagnetic unit cell.

21 . The apparatus of claim 20 , wherein the at least two assemblages includes at least two planar or an arcuate assemblages of artificially structured electromagnetic unit cells.

22 . The apparatus of claim 20 , further comprising the magnetic resonant imaging or the nuclear magnetic resonant device.

23 . (canceled)

24 . An apparatus comprising:
a radiofrequency electromagnetic wave conducting structure configured to distribute a pulse of radiofrequency electromagnetic waves as an incident pulse of radiofrequency electromagnetic waves to each of at least two assemblages of artificially structured electromagnetic unit cells; the at least two assemblages of artificially structured electromagnetic un

Assignees

• Elwha Llc
• Elwha Llc

Inventors

• Driscoll Tom
• Smith David R
• Urzhumov Yaroslav A

Classifications

• G01R33/3621

  NMR receivers or demodulators, e.g. preamplifiers, means for frequency modulation of the MR signal using a digital down converter, means for analog to digital conversion [ADC] or for filtering or processing of the MR signal such as bandpass filtering, resampling, decimation or interpolation · CPC title

• G01R33/3614

  RF power amplifiers · CPC title

• G01R33/3607

  RF waveform generators, e.g. frequency generators, amplitude-, frequency- or phase modulators or shifters, pulse programmers, digital to analog converters for the RF signal, means for filtering or attenuating of the RF signal · CPC title

• G01R33/36 Primary

  Electrical details, e.g. matching or coupling of the coil to the receiver · CPC title

• G01R33/345

  of waveguide type (G01R33/343 takes precedence) · CPC title