Balanced magnetoresistive frequency mixer

Patent metadata

Field	Value
Publication number	US-10873294-B2
Application number	US-201716326342-A
Country	US
Kind code	B2
Filing date	Aug 17, 2017
Priority date	Aug 18, 2016
Publication date	Dec 22, 2020
Grant date	Dec 22, 2020

Abstract

A balanced magnetoresistive frequency mixer comprises a first spiral coil, a second spiral coil, a balanced magnetoresistive sensor bridge, and a magnetic shielding layer. The coils are located between the magnetic shielding layer and the sensor bridge. The sensor bridge comprises a magnetoresistive full bridge consisting of four bridge arms and a balancing bridge arm connected to the power supply end of the full bridge. The four bridge arms contain pairs located in a first sub region and a second sub region above or below the first spiral coil, the balancing arm is located in a third sub region above or below the second spiral coil, a first frequency signal is input into the first spiral coil, a second frequency signal is input into the second spiral coil, and a frequency-mixed signal is output from a signal output end of the full bridge.

First claim

The invention claimed is:

1. A balanced magnetoresistive frequency mixer, comprising:
a spiral coil;
a balanced magnetoresistive sensor bridge; and
a magnetic shielding layer,
wherein the spiral coil is located between the magnetic shielding layer and the balanced magnetoresistive sensor bridge,
wherein the spiral coil comprises a first spiral coil and a second spiral coil, an upper surface or a lower surface of the first spiral coil has a first sub region and a second sub region in which the current flows in opposite directions, and an upper surface or a lower surface of the second spiral coil has a third sub region in which the current flows in one direction,
wherein the balanced magnetoresistive sensor bridge comprises a magnetoresistive full bridge and a balancing magnetoresistive arm connected to the magnetoresistive full bridge, the magnetoresistive full bridge consists of four magnetoresistive bridge arms, two of which are located in the first sub region and the other two are located in the second sub region, and the balancing magnetoresistive arm is located in the third sub region,
wherein a first frequency signal is input into the first spiral coil ( 40 ), a second frequency signal is input into the second spiral coil, and a frequency-mixed signal is output from a signal output end of the magnetoresistive full bridge, wherein the output frequency of the frequency-mixed signal is a sum of or a difference between the frequencies of the first frequency signal and the second frequency signal.

2. The balanced magnetoresistive frequency mixer according to claim 1 , wherein
there is one balancing magnetoresistive arm that is connected to a power supply output end or an input end of the magnetoresistive full bridge; or
there are two balancing magnetoresistive arms that are connected to a power supply output end and an input end of the magnetoresistive full bridge, respectively.

3. The balanced magnetoresistive frequency mixer according to claim 2 , wherein the magnetoresistive bridge arms and the balancing magnetoresistive arm separately comprise M*N arrayed magnetic tunnel junctions, the magnetic tunnel junctions in each column are connected in series to form a magnetic tunnel junction cell string, the magnetic tunnel junction cell strings are connected in series, in parallel, or in a series/parallel manner to form a two-port structure, N denotes a column of an arrayed structure, M denotes a row of the arrayed structure, and N and M are respectively positive integers greater than or equal to 1.

4. The balanced magnetoresistive frequency mixer according to claim 3 , wherein sensitive axes of the magnetic tunnel junctions in the magnetoresistive bridge arms are all perpendicular to a current direction of the first spiral coi, sensitive axes of the magnetic tunnel junctions in the balancing magnetoresistive arm are all perpendicular to a current direction of the second spiral coil, and distribution characteristics of sensitive axial magnetic fields of the magnetic tunnel junctions in the first sub region are opposite to those of the magnetic tunnel junctions in the second sub region.

5. The balanced magnetoresistive frequency mixer according to claim 3 , wherein the magnetic tunnel junctions in the first sub region and the magnetic tunnel junctions in the second sub region are connected in identical structures and arranged symmetrically.

6. The balanced magnetoresistive frequency mixer according to claim 3 , wherein
resistances of the magnetic tunnel junctions in the first sub region and the second sub region are respectively linear to sensitive axial magnetic fields of the magnetic tunnel junctions generated by the first spiral coil; and
resistances of the magnetic tunnel junctions in the third sub region are linear to sensitive axial magnetic fields of the magnetic tunnel junctions generated by the second spiral coil.

7. The balanced magnetoresistive frequency mixer according to claim 3 , wherein the magnetic tunnel junctions in the first sub region and the second sub region are perpendicular or parallel to the current direction of the first spiral coil, and the magnetic tunnel junctions in the third sub region are perpendicular or parallel to the current direction of the second spiral coil.

8. The balanced magnetoresistive frequency mixer according to claim 1 , wherein the first frequency signal is connected to the first spiral coil actively or passively, the second frequency signal is connected to the second spiral coil passively or actively, and the frequency-mixed signal is connected to the signal output end of the balanced magnetoresistive sensor bridge passively or actively.

9. The balanced magnetoresistive frequency mixer according to claim 1 , wherein the spiral coil is a coil of a high-conductivity metal material comprising one or more of copper, gold, silver, aluminum, and tantalum, and the magnetic shielding layer is a layer of a high-permeability ferromagnetic alloy comprising one or more of NiFe, CoFeSiB, CoZrNb, CoFeB, FeSiB, and FeSiBNbCu.

10. The balanced magnetoresistive frequency mixer according to claim 1 , wherein the thickness of the spiral coil is 1-20 μm, the width of the spiral coil is 5-40 μm, a spacing between two adjacent spiral coils is 10-100 μm, and the thickness of the magnetic shielding layer is 1-20 μm.

Assignees

• Multidimension Technology Co Ltd

Inventors

• Deak James Geza
• Zhou Zhimin

Classifications

• H03D7/14 Primary

  Balanced arrangements · CPC title

• G01R33/09 Primary

  Magnetoresistive devices · CPC title

• G01R33/0094

  Sensor arrays · CPC title

• H03D2200/0074

  using a resistive mixer or a passive mixer · CPC title

• G01R33/098

  comprising tunnel junctions, e.g. tunnel magnetoresistance sensors · CPC title