| 摘要 |
A magnetoresistive mixer, comprising a spiral coil, a bridge-type magnetoresistive sensor and a magnetic shielding layer, wherein the spiral coil is located between the bridge-type magnetoresistive sensor and the magnetic shielding layer. Four tunnel magnetoresistive sensor units forming the bridge-type magnetoresistive sensor respectively contain N array-type magnetic tunnel junction rows. The magnetic tunnel junction rows are connected in series, parallel, or combination of series and parallel connections to form two port structures. The four tunnel magnetoresistive sensor units are respectively located in two regions of the spiral coil having opposite current directions, sensing axes of magnetic tunnel junctions are perpendicular to the current directions, and in addition, the distribution characteristics of magnetic fields in directions of the sensing axes of the tunnel magnetoresistive sensor units to the magnetic field in the two regions are opposite, and the distribution characteristics in a single region are the same. The first frequency signal is input through the two ends of the spiral coil, the second frequency signal is input between the power and -ground ports of the bridge-type magnetoresistive sensor, and mixing signals are output through a signal output end of the bridge-type magnetoresistive sensor. The magnetoresistive mixer has the characteristics of good linearity, good input signal isolation, and low power consumption. |
| 主权项 |
1. A magnetoresistive mixer, for mixing a first frequency signal source input and a second frequency signal source input to obtain a mixing signal, the magnetoresistive mixer comprising:
a spiral coil, a bridge-type magnetoresistive sensor and a magnetic shielding layer, wherein the spiral coil is located between the magnetic shielding layer and the bridge-type magnetoresistive sensor; wherein the bridge-type magnetoresistive sensor comprises four magnetoresistive sensor units forming a bridge-type structure, the magnetoresistive sensor units being respectively located, in pairs, in two regions above or below the spiral coil having opposite current directions; wherein each of the magnetoresistive sensor units comprises N array-type magnetic tunnel junction rows, wherein each array-type magnetic tunnel junction row consists of M magnetic tunnel junctions, M and N are both positive integers, the array-type magnetic tunnel junction rows are connected in series connection, parallel connection, or combination of series connections and parallel connections to form two port structures, and sensing axes of the magnetic tunnel junctions are perpendicular to the current directions in the spiral coil within the region where the magnetoresistive sensor unit is located; wherein, in two of the regions, distribution characteristics of magnetic fields in directions of the sensing axes of the magnetic tunnel junctions in the magnetoresistive sensor units are opposite, while in one of the regions, distribution characteristics of magnetic fields in directions of the sensing axes of the magnetic tunnel junctions in the magnetoresistive sensor units are the same; wherein the first frequency signal source is input through the spiral coil so as to convert the first frequency signal source to a magnetic field signal having the same frequency as that of a magnetic field in the direction of the sensing axis of the magnetic tunnel junctions and act upon the magnetic tunnel junctions, causing resistances of the magnetoresistive sensor units to change, and the second frequency signal source is input through the power source and ground ports of the bridge-type magnetoresistive sensor, causing voltages on two ends of the magnetoresistive sensor units to change; and wherein the mixing signal is output through a signal output end of the bridge-type magnetoresistive sensor, and a signal frequency of the output mixing signal is the sum or the difference of frequencies of the first frequency signal source and the second frequency signal source. |
