Signal transmission device

A signal transmission device, comprising:

• an input signal conductor in which an input signal current flows and thereby generating an input signal magnetic field;
• a magnetically-biasing conductor in which a biasing current flows and thereby generating a biasing magnetic field;
• a first magnetoresistive element and a second magnetoresistive element in each of which a sensing current flows and thereby generating a self-biasing magnetic field, and each including a magnetization free layer having a magnetization direction which varies in response to the input signal magnetic field, the biasing magnetic field, and the self-biasing magnetic field, the first magnetoresistive element exhibiting a resistance change in an increasing-decreasing direction, and the second magnetoresistive element exhibiting a resistance change in another increasing-decreasing direction different from the increasing-decreasing direction of the first magnetoresistive element;
• and
• a difference detector outputting an output signal according to a difference between a resistance value of the first magnetoresistive element and a resistance value of the second magnetoresistive element,
• wherein each of the biasing magnetic field and the self-biasing magnetic field is applied to the magnetization free layer in a same direction to each other.

A signal transmission device, comprising:

• an input signal conductor in which an input signal current flows and thereby generating an input signal magnetic field;
• a magnetically-biasing conductor in which a biasing current flows and thereby generating a biasing magnetic field;
• a first magnetoresistive element, a second magnetoresistive element, a third magnetoresistive element, and a fourth magnetoresistive element in each of which a sensing current flows and thereby generating a self-biasing magnetic field, and each including a magnetization free layer having a magnetization direction which varies in response to the input signal magnetic field, the biasing magnetic field, and the self-biasing magnetic field, each of the first magnetoresistive element to the fourth magnetoresistive element including a first terminal and a second terminal;
• and
• a difference detector,
• wherein the first magnetoresistive element to the fourth magnetoresistive element establish a bridge circuit, in which the first terminal of the first magnetoresistive element and the first terminal of the second magnetoresistive element are connected in a first connection point, the first terminal of the third magnetoresistive element and the first terminal of the fourth magnetoresistive element are connected in a second connection point, the second terminal of the first magnetoresistive element and the second terminal of the fourth magnetoresistive element are connected in a third connection point, and the second terminal of the second magnetoresistive element and the second terminal of the third magnetoresistive element are connected in a fourth connection point,
• both a resistance value of the first magnetoresistive element and a resistance value of the third magnetoresistive element change in a same increasing-decreasing direction, in response to the input signal magnetic field, the biasing magnetic field, and the self-biasing magnetic field,
• both a resistance value of the second magnetoresistive element and a resistance value of the fourth magnetoresistive element change in another increasing-decreasing direction different from the increasing-decreasing direction of the first magnetoresistive element and the third magnetoresistive element, in response to the input signal magnetic field, the biasing magnetic field, and the self-biasing magnetic field,
• the difference detector detects a differential potential which appears between the first connection point and the second connection point when a voltage is applied between the third connection point and the fourth connection point, and
• each of the biasing magnetic field and the self-biasing magnetic field is applied to the magnetization free layer in a same direction to each other.