Physical processes in a quantum two-barrier heterostructure, which is the basis for the development of tunnel-resonant diodes, are considered. These studies have shown that tunnel resonance diodes can be used as temperature sensors with a frequency output signal. The use of devices with negative differential resistance makes it possible to significantly simplify the design of temperature sensors in the entire radio frequency range, at which, depending on the operating modes of the sensor, an output signal can be obtained both in the form of harmonic oscillations and in the form of impulse oscillations of a special form. The study of the characteristics of the sensor is based on the equivalent circuit of the tunnel-resonant diode, which takes into account its capacitive and inductive properties. The current-voltage characteristic of the sensor has a falling section, which is responsible for the appearance of a negative differential resistance in this section. The descending section arises due to a decrease in the current that flows through the double-barrier quantum heterostructure, with an increase in voltage. A decrease in the current occurs due to a decrease in the transparency coefficient of the potential barriers of the heterostructure. A mathematical model of the temperature sensor has been developed, on the basis of which the analytical dependences of the change in the elements of the equivalent circuit of the sensor on temperature, as well as the transformation function and sensitivity, have been determined. It is shown that the main contribution to changes in the conversion function and sensor sensitivity is made by the change in the negative differential resistance with a change in temperature. This, in turn, results in different readings of the instrument’s output frequency. The sensor sensitivity was varied from 480 kHz/0С to 220 kHz/0С in the temperature range from -150 0С to 50 0С.
RESEARCH ON A MAGNETIC FIELD SENSOR WITH A FREQUENCY OUTPUT SIGNAL BASED ON A TUNNEL-RESONANCE DIODE
