Self-adaptive temperature adjusting system and method for lithium niobate surface acoustic wave filter

Abstract

The invention relates to the field of semiconductor devices, in particular to a self-adaptive temperature adjusting system and method for a lithium niobate surface acoustic wave filter. A temperature sensor, a memristor differential pair, a temperature adjusting device and the SAW filter are combined together, the self-adaptive temperature adjusting system of the SAW filter is provided, and the temperature sensor, the memristor differential pair and the temperature adjusting device are used in cooperation with circuits to achieve self-adaptive linkage of all assemblies; and a highly integrated scheme integrated on the lithium niobate substrate is further provided, so that the power consumption, the volume and the noise of the whole adaptive temperature control system are reduced, and the reliability and the ductility of the system are improved at the same time. The integrated design not only can optimize the overall performance of the SAW filter, but also has the advantages of low power consumption, high reliability and wide adaptation scene, and provides an innovative solution for the next generation of high-frequency communication, aerospace and power electronics fields.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor devices, and particularly to an adaptive temperature regulation system and method for a lithium niobate surface acoustic wave filter. Background Art

[0002] Lithium niobate surface acoustic wave (SAW) filters are widely used in passive radio frequency devices, communication systems, sensors, and other fields due to their high electromechanical coupling coefficient and low insertion loss characteristics. Although lithium niobate SAW filters perform well in many high-frequency applications, their performance is significantly affected by temperature changes. Temperature changes may cause frequency drift, bandwidth variation, and increased insertion loss, thus affecting the stability and reliability of the system.

[0003] Currently, research on the temperature characteristics of lithium niobate SAW filters mainly focuses on material selection and process optimization. However, with the continuous improvement of filter performance requirements in modern communication systems, simply relying on static design and material optimization is difficult to meet the needs in dynamic environments. Therefore, an adaptive temperature regulation technology is needed to monitor and adjust the operating temperature of SAW filters in real time to ensure their stability under different operating conditions. Summary of the Invention

[0004] In view of the above problems and deficiencies, the present invention proposes an adaptive temperature regulation system and method for a lithium niobate SAW filter to further reduce the impact of temperature on the lithium niobate SAW filter and thus improve its performance.

[0005] An adaptive temperature regulation system for a lithium niobate surface acoustic wave filter consists of four parts: a SAW filter, a temperature sensor, a memristor differential pair, and a temperature regulation device.

[0006] The SAW filter is composed of lithium niobate SAW resonators.

[0007] The temperature sensor real-time collects the operating temperature of the SAW filter, converts the temperature-induced change into a temperature voltage signal; the temperature voltage signal determines the temperature deviation direction through a window comparator in a threshold comparison circuit and outputs corresponding high and low levels.

[0008] The memristor differential pair consists of two memristors with opposite resistive switching characteristics and self-rectifying characteristics, receives the high and low levels output by the threshold comparison circuit, and drives the temperature regulation device.

[0009] The temperature regulation device includes a heating and cooling system, which is driven by the memristor differential pair, and provides heating and cooling to restore the SAW filter to the rated temperature range when it exceeds the rated temperature.

[0010] Further, the temperature sensor is composed of a lithium niobate SAW resonator, and is subsequently connected to a frequency-voltage converter to convert the frequency change of the SAW resonator caused by temperature into a voltage signal, which is conducive to the integrated miniaturization of the entire adaptive temperature regulation system.

[0011] Further, the temperature sensor is a temperature sensor using a metal wire with a thermal resistance effect, which has both sensitivity and integration of the entire system.

[0012] Further, the memristor differential pair is composed of two memristors based on a lithium niobate single crystal thin film, which is conducive to the integrated miniaturization of the entire adaptive temperature regulation system.

[0013] Further, the heating system in the temperature regulation device realizes temperature rise control by driving a micro-scale resistance wire with current, which is conducive to the integrated miniaturization of the entire adaptive temperature regulation system.

[0014] Further, the refrigeration system is an air-cooling system to cool down the SAW filter.

[0015] Further, the refrigeration system uses a micro-refrigeration device (such as micro-channel refrigeration) to cool down the SAW filter, and has the integrated miniaturization of the entire system.

[0016] Further, the temperature sensor is composed of a lithium niobate SAW resonator, the memristor differential pair uses a memristor based on a lithium niobate single crystal thin film, and the heating system of the temperature regulation device uses a micro-scale resistance wire, which are integrated on a lithium niobate substrate together with the SAW filter; then a micro-channel refrigeration system is prepared on the lithium niobate substrate; making the entire system highly integrated.

[0017] The working process of the above-mentioned adaptive temperature regulation system for the lithium niobate surface acoustic wave filter is specifically as follows:

[0018] Step 1: During the operation of the SAW filter, the temperature changes, and the temperature change is detected by the temperature sensor. The change caused by temperature is converted into a temperature voltage signal V temp .

[0019] Step 2: The temperature voltage signal judges the temperature deviation direction through a window comparator in the threshold comparison circuit and outputs corresponding high and low levels;

[0020] A window comparator composed of two voltage comparators judges whether the temperature voltage signal exceeds the upper and lower limits of the threshold value, so as to trigger corresponding control signals; when the input voltage V temp is greater than the high temperature threshold V th_high , the upper limit voltage comparator outputs a high level, and the lower limit voltage comparator outputs a low level, indicating refrigeration enable; when V temp is less than the low temperature threshold Vth_low When the upper limit voltage comparator outputs a low level and the lower limit voltage comparator outputs a high level, it indicates heating enable; when V temp is in the range of V th_high and V th_low When between them, both voltage comparators output a high level, indicating that temperature regulation is not triggered within the window range.

[0021] Step 3: Connect the voltages output by the above upper and lower limit voltage comparators to the two memristors of the memristor differential pair respectively to output the corresponding currents; the two memristors in the memristor differential pair have opposite resistive switching characteristics and self-rectifying characteristics. Apply the corresponding voltage to the memristor through the voltage output by the comparator, and the difference between the output currents is I control .

[0022] Step 4: Determine whether to use heating or cooling based on the positive or negative of I control : If the value of I control is positive, it indicates that the temperature of the SAW filter is higher than the high temperature threshold at this time, and I control drives the refrigeration system to cool down; if the value of I control is negative, it indicates that the temperature is lower than the low temperature threshold at this time, and I control drives the micro-scale resistance wire to heat up the system.

[0023] In summary, the present invention combines a temperature sensor, a memristor differential pair, a temperature regulation device with a SAW filter, and proposes an adaptive temperature regulation system for a SAW filter. By using a temperature sensor, a memristor differential pair, and a temperature regulation device, and cooperating with a circuit, the adaptive linkage of each component is realized; and a highly integrated solution that is all integrated on a lithium niobate substrate is further provided, reducing the power consumption, volume, and noise of the entire adaptive temperature control system, while improving the reliability and extensibility of the system. This integrated design can not only optimize the overall performance of the SAW filter, but also has low power consumption, high reliability, and a wide range of adaptation scenarios, providing an innovative solution for the next generation of high-frequency communication, aerospace, and power electronics fields. Description of the Drawings

[0024] Figure 1 is the working flow chart of the adaptive temperature regulation system of the lithium niobate surface acoustic wave filter in the embodiment;

[0025] Figure 2 is the schematic diagram of the window comparator circuit in the embodiment. Detailed Embodiment

[0026] The present invention will be further described in detail below with reference to the drawings and embodiments.

[0027] In this embodiment, the adaptive temperature regulation system of the lithium niobate surface acoustic wave filter adopts a fully integrated architecture: the temperature sensor is composed of a lithium niobate SAW resonator, the memristor differential pair uses a memristor based on a lithium niobate single crystal thin film, and the heating system of the temperature regulation device uses a micro-scale resistance wire, which is integrated on the lithium niobate substrate together with the SAW filter; then a microchannel refrigeration system is prepared on the lithium niobate substrate; making the whole system highly integrated.

[0028] The specific working process is as follows:

[0029] Step 1. During the operation of the SAW filter, a temperature change occurs, and the temperature sensor receives the temperature change. The change in the resonance frequency of the SAW resonator with temperature is expressed as:

[0030] f(T) = f0[1 + TCF·(T - T0)]

[0031] By measuring the frequency offset Δf = f(T) - f0, the temperature change ΔT = Δf / (f0·TCF) can be obtained.

[0032] Step 2. The temperature sensor outputs a frequency change, and the frequency is converted into a voltage V through a frequency-voltage converter temp .

[0033] Step 3. When the input voltage V temp is greater than the high-temperature threshold V th_high , the upper limit voltage comparator outputs a high level, indicating refrigeration enabling; when V temp is less than the low-temperature threshold V th_low , the lower limit voltage comparator outputs a high level, indicating heating enabling; when V temp is between V th_high and V th_low , both voltage comparators output a high level, indicating that temperature regulation is not triggered within the window range to avoid frequent switching of the temperature control device.

[0034] By comparing the threshold with the voltage, the direction of the temperature deviation (temperature rise / temperature drop) is judged, and the corresponding control signal is triggered. As shown in this embodiment Figure 2 , two operational amplifiers U1 and U2 are used to set the upper and lower thresholds V th_high and V th_low . In U1, the inverting input terminal is connected to the threshold high voltage V th_high through a resistor voltage division network, and the non-inverting input terminal is directly connected to the input signal V temp . When V temp is greater than V th_high , a high level is output, otherwise a low level is output. In U2, the non-inverting input terminal is connected to the threshold low voltage V th_low through a resistor voltage division network, and the inverting input terminal is directly connected to the input signal Vtemp When V temp is less than V th_low , a high level is output; otherwise, a low level is output.

[0035] Step 4: Input the voltage into the memristor differential pair and dynamically regulate the output.

[0036] Connect the outputs of U1 and U2 to the memristor differential pair, where the two memristors have opposite resistive switching characteristics and self-rectifying characteristics. The finally output current I control is expressed as:

[0037] I control = I heat - I cool

[0038] Since a high level will reduce the resistance of the memristor and cause the corresponding current to increase. Therefore, when the temperature of the SAW filter is too high, U1 outputs a high level, U2 outputs a low level, and the current of I heat is greater than I cool , and I control outputs a positive value; while when the temperature of the SAW filter is too low, U1 outputs a low level, U2 outputs a high level, and the current of I heat is less than I cool , and I control outputs a negative value.

[0039] Step 5: Judge heating or cooling according to the positive or negative of I control . If I control is positive, it will drive the microchannel refrigeration system to cool the SAW filter; if I control is negative, it will drive the micro-scale resistance wire to heat the SAW filter.

[0040] As can be seen from the above examples, the present invention realizes an adaptive temperature regulation system for a lithium niobate surface acoustic wave filter. This system can dynamically adjust the temperature according to the temperature change of the filter, so as to ensure that the filter works under the best performance. This adaptive adjustment not only improves the stability and reliability of the filter, but also reduces the risk of performance degradation caused by temperature fluctuations. Through real-time monitoring and regulation, the system can timely respond to environmental changes, achieving higher precision and flexibility, and has broad application prospects.

Claims

1. An adaptive temperature regulation system for a lithium niobate surface acoustic wave filter, characterized in that: It consists of four parts: a SAW filter, a temperature sensor, a memristor differential pair, and a temperature regulation device; The SAW filter is composed of a lithium niobate SAW resonator; The temperature sensor real-time collects the operating temperature of the SAW filter, converts the change caused by temperature into a temperature voltage signal; the temperature voltage signal judges the temperature deviation direction through the window comparator in the threshold comparison circuit and outputs the corresponding high and low levels; The memristor differential pair is composed of two memristors with opposite resistive switching characteristics and self-rectifying characteristics, receives the high and low levels output by the threshold comparison circuit, and drives the temperature regulation device; The temperature regulation device includes a heating and a cooling system, is driven by the memristor differential pair, and when the SAW filter exceeds the rated temperature, provides heating and cooling to make it return to the rated temperature range.

2. The adaptive temperature regulation system of the lithium niobate surface acoustic wave filter according to claim 1, characterized in that: The temperature sensor is composed of a lithium niobate SAW resonator, and then accesses a frequency-voltage converter to convert the frequency change of the SAW resonator caused by temperature into a voltage signal.

3. The adaptive temperature regulation system of the lithium niobate surface acoustic wave filter according to claim 1, characterized in that: The temperature sensor is a temperature sensor using a metal wire utilizing the thermal resistance effect.

4. The adaptive temperature regulation system of the lithium niobate surface acoustic wave filter according to claim 1, wherein: The memristor differential pair is composed of two memristors based on a lithium niobate single crystal thin film.

5. The adaptive temperature regulation system of the lithium niobate surface acoustic wave filter according to claim 1, characterized in that: The heating system in the temperature regulation device realizes heating control by driving a micro-scale resistance wire to generate heat through current.

6. The adaptive temperature regulation system of the lithium niobate surface acoustic wave filter according to claim 1, wherein: The cooling system is an air-cooling system to cool the SAW filter.

7. The adaptive temperature regulation system of the lithium niobate surface acoustic wave filter according to claim 1, characterized in that: The cooling system adopts microchannel refrigeration to cool the SAW filter.

8. The adaptive temperature regulation system of the lithium niobate surface acoustic wave filter according to claim 1, characterized in that: The temperature sensor is composed of a lithium niobate SAW resonator, the memristor differential pair adopts a memristor based on a lithium niobate single crystal thin film, the heating system of the temperature regulation device adopts a micro-scale resistance wire, and is integrated with the SAW filter on a lithium niobate substrate; then a microchannel cooling system is fabricated on the lithium niobate substrate; making the whole system highly integrated.

9. The adaptive temperature regulation system of the lithium niobate surface acoustic wave filter according to claim 1, characterized in that, The specific working process is as follows: Step 1: During the operation of the SAW filter, the temperature changes. The temperature sensor detects the temperature change and converts the change caused by the temperature into a temperature voltage signal V through a circuit temp ; Step 2: The temperature voltage signal judges the temperature deviation direction through the window comparator in the threshold comparison circuit and outputs the corresponding high and low levels; A window comparator composed of two voltage comparators is used to determine whether the temperature voltage signal exceeds the upper and lower limits of the threshold, so as to trigger the corresponding control signal; when the input voltage V temp is greater than the high-temperature threshold V th_high , the upper-limit voltage comparator outputs a high level, and the lower-limit voltage comparator outputs a low level, indicating refrigeration enabling; when V temp is less than the low-temperature threshold V th_low , the upper-limit voltage comparator outputs a low level, and the lower-limit voltage comparator outputs a high level, indicating heating enabling; when V temp is between V th_high and V th_low , both voltage comparators output high levels, indicating that temperature regulation is not triggered within the window range; Step 3: Connect the voltages output by the above upper and lower limit voltage comparators to the two memristors of the memristor differential pair respectively, and output the corresponding currents; The two memristors in the memristive differential pair have opposite resistive switching characteristics and self-rectifying characteristics. A corresponding voltage is applied to the memristors through the voltage output by the comparator, and the difference between the output currents is I control ; Step 4. Determine whether to use heating or cooling based on the positive or negative value of I control : If the value of I control is positive, it means that the temperature of the SAW filter is higher than the high temperature threshold at this time, and I control drives the refrigeration system to cool down; if the value of I control is negative, it means that the temperature is lower than the low temperature threshold at this time, and I control drives the micro-scale resistance wire to heat up the system.

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