Temperature compensation method for thermistor power sensor and device thereof

Abstract

The application discloses a temperature compensation method and device of a thermistor power sensor, which comprises arranging multiple temperature sensing elements inside the power sensor, collecting temperature data on the inside of the power sensor shell, the inside of the power flange base and the top of the thermistor element protection barrel in real time; obtaining a compensation value of power drift caused by the ambient temperature through the reference end of the power sensor; and calculating the output power after temperature compensation by using a compensation model based on the temperature data of the multiple temperature sensing elements and the compensation value of the reference end, so that the output power after compensation of the reference end is compensated again by using the temperature value of multiple key positions, the power error caused by the change of the working end with temperature is eliminated, the output power error caused by insufficient process level can be effectively offset, and the stability of power measurement is significantly improved.

Description

Technical Field

[0001] This invention relates to the field of microwave remote sensing geological disaster monitoring technology, and in particular to a temperature compensation method and apparatus for a thermistor power sensor. Background Technology

[0002] With the widespread application of radio frequency and microwave technologies in communications, radar, and electronic testing, higher demands are placed on the accuracy and stability of power measurements. As a core measurement component, power sensors must possess high sensitivity and good temperature stability. Thermistor-type power sensors, due to their high measurement accuracy, good linearity, and adaptability to high frequencies, have become the preferred choice for many application scenarios.

[0003] A thermistor-type power sensor mainly consists of a waveguide mount, a thermistor element, and a sensing chip. During operation, an RF signal is introduced through the waveguide port, causing the sensing chip to heat up. This heated chip then conducts heat to the thermistor element, causing a change in its resistance. To measure RF power, a DC bias voltage is applied to the thermistor element before the RF input. After the temperature stabilizes, an RF signal is input, further heating the element. The power meter automatically adjusts the bias voltage to maintain a constant thermistor resistance, and the RF power can be calculated from the change in the bias voltage.

[0004] Traditional methods employ a reference terminal symmetrically positioned to the working end, using its output value to compensate for power drift caused by temperature fluctuations at the working end. However, due to limitations in laboratory manufacturing processes, perfect symmetry is difficult to achieve during sensor fabrication, often resulting in residual errors in the compensation from the reference terminal to the working end.

[0005] In the prior art, in order to compensate for the influence of ambient temperature changes on the thermal power sensor during operation, a temperature compensation scheme with a double-ended symmetrical structure is usually adopted.

[0006] This solution is based on the traditional dual-ended thermistor power sensor structure, integrating a temperature acquisition system within the power sensor. This system includes multiple temperature sensing elements used to collect temperature data from the inner wall of the sensor housing, the inner side of the power flange, and the area above the thermistor protection chamber. Real-time monitoring of internal temperature changes allows for secondary compensation of the traditional dual-ended sensor's output power, achieving precise correction of errors caused by temperature variations. Summary of the Invention

[0007] The purpose of this invention is to provide a temperature compensation method and apparatus for a thermistor power sensor, aiming to solve the problem that traditional reference-end compensation methods cannot effectively eliminate temperature errors under conditions of low technological level.

[0008] To achieve the above objectives, the present invention is implemented according to the following technical solution:

[0009] In one aspect, the present invention includes the following steps:

[0010] Multiple temperature sensing elements are set inside the power sensor to collect temperature data in real time from the inner wall of the sensor housing, the inner side of the power flange seat, and the top of the thermistor protection barrel.

[0011] The compensation value for power drift caused by ambient temperature is obtained through the reference terminal of the power meter of the power sensor.

[0012] Based on the temperature data from the multiple temperature sensing elements and the reference compensation value, the output power after temperature compensation is calculated using a compensation model.

[0013] The compensation calculation model is shown in the formula:

[0014]

[0015] in, This is the power output after temperature compensation; This is the power value at the working end; Reference power value; This indicates the local temperature value collected by the temperature sensor; Its corresponding temperature compensation coefficient; This is the power correction factor.

[0016] Furthermore, the temperature sensing element is a thermocouple or other thermistor, and is arranged on the inner wall of the sensor, the inner side of the power flange seat, or the upper side of the protective barrel.

[0017] Furthermore, the power sensor performs the calculation of the compensation model through a signal processing platform, which is used to receive power data and temperature acquisition data from the reference and working ends of the power meter.

[0018] On the other hand, a temperature compensation device for a thermistor power sensor includes a sensor body, a temperature acquisition system, and a signal processing platform. A power meter is disposed outside the sensor, and the power meter is provided with a working end and a reference end output. The temperature acquisition system includes multiple temperature sensing elements for acquiring the temperature of the inner wall of the sensor housing, the inner side of the power flange seat, and the top of the thermistor protection barrel. The signal output end of the temperature acquisition system and the signal output end of the sensor body are respectively connected to the signal input end of the signal processing platform, which is used to calculate the output power after temperature compensation.

[0019] Furthermore, the temperature sensing element is covered with a sealed barrel to reduce external temperature field interference.

[0020] Furthermore, the reference end and the working end of the sensor body are symmetrically arranged, and the reference end does not receive radio frequency signals.

[0021] Compared with the prior art, the embodiments of the present invention have at least the following advantages or beneficial effects:

[0022] 1. This invention collects data from multiple key locations in real time and uses these temperature values ​​to recompensate the output power after compensation at the reference end, eliminating the power error caused by temperature changes in the compensated power output. This method can effectively offset the output power error caused by insufficient process level and significantly improve the stability of power measurement. Attached Figure Description

[0023] Figure 1 is a block diagram of a thermistor power sensor with a temperature compensation method for the thermistor power sensor according to the present invention.

[0024] Figure 2 is a schematic diagram of a thermistor power sensor with a temperature compensation method for a thermistor power sensor according to the present invention.

[0025] Figure 3 is a schematic diagram of the waveguide port of a thermistor power sensor with a temperature compensation method for a thermistor power sensor according to the present invention.

[0026] Figure 4 is a side view of the thermistor power sensor c, which is a temperature compensation method for the thermistor power sensor according to the present invention.

[0027] Figure 5 is a schematic diagram of a thermistor power sensor base type power sensor with a temperature compensation method for the thermistor power sensor according to the present invention.

[0028] Figure 6 is a schematic diagram comparing the power of WR5* and PM5 without power in the temperature compensation method of the thermistor power sensor of the present invention.

[0029] Figure 7 shows a comparison of the PM5 / WR5* power ratio in the temperature compensation method of the thermistor power sensor of the present invention. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0031] Reference Figure 1As shown, the present invention provides a temperature compensation method for a thermistor power sensor, comprising: setting multiple temperature sensing elements inside the power sensor, and collecting temperature data in real time near the sensing chip, around the thermistor elements, and inside the waveguide structure.

[0032] The power drift compensation value caused by ambient temperature is obtained through the reference terminal of the power meter of the power sensor;

[0033] Based on the temperature data from the multiple temperature sensing elements and the reference compensation value, the output power after temperature compensation is calculated using a compensation model.

[0034] This invention is based on the traditional dual-ended thermistor power sensor structure, and integrates a temperature acquisition system within it, such as... Figure 2 As shown in the figure. The sensor mainly includes a waveguide mount, a sensing chip, a thermistor, and a temperature acquisition component.

[0035] like Figure 3 As shown, the radio frequency signal is incident from the waveguide port (5) and enters as shown. Figure 5 The waveguide cavity (8) shown is in contact with the sensing chip (6). The sensing chip heats up due to receiving radio frequency power, and the thermistor (7) attached to the sensing chip heats up and its resistance changes accordingly.

[0036] To measure radio frequency (RF) power, a bias voltage must be applied to the thermistor before inputting the RF signal, and the RF signal must be input after the temperature stabilizes. At this time, the thermistor heats up further, causing its resistance to change; the DC bias voltage provided by the power meter will automatically adjust to keep the thermistor's operating resistance constant, so the magnitude of the RF power can be calculated based on the change in bias voltage.

[0037] The sensor's integrated temperature acquisition system monitors the temperature of key locations such as the inner wall of the sensor housing and the inner side of the power flange in real time. This data is combined with a reference power value, and an algorithm is used to recalculate the compensated power output.

[0038] To suppress measurement errors caused by ambient temperature fluctuations, traditional thermistor-type power sensors typically have a symmetrical reference end (10) with the same structure as the working end (9), but it does not receive radio frequency signals. This reference end is used to sense the ambient temperature and compensate for temperature errors in the output power of the working end. However, under the limited laboratory process capabilities, it is difficult to achieve complete symmetry between the reference end and the working end in sensor manufacturing, resulting in residual errors in the compensation effect and limiting the measurement stability and accuracy.

[0039] Therefore, based on the above structure, this invention proposes an enhanced temperature compensation structure, which integrates multiple temperature sensing elements (3) inside the sensor to form a temperature acquisition system (1) for real-time acquisition of temperature information at key locations such as the inner wall of the sensor housing, the inner side of the power flange seat, and the top of the thermistor protection barrel; in addition, a sealed small barrel (2) fixed by screws is installed outside the thermistor to reduce the influence of room temperature fluctuations on the internal temperature field of the sensor, thereby improving the consistency of compensation between the reference end and the working end.

[0040] The compensation system of the present invention also includes a signal processing platform (ZYNQ) that is compatible with the sensor, used to receive the bias voltage signal output by the thermistor, the power data of the reference terminal and the working terminal, and the multi-point temperature information provided by the temperature acquisition system.

[0041] The compensation calculation model is shown in the formula:

[0042]

[0043] in, This is the power output after temperature compensation; This is the power value at the working end; Reference power value; This represents the local temperature coefficient collected by the temperature sensor. Its corresponding temperature compensation coefficient; is the power correction factor; e is a constant.

[0044] In this implementation example, such as Figures 2 to 5 As shown, the sensor includes: waveguide base (4), temperature sensing element (3), waveguide port (5), waveguide cavity (8), sensing chip (6), thermistor (7), working end (9), reference end (10), sealed barrel (2), and temperature acquisition system (1).

[0045] The sensing chip is made of silicon (Si) substrate, which has good thermal conductivity and is used to absorb radio frequency power and generate heat. The sensing chip is attached to the waveguide with thermal conductive gel (Kafuter K-5204K), and the thermistor (thin-film platinum resistance PT1000, room temperature resistance 1000 ohms) is attached to the sensing chip with thermal conductive gel. The temperature acquisition system (1) is used to acquire and amplify the voltage of the temperature detection element, and includes 6 temperature detection elements (thermocouple model: Kapsen thermocouple K type), which are respectively arranged on the inner wall of the sensor, the inner side of the power flange seat, and the upper side of the protective barrel. The output voltage of the thermocouple will change with the temperature, and the resistance of the thin-film platinum resistance PT1000 will change with the temperature.

[0046] Work process:

[0047] The tests were conducted in the terahertz frequency band, and the power mount sensor used belonged to the WR5 band; therefore, the device of this invention is abbreviated as WR5. To verify the effectiveness of the temperature compensation structure described in this invention, a power sensor PM5 (model omitted) was introduced as a comparison standard. The output stability of PM5 and WR5 under zero power input and actual input conditions was analyzed in the tests.

[0048] The testing process is as follows:

[0049] First, an external power meter applies a bias voltage (3V) to the thermistor to drive it into a thermally stable state.

[0050] The sensing chip (6) is not subject to external radio frequency excitation at this time, but is only affected by the ambient temperature;

[0051] The temperature acquisition system (1) acquires the tiny voltage difference caused by the internal temperature change and processes it through the ZYNQ signal processing platform;

[0052] The bias voltage values ​​of the thermistors at the working and reference terminals are recorded synchronously and denoted as follows:

[0053] This is the bias voltage for the thermistor (PT1000) at the working end;

[0054] The bias voltage for the reference thermistor (PT1000);

[0055] This is the output power value after reference terminal temperature compensation;

[0056] ;

[0057] It is a constant;

[0058] This is the power correction factor;

[0059] The signal processing platform uses the following computational model:

[0060]

[0061] The voltage output by the temperature sensing element ( Standardize to obtain the temperature coefficient ( ),in This is the average voltage value. Standard deviation voltage value:

[0062]

[0063] Further compensation For the final power output, This is the power output after reference compensation. This represents the local temperature coefficient collected by the temperature sensor. Its corresponding temperature compensation system:

[0064] After 2.5 hours of continuous input without radio frequency signal, Figure 6 Data shows:

[0065] The WR5 has an output power fluctuation range of ±3.5 μW without compensation.

[0066] After being processed by the temperature compensation structure of this invention, the output fluctuation is reduced by 83%, and the fluctuation amplitude is less than ±0.6 μW;

[0067] The results are highly consistent with those of PM5, verifying that this structure has a good compensation effect.

[0068] In the second phase of the above experiment, the signal source (Hewlett-Packard HP 83752A) was turned on with an output power of 14GHz 1.9dBm, and a terahertz band spread spectrum module (TLSE-140220-0530-05, with an output frequency range of 140GHz ~ 220 GHz) was used to transmit the signal simultaneously to WR5 on the side arm and PM5 on the main arm through a directional coupler, and a test was conducted for 2.5 hours.

[0069] like Figure 7 The figure shows the power ratio curves of PM5 / WR5* and PM5 / WR5 during the RF power test. Using the output power of PM5 as a reference standard, the ratios of PM5 relative to WR5* and WR5 were constructed respectively. The results show that, under the condition of compensation using the temperature sensing element described in this invention, the power output of WR5 is more stable, and the fluctuation of the measurement results is significantly reduced.

[0070] In summary, the enhanced temperature compensation structure proposed in this embodiment exhibits excellent resistance to temperature drift and power measurement stability under actual process conditions. Compared with the existing reference device PM5, it shows lower output fluctuations under both zero-power and high-power conditions. Under power conditions, it also shows more stable output compared with single-reference-terminal compensation, verifying the effectiveness and application value of the structure of this invention.

[0071] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A temperature compensation method for a thermistor power sensor, characterized in that, Includes the following steps: Multiple temperature sensing elements are installed inside the power sensor to collect temperature data in real time on the inside of the power sensor housing, the inside of the power flange seat, and the top of the thermistor protection barrel. The compensation value for power drift caused by ambient temperature is obtained through the reference terminal of the power sensor. Based on the temperature data from the multiple temperature sensing elements and the reference compensation value, the output power after temperature compensation is calculated using a compensation model. The compensation calculation model is shown in the formula: in, This is the power output after temperature compensation; Measure the power value at the working end; This is a reference power value; This indicates the local temperature value collected by the temperature sensor; Its corresponding temperature compensation coefficient; This is the power correction factor for the reference terminal.

2. The temperature compensation method for a thermistor power sensor according to claim 1, characterized in that, The temperature sensing element is a thermocouple or other thermistor, which is arranged on the inner wall of the sensor housing, the inner side of the power flange seat, and the upper side of the thermistor protection barrel.

3. The temperature compensation method for a thermistor power sensor according to claim 1, characterized in that, The power sensor performs the calculation of the compensation model through a signal processing platform, which is used to receive power data and temperature acquisition data from the reference and working ends of the power meter.

4. A temperature compensation device for a thermistor power sensor, used to perform the method as described in any one of claims 1-3, comprising a sensor, a power meter disposed outside the sensor, the power meter being provided with a working terminal and a reference terminal output, characterized in that, It also includes a temperature acquisition system and a signal processing platform. The temperature acquisition system includes multiple temperature sensing elements for acquiring the temperature of the inner wall of the sensor housing, the inner side of the power flange seat, and the thermistor protection barrel. The signal output terminal of the temperature acquisition system and the signal output terminal of the power meter are respectively connected to the signal input terminal of the signal processing platform. The signal processing platform is used to calculate the output power after temperature compensation.

5. The temperature compensation device for a thermistor power sensor according to claim 4, characterized in that, The temperature sensing element is covered by a sealed casing to reduce external temperature field interference.

6. The temperature compensation device for a thermistor power sensor according to claim 4, characterized in that, The reference end and the working end of the sensor body are symmetrically arranged, and the reference end does not receive radio frequency signals.

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