Terahertz thermoelectric power sensing chip, thermoelectric power sensor and application

Abstract

The invention belongs to the technical field of thermoelectric power sensors, and particularly relates to a terahertz thermoelectric power sensing chip, a thermoelectric power sensor and application. The structural form of the chip is a heat insulation layer / absorption layer / isolation layer / thermopile / isolation layer / direct current resistor / heat insulation layer. The terahertz signal power absorbed by the absorption layer causes the temperature change of the absorption layer; the thermopile determines the incident power of the terahertz signal by determining the temperature variation of the absorption layer; generalized efficiency is used as the correction calibration amount of the power transmission standard by the direct-current resistor. The terahertz thermoelectric power sensing chip provided by the invention is applied to a thermoelectric power sensor, and the sensor adopts a high-precision and low-standing-wave ultra-wideband waveguide matching load to absorb high-frequency microwave signal power, so that the problem that the measurement frequency of a power meter is limited is solved; the measurement frequency range of the waveguide type thermoelectric power sensor is expanded to 1.1 THz, and the waveguide type thermoelectric power sensor can be used for measuring terahertz signals.

Description

Technical Field

[0001] This invention belongs to the field of thermoelectric power sensor technology for measuring terahertz signals, specifically involving terahertz thermoelectric power sensing chips, thermoelectric power sensors, and their applications. Background Technology

[0002] The main characteristics and trends in the current development of electronic technology are increasingly higher operating frequencies and wider frequency ranges, with research on electronic equipment in fields such as radar and communications entering the terahertz band. Therefore, to meet the power testing needs of related terahertz electronic equipment, it is urgent to extend the operating frequency range of power meters to the terahertz band.

[0003] Currently, common thermoelectric power sensors include coaxial connectors, microstrip lines, load terminals, and thermopile components. Microwave signals are transmitted to the load terminals via the coaxial connectors and microstrip lines, where the microwave power is converted into heat. The Seebeck effect then allows the thermopile, placed near the load terminals, to convert the heat into DC voltage. Furthermore, an E-plane probe can be used to transition from waveguide to microstrip line, thus forming a waveguide thermoelectric power sensor.

[0004] Coaxial thermoelectric power sensors can measure frequencies up to 110 GHz, but this is limited by the manufacturing process of coaxial connectors, making it difficult to extend the frequency further. Waveguide thermoelectric power sensors can measure even higher frequency microwave signals, up to 220 GHz, but as the frequency increases, the dimensions of the microstrip line and waveguide decrease significantly. At this point, the dispersion effect of the microstrip line, the cutoff characteristics of the waveguide, and the mode conversion between the two become more difficult, leading to a sharp increase in the standing wave ratio (VSWR), making it difficult to meet the measurement accuracy requirements. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a terahertz thermoelectric power sensing chip and a thermoelectric power sensor using this chip. The sensor employs a high-precision, low-VSWR ultrawideband waveguide matched load to absorb high-frequency microwave signal power, solving the problem of limited measurement frequency of power meters. This extends the measurement frequency range of the waveguide thermoelectric power sensor to 1.1THz, making it suitable for measuring terahertz signals.

[0006] The technical solution adopted by the present invention to solve its technical problem is as follows: a terahertz thermoelectric power sensing chip, the chip is a composite chip, and the structure is a heat insulation layer / absorption layer / isolation layer / thermopile / isolation layer / DC resistor / heat insulation layer; The absorption layer is used as a radio frequency load, and the absorbed terahertz signal power will cause the temperature of the absorption layer to change; Thermopile, as a temperature sensing device, uses the Seebeck effect of thermocouples to determine the temperature change of the absorption layer, thereby determining the incident power of terahertz signals. DC resistors are used as heaters, and generalized efficiency is used as a correction calibrator for power transfer standards.

[0007] Preferably, a thermopile consisting of multiple pairs of thermocouples connected in series is fabricated on the radio frequency load and distributed around the radio frequency load.

[0008] Preferably, the absorption layer is a silicon material with a resistive layer plated on the outside; the DC resistor is tantalum nitride; the heat insulation layer is polyimide; and the isolation layer is silicon dioxide.

[0009] Preferably, the silicon material is first doped and then a resistive layer is deposited on its surface to form an absorption layer.

[0010] A thermoelectric power sensor for measuring terahertz signals includes: a housing, a chip, and a waveguide, wherein the chip is encapsulated in a waveguide; the chip is the aforementioned terahertz thermoelectric power sensor chip, the housing has a double-layer structure, and the waveguide is used to guide the terahertz signal to propagate to the radio frequency load.

[0011] Preferably, the inner cavity between the two layers of the double-layer shell is filled with silicon dioxide powder; a thermal isolation section is provided in the middle of the waveguide, and the thermal isolation section is made of ABS plastic with copper plating on the surface.

[0012] Preferably, the chip is positioned along the long side of the rectangular waveguide. Place it at an angle.

[0013] The aforementioned application of thermoelectric power sensors for measuring terahertz signals is applied to... Power measurement within the frequency range.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The terahertz thermoelectric power sensing chip proposed in this invention adopts a composite structure design to integrate an RF load, a thermopile, and a DC resistance heater; the load converts the input high-frequency signal into heat energy, and a thermopile is placed on the load to convert the heat into DC voltage to achieve power measurement.

[0015] 2. The present invention proposes a thermoelectric power sensor for measuring terahertz signals. It uses a high-precision, low-VSWR ultrawideband waveguide matched load to convert the input high-frequency signal into heat energy, and places a thermopile on the load to convert the heat into DC voltage to achieve power measurement.

[0016] 3. This invention proposes a terahertz thermoelectric power sensing chip, which utilizes the high-pass characteristics of waveguides and the insensitivity of power sensing chips to waveguide modes to achieve power measurement in the frequency range of 75GHz to 1.1THz, thus solving the problem of limited measurement frequency.

[0017] 4. This invention employs a metal waveguide with a thermally isolated section and a double-layer thermal insulation structure to isolate the power sensor from the external temperature, reducing heat exchange with the external environment and minimizing drift caused by changes in ambient temperature. Furthermore, the power sensing chip is also encased in a thermal insulation layer, further reducing the impact of ambient temperature on the measurement results.

[0018] In summary, the sensor in this invention uses a high-precision, low-VSWR ultrawideband waveguide matched load to convert the input high-frequency signal into heat energy, and places a thermopile on the load to convert the heat into DC voltage to achieve power measurement; at the same time, by placing a resistance heater in the center of the load, the DC power substitution problem is solved, and traceable power calibration is achieved; the problem of limited measurement frequency of the power meter is solved, and power measurement in the frequency range of 75GHz to 1.1THz is realized. Attached Figure Description

[0019] Figure 1 This is a basic structural diagram of a thermoelectric power sensor.

[0020] Figure 2 This is a structural diagram of a power sensor chip.

[0021] Figure 3 The diagram shows the power measurement of the WR10 waveguide in the frequency range of 75 GHz to 110 GHz.

[0022] Figure 4 The diagram shows the power measurement in the frequency range of 0.75THz to 1.1THz using a WR1.0 waveguide adapter. Detailed Implementation

[0023] To facilitate understanding of the present invention, it will be described in more detail below with reference to the accompanying drawings and specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention.

[0024] Example 1: A thermoelectric power sensor for measuring terahertz signals. Figure 1 The basic structure of a terahertz thermoelectric power sensor is given, and its basic components include: WR10 waveguide, heat insulation section, radio frequency load, thermopile, resistance heater, and housing.

[0025] In this patent, an integration of an RF load, a thermopile, and a resistance heater is achieved through a power sensing chip. This composite chip employs... In terms of structure, silicon is used as the RF load, and the absorbed terahertz signal power will cause temperature changes in the silicon layer. To better absorb terahertz signal power, we increase the bulk conductivity of the silicon material through doping to improve its absorption capability, and deposit a resistive layer with suitable resistivity to achieve better impedance matching. Common semiconductor doping processes are used, and doping with arsenic, aluminum, or gallium is possible. After doping, the bulk conductivity of the silicon material is [missing value]. Within the range; the resistive layer is generally a TaN thin film resistor, with a sheet resistance value of [value missing]. Thermopiles are used as temperature sensing devices, and the Seebeck effect of thermocouples is used to determine the temperature change of the silicon layer, thereby determining the incident power of the terahertz signal. The TaN (tantalum nitride) layer is used as a DC resistance heater, mainly to solve the power substitution problem in the transmission standard, and the generalized efficiency is used as a correction calibration value for the power transmission standard. The silicon dioxide layer is mainly used for electrode isolation, while polyimide is used for chip thermal insulation to reduce the impact of ambient temperature.

[0026] A thermopile consisting of multiple pairs of thermocouples connected in series is fabricated on an RF load and distributed around the RF load. The Seebeck effect of the thermocouples is used to measure the heat generated by the power absorbed in the RF load, thereby converting it into DC voltage.

[0027] In this patent, the designed terahertz thermoelectric power sensor operates over an extremely wide frequency range. Based on its performance characteristics, this patent utilizes a power sensing chip with... The WR10 waveguide port is installed at an angle to enable power measurement within the 75GHz–110GHz frequency range. The angled structure effectively inserts an impedance along the electromagnetic wave propagation path, gradually transitioning from the waveguide impedance to the RF load impedance. This gradual impedance change reduces the reflection coefficient at the waveguide port. Figure 3 As shown. Meanwhile, to meet the needs of users in different waveguide bands, a series of waveguide adapters are used to transfer terahertz signals to the WR10 waveguide, thereby enabling high-frequency microwave signal power measurement. For example... Figure 4 As shown, a WR1.0 waveguide adapter is used to achieve power measurement in the 0.75THz~1.1THz frequency band.

[0028] Different waveguide adapters correspond to different frequency bands, such as WR10 for 75GHz to 110GHz; WR8 for 90GHz to 140GHz; WR4.3 for 140GHz to 220GHz; WR2.8 for 220GHz to 330GHz; WR1.9 for 30GHz to 500GHz; WR1.5 for 400GHz to 600GHz; WR1.2 for 500GHz to 750GHz; and WR1.0 for 750GHz to 1100GHz. Power measurement from 75GHz to 1.1THz can be achieved through a series of waveguide adapters.

[0029] The sensor consists of inner and outer metal shells, with silica powder filling the interior to reduce heat exchange with the external environment and decrease drift caused by changes in ambient temperature. Meanwhile, copper-plated ABS plastic (acrylonitrile-butadiene-styrene) is used to create a metal waveguide with a thermally insulating section, reducing the waveguide's heat transfer characteristics and improving measurement accuracy.

[0030] The working principle of a terahertz thermoelectric power sensor is as follows: The working principle of this technical solution is as follows: the terahertz signal is transmitted to the RF load through the WR10 waveguide, and the generated Joule heat is transferred to the periphery of the chip, creating a temperature gradient. The Seebeck effect of the thermocouple is used to measure the heat generated by the power absorbed in the RF load, thereby converting it into DC voltage. Simultaneously, a resistance heater is placed in the center of the load to solve the DC power substitution problem, achieving traceable power calibration. Firstly, the incident power of the thermoelectric power sensor... Absorbed power in RF load The relationship between them can be expressed as: (1); in, Represents the reflection coefficient of a thermoelectric power sensor. Generalized efficiency. Expressed as the DC substitution power in the DC resistance under the same thermopile output voltage. With RF power in RF load The ratio can be expressed as: (2); in It is the output voltage of the thermopile in DC measurements. This refers to the output voltage of the thermopile in radio frequency measurements. DC substitution power. The incident power can be measured using a precision multimeter. By combining formula (1) and formula (2), the incident power can be calculated.

[0031] (3).

[0032] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A terahertz thermoelectric power sensing chip, characterized in that, The chip is a composite chip with a structure of heat insulation layer / absorption layer / isolation layer / thermopile / isolation layer / DC resistor / heat insulation layer; The absorption layer is used as a radio frequency load, and the absorbed terahertz signal power will cause the temperature of the absorption layer to change; Thermopile, as a temperature sensing device, uses the Seebeck effect of thermocouples to determine the temperature change of the absorption layer, thereby determining the incident power of terahertz signals. DC resistors are used as heaters, and generalized efficiency is used as a correction calibrator for power transfer standards.

2. The terahertz thermoelectric power sensing chip according to claim 1, characterized in that, A thermopile consisting of multiple pairs of thermocouples connected in series is fabricated on the RF load and distributed around the RF load.

3. The terahertz thermoelectric power sensing chip according to claim 1, characterized in that, The absorption layer is made of silicon material with a resistive layer plated on the outside; the DC resistor is made of tantalum nitride; the heat insulation layer is made of polyimide; and the isolation layer is made of silicon dioxide.

4. The terahertz thermoelectric power sensing chip according to claim 1, characterized in that, Silicon material is first doped and then a resistive layer is deposited on its surface to form an absorption layer.

5. A thermoelectric power sensor for measuring terahertz signals, characterized in that, include: The device comprises a housing, a chip, and a waveguide, wherein the chip is encapsulated in a waveguide; the chip is a terahertz thermoelectric power sensor chip as described in any one of claims 1-4, the housing has a double-layer structure, and the waveguide is used to guide the terahertz signal to propagate to the radio frequency load.

6. The thermoelectric power sensor for measuring terahertz signals according to claim 5, characterized in that, The outer shell has a double-layer structure, and the inner cavity between the two layers is filled with silicon dioxide powder; the waveguide has a thermal isolation section in the middle, which is made of ABS plastic with copper plating on the surface.

7. The thermoelectric power sensor for measuring terahertz signals according to claim 5, characterized in that, The chip is along the long side of the rectangular waveguide Place it at an angle.

8. The application of the thermoelectric power sensor for measuring terahertz signals as described in claim 5, characterized in that, Applied to Power measurement within the frequency range.

Images