CN217332632U

CN217332632U - Variable-temperature testing device for complex dielectric constant of strip line resonance method

Info

Publication number: CN217332632U
Application number: CN202220001993.4U
Authority: CN
Inventors: 何博阳; 张少斐; 惠磊; 范婷婷
Original assignee: Ningbo Turbulence Electronic Technology Co ltd
Current assignee: Ningbo Turbulence Electronic Materials Co ltd
Priority date: 2022-01-04
Filing date: 2022-01-04
Publication date: 2022-08-30
Anticipated expiration: 2032-01-04

Abstract

A variable temperature testing device for complex dielectric constant of a strip line resonance method belongs to the technical field of microwave testing. The device comprises a sample clamp, a pressurizing device, a pressure probe, a high-low temperature liquid circulation temperature control system, a vector network analyzer, a temperature probe and a temperature display. The sample clamp comprises an upper clamp and a lower clamp, the upper clamp comprises a plurality of cylindrical mounting holes and a snake-shaped bent pipe fixed in the mounting holes, and a temperature measuring probe preformed hole is formed in the lower clamp. The sample clamp is made of brass with good thermal conductivity, and the outer layer of the sample clamp is wrapped by heat-insulating cotton. The device can test the dielectric constant and dielectric loss of the low-loss material under the temperature condition of minus 40-150 ℃ and 1-12 GHz, and has the advantages of simple device operation, low energy consumption and accurate temperature control.

Description

Variable-temperature testing device for complex dielectric constant of strip line resonance method

Technical Field

The utility model belongs to a microwave test technical field relates to a alternating temperature testing arrangement that is used for compound dielectric constant of stripline resonance method, indicates a device that measures the compound dielectric constant of dielectric material under the different ambient temperature with stripline resonance method particularly.

Background

With the development of ultrahigh frequency and millimeter wave application in recent years, the market puts higher requirements on the dielectric property of the printed circuit board under high frequency. For example, with the development of automatic driving and the landing of auxiliary driving functions, it is a hot spot in the field of high-frequency board manufacture to prepare a material suitable for automotive millimeter wave radar applications. The automobile radar is required to accurately and rapidly work under different environmental temperatures, which puts high requirements on the complex dielectric constant temperature drift performance of the dielectric material substrate. Therefore, measuring and evaluating the change degree of the complex dielectric constant of the material under different environmental temperatures is an important work in the aspect of testing millimeter wave application materials.

The loss tangent value of a material which can be applied in the millimeter wave field is low (< 0.005), so that the complex dielectric constant of the material is often measured by a resonance method. Similar devices and methods have been reported for measuring the complex dielectric constant of low loss materials using resonance at different temperatures. For example, the invention patent with the publication number of CN101187683B discloses a method for testing the complex dielectric constant of a low-loss material at high temperature by adopting a cylindrical high-Q resonant cavity in a vacuum high-temperature furnace, wherein the testing frequency range is 7-18 GHz, and the testing temperature can reach 1500 ℃. The patent application with publication number CN102393490A discloses a device for measuring the high-temperature complex dielectric constant of a dielectric material, which adopts a rectangular waveguide resonant cavity and a high-temperature furnace as main bodies. The invention patent with the publication number of CN108680839B discloses a system and a method for high-temperature testing of the complex dielectric constant of a material by adopting a coaxial resonant cavity. However, no patent is disclosed about a complex dielectric constant temperature change testing device by a strip line resonator method.

The literature' allows for excessiveness; a temperature-varying test [ D ] of the complex dielectric constant by a strip line resonator method; university of electronic technology; in 2008 ", a device for temperature-changing test by using a strip line resonator method is built. The design temperature range is-100 ℃ to 150 ℃, and the test frequency range is 1-18 GHz. The cooling system adopts liquid nitrogen for refrigeration, and the heating system adopts a heating resistor and a temperature controller for control. But because: (1) the test probe is in a temperature-changing environment, so that system errors are introduced; (2) the liquid nitrogen flow is difficult to control, and the flatness of the temperature is influenced; (3) the variable temperature test box influences the resonant frequency and other factors. There is therefore a great need for improvement of the above-mentioned devices.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a alternating temperature testing arrangement that is used for compound dielectric constant of stripline resonance method. The device needs to measure the complex dielectric constant of the thin plate material between minus 40 ℃ and 150 ℃ and between 1 GHz and 12GHz, and needs to be suitable for low-loss microwave materials and millimeter wave materials.

The technical idea of the utility model is as follows: on the basis of the existing mature equipment and method (national standard GB/T12636-90) for measuring complex dielectric constant by using a stripline resonator method at normal temperature, in order to enable the material to be measured to be in a constant high-temperature or low-temperature environment, the utility model discloses a fixed snakelike bend in the interior of a traditional clamp, a liquid medium with constant temperature circulation is introduced into the snakelike bend, and a constant low-temperature source or a constant high-temperature source is obtained. Meanwhile, the outer layer of the clamp is wrapped with a heat insulation material. When the heat transfer of the whole system reaches a steady state, an approximately constant temperature environment can be obtained around the sample to be measured. The actual temperature of the periphery of the sample to be detected is obtained by detecting through a precise temperature probe.

The detailed technical scheme of the utility model is as follows:

a variable-temperature testing device for dielectric constant of a strip line resonance method comprises a vector network analyzer, a strip line resonator clamp, a clamp pressurizing device, a pressure probe, a high-low temperature liquid circulation temperature control system, a temperature probe and a temperature display.

The strip line resonator clamp is internally provided with a heat transfer pipe, the heat transfer pipe is provided with a liquid outlet and a liquid inlet, the liquid outlet and the liquid inlet are respectively connected with a liquid inlet pipeline and a liquid outlet pipeline of a high-low temperature liquid circulation temperature control system, and a strip line resonator consisting of a sample to be measured is arranged in the strip line resonator clamp to obtain stable environment temperature.

Further, the strip line resonator jig includes an upper jig and a lower jig, the strip line resonator composed of the sample to be measured is placed between the fitted upper jig and lower jig, and the heat transfer pipe is installed in at least one of the upper jig and the lower jig.

Further, the heat transfer pipe is a serpentine bent pipe with enhanced heat transfer effect and is assembled in the mounting hole of the corresponding clamp, and a constant-temperature liquid medium in the temperature range of-40-150 ℃ circulates in the serpentine bent pipe.

Furthermore, at least one of the upper clamp and the lower clamp is provided with a prepared hole, and a temperature probe is fixed in the prepared hole.

Further, the upper clamp is provided with a lower convex part, the lower clamp is provided with an upper concave part matched with the lower convex part, the heat transfer pipe is assembled in an upper clamp mounting hole at the lower convex part, the temperature probe is mounted in a lower clamp reserved hole at the bottom end of the upper concave part, and the strip line resonator composed of the sample to be measured is arranged between the assembled lower convex part and the assembled upper concave part.

Further, the strip line resonator jig is a jig made of a metal material having thermal conductivity and high electrical conductivity, and the heat transfer pipe is a pipe made of a metal material having thermal conductivity and bendability.

Preferably, the heat transfer pipe is a pipe made of brass, and the strip line resonator clamp is a clamp made of brass.

Furthermore, a copper foil is padded between the strip line resonator composed of the sample to be measured and the strip line resonator clamp.

Furthermore, the periphery of the strip line resonator clamp is wrapped with an insulating layer.

The shape and size of the insulating layer are not limited as long as the installation and use of the clamp-adding pressurizing device, the temperature probe and the vector network analyzer connecting probe are not influenced.

Compared with the prior art, the beneficial effects of the utility model are that:

(1) the utility model discloses a high low temperature liquid circulation temperature control system of commercialization provides cold source and heat source medium, and the control by temperature change of medium is easy and simple to handle, does not involve the use of liquid nitrogen.

(2) The utility model discloses a constant temperature medium and brass anchor clamps's heat-conduction comes for the material heating and cooling that awaits measuring, compares the volume less with high temperature furnace or thermostated container in the prior art scheme, and consequently relative energy consumption is less.

(3) The utility model discloses the stability of well await measuring the material temperature depends on the temperature stability of circulating medium, and control accuracy is high, is far superior to the control by temperature change precision of electric heating pipe and temperature controller combination.

The utility model discloses a device can provide the material environmental temperature scope that awaits measuring and be-40-150 degrees centigrade, and test frequency range is 1-12 GHz, is fit for being used for low-loss material's dielectric constant and dielectric loss's alternating temperature to be measured, can play important role in microwave and millimeter wave application test field.

Drawings

Embodiments of the present invention will be described with reference to the accompanying drawings, in which

Fig. 1 is a schematic connection diagram of a temperature-varying testing apparatus for complex dielectric constant by stripline resonance method according to the present invention.

Fig. 2 is a schematic view of the three-dimensional structure of the stripline resonator clamp in the temperature-variable testing apparatus when the material to be tested is loaded.

Fig. 3 is a schematic side view of the upper clamp according to the present invention.

Fig. 4 is a schematic view of a three-dimensional structure of the lower clamp provided by the present invention.

The specific implementation mode is as follows:

the technical solutions in the embodiments of the present invention will be described clearly below with reference to the accompanying drawings, and it should be understood that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art based on the teachings of the following embodiments, are within the scope of the present invention.

The terms first, second and the like in the description and in the claims of the present application are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It will be appreciated that the data so used may be interchanged under appropriate circumstances such that embodiments of the application may be practiced in sequences other than those illustrated or described herein, and that the terms "first," "second," and the like are generally used herein in a generic sense and do not limit the number of terms, e.g., the first term can be one or more than one. In addition, "and/or" in the specification and claims means at least one of connected objects, a character "/" generally means that a preceding and succeeding related objects are in an "or" relationship.

As shown in fig. 1, the utility model provides a alternating temperature testing arrangement for compound dielectric constant of stripline resonance method, including vector network analytical instrument, stripline syntonizer anchor clamps (sample anchor clamps), anchor clamps pressure device and pressure probe, high low temperature liquid circulation temperature control system, temperature probe and temperature display.

The high-low temperature liquid circulation temperature control system (high-low temperature all-in-one machine) adopted in the embodiment is mature marketization equipment and has the functions of heating and refrigerating. The model can be selected from small laboratory-level high-low temperature integrated machines such as Jiangsu Xinshengzhe temperature control equipment Co.

Dimethyl silicone oil is preferably selected as a circulating medium of the high-low temperature all-in-one machine in the embodiment, and the high-low temperature all-in-one machine can be used for a long time at the temperature of-50 ℃ to 150 ℃. The trade mark can be selected from PMX-200 of Dow Corning company.

The shape, structure and combination form of the sample holder and the material to be measured provided in this embodiment are shown in fig. 2. The sample holder includes an upper holder 21 and a lower holder 22. During testing, the first strip line sample plate 23 to be tested and the second strip line sample plate 24 to be tested form a strip line resonator, and the strip line resonator is installed between the upper clamp and the lower clamp. The positioning and the connection between the clamps are realized through positioning screw holes and screws at four corners. The first strip line sample plate 23 to be tested and the second strip line sample plate 24 to be tested are two pieces of low-loss dielectric materials with the same size, wherein the strip line is etched in the center of the first strip line sample plate 23 to be tested. 1 layer of copper foil 25 is padded between the sample to be measured and the upper clamp and the lower clamp respectively. The thickness of the copper foil is 1-2 oz.

Fig. 2 and 3 show the structure of the upper jig, respectively. 4 positioning threaded holes (not marked) are distributed on the top surface of the upper clamp 21 for positioning. The upper clamp 21 is provided with a lower convex part 211, and 4 cylindrical through holes, namely mounting holes, are distributed in the center of the upper clamp 21 at the lower convex part 211 for fixing the heat transfer pipe 33. The heat transfer pipe 33 is a serpentine pipe, and has good heat transfer efficiency. The heat transfer pipe 33 has a liquid inlet and a liquid outlet, which are connected to the liquid outlet and the liquid inlet of the high and low temperature liquid circulation temperature control system, respectively, so that a constant temperature liquid medium in the temperature range of-40 to 150 ℃ can be circulated in the bend.

The shape and structure of the lower clamp 22 are shown in fig. 2 and 4, and the lower clamp 22 is provided with an upper concave portion 222 matched with the lower convex portion 211, the lower clamp 22 is provided with four positioning threaded holes 41, and a cylindrical half-hole 42, i.e. a reserved hole, is further formed at the bottom end of the upper concave portion 222, and the reserved hole is used for fixing a temperature probe for accurately reading the temperature of the center position of the top surface of the lower clamp 22, and the temperature is approximately equal to the actual ambient temperature of the sample to be measured. And a strip line resonator composed of a sample to be measured is disposed between the lower protrusion 211 and the upper recess 222 which are assembled.

In this embodiment, the sample holder and the heat transfer tube are made of brass. Brass has excellent thermal conductivity and thus helps to establish thermal equilibrium as quickly as possible. In addition, the brass has good conductive performance, and the clamp can play a good role in electromagnetic shielding.

In this embodiment, the sample holder is wrapped up with the heat preservation all around, and wherein the heat preservation is preferably cotton that keeps warm. And a small hole is reserved at the coaxial probe connected with the temperature probe and the vector network analyzer, so that the probe can be conveniently moved during adjustment. And the heat exchange of heat convection between the clamp and the outside air can be reduced by the heat insulation cotton.

In this embodiment, the upper and lower surfaces of the sample holder are padded with hard insulation boards in contact with the pressurizing means. The heat insulation plate can reduce the heat conduction and exchange of the clamp and the metal contact surface.

The use step of device as follows:

s1, placing a strip line resonator composed of a sample to be tested between an upper clamp and a lower clamp, respectively placing 1 layer of copper foil between the upper surface and the lower surface of the strip line resonator and the clamps, and connecting and fixing the upper clamp and the lower clamp by 4 screws;

s2, placing the combined body on a pressurizing device, pressurizing the upper surface and the lower surface of the sample clamp by using the pressurizing device, stopping when the pressure shows to-be-determined testing pressure, and maintaining constant pressure;

s3, adjusting the position of an input/output probe connected with the vector network analyzer until a proper resonance peak is called;

s4, wrapping the sample clamp with a heat insulation material;

and S5, setting the temperature of the circulating liquid, turning on the circulating pump, and waiting for the system to reach heat balance. The liquid flow rate is determined according to the actual size of the sample clamp and the diameter of the heat transfer pipe;

and S6, after the system reaches thermal equilibrium, the temperature probe testing temperature does not change, and the temperature is the environment temperature of the material to be tested. By adopting the test method and the calculation method of the national standard GB/T12636-90, the dielectric constant and the loss tangent of the material to be tested under the temperature condition can be tested.

Utilize the device of the utility model, a plurality of temperature values in the range of-40 to 150 ℃ can be set, and the complex dielectric constant of the low-loss dielectric material under different temperature conditions is measured. From the above series of results, a temperature-dielectric constant curve and a temperature-loss tangent curve in the temperature range can be made. If the temperature-dielectric constant curve has a linear region in the temperature range, the thermal change rate of the dielectric constant can be further determined. This rate of change can be used as a criterion for determining the stability of the dielectric properties of the low loss material with respect to temperature. The method has important significance for material type selection of radio frequency engineers and evaluation on whether the material to be tested can meet the requirements of millimeter wave application after being manufactured into a device.

Claims

1. The utility model provides a alternating temperature testing arrangement for compound dielectric constant of stripline resonance method which characterized in that, includes stripline syntonizer anchor clamps and high low temperature liquid circulation temperature control system, the heat-transfer pipe is equipped with in the stripline syntonizer anchor clamps, the heat-transfer pipe has liquid flow export and liquid inlet port, liquid flow export and liquid inlet port are connected with the feed liquor pipeline and the play liquid pipeline of high low temperature liquid circulation temperature control system respectively, and the stripline syntonizer that constitutes by the sample that awaits measuring then places stripline syntonizer anchor clamps in order to obtain stable ambient temperature in the place.

2. The apparatus for testing temperature change of complex dielectric constant by stripline resonance as recited in claim 1, wherein the stripline resonator holder comprises an upper holder and a lower holder, the stripline resonator constituted by the sample to be tested is disposed between the fitted upper and lower holders, and the heat transfer pipe is mounted in at least one of the upper and lower holders.

3. The apparatus for testing temperature change with complex dielectric constant by strip line resonance method according to claim 2, wherein said heat transfer pipe is a serpentine pipe having enhanced heat transfer effect and fitted in the mounting hole of the corresponding jig, said serpentine pipe internally circulating a constant temperature liquid medium within a temperature range of-40 to 150 ℃.

4. The temperature-varying test device for complex dielectric constant of the stripline resonance method as recited in claim 2 or 3, wherein at least one of the upper clamp and the lower clamp is provided with a prepared hole, and a temperature probe is fixed in the prepared hole.

5. The apparatus for testing temperature-varying complex dielectric constant according to claim 4, wherein the upper jig has a lower convex portion, the lower jig has an upper concave portion matching the lower convex portion, the heat transfer pipe is assembled in an upper jig mounting hole at the lower convex portion, the temperature probe is mounted in a lower jig prepared hole at the bottom end of the upper concave portion, and the strip line resonator composed of the sample to be tested is interposed between the assembled lower convex portion and upper concave portion.

6. The apparatus according to claim 1, wherein the stripline resonator jig is a jig made of a metal material having thermal conductivity and high electrical conductivity, and the heat transfer pipe is a pipe made of a metal material having thermal conductivity and flexibility.

7. The apparatus for testing temperature change of complex dielectric constant of stripline resonator as claimed in claim 1, wherein the fixture of stripline resonator is surrounded by a thermal insulation layer.