CN103344201A - Strain sensor of micro-strip antenna - Google Patents

Abstract

Disclosed is a strain sensor of a micro-strip antenna. The strain sensor comprises a conductor patch, a medium substrate and a metal earth plate. A metal thin layer is deposited or pasted on one face of the medium substrate as the metal earth plate, and the metal conductor patch 1 is arranged on the other face of the medium substrate. The strain sensor is arranged on the surface of a structure to be measured, when the structure to be measured deforms, strain is transmitted to the whole sensor, offset of center frequency of the whole sensor happens accordingly, the offset and the strain have a linear relation, and the magnitude of the strain can be deduced through measuring the offset. The strain sensor of the micro-strip antenna is simple in structure, convenient to install, high in reliability and capable of achieving measurement of the structural strain.

Description

A kind of strain transducer of microstrip antenna

Technical field

The present invention relates to the strain measurement technique field, particularly a kind of strain transducer of microstrip antenna.

Background technology

Structure comprises bridge, building, pipeline, aircraft, car and boat, dam etc., tends to occur because tired crackle and the fracture that causes in long-term use.If can must detect and repair crackle early, will avoid the generation of a lot of accidents so.In monitoring structural health conditions, how to find as early as possible that the crack is epochmaking problem always.Crackle originates in stress raiser usually, therefore in the key position placement sensor, monitors strain, can be used as the sign of early fatigue fracture.More existing technology comprise Fibre Optical Sensor, the metal forming strainometer, perhaps UT (Ultrasonic Testing) is helpful to crack detection, but existing sensor, need structurally lay tediously long cable, this makes that its equipment cost is too high, and is not suitable for extensive, large tracts of land use.

In recent years, in numerous monitoring structural health conditions new technologies, people extensively explore wireless technology.Compared to traditional cable system, wireless system has significant advantage at cost.This system comprises analog to digital converter usually, microprocessor and wireless transceiver.These device great majority lean on battery operation, and obtain data from traditional sensor.For example, strain measurement is to use the metal forming strainometer that connects wireless device to realize.In a word, wireless technology is mainly used to transmitting digitized sensing data, and sensor itself is not related to.

Summary of the invention

In order to overcome the deficiency that above-mentioned prior art exists, the object of the present invention is to provide a kind of strain transducer of microstrip antenna, with the electromagnetic strain dependent behavior in the microstrip antenna, namely when microstrip antenna itself deforms, corresponding skew also takes place in its centre frequency, as sensing mechanism, invent simple in structure, convenient installation, reliability height, can realize the measurement to structural strain.

For achieving the above object, technical scheme of the present invention is:

A kind of strain transducer of microstrip antenna comprises conductor patch 1, dielectric substrate 2, and metal ground plate 3, dielectric substrate 2 one sides deposit or are pasted with thin metal layer as metal ground plate 3, and dielectric substrate 2 another sides are provided with metallic conductor paster 1.

Described metallic conductor paster 1 is arranged on dielectric substrate 2 another sides by the mode of photoetching, corrosion or sputter.

Described conductor patch 1 adopts the metal good conductor with metal ground plate 3, comprises copper, silver or golden.

Described dielectric substrate 2 adopts insulating material, comprises teflon or polyimide.

Described center sensor frequency and sensor material, size relationship are shown below:

${\mathrm{\ϵ}}_e=\frac{{\mathrm{\ϵ}}_r+1}{2}+\frac{{\mathrm{\ϵ}}_r-1}{2}{(1+\frac{10h}{a})}^{-\frac{1}{2}}$

$\mathrm{\Δl}=0.412h\left(\frac{{\mathrm{\ϵ}}_e+0.3}{{\mathrm{\ϵ}}_e-0.258}\right)\left(\frac{\frac{a}{h}+0.264}{\frac{a}{h}+0.813}\right)$

$f_r=\frac{c}{2(b+2\mathrm{\Δl})\sqrt{{\mathrm{\ϵ}}_e}}$

In the formula, ε _rRelative dielectric constant for dielectric substrate 2; H is the thickness of dielectric substrate 2; A and b are respectively the length of conductor patch 1 and wide; C is vacuum light speed; ε _eBe effective dielectric constant; Δ l is compensating length; f _rCentre frequency for sensor.

Whole sensor is pasted on body structure surface to be monitored, by carrier deviation being monitored the strain that can know that just structure produces.Simple, the convenient installation of the sensor construction that the present invention relates to, reliability height can be realized request for utilization is satisfied in the monitoring of structural strain real-time online.

Description of drawings

Accompanying drawing is sensor construction synoptic diagram of the present invention.

Embodiment

The present invention will be described in more detail below in conjunction with accompanying drawing.

As shown in drawings, a kind of strain transducer of microstrip antenna comprises conductor patch 1, dielectric substrate 2, and metal ground plate 3, dielectric substrate 2 one sides deposit or are pasted with thin metal layer as metal ground plate 3, and dielectric substrate 2 another sides are provided with metallic conductor paster 1.

Described metallic conductor paster 1 is arranged on dielectric substrate 2 another sides by the mode of photoetching, corrosion or sputter.

Conductor patch 1 adopts the metal good conductor with metal ground plate 3, comprises copper, silver or golden.

Dielectric substrate 2 adopts insulating material, comprises teflon or polyimide.

Described center sensor frequency and sensor material, size relationship are shown below:

${\mathrm{\ϵ}}_e=\frac{{\mathrm{\ϵ}}_r+1}{2}+\frac{{\mathrm{\ϵ}}_r-1}{2}{(1+\frac{10h}{a})}^{-\frac{1}{2}}$

$\mathrm{\Δl}=0.412h\left(\frac{{\mathrm{\ϵ}}_e+0.3}{{\mathrm{\ϵ}}_e-0.258}\right)\left(\frac{\frac{a}{h}+0.264}{\frac{a}{h}+0.813}\right)$

$f_r=\frac{c}{2(b+2\mathrm{\Δl})\sqrt{{\mathrm{\ϵ}}_e}}$

In the formula, ε _rRelative dielectric constant for dielectric substrate 2; H is the thickness of dielectric substrate 2; A and b are respectively the length of conductor patch 1 and wide; C is vacuum light speed; ε _eBe effective dielectric constant; Δ l is compensating length; f _rCentre frequency for sensor.

Principle of work of the present invention is: with setting of the present invention and body structure surface to be measured, when treating that geodesic structure deforms, strain is delivered on the whole sensor, the skew of the corresponding generative center frequency of whole sensor, there is linear relationship between side-play amount and the strain, just can derives the size of strain by measuring side-play amount.

With specific embodiment the present invention is further described below.

Embodiment one:

Dielectric substrate 2 materials are selected polyimide, are of a size of the thin slice of 10mm*10mm*0.05mm, and conductor patch 1 material is selected copper, are of a size of the film of 4mm*5mm*0.01mm.Metal ground plate 3 materials are selected copper, are of a size of the film of 10mm*10mm*0.01mm, and the centre frequency scope of She Ji strain transducer correspondence is at 16GHz～20GHz like this.Coated on bottom side daub at metal ground plate 3 just can be pasted on metal structure surface to be monitored.During working sensor, by the skew of measuring center frequency, can obtain the size of strain.The strain sensitivity of this sensor is 16.7kHz/ μ ε.

Embodiment two:

Dielectric substrate 2 materials are selected teflon, are of a size of the thin slice of 10mm*10mm*0.05mm, and conductor patch 1 material is selected copper, are of a size of the film of 4mm*5mm*0.01mm.Metal ground plate 3 materials are selected copper, are of a size of the film of 10mm*10mm*0.01mm, and the centre frequency scope of She Ji strain transducer correspondence is at 20GHz～25GHz like this.At the coated on bottom side daub of metal ground plate 3, just can be pasted on reinforced concrete structure to be monitored surface.During working sensor, by the skew of measuring center frequency, can obtain the size of strain.The strain sensitivity of this sensor is 21.6kHz/ μ ε.

Embodiment three:

Dielectric substrate 2 materials are selected polyimide, are of a size of the thin slice of 20mm*20mm*0.05mm, and conductor patch 1 material is selected copper, are of a size of the film of 8mm*10mm*0.01mm.Metal ground plate 3 materials are selected copper, are of a size of the film of 20mm*20mm*0.01mm, and the centre frequency scope of She Ji strain transducer correspondence is at 8GHz～10GHz like this.At the coated on bottom side daub of metal ground plate 3, just can be pasted on composite structure to be monitored surface.During working sensor, by the skew of measuring center frequency, can obtain the size of strain.The strain sensitivity of this sensor is 9.1kHz/ μ ε.

Claims (3)

1. the strain transducer of a microstrip antenna, it is characterized in that, comprise conductor patch (1), dielectric substrate (2) and metal ground plate (3), dielectric substrate (2) one side deposits or is pasted with thin metal layer as metal ground plate (3), and dielectric substrate (2) another side is provided with metallic conductor paster (1); Conductor patch 1 adopts the metal good conductor with metal ground plate (3), comprises copper, silver or golden; Dielectric substrate (2) adopts insulating material, comprises teflon or polyimide.

2. the strain transducer of a kind of microstrip antenna according to claim 1 is characterized in that, described metallic conductor paster (1) is arranged on dielectric substrate (2) another side by the mode of photoetching, corrosion or sputter.

3. the strain transducer of a kind of microstrip antenna according to claim 1 is characterized in that, described center sensor frequency and sensor material, size relationship are shown below:

${\mathrm{\ϵ}}_e=\frac{{\mathrm{\ϵ}}_r+1}{2}+\frac{{\mathrm{\ϵ}}_r-1}{2}{(1+\frac{10h}{a})}^{-\frac{1}{2}}$

$\mathrm{\Δl}=0.412h\left(\frac{{\mathrm{\ϵ}}_e+0.3}{{\mathrm{\ϵ}}_e-0.258}\right)\left(\frac{\frac{a}{h}+0.264}{\frac{a}{h}+0.813}\right)$

$f_r=\frac{c}{2(b+2\mathrm{\Δl})\sqrt{{\mathrm{\ϵ}}_e}}$

In the formula, ε _rRelative dielectric constant for dielectric substrate 2; H is the thickness of dielectric substrate 2; A and b are respectively the length of conductor patch 1 and wide; C is vacuum light speed; ε _eBe effective dielectric constant; Δ l is compensating length; f _rCentre frequency for sensor.

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