CN103337696A - Variable polarization panel antenna unit - Google Patents

Abstract

The invention relates to a variable polarization panel antenna unit, which is formed by slot coupling a plurality of metal layers from top to bottom; the topmost metal layer from top to bottom is a radiation patch printed layer, and the surface of the printed layer is printed with a radiation patch; the second layer is an etched coupling slot; the third layer is a microstrip line feeder network layer which is provided with a strip line feeder network thereon; and the forth layer is a grounding plate, and the forth layer and the second and third layers form a strip line transmission line. The U-shaped slot provided by the invention uses a vertical part arm length as a moderating variable, and an impedance deploying range is expanded obviously; a double-port feed structure is adopted, when the antenna works in a circular polarization mode, the TM10 and TM01 degeneracy mode field distribution has very good symmetry, and the circular polarization orthogonal isolation is high; and a strip line feed network structure is adopted, thereby not only effectively reducing spurious radiation and back reflection, but not increasing the profile thickness of the panel antenna excessively.

Description

Polarization plate aerial unit

Technical field

The present invention relates to a kind of plate aerial, especially a kind of broadband, polarization groove coupling multilayer plate aerial.

Background technology

In the measure of plate aerial improvement in performance, every index is mutual restriction often, and for example to adopt the high dielectric constant substrate be one of direct efficient means of antenna miniaturization, however ε _rRising can cause aerial radiation Q value to raise again, frequency band narrows down.Therefore, during designing antenna, every index request be weigh, baseplate material, antenna structure, patch shape, feeding classification etc. conscientiously chosen.

Summary of the invention

The technical problem to be solved in the present invention is: propose a kind of novel broadband, polarization groove coupling multilayer plate aerial unit.

The technical solution adopted in the present invention is: a kind of polarization plate aerial unit, by the multiple layer metal layer from top to bottom groove be coupled to form; The metal level of the top-down the superiors is the radiation patch printing layer, and radiation patch is printed on the printing layer surface; The second layer is the etching coupling slot; The 3rd layer is microstrip line feeder network layer, and it is provided with the strip line feeder network; The 4th layer is ground plate, described the 4th layer and second and third layer formation band line transmission line.

Antenna element of the present invention by the feedback of band line side or coaxial probe at the bottom of the feedback mode by the electromagnetic wave of feed port feed-in, guide to band line terminal through band line feeding network and form the strength of voltage, along the line to source end λ _gStrength ,/4 magnetic fields connects the coupling slot magnetic coupling to antenna element by band line upper strata, wherein λ _gBe medium wavelength in the uniform dielectric band line; The aerial radiation paster at two ends because the truncation effect of wide microstrip line terminal forms equivalent radiating slot, the two pairs of opposite side sew on tangential electric field component can equivalence be two pairs of constant amplitude homophase magnetic current sources to space radiation, produce radiation field of aerial.

The mode of grooving of the coupling slot of the second layer of the present invention is etching U-shaped coupling slot; Adopt U-lag coupling feed, multi-layer sheet antenna structure, be similar in Circuit theory when the staggered tuning close coupling loop of employing, frequency band will broadening.The mode of grooving of the coupling slot of the second layer can also be rectangular channel, polygon groove, line segment groove, bowtie shaped slot or dumb-bell slot.Bowtie shaped slot is that variable is allocated with each arm subtended angle α, dumb-bell slot is allocated with groove two terminal circle radius r, adjustable range is raying paster below spatial limitation to a great extent all, and U-lag with " | " part brachium as regulated variable, impedance allotment scope obviously increases.

Plate aerial of the present invention unit adopts the dual-port feed, when a feed port feed-in microwave energy, when the another port connects matched load, the dielectric resonant chamber of being made up of paster, ground plate and substrate has encouraged the TM10 mould, at paster terminal equivalence radiating slot with single linear polarization to the space radiation microwave energy, two feed mouths feed-in simultaneously microwave energy adopts the same coordinate system, the dielectric resonant chamber underexcitation plays TM10, TM01 degenerate mode, the phase relation of the control two-port feed width of cloth; Described antenna element can be realized left-hand circular polarization and right-handed circular polarization respectively.Adopt the single-point feedback to realize circular polarization, additional discontinuous segment size, feed position that antenna polarization characteristics is introduced radiating element are very responsive, are unsuitable for Project Realization.And adopt dual-port feed structure of the present invention, during the work of antenna circular polarization, TM10, the field distribution of TM01 degenerate mode have good symmetry, circular polarization quadrature isolation height.

Tradition microstrip antenna feeding network and radiation patch are printed on same one deck of dielectric-slab, and feeder line can produce parasitic radiation like this, and this becomes at the Ku wave band and does not allow to ignore.The common measure that reduces microstrip line parasitic radiation is the both sides that radiation patch, microstrip line feeder network are printed on the floor, brought another drawback to produce the microstrip line back reflection exactly like this, a kind of improved measure is to place reflecting plate (or back of the body chamber) under microstrip line, because the distance of reflecting plate and microstrip line network place layer (or back of the body chamber thickness) is generally λ ₀/ 4, this has increased the section size of plate aerial undoubtedly.The present invention adopts strip line feeding network structure, and the radiation patch of described radiation patch printing layer is apart from shape, has both effectively reduced parasitic radiation, back reflection, is unlikely to too much to increase the plate aerial sectional thickness again.

The invention has the beneficial effects as follows: as regulated variable, impedance allotment scope obviously increases the U-lag that the present invention provides with " | " part brachium; Adopt the dual-port feed structure, during the work of antenna circular polarization, TM10, the field distribution of TM01 degenerate mode have good symmetry, circular polarization quadrature isolation height; Adopt strip line feeding network structure, both effectively reduced parasitic radiation, back reflection, be unlikely to too much to increase the plate aerial sectional thickness again.

Description of drawings

The present invention is further described below in conjunction with drawings and Examples.

Fig. 1 (a)～(b) is multi-layer groove coupling flat plate antenna structure schematic diagram of the present invention;

Fig. 2 (a)～(e) is the common fluting form of groove coupled antenna;

Fig. 3 (a)～(b) is for opening butterfly, dumb-bell slot multi-layer groove coupling plate aerial;

Fig. 4 is groove coupling multilayer plate aerial equivalent circuit diagram;

Fig. 5 is the coordinate system figure of paster antenna radiation field;

Fig. 6 (a) is that antenna pattern is with the flute length change curve; (b) be that antenna radiation efficiency is with the flute length change curve;

Fig. 7 (a) is that the antenna pattern of another kind of value is with the flute length change curve; (b) be that the antenna radiation efficiency of another kind of value is with the flute length change curve;

Fig. 8 (a) is that S11 is with the terminal minor matters length variations of U-lag; (b) be that S12 is with the terminal minor matters length variations of U-lag;

Fig. 9 is that antenna pattern is with the slotting position change curve.

Embodiment

The present invention is further detailed explanation with preferred embodiment by reference to the accompanying drawings now.These accompanying drawings are the schematic diagram of simplification, basic structure of the present invention only is described in a schematic way, so it only show the formation relevant with the present invention.

A kind of polarization plate aerial unit as shown in Figure 1, by the multiple layer metal layer from top to bottom groove be coupled to form; The metal level of the top-down the superiors is the radiation patch printing layer, and radiation patch is printed on the printing layer surface; The second layer is the etching coupling slot; The 3rd layer is microstrip line feeder network layer, and it is provided with the strip line feeder network; The 4th layer is ground plate, described the 4th layer and second and third layer formation band line transmission line.

Coupling slot mode of grooving of the present invention can have various ways except outside the simple rectangular channel, shown in Fig. 2 (a)～(e), Fig. 3 (a) and (b) shown in be out bowtie shaped slot, dumb-bell slot.

For rectangular microstrip antenna, the length L value of paster is slightly smaller than λ _g/ 2, can be determined by following formula:

$L=0.5{\mathrm{\λ}}_g-2\mathrm{\ΔL}=\frac{c}{2f_r\sqrt{{\mathrm{\ϵ}}_e}}-2\mathrm{\ΔL}---\left(1\right)$

In the formula: $\mathrm{\ΔL}=0.412h\frac{({\mathrm{\ϵ}}_e+0.3)(W/h+0.264)}{({\mathrm{\ϵ}}_e-0.258)(W/h+0.8)}$

Adopt medium wavelength in the uniform dielectric band line

During antenna work, two groups of opposite side all might produce effective radiating slot, so antenna patch is designed to square basic shape, the length of side all can be determined by formula (1).

Band line feeding network is got 50 Ω characteristic impedances, and according to the baseplate material difference, live width is determined by following formula:

$W=\left\{\begin{array}{cc}h(\frac{30\mathrm{\&pi;}}{\sqrt{{\mathrm{\&epsiv;}}_r}{Z}_0}-0.441)& \sqrt{{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="0"\; label="r\; Z"\; filenames="DEST\_PATH\_HSB0000113270870000023.png,DEST\_PATH\_HSB0000113270870000031.png"\; state="\{\{state\}\}">r</figure-callout>}}}{Z}_{}{}_0<120\mathrm{\&Omega;}\\ h(0.85-\sqrt{0.6-(\frac{30\mathrm{\&pi;}}{\sqrt{{\mathrm{\&epsiv;}}_e}{Z}_0}-0.441)})& \sqrt{{\mathrm{\&epsiv;}}_{\mathrm{<figure-callout\; id="0"\; label="r\; Z"\; filenames="DEST\_PATH\_HSB0000113270870000023.png,DEST\_PATH\_HSB0000113270870000031.png"\; state="\{\{state\}\}">r</figure-callout>}}}{Z}_{}{}_0>120\mathrm{\&Omega;}\end{array}\right.---\left(2\right)$

Slotting position should be positioned at from strip line end voltage maximum place along the line to source end λ _gStrength ,/4 magnetic fields, note and end effect physical length are slightly less than λ _g/ 4.

Groove coupling multilayer plate aerial is because the equivalent radiating slot place at rectangular radiation unit two ends produces the electric field discontinuous segment, and open circuit place charge concentration has stored electric energy, and the end effect equivalence is an electric capacity.After the radiation of considering the slit, the admittance that G and susceptance jB parallel connection are led with electricity of equivalence in little band radiation element two ends is connected on the two ends of microstrip transmission line, coupling place of self-magnetic field groove to the antenna terminal equivalent electric circuit as shown in Figure 4:

Surface patch and transmission line model are combined, study model shown in Figure 1 and equivalent electric circuit shown in Figure 4, on the separated time during arbitrfary point, the input impedance of distributing point place is distributing point on the paster in the rectangular patch broadside:

$Z_1=\frac{1}{Y_0}[\frac{{\mathrm{<figure-callout\; id="0"\; label="Z"\; filenames="DEST\_PATH\_HSB0000113270870000023.png,DEST\_PATH\_HSB0000113270870000031.png"\; state="\{\{state\}\}">Z</figure-callout>}}_0\cos \mathrm{\&beta;}{L}_1+j{Z}_w\sin \mathrm{\&beta;}{L}_1}{Z_w\cos \mathrm{\&beta;}{L}_1+\mathrm{<figure-callout\; id="0"\; label="j\; Z"\; filenames="DEST\_PATH\_HSB0000113270870000023.png,DEST\_PATH\_HSB0000113270870000031.png"\; state="\{\{state\}\}">j</figure-callout>}{Z}_{}{}_0\sin \mathrm{\&beta;}{L}_1}+\frac{{\mathrm{<figure-callout\; id="0"\; label="Z"\; filenames="DEST\_PATH\_HSB0000113270870000023.png,DEST\_PATH\_HSB0000113270870000031.png"\; state="\{\{state\}\}">Z</figure-callout>}}_0\cos \mathrm{\&beta;}{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000882834700014.png"\; state="\{\{state\}\}">L</figure-callout>}}_2+j{Z}_w\sin \mathrm{\&beta;}{L}_2}{Z_w\cos \mathrm{\&beta;}{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000882834700014.png"\; state="\{\{state\}\}">L</figure-callout>}}_2+\mathrm{<figure-callout\; id="0"\; label="j\; Z"\; filenames="DEST\_PATH\_HSB0000113270870000023.png,DEST\_PATH\_HSB0000113270870000031.png"\; state="\{\{state\}\}">j</figure-callout>}{Z}_{}{}_0\sin \mathrm{\&beta;}{L}_2}{]}^{-1}---\left(3\right)$

In the formula:

$\left\{\begin{array}{c}{Z}_w=\frac{1}{Y_w}=\frac{1}{G_w+j{B}_w}\\ G_w=0.0083W/{\mathrm{\&lambda;}}_0\\ B_w=0.01668\frac{\mathrm{\&Delta;L}}{h}\frac{W}{{\mathrm{\&lambda;}}_0}{\mathrm{\&epsiv;}}_e\\ {\mathrm{\&epsiv;}}_e=\frac{{\mathrm{\&epsiv;}}_r+1}{2}+\frac{{\mathrm{\&epsiv;}}_r-1}{2}{(1+\frac{12h}{W})}^{-1/2}\\ \frac{\mathrm{\&Delta;L}}{h}=0.412\frac{({\mathrm{\&epsiv;}}_e+0.3)(W/h+0.264)}{({\mathrm{\&epsiv;}}_e-0.258)(W/h+0.8)}\\ W=L\end{array}\right.---\left(4\right)$

Band line terminal is to coupling slot, and U-lag to the coupling effect of rectangular patch can be respectively with a lump capacitive reactance X _C1, X _C2Represent that like this, 50 Ω characteristic impedance band line terminal input admittances are:

$Y_{\mathrm{in}}=\frac{1}{Z_1}+j(X_{C1}+X_{C2})---\left(5\right)$

As two radiating slots of rectangular patch antenna among Fig. 5 can equivalence for only have along the y durection component and with the irrelevant magnetic current of x component, each radiating slot equivalent magnetic current density is

For whole rectangular patch, the radiation of antenna equivalence can be determined by following formula for the radiation of binary seam battle array, the radiation field of antenna:

In the formula

$A=-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="HSA00000882834700014.png"\; state="\{\{state\}\}">j</figure-callout>}\frac{2\mathrm{VW}}{\mathrm{\&lambda;}{r}^{\&prime;}}{e}^{-j{k}_0{r}^{\&prime;}},$ R ' is show up a little distance of micro strip center.Obtain the antenna pattern function thus:

Then The time H face directional diagram with

The time E face directional diagram be:

The half-power angle width of antenna main lobe can be similar to by following formula and calculate:

$\left\{\begin{array}{c}2{\mathrm{\&theta;}}_{0.5E}=2{\cos }^{-1}{\left[\frac{1}{2(1+\frac{\mathrm{\&beta;L}}{2})}\right]}^{1/2}\\ 2{\mathrm{\&theta;}}_{0.5H}=2{\cos }^{-1}{\left[\frac{7.03}{(3{\mathrm{\&beta;}}^2{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000882834700014.png"\; state="\{\{state\}\}">L</figure-callout>}}^2+{\mathrm{\&beta;}}^2{h}^2)}\right]}^{1/2}\end{array}\right.---\left(9\right)$

Obtaining directivity of antenna easily is: $D=\frac{8{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000882834700014.png"\; state="\{\{state\}\}">L</figure-callout>}}^2{\mathrm{\&pi;}}^2}{{\&Integral;}_0^{2\mathrm{\&pi;}}{\sin }^2\left(\frac{\mathrm{\&beta;}L\cos \mathrm{\&theta;}}{2}\right){\tan }^2\mathrm{\&theta;}\sin \mathrm{\&theta;d\&theta;}{\mathrm{\&lambda;}}^2}---\left(10\right)$

Each laminar substrate of multi-layer sheet antenna shown in Figure 1 is chosen for: the top layer plate DIELECTRIC CONSTANT _r=2.3, thickness h ₁=0.5mm, dielectric loss tg δ=0.0013, lower two layers plate DIELECTRIC CONSTANT _r=2.65, thickness h ₂=h ₃=0.8mm, dielectric loss tg δ=0.0025, substrate size 30mm * 30mm, patch size 6.9mm * 6.9mm.Antenna one port connects feed, and the another port connects matched load, is operated in horizontal polarization mode.

Ground plate U-lag groove width, "-" part flute length mainly influence the radiation efficiency of groove coupling plate aerial on the band line, antenna E face directional diagram and radiation efficiency calculated curve when Fig. 6,7 provides two variablees and gets different value.

The coupling slot flute length is little to radiation pattern, radiation efficiency influence as seen from Figure 6, and this illustrates that also energy mainly upwards is coupled by U-lag owing to the constraint guiding function of band line to microwave energy around the band line.Fig. 7 shows that antenna radiation efficiency conversion fluctuation was bigger when groove width was got different value, simultaneously antenna directivity, main radiation direction max gain change are obvious, the gain of oversized slots Wide antenna main radiation direction descends on the contrary, this is mainly due to the increase along with groove width, U-lag produces distortion along vertical channel long side direction electric field, can not regard definite value as, and then cause paster antenna equivalent magnetic current radiation source to distort, influence radiation pattern.

Ground plate U-lag " | " part is matching properties as the input impedance that terminal open circuit allotment minor matters mainly influence antenna on the strip line, periodic structure according to the band line, its length should be got less than a medium wavelength, antenna single port S calculation of parameter curve when Fig. 8 provides U-lag " | " part and gets the different length value.Increase resonance frequency along with U-lag " | " part minor matters length reduces as can be seen, and Fig. 8 (b) shows that groove coupling multilayer plate aerial two input ports by this conceptual design have good port isolation characteristic simultaneously.

Crack the position be antenna to carry out groove coupling place be the principal element that influences antenna pattern, Fig. 9 provides U-lag slotting position fed_poi and paster centre distance antenna E face directional diagram calculated curve when changing.As can be seen, antenna has good directivity when slotting near the paster center, along with slotting position departs from the paster center, the antenna main radiation direction departs from θ=0 °, gain also decreases, when this mainly comes from fluting and is positioned at positive center, and two radiating slot position symmetries, it is identical to go into apparent impedance from groove coupling place, and equivalent magnetic current source, the radiation patch two ends width of cloth has high consistency mutually.

When adopting strip line as feeding network and traditional microstrip line (feeder network and radiation patch are in the both sides, floor) feed, antenna element lower half-space back lobe antenna pattern is chosen coordinate system and is made under the antenna θ=90 °.Adopt traditional feed microstrip line mode, the antenna backward radiation is comparatively obvious, the strip line feed structure that provides for this paper, although because the antenna substrate size is limited, still have portion of energy and form back lobe from the radiation of dielectric-slab edge, but the antenna back lobe obviously reduces, can effectively reduce the back reflection effect.

Just the specific embodiment of the present invention of describing in the above specification, various not illustrating is construed as limiting flesh and blood of the present invention, the person of an ordinary skill in the technical field after having read specification can to before described embodiment make an amendment or be out of shape, and do not deviate from essence of an invention and scope.

Claims (6)

1. polarization plate aerial unit is characterized in that: by the multiple layer metal layer from top to bottom groove be coupled to form; The metal level of the top-down the superiors is the radiation patch printing layer, and radiation patch is printed on the printing layer surface; The second layer is the etching coupling slot; The 3rd layer is microstrip line feeder network layer, and it is provided with the strip line feeder network; The 4th layer is ground plate, described the 4th layer and second and third layer formation band line transmission line.

2. polarization plate aerial as claimed in claim 1 unit, it is characterized in that: the mode of grooving of the coupling slot of the described second layer is etching U-shaped coupling slot.

3. polarization plate aerial as claimed in claim 1 unit, it is characterized in that: the mode of grooving of the coupling slot of the described second layer also comprises rectangular channel, polygon groove, line segment groove, bowtie shaped slot or dumb-bell slot.

4. polarization plate aerial as claimed in claim 1 unit, it is characterized in that: described antenna element is presented mode by the electromagnetic wave of feed port feed-in at the bottom of being with the feedback of line side or coaxial probe, guide to band line terminal through band line feeding network and form the strength of voltage, along the line to source end λ _gStrength ,/4 magnetic fields connects the coupling slot magnetic coupling to antenna element by band line upper strata, wherein λ _gBe medium wavelength in the uniform dielectric band line; The aerial radiation paster at two ends because the truncation effect of wide microstrip line terminal forms equivalent radiating slot, the two pairs of opposite side sew on tangential electric field component can equivalence be two pairs of constant amplitude homophase magnetic current sources to space radiation, produce radiation field of aerial.

5. polarization plate aerial as claimed in claim 4 unit, it is characterized in that: described plate aerial unit adopts the dual-port feed, when a feed port feed-in microwave energy, when the another port connects matched load, the dielectric resonant chamber of being made up of paster, ground plate and substrate has encouraged the TM10 mould, at paster terminal equivalence radiating slot with single linear polarization to the space radiation microwave energy, two feed mouths feed-in simultaneously microwave energy, adopt the same coordinate system, the dielectric resonant chamber underexcitation plays TM10, TM01 degenerate mode, the phase relation of the control two-port feed width of cloth; Described antenna element can be realized left-hand circular polarization and right-handed circular polarization respectively.

6. polarization plate aerial as claimed in claim 1 unit is characterized in that: the radiation patch of described radiation patch printing layer is for apart from shape.

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