CN203553318U - Miniature SIW matching load - Google Patents

Abstract

The utility model discloses a miniature SIW (Substrate Integrated Waveguide) matching load used for a microwave integrated circuit. The matching load includes an upper-layer metal face, a middle dielectric slab, a lower-layer metal face. The middle dielectric slab is located between the upper-layer metal face and the lower-layer metal face. Two lines of metal post alignments are arranged between the upper-layer metal face and the lower-layer metal face. Each line of metal post alignments includes a plurality of metal posts and each metal post contacts the upper-layer metal face and the lower-layer metal face. The tail ends of the two lines of metal post alignments are provided with tail-end metal post alignments and the inner sides of the tail-end metal post alignments are provided with a microwave-absorbing material. The matching load is simple in principle and easy to design and capable of realizing index requirements through traditional PCB machining and mechanical machining processes. The load is applicable to different SIW circuits and fills domestic blank in the project.

Description

Miniaturized substrate integrated waveguide matched load

Technical field

The utility model belongs to microwave and millimeter wave hybrid integrated circuit field, particularly a kind of miniaturized substrate integrated waveguide matched load.

Background technology

Matched load is a kind of microwave device of single port, the complete microwave energy absorbing of energy in the ideal case, but current other transmission line, such as waveguide, microstrip line, coaxial line etc., the match circuit that has various forms of broadband/arrowbands, is widely used in various circuit and system.Application substrate integration wave-guide is the planar structure that the design platform of this class maturation of SIW (Substrate Integrated Waveguide) is realized, merged the advantage of rectangular waveguide and microstrip line, have advantages of that volume is little, lightweight, relative bandwidth is wider, can bear higher power threshold simultaneously, Q value is also higher, it is very outstanding that theoretical and experiment all shows that this class planar structure has advantages of, therefore can in microwave and millimeter wave circuit, hybrid integrated circuit (HMIC) and millimeter wave monolithic integrated circuit (MMIC), well be applied.As document 1 (" Integrated microstrip and rectangular waveguide in planar form ", IEEE Microwave and Wireless Comp.Lett., Vol.11, No.2, 2001, pp.68-70), document 2 (" A Planar Magic-T Using Substrate Integrated Circuits Concept, " IEEE Microwave and Wireless Comp.Lett., Vol.18, No.6, 2008, pp386-388), and document 3 (" substrate integration wave-guide hybrid power divider feed logarithm periodic antenna, " electric wave science journal, 2011, 26 (3), pp.437-442) in, all than detail the novel microwave millimeter-wave planar passive circuit that designs of this class new technology of employing substrate integration wave-guide (SIW).But, as the matched load of a vitals, but seldom see.Document 4(" Hiromitsu U; Masatoshi N; Akira I; et al.A Post-Wall Waveguide (SIW) Matched Load with Thin-Film Resistor[A] .Proceedings of Asia Pacific Microwave Conference2010:1597-1600 ") be the article of unique relevant SIW load of delivering so far, this structure of describing in literary composition has adopted film resistor (Thin Film Resistor-TFR), can be in the bandwidth of X-band 20%, realization-20dB return loss.But still there are some shortcomings in this class formation, mainly contains: (1) narrow bandwidth; (2) circuit cannot be debugged substantially; (3) preparation technology is more complicated, needs special production equipment, and its cost is also higher.

Utility model content

The technical problem that the utility model solves is to provide a kind of miniaturized substrate integrated waveguide matched load that contains absorbing material.

The technical solution that realizes the utility model object is: a kind of miniaturized substrate integrated waveguide matched load, comprise upper strata metal covering, intermediate medium plate, lower metal face, intermediate medium plate is between upper strata metal covering and lower metal face, two row's metal column alignments are set between upper strata metal covering and lower metal face, every row's metal column alignment includes some metal columns, each metal column all contacts with upper strata metal covering and lower metal face, end in two row's metal column alignments arranges end metal column alignment, the inner side of metal column alignment arranges microwave absorbing material endways.

Described microwave absorbing material be shaped as cuboid, the long limit of this microwave absorbing material is near end metal column alignment.

Described microwave absorbing material be shaped as wedge shape, the long right-angle side of this microwave absorbing material or hypotenuse are near any row in two row's metal column alignments, the short right-angle side of microwave absorbing material is near end metal column alignment.

Described microwave absorbing material comprises two wedge shape microwave absorbing materials, and these two wedge shape microwave absorbing materials are respectively near row's metal column alignment, and the short right-angle side of microwave absorbing material is near end metal column alignment.

Described microwave absorbing material comprises a cuboid microwave absorbing material and two wedge shape microwave absorbing materials, these two wedge shape microwave absorbing materials are respectively near row's metal column alignment, the short right-angle side of microwave absorbing material is near end metal column alignment, and the long limit of cuboid microwave absorbing material is near end metal column alignment.

Microwave absorbing material is the elastomeric material of ferrite doped calcium, and its form is solid or liquid.

Distance between the upper strata metal covering of miniaturized substrate integrated waveguide matched load and lower metal face outer surface is 0.125mm, 0.254mm, 0.508mm, 0.762mm, 1.016mm or 1.524mm.

Compared with prior art, its remarkable advantage is the utility model: 1) miniaturized substrate integrated waveguide matched load of the present utility model, and bandwidth can reach several octaves with interior from 5% always; 2) miniaturized substrate integrated waveguide matched load circuit index of the present utility model is relatively stable, also can after production, carry out necessary debugging simultaneously, meets the demand under specified conditions; 3) structural design is simple, can adopt conventional PCB printed board manufacture craft, traditional process for machining, and manual seating means, and economy is outstanding; 4) design principle is simple, and substrate material is not almost had to specific (special) requirements, can meet all microwave base plates, has versatility widely.

Below in conjunction with accompanying drawing, the utility model is described in further detail.

Accompanying drawing explanation

Fig. 1 is the floor map of the utility model arrowband integrated waveguide matched load structure.

Fig. 2 is the schematic perspective view of the utility model arrowband integrated waveguide matched load structure.

Fig. 3 is the floor map of the utility model broadband integrated waveguide matched load structure.

Fig. 4 is the schematic perspective view of the utility model broadband integrated waveguide matched load structure.

Fig. 5 perpendicular polarization electromagnetic wave is at the interfacial principle of reflection figure of lossy dielectric.

Fig. 6 perpendicular polarization electromagnetic wave is at the interfacial principle of reflection figure of the lossy dielectric with metallic plate.

Fig. 7 Broadband Matching loaded work piece schematic diagram.

Fig. 8 is the reflection coefficient simulation result figure of the utility model arrowband integrated waveguide matched load.

Fig. 9 is the reflection coefficient simulation result figure of the utility model broadband integrated waveguide matched load.

Embodiment

Below in conjunction with accompanying drawing, the utility model is described in further detail.

In conjunction with Fig. 1 to Fig. 4, the utility model substrate integration wave-guide matched load comprises upper strata metal covering 1, intermediate medium plate 2, lower metal face 3, two row's metal column alignments 4, end metal column alignment 5 and microwave absorption piece 6.Its at the middle and upper levels metal covering 1 be positioned at the upper surface of intermediate medium plate 2, underlying metal face 3 is positioned at the lower surface of intermediate medium plate 2, at metal covering 1 or 2, make a call to two row's plated-through holes, or filling metal paste becomes metal column, make a call to endways row's metal column alignment 5, in the place near end metal column alignment 5, fill microwave absorbing material 6, for microwave energy absorbing, the place that does not add metal column alignment is signal input port.The width of load and the radius of metal column can calculate according to existing formula (1)-(2):

$a^{\′}=\frac{a}{\mathrm{\π}}\mathrm{arccot}\left(\frac{\mathrm{\πW}}{4a}\ln \frac{W}{4R}\right)---\left(1\right)$

R＜0.1λ _g,W＜4R,R＜0.2a (2)

Wherein a ' is the width of SIW, and R is metal column radius, and W is the spacing of adjacent metal post, and a is the width of the rectangular waveguide RW (Rectangular Waveguide) of transmission characteristic equivalence, λ _gwavelength for rectangular waveguide RW.The spacing of generally choosing between 1/10, two metal column that metal column radius is less than substrate integration wave-guide cut-off wavelength is less than metal column diameter length, and does suitably to regulate.The width of upper strata metal covering corresponds to the more than 1/2nd of substrate integrated wave guide structure cut-off frequency wavelength.Same two rows of specification of the metal column of terminal, the absorbing material of terminal should design different forms according to the requirement of different operating frequency and bandwidth simultaneously, makes the index of design be issued to the best in given requirement.

The utility model substrate integration wave-guide matched load structure, in metal column alignment 4 and end metal column alignment 5, the radius of each metal column is generally 0.2～0.5mm, distance between every two metal columns is generally 0.2～2mm, and actual parameter is relevant with operating frequency, need to carry out careful design.

The utility model substrate integration wave-guide matched load structure, its basic principle is that upper strata metal covering 1, lower metal face 3 and two row's metal column alignments 4 form the transmission line form that is similar to rectangular waveguide, just because the height of intermediate medium plate 2 is generally lower, for 0.254mm～2.54mm left and right, therefore be easier to Planar integration, terminal is carried out short circuit by 5 simultaneously, and inside circuit is filled microwave absorbing material, for absorbing the electromagnetic wave of characteristic frequency and bandwidth.

Wherein microwave absorbing material is shaped as rectangle, circle, ellipse, triangle or trapezoidal, and other shape, can arrange as required.

Described end metal column alignment 5, is generally single, also can be by many rows mode arranged side by side, to reach better shielding properties.

Owing to only transmitting TE in SIW _m0, in SIW, there is not horizontally-polarized electromagnetic wave.Therefore, for the design of SIW load, we only consider perpendicular polarization electromagnetic wave, calculate for simplifying simultaneously, suppose conductivityσ=0 in All Media.

For the matched load of arrowband, at the interface of bi-material, as shown in Figure 5, vertically polarized wave at the interfacial voltage reflection coefficient of lossy dielectric is

${\mathrm{\Γ}}_{\⊥}=\frac{{\mathrm{\η}}_2\cos {\mathrm{\θ}}_i-{\mathrm{\η}}_1\cos {\mathrm{\θ}}_t}{{\mathrm{\η}}_2\cos {\mathrm{\θ}}_i+{\mathrm{\η}}_1\cos {\mathrm{\θ}}_t}---\left(3\right)$

$T_{\⊥}=\frac{2{\mathrm{\η}}_2\cos {\mathrm{\θ}}_i}{{\mathrm{\η}}_2\cos {\mathrm{\θ}}_i+{\mathrm{\η}}_1\cos {\mathrm{\θ}}_t}---\left(4\right)$

Wherein,

for the intrinsic impedance of bi-material, and ε ₁, μ ₁and ε ₂, μ ₂be respectively complex dielectric permittivity and the complex permeability of two media.

From the law of refraction, when incidence angle is greater than incident critical angle, i.e. θ _i> θ _ctime, θ _t90 ° of >, electromagnetic wave is total reflection at dielectric surface, wherein

but because vertically polarized wave does not exist Brewster's angle (Brewster Angle), so Γ _⊥≠ 0, i.e. reflection cannot be eliminated completely.When the thickness medium that is d is connected with desired metallic is dull and stereotyped, as shown in Figure 6, transmitted wave T _⊥total reflection occurs at dull and stereotyped d place, and its input impedance and reflection coefficient are respectively

and Γ _d=-1, at coordinate z=0 place, its input impedance is.

$Z_{{\mathrm{in}}_0}={\mathrm{\η}}_2\tanh ({\mathrm{\γ}}_{2}d/\cos {\mathrm{\θ}}_t)---\left(5\right)$

Wherein

for propagation constant, therefore, in z=0 place reflection coefficient formula (1), become

$\mathrm{\Γ}=\frac{Z_{{\mathrm{in}}_0}\cos {\mathrm{\θ}}_i-{\mathrm{\η}}_1\cos {\mathrm{\θ}}_t}{Z_{{\mathrm{in}}_0}\cos {\mathrm{\θ}}_i+{\mathrm{\η}}_1\cos {\mathrm{\θ}}_t}---\left(6\right)$

Convolution (5) and formula (6), in the situation that dielectric material characteristic is definite, reflection coefficient size is by d and θ _idetermine, when Г=0, without reflection of electromagnetic wave, corresponding load is matched load.

For Broadband Matching load, its basic principle is, makes electromagnetic wave that refraction enters lossy dielectric total reflection occur lossy dielectric is inner, and total reflection number of times is more, and electromagnetic wave is absorbed also more, thereby reflection is fewer, as Fig. 7.

The utility model substrate integration wave-guide matched load, metal level 1 can be identical with the width of intermediate medium plate 2 with 3 width, also can be less than intermediate medium plate 2.In matched load, the shape of absorbing material can be rectangle, can be also wedge type or other shape, can suitably adjust according to the requirement of the frequency range of structure applications and compact dimensions, and to meet the needs of different indexs, the quantity of absorbing material is at least one.

The utility model substrate integration wave-guide matched load, the dielectric constant of intermediate medium plate is generally 2～16, and the thickness of levels intermediate medium plate is generally 0.254～2.54mm.

Below in conjunction with example, the utility model is described in more detail:

The utility model substrate integration wave-guide matched load, it has adopted a kind of substrate integration wave-guide as carrier, in conjunction with microwave absorbing material, the matched load of design arrowband and the two kinds of different frequency bandwidth in broadband.The width of arrowband and broadband intermediate medium plate and be highly all 20mm and 1.016mm wherein, and length is respectively 25mm and 45mm left and right, the dielectric constant of intermediate medium plate is 2.94, plated-through hole diameter is 0.8mm, hole center distance is 1.2mm, and between two row's metal column alignments [4], hole centre distance is 13.8mm.Arrowband absorbing material is rectangle, and quantity is 1, is of a size of 13.2mm*1mm; Wide band absorption material is wedge type, and quantity is 1, is of a size of 32.7mm*32.8mm*3.8mm.The operating frequency of arrowband load design is 9.5GHz～10.5GHz, and relative bandwidth is 10%, and return loss is 1.2 left and right, and simulation result is as Fig. 8; The operating frequency of broadband load design is 8.9GHz～12.3GHz, and relative bandwidth is 32%, return loss 1.2 left and right, and simulation result is as Fig. 9.

More than method for designing and the instantiation design of proposed substrate integration wave-guide matched load.The result of the utility model design example shows: the load of the utility model substrate integration wave-guide can meet the actual demand in arrowband and broadband, and volume is small and exquisite, lightweight, and the coupling that is applicable to various SIW systems is used.

Claims (7)

1. a miniaturized substrate integrated waveguide matched load, it is characterized in that, comprise upper strata metal covering [1], intermediate medium plate [2], lower metal face [3], intermediate medium plate [2] is positioned between upper strata metal covering [1] and lower metal face [3], two row's metal column alignments [4] are set between upper strata metal covering [1] and lower metal face [3], every row's metal column alignment includes some metal columns, each metal column all contacts with upper strata metal covering [1] and lower metal face [3], end in two row's metal column alignments [4] arranges end metal column alignment [5], the inner side of metal column alignment [5] arranges microwave absorbing material [6] endways.

2. miniaturized substrate integrated waveguide matched load according to claim 1, is characterized in that, described microwave absorbing material [6] be shaped as cuboid, the long limit of this microwave absorbing material [6] is near end metal column alignment [5].

3. miniaturized substrate integrated waveguide matched load according to claim 1, it is characterized in that, described microwave absorbing material [6] be shaped as wedge shape, the long right-angle side of this microwave absorbing material [6] or hypotenuse are near any row in two row's metal column alignments [4], and the short right-angle side of microwave absorbing material [6] is near end metal column alignment [5].

4. miniaturized substrate integrated waveguide matched load according to claim 1, it is characterized in that, described microwave absorbing material [6] comprises two wedge shape microwave absorbing materials, these two wedge shape microwave absorbing materials are respectively near row's metal column alignment, and the short right-angle side of microwave absorbing material [6] is near end metal column alignment [5].

5. miniaturized substrate integrated waveguide matched load according to claim 1, it is characterized in that, described microwave absorbing material [6] comprises a cuboid microwave absorbing material and two wedge shape microwave absorbing materials, these two wedge shape microwave absorbing materials are respectively near row's metal column alignment, the short right-angle side of microwave absorbing material [6] is near end metal column alignment [5], and the long limit of cuboid microwave absorbing material is near end metal column alignment [5].

6. according to the miniaturized substrate integrated waveguide matched load described in claim 1,2,3,4 or 5, it is characterized in that, the elastomeric material that microwave absorbing material [6] is ferrite doped calcium, its form is solid or liquid.

7. according to the miniaturized substrate integrated waveguide matched load described in claim 1,2,3,4 or 5, it is characterized in that, the distance between the upper strata metal covering [1] of miniaturized substrate integrated waveguide matched load and lower metal face [3] outer surface is 0.125mm, 0.254mm, 0.508mm, 0.762mm, 1.016mm or 1.524mm.

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