CN104934662A - Substrate integrated waveguide ferrite tunable band-pass filter - Google Patents

Abstract

The invention belongs to the technical field of tunable filters, and relates to a substrate integrated waveguide ferrite tunable band-pass filter. The substrate integrated waveguide ferrite tunable band-pass filter comprises an upper metal copper coating layer, a dielectric layer, a narrow-edge metalized through holes, a lower metal copper coating layer and central inductive metallized through holes, wherein the lower metal copper coating layer is sequentially provided with the dielectric substrate and the upper metal copper coating layer, the upper metal copper coating layer and the lower metal copper coating layer are connected through two rows of mutually parallel narrow-edge metallized through holes, and the upper metal copper coating layer and the lower metal copper coating layer form a substrate integrated waveguide together with the dielectric layer; and the center of the substrate integrated waveguide is provided with a row of central inductive metalized through holes. The substrate integrated waveguide ferrite tunable band-pass filter is characterized in that the dielectric layer is provided with ferrite blocks in an embedded mode at positions close to the two rows of narrow-edge metallized through holes, and the upper surface and the lower surface of each ferrite block are metallized and respectively connected with the upper metal copper coating layer and the lower metal copper coating layer in a conduction mode. According to the invention, the ferrite loaded substrate integrated waveguide tunable band-pass filter is realized so as to meet requirements for the tunable band-pass filter in a substrate integrated system.

Description

A kind of substrate integration wave-guide ferrite variable band-pass filter

Technical field

The invention belongs to tunable filter technical field, particularly a kind of ferrite variable band-pass filter based on substrate integrated waveguide technology.

Background technology

Obtain very large development after being suggested in 2000 based on the concept of the substrate integrated circuit of ordinary printed circuit board (PCB) technique, wherein of greatest concern is substrate integrated waveguide technology.In recent years, on the basis that substrate integrated wave guide structure transmission characteristic is fully studied, achieve the magnetic control device such as ferrite tunable filter based on substrate integrated waveguide technology, greatly advance the new development of substrate integrated waveguide technology.At present, restructural and miniaturization are the main development directions of filter.

Traditional waveguide variable band-pass filter volume is bigger than normal, processed complex, with high costs, be difficult to planar circuit integrated, in order to improve circuit integrated level, cut down finished cost, researcher proposes to adopt substrate integrated wave guide structure to realize variable band-pass filter, and entirety can be divided into two classes: electric tune type and magnetic tune type.Electricity tune type mainly utilizes varactor to be loaded on band pass filter, controls filter operating frequency by controlling varactor both end voltage, but be limited by varactor operating frequency and power capacity, the tunable filter of electric tune type is difficult to work to very high-frequency; Magnetic tune type mainly utilizes ferrite loaded ribbon bandpass filter, and change filter operating frequency by changing direct current biasing added on ferrite, because ferrite belongs to the less material of a class high-frequency loss, magnetic tune type tunable filter can accomplish very high-frequency.

At present, document " Simultaneous electric and magnetic two-dimensionally tunedparameter-agile SIW devices; " (S.Adhikari, A.Ghiotto, and K.Wu, IEEE Trans.Microw.Theory Tech., vol.61, no.1, pp.423-435, Jan.2013.) openly substrate integration wave-guide variable band-pass filter employing ferrite and varactor common Loading Control resonant cavity frequency realize.Its operation principle is, changes added DC magnetic and is biased to change resonant frequency, regulates resonant frequency simultaneously, and then realize the change of band pass filter working frequency range by coupling between resonant cavity by changing varactor both end voltage.Although it is adjustable that this structure achieves filter frequencies, need direct current biasing and voltage co-controlling, namely automatically controlled and magnetic control combines, complex structure, and because substrate integration wave-guide is equipotentiality body, directly can not be biased voltage, need other independent circuit to realize voltage control.

Document " Magnetically Tunable Ferrite-Loaded Half-Mode Substrate IntegratedWaveguide " (S.Adhikari, S.Hemour, A.Ghiotto, and K.Wu, IEEE Micro.Wireless Comp.Lett., vol.25, no.3, pp.172-174, March 2015. " open substrate integration wave-guide variable band-pass filter adopts and on half module substrate integrated wave guide, loads ferrite and lumped capacity to realize band pass filter bandwidth adjustable, but there are the following problems: 1) half-modular substrate integral wave guide filter is semi-open structure, easily by other signal disturbing in circuit, Electro Magnetic Compatibility is poor, 2) only achieve the adjustable of bandwidth, do not realize the adjustment of operating frequency in same band situation, 3) adjustment of capacitance needs to change electric capacity, and during actual use, feasibility is little.

Load the design of variable band-pass filter at present for the ferrite based on substrate integration wave-guide, there is no suitable scheme.

Summary of the invention

The object of the present invention is to provide a kind of based on substrate integration wave-guide ferrite variable band-pass filter, realize ferrite load substrates integrated waveguide variable band-pass filter, to meet in substrate integrated system variable band-pass filter demand.To achieve these goals, technical scheme of the present invention is:

A kind of substrate integration wave-guide ferrite variable band-pass filter, comprises metal copper clad layers 1, dielectric layer 3, narrow limit plated-through hole 4, lower metal copper clad layers 5, center perception plated-through hole 6; Wherein, lower metal copper clad layers 5 sets gradually medium substrate 3 and upper metal copper clad layers 1, upper metal copper clad layers 1 is arranged by two the narrow limit plated-through hole 4 be parallel to each other with lower metal copper clad layers 5 and is connected conducting, forms substrate integration wave-guide together with dielectric layer 3; A row center perception plated-through hole 6 is offered at described substrate integration wave-guide center, it is characterized in that, embed respectively near described two row narrow limit plated-through holes 4 in described dielectric layer 3 and be provided with ferrite block 2, the upper and lower surface metalation of ferrite block 2, be connected conducting with upper and lower metal copper clad layers.

Further, described ferrite block 2 near plated-through hole side, narrow limit surface metalation, and then replaces the narrow limit plated-through hole of its corresponding position.

Further, the length of described ferrite block 2 is more than or equal to the total length of center perception plated-through hole 6, namely in center perception plated-through hole furthest apart two through holes between distance.

It should be noted that, above-mentioned ferrite block 2 is positioned at the position near narrow limit plated-through hole 4, its " near " refer to close as much as possible in the scope of processing technology permission but be not connected.

In the present invention, magnetic anisotropy when mainly utilizing electromagnetic wave to propagate in ferrite makes ferrite variable band-pass filter, namely by changing external dc magnetic bias size, the ferrite relative permeability be carried in substrate integration wave-guide can correspondingly change, and then cause and be loaded with ferritic substrate integration wave-guide cut-off frequency and change, in conjunction with in the middle of row's metal throuth hole coupling cause filter working band to change.

Beneficial effect of the present invention:

The present invention is by substrate integrated waveguide technology and Ferrite Material ferrite variable band-pass filter designed in conjunction, compared to traditional metal waveguide ferrite tape bandpass filter cost lower, is easy to complanation and integrated; , compare with existing substrate integration wave-guide band pass filter meanwhile, when realizing suitable working band and regulating, just can control the working band of band pass filter only by external dc magnetic bias, do not need applying bias simultaneously to control varactor.In addition, owing to not using the electric capacity original paper of lump, can not be limited by operating frequency and the rated power of these original papers, filter can be designed into higher frequency, is applied to more high-power.Major advantage has following 2 points:

(1) the invention provides based on substrate integration wave-guide ferrite variable band-pass filter compared to conventional metals waveguide type variable band-pass filter and common substrate integrated waveguide variable band-pass filter, while remaining the large characteristic of the former power capacity, higher than the latter working frequency range, power capacity is larger;

(2) compared to the embedded substrate integration wave-guide tunable filter of ordinary ferrite, because the present invention mainly relies on additional magnetic bias to regulate filter working band, do not need to carry out bias voltage control simultaneously, more easy of integration in complanation circuit.

Accompanying drawing explanation

Fig. 1 is substrate integration wave-guide ferrite variable band-pass filter structure three-dimensional schematic diagram in embodiment 1;

Fig. 2 is Fig. 1 structure cross-sectional; Wherein, 1 be dielectric layer for upper metal copper clad layers, 2 is three metallization ferrite blocks, 3,4 be narrow limit plated-through hole, 5 be perceptual plated-through hole centered by lower metal copper clad layers, 6.

Fig. 3 is the structure vertical view of substrate integration wave-guide ferrite variable band-pass filter in embodiment 2.

Fig. 4 is Fig. 3 structure cross-sectional; Wherein, 7 is double-sided metallization ferrite block.

Embodiment

Below in conjunction with embodiment and accompanying drawing, the present invention is further detailed explanation.

The working frequency range based on substrate integration wave-guide ferrite variable band-pass filter is provided to depend primarily on substrate integration wave-guide width in the present invention and metal throuth hole diameter and spacing are arranged in center one.Its specific design step:

1) selected baseplate material, selects suitable substrate integrated waveguide width (two row narrow limit plated-through hole 4 spacing) according to filter working band;

2) according to formula:

$\frac{1+\cos [2\mathrm{\π}{f}_c(W_2-2W_f)\sqrt{{\mathrm{\μ}}_s{\mathrm{\ϵ}}_s}}{1-\cos [2\mathrm{\π}{f}_c(W_2-2W_f)\sqrt{{\mathrm{\μ}}_s{\mathrm{\ϵ}}_s}}=\left(\frac{\left|{\mathrm{\μ}}_f\right|{\mathrm{\ϵ}}_s}{{\mathrm{\μ}}_s{\mathrm{\ϵ}}_f}\right)\tan h^2\left[2\mathrm{\π}{f}_c{W}_f\sqrt{\left|{\mathrm{\μ}}_f{\mathrm{\ϵ}}_f\right|}\right],$ Wherein, f _cfor cut-off frequency, W _ffor ferrite block width, W ₂for substrate integration wave-guide width, μ _sand ε _sbe respectively cut-off substrate magnetic permeability and dielectric constant; μ _fand ε _fbe respectively ferrite effective permeability and dielectric constant;

Determine to be loaded with ferritic substrate integration wave-guide cut-off frequency, and then calculate the effective dielectric constant of substrate integration wave-guide, wherein ferrite block width should be as far as possible wide, ensures wider frequency band adjustable extent, but should be not more than the double diameter of narrow limit plated-through hole 4;

3) according to the quantity that will design band pass filter isolation choose reasonable center perception plated-through hole 6, the more isolations of through hole 6 quantity are better, but insertion loss also can increase thereupon simultaneously:

4) determine the pitch of holes of center perception plated-through hole 6, spacing initial value is at λ _g/ 2, λ _gfor substrate integration wave-guide guide wavelength, concrete value is suitably optimized further;

5) by the dynamic impedance value that will design required for band pass filter bandwidth determination filter, and then the diameter of center perception plated-through hole 6 is determined by the plated-through hole equivalent-circuit model of classics; Generally speaking, this structure, mainly through the quantity of first selected center perception plated-through hole 6, is then determined to load ferrite block size, and finally the diameter of selected perceptual plated-through hole 6 realizes variable band-pass filter design.

Embodiment 1

As shown in Figure 1 and Figure 2, substrate integration wave-guide ferrite variable band-pass filter in the present embodiment, comprises metal and covers 1, three, copper upper strata (near substrate integration wave-guide narrow limit lateral surface and upper and lower surface) metallized ferrite block 2, medium substrate 3, narrow limit plated-through hole 4, metal Fu Tong lower floor 5, center perception plated-through hole 6; Substrate integration wave-guide covers copper upper strata 1 by metal and is connected with the narrow limit plated-through hole 4 that metal Fu Tong lower floor 5 is parallel to each other by two rows, forms together with corresponding medium substrate 3; Perceptual plated-through hole 6 centered by described substrate integrated waveguide medium layer 3 center, in medium substrate 3, both sides are embedded with three metallized ferrite blocks 2, the lateral surface of two pieces of ferrite blocks 2 is respectively near two row narrow limit plated-through hole 4 axial location, can make the appropriate adjustments according to used medium substrate and ferritic dielectric constant ferrite block position, but the length of ferrite block 2 should not be less than the distance of the Liang Ge center perception plated-through hole 6 of lie farthest away; The narrow limit plated-through hole of ferrite block 2 lateral surface opposite position and then be substituted.The ferrite block that both sides are relatively grown can also be made into polylith in addition, such ferrite is more easily processed, and is not easy to damage during assembling simultaneously.

As embodiment, the substrate integration wave-guide ferrite variable band-pass filter of this structure is designed to: the medium substrate dielectric constant selected is 2.2, thickness 0.508mm, and loss angle tangent is 0.0009; That ferrite sheet adopts is YIG-1850, relative dielectric constant 14.5,3dB live width 20Oe, loss angle tangent 0.0002, saturation magnetization 1850Gs; Substrate integration wave-guide width 11.2mm, narrow limit plated-through hole diameter 0.6mm, through-hole spacing 1.2mm; Center perception plated-through hole 6 diameter is respectively 0.6mm, 2mm, through-hole spacing L1=11.6mm, L2=10.4mm; The thick 0.508mm of ferrite block, length 34mm, width 1mm.When added DC magnetic is biased be increased to 0.2T gradually by 0T time, band pass filter operating frequency changes to 13.4GHz from 12.5GHz.Insertion loss is less than 1.6dB, and return loss is better than 15dB.

Embodiment 2

As shown in Figure 3, Figure 4, substrate integration wave-guide ferrite variable band-pass filter in the present embodiment, comprises for metal covers copper upper strata 1, the ferrite block 7 of upper and lower surface metalation, medium substrate 3, narrow limit plated-through hole 4, metal Fu Tong lower floor 5, center perception plated-through hole 6; Substrate integration wave-guide covers copper upper strata 1 by metal and is connected with the plated-through hole 4 that metal Fu Tong lower floor 5 is parallel to each other by two rows, forms together with corresponding medium substrate 3; Perceptual plated-through hole 6 centered by described substrate integrated waveguide medium layer 3 center, substrate integration wave-guide both sides are embedded with the metallized ferrite block 7 of upper and lower surface, narrow limit plated-through hole 4 of should trying one's best when processing technology allows outside ferrite block 7.

The design's structure does not need to metallize to ferrite side, first ferrite block can be imbedded medium substrate man-hour in actual adding, then overall to upper surface paving copper, reduces processed complex degree; Carry out this kind of design of filter when high-frequency, ferrite block can be smaller, now carries out metallization difficulty to it larger, so this structure is especially useful at high band.

The above, be only the specific embodiment of the present invention, arbitrary feature disclosed in this specification, unless specifically stated otherwise, all can be replaced by other equivalences or the alternative features with similar object; Step in disclosed all features or all methods or process, except mutually exclusive feature and/or step, all can be combined in any way.

Claims (3)

1. a substrate integration wave-guide ferrite variable band-pass filter, comprises metal copper clad layers (1), dielectric layer (3), narrow limit plated-through hole (4), lower metal copper clad layers (5), center perception plated-through hole (6); Wherein, lower metal copper clad layers (5) sets gradually dielectric layer (3) and upper metal copper clad layers (1), upper metal copper clad layers (1) is arranged by two narrow limit plated-through hole (4) be parallel to each other with lower metal copper clad layers (5) and is connected, forms substrate integration wave-guide together with dielectric layer (3); Form substrate integration wave-guide center offer one row center perception plated-through hole (6), it is characterized in that, embed respectively near described two rows narrow limit plated-through hole (4) in described dielectric layer (3) and be provided with ferrite block (2), the upper and lower surface metalation of ferrite block (2), is connected conducting with upper and lower metal copper clad layers.

2., by substrate integration wave-guide ferrite variable band-pass filter described in claim 1, it is characterized in that, described ferrite block (2) near plated-through hole side, narrow limit surface metalation, and then replaces the narrow limit plated-through hole of its corresponding position.

3. by substrate integration wave-guide ferrite variable band-pass filter described in claim 1,2, it is characterized in that, the length of described ferrite block (2) is more than or equal to the total length at center perception plated-through hole (6).