CN1697248A - Wave-guide integrated on substrate-electronic band gap band pass filter - Google Patents

Abstract

The disclosed filter includes a medium base plate. Metal pasters covered on both sides of the said base plate are as a top surface and floor. Substrate integration wave-guide (SIW) on base plate is setup at the medium base plate, and electronic band gap is setup at floor. Input end and output end are connected to integrated wave-guide on same base plate respectively. Structure of electronic band gap is composed of compact type units of electronic band gap arranged in array in same plane. Advantages are: small size of integrated structure of electronic band gap with SIW in filter, easy to be integrated with other ICs, wide frequency selectivity, simple designing method, and possible to add number of identical unit of structure of electronic band gap to increase frequency selectivity.

Description

Substrate integration wave-guide--electronic band gap band pass filter

Technical field

The present invention relates to a kind of design that can be applied to the microwave and millimeter wave circuit, also can be used for substrate integration wave-guide--the electronic band gap band pass filter of microwave and millimeter wave integrated circuit (IC) design in system in package (SOP), System on Chip/SoC (SOC) the equal altitudes integrated system.

Background technology

The microwave and millimeter wave band pass filter has a large amount of application in the communication system that develops rapidly.Along with the fast development of wide-band communication system, the filter of broad passband has urgent demand to having very.Utilize traditional structures such as metal ridge waveguide can form broadband microwave and millimeter wave band pass filter.But the filter of these forms at first is difficult to accomplish the relative bandwidth (〉=50%) of non-constant width, secondly the band pass filter volume ratio of these forms is huger, be difficult to other microwave and millimeter wave devices integrated, the band pass filter processing cost of the 3rd these forms is relatively more expensive, and the requirement of machining accuracy is than higher.In order to overcome these difficulties, need a kind of very wide bandwidth (〉=50%) that has, volume is little, and is in light weight, and processing cost is low, is easy to integrated microwave and millimeter wave band pass filter.

Summary of the invention

The invention provides a kind of filter needs that can satisfy in broadband or the radio ultra wide band system, be easy to substrate integration wave-guide--electronic band gap band pass filter that microwave and millimeter wave circuit in the communication system and microwave and millimeter wave high performance filter are integrated again, it have volume little, be easy to integrated, processing cost is cheaper, the advantage that frequency selectivity is good is particularly suitable for the design of large-scale production and microwave and millimeter wave integrated circuit.

The present invention adopts following technical scheme:

A kind of substrate integration wave-guide--electronic band gap band pass filter, comprise: two-sided being covered with respectively as end face, the dielectric substrate of the metal patch on ground, on dielectric substrate, be provided with substrate integration wave-guide, this substrate integration wave-guide is made up of 2 row metal through holes at least, metal patch is connected by plated-through hole, on the ground of dielectric substrate, be provided with the electronic band gap structure, on the end face of dielectric substrate, be provided with input with output and be connected with same substrate integration wave-guide respectively, the electronic band gap structure is made up of the compact electronic band gap unit, isoplanar by arrayed, have at least compact electronic band gap unit, 1 row isoplanar to be positioned on the ground of substrate integration wave-guide interior zone, the plated-through hole that is used to constitute substrate integration wave-guide lays respectively in each electronic band gap unit of compact electronic band gap unit, 2 row isoplanar, and this compact electronic band gap unit, 2 row isoplanar lays respectively at the both sides of the compact electronic band gap unit, isoplanar of substrate integration wave-guide interior zone.

Compared with prior art, the present invention has following advantage:

The present invention utilizes the two row or multi-row plated-through hole on dielectric substrate, forms substrate integration wave-guide.The present invention has utilized the high pass of substrate integration wave-guide to select the band resistance characteristic of characteristic and electronic band gap structure frequently, and hard-packed and substrate integration wave-guide combines with electronic band gap, thereby has formed high performance filter, and the volume of device greatly reduces simultaneously.In this Filter Structures, all structures can utilize traditional PCB or LTCC technology to realize, a series of metal throuth hole array on the main dielectric substrate of total constitutes simultaneously, thereby reduced production cost, helped this filter integrated in the microwave and millimeter wave circuit design simultaneously; We have designed a kind of input and output of broadband preferably coupled structure and the electronic band gap structure have closely been integrated with substrate integration wave-guide; The realization of this filter mainly is to utilize the high pass of substrate integration wave-guide to select the band resistance characteristic of characteristic and electronic band gap structure to realize frequently.Has very substrate integration wave-guide--the electronic band gap band pass filter of broadband and fabulous selectivity characteristic by regulating the size of substrate integration wave-guide and electronic band gap structure, can forming; This filter design method is simple, can be by increasing the number of identical electronic bandgap structure unit, and the frequency that greatly increases filter selects characteristic.The present invention specifically has following advantage:

1) this filter integrates electronic band gap structure (PBG) and substrate integration wave-guide (SIW) closely, and device size is smaller, is easy to other circuit integrated in the design of microwave and millimeter wave circuit.This filter can utilize PCB commonly used or LTCC technology to realize that the agent structure of filter is the metal throuth hole array on dielectric substrate, and compact conformation satisfies the requirement of low-cost large-scale processing;

2) can realize high performance frequency selectivity in very wide frequency band range, method for designing is fairly simple, can be by between input and output, increasing the number of identical electronic bandgap structure unit, and the frequency that increases filter greatly selects characteristic.

Description of drawings

Fig. 1 is a structural front view of the present invention.

Fig. 2 is a structure rearview of the present invention.

Fig. 3 is a structure side view of the present invention.

Fig. 4 is the test result figure to the embodiment of the invention, and this test result has comprised the Insertion Loss of two sub-miniature A connectors.

The structure rearview of Fig. 5 embodiment of the invention 1.

The structure rearview of Fig. 6 embodiment of the invention 2.

The structure rearview of Fig. 7 embodiment of the invention 3.

Embodiment

A kind of substrate integration wave-guide--electronic band gap band pass filter, comprise: two-sided being covered with respectively as end face, the metal patch 21 on ground, 22 dielectric substrate 3, on dielectric substrate 3, be provided with substrate integration wave-guide, this substrate integration wave-guide is made up of 2 row metal through holes 1 at least, metal patch 21,22 by plated-through hole 1 connection, on the ground of dielectric substrate 3, be provided with the electronic band gap structure, on the end face of dielectric substrate 3, be provided with input 2 with output 5 and be connected with same substrate integration wave-guide respectively, the electronic band gap structure is made up of the compact electronic band gap unit, isoplanar 4 by arrayed, have at least compact electronic band gap unit, 1 row isoplanar to be positioned on the ground of substrate integration wave-guide interior zone, the plated-through hole that is used to constitute substrate integration wave-guide lays respectively in each electronic band gap unit of compact electronic band gap unit, 2 row isoplanar, and this compact electronic band gap unit, 2 row isoplanar lays respectively at the both sides of compact electronic band gap unit, isoplanar of substrate integration wave-guide interior zone (as Fig. 2, Fig. 5 is to shown in Figure 7).

Above-mentioned plated-through hole can be 2,3,5,8 or 11 row.In the present embodiment, can there be compact electronic band gap unit, 1,3,4,6,9 or 12 row isoplanar to be positioned on the ground of substrate integration wave-guide interior zone.

To test shows of the present invention: this filter has very wide bandwidth, well frequency selectivity.Tested object be utilize that the PCB technology realized 11 unit ultra broadband substrate integration wave-guides--electronic band gap band pass filter (Wideband SIW-PBG Filter) arranged.This filter is of a size of 5.5 * 4.2cm ²

The present invention adopts following method to carry out adjusting to the size of substrate integration wave-guide and compact electronic band gap unit, isoplanar:

At first we regulate the diameter and the spacing of the metal throuth hole that constitutes substrate integration wave-guide according to the relation between rectangular waveguide and the substrate integration wave-guide:

${\mathrm{\λ}}_c\·f_c=C_0/\sqrt{{\mathrm{\μ}}_r{\mathrm{\ϵ}}_r}---\left(1.1\right)$

F in the following formula _cBe the cut-off frequency of rectangular waveguide in the rectangular waveguide commonly used, in design, get the lowest operating frequency in the operating frequency range of this filter, λ _cBe the cut-off wavelength of rectangular waveguide in the rectangular waveguide commonly used, C ₀For the propagation of light in the free space several times, μ _rBe the magnetic relative dielectric constant of rectangular waveguide medium, ε _rBe the electric relative dielectric constant of rectangular waveguide medium, we can be in the hope of the cut-off wavelength of rectangular waveguide by this formula.

λ _c＝2a _rec (1.2)

a _RecBe the rectangular waveguide width edge length of correspondence, we can be in the hope of required rectangular waveguide width edge length a by (1.2) formula _Rec1

${\mathrm{\λ}}_g=\frac{\mathrm{\λ}}{\sqrt{1-{\left(\frac{\mathrm{\λ}}{{\mathrm{\λ}}_c}\right)}^2}}---\left(1.3\right)$

Pairing operation wavelength when λ is operated in frequency f, λ _gGuide wavelength when being operated in frequency f in the rectangular waveguide, when getting frequency f when being the maximum operating frequency of filter, by (1.3) formula, we can be in the hope of the guide wavelength λ of required rectangular waveguide _G1, for bottom line reduces the leakage of substrate integration wave-guide sidewall, we choose spacing VSP between the metal throuth hole smaller or equal to 1/8th guide wavelength λ _G1, the diameter of metal throuth hole is greater than 1/32nd guide wavelength λ _G1It is also less than ten sixth guide wavelength λ simultaneously _G1

After the diameter and spacing of the metal throuth hole of having determined the formation substrate integration wave-guide, we try to achieve the spacing between the two row metal through holes that constitute substrate integration wave-guide according to following relational expression, that is the width W SIW of substrate integration wave-guide.

$\stackrel{\‾}{a}=\frac{a_{\mathrm{rec}}}{\mathrm{WSIW}}={\mathrm{\ξ}}_1+\frac{{\mathrm{\ξ}}_2}{\frac{\mathrm{VSP}}{D}+\frac{{\mathrm{\ξ}}_1+{\mathrm{\ξ}}_2-{\mathrm{\ξ}}_3}{{\mathrm{\ξ}}_3-{\mathrm{\ξ}}_1}}---\left(1.4\right)$

A is a normalization factor in the following formula, and it has reflected the relation between substrate integration wave-guide and the rectangular waveguide, a _RecRelational expression between the rectangular waveguide, ξ ₁, ξ ₂, ξ ₃Be defined as follows respectively:

${\mathrm{\ξ}}_1=1.0198+\frac{0.3465}{\frac{\mathrm{WSIW}}{\mathrm{VSP}}-1.0684},$ ${\mathrm{\ξ}}_2=-0.1183-\frac{1.2729}{\frac{\mathrm{WSIW}}{\mathrm{VSP}}-1.2010},$ ${\mathrm{\ξ}}_3=1.0082-\frac{0.9163}{\frac{\mathrm{WSIW}}{\mathrm{VSP}}+0.2152}---\left(1.5\right)$

We use electromagnetism all-wave algorithm (Finite Difference-Time Domain divides algorithm) that the electronic band gap structure that compact electronic band gap unit, isoplanar constitutes is carried out Electromagnetic Simulation, thereby obtained the stop-band frequency of electronic band gap structure, we are optimized the electronic band gap structure through electromagnetism all-wave algorithm, make the stop-band frequency of electronic band gap structure and the upper limit operating frequency of this filter equate, thereby obtained the size of electronic band gap unit.

Claims (1)

1, a kind of substrate integration wave-guide--electronic band gap band pass filter, comprise: two-sided being covered with respectively as end face, the metal patch (21 on ground, 22) dielectric substrate (3), on dielectric substrate (3), be provided with substrate integration wave-guide, this substrate integration wave-guide is made up of 2 row metal through holes (1) at least, metal patch (21,22) connect by plated-through hole (1), on the ground of dielectric substrate (3), be provided with the electronic band gap structure, on the end face of dielectric substrate (3), be provided with input (2) with output (5) and be connected with same substrate integration wave-guide respectively, it is characterized in that the electronic band gap structure is made up of the compact electronic band gap unit, isoplanar (4) by arrayed, have at least compact electronic band gap unit, 1 row isoplanar to be positioned on the ground of substrate integration wave-guide interior zone, the plated-through hole that is used to constitute substrate integration wave-guide lays respectively in each electronic band gap unit of compact electronic band gap unit, 2 row isoplanar, and this compact electronic band gap unit, 2 row isoplanar lays respectively at the both sides of the compact electronic band gap unit, isoplanar of substrate integration wave-guide interior zone.

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