CN105428760A - Small high-pass filter employing substrate integrated waveguide - Google Patents

Abstract

The invention relates to a small high-pass filter employing a substrate integrated waveguide. The small high-pass filter comprises metal layers and metalized through holes, wherein the metal layers cover the upper surface and the lower surface of a dielectric layer; the metalized through holes are connected with upper and lower two layers of copper coils; the metalized through holes are vertical to the upper metal layer and the lower metal layer; the metalized through holes and the dielectric layer form a similar waveguide structure; and a microwave and millimeter-wave circuit system is connected through waveguide to micro-strip transition. The small high-pass filter has the advantages of being small in size, low in cost, convenient to integrate with a system, low in difference loss, high in suppression degree and the like.

Description

A kind of miniaturized substrate integrated waveguide high pass filter

Technical field

The invention belongs to millimeter waveguide technical field of filtering, relate to the mini filter based on substrate integrated waveguide technology.

Background technology

Millimeter wave is in an increasingly wide range of applications in the fields such as radar communication, satellite communication and navigation, and filter is as the vitals of millimeter wave receiver, also play very important role, its filtering performance is one of key factor affecting receiver performance.

For adapting to developing rapidly of the industry such as electronics and radio communication, microwave and millimeter wave system is just fast-developing towards aspects such as miniaturization, high-performance, low costs, millimeter wave filter is as the vitals of millimeter-wave systems, also be faced with more and more higher requirement, as: less volume, lower differential loss, the outer higher suppression of band, lower cost, more easily with the system integration.Substrate integration wave-guide has the advantage of waveguide and planar circuit concurrently, has relatively high Q value and is easy to integrated advantage.Substrate integration wave-guide is connected with upper lower metal layer by via hole metallized on substrate, forms the version of similar waveguide.This version inherits the advantage of waveguide and planar circuit, inherently plays an important role in microwave and millimeter wave system.

Summary of the invention

The technical problem solved

In order to solve the bulky problem of existing filter, the present invention proposes a kind of miniaturized substrate integrated waveguide high pass filter.

Technical scheme

A kind of miniaturized substrate integrated waveguide high pass filter, is characterized in that comprising dielectric substrate, is covered in the upper metal level on dielectric substrate two sides and lower metal layer, multiple metallization via holes through dielectric substrate; Upper metal level comprises 50 ohm of input microstrip lines, input micro-take to substrate integration wave-guide changeover portion, substrate integration wave-guide, output micro-take substrate integration wave-guide changeover portion to and 50 ohm export microstrip lines, metallization via hole is positioned at substrate integration wave-guide, and lower metal layer is metal ground; The broadside W of described substrate integration wave-guide _swith the broadside W of rectangular waveguide _rconversion formula as follows:

$\stackrel{\‾}{a}=\frac{W_R}{W_S}={\mathrm{\ξ}}_1+\frac{{\mathrm{\ξ}}_2}{\frac{p}{d}+\frac{{\mathrm{\ξ}}_1+{\mathrm{\ξ}}_2-{\mathrm{\ξ}}_3}{{\mathrm{\ξ}}_3-{\mathrm{\ξ}}_1}}$

${\mathrm{\ξ}}_1=1.0198+\frac{0.3465}{\frac{W_S}{p}-1.0684}$

${\mathrm{\ξ}}_2=-0.1183-\frac{1.2729}{\frac{W_S}{p}-1.2010}$

${\mathrm{\ξ}}_3=1.0082-\frac{0.9163}{\frac{W_S}{p}+0.2152}$

Wherein, d is metallic vias diameter, and p is metallic vias distance.

Described metallization via hole is 14, and crossing pore radius is 0.3 millimeter.

Described dielectric substrate (5) is Rogers5880.

Beneficial effect

A kind of miniaturized substrate integrated waveguide high pass filter that the present invention proposes, has that volume is little, cost is low, structure is simple, facilitates and the advantage such as the system integration, low differential loss, high degree of suppression.

Accompanying drawing explanation

Fig. 1 substrate integration wave-guide high pass filter top view

Fig. 2 substrate integral wave guide filter bottom view

Fig. 3 substrate integration wave-guide high pass filter end view

Fig. 4 substrate integration wave-guide high pass filter S parameter simulation curve

Embodiment

Now in conjunction with the embodiments, the invention will be further described for accompanying drawing:

The composition of Miniaturized substrate integrated high-pass filter comprises the metal level being covered in the upper and lower surface of dielectric layer and the metallization via hole being connected upper and lower two-layer Copper Foil.Wherein metallize via hole perpendicular to upper and lower metal level, and form the structure of similar waveguide together with dielectric layer, by waveguide to microstrip transition access microwave and millimeter wave Circuits System, as shown in Figure 1, Figure 2, Figure 3 shows.

A kind of substrate integral wave guide filter comprises: a slice dielectric substrate, uses Rogers5880 here, to see in Fig. 1, Fig. 3 shown in 5, be covered in the metal level that substrate is upper and lower, as in Fig. 1,2,3, shown in 3,6, through the metallization via hole of top bottom, as shown in Figure 1, Figure 2, in Fig. 3, shown in 4.In Fig. 1,1 is 50 ohm of band lines, and 2 take substrate integration wave-guide transition to for micro-.

In millimeter wave converter unit, often can run into and need by X-band by up-conversion, changing to the situation that Ka frequency range exports, is unwanted signal at output X-band, must filtering.Although use MEMS filter can filtering X-band signal, except needing to pay high cost, complicated micro-assembling assembly technology be also needed to coordinate.Not only volume is large to use traditional waveguide filter, and claimed structure machining accuracy is high, and makes whole system assembling become more complicated, reduces the reliability of whole system.Use traditional microstripline filter, although assembling is simple, but needs larger space, run counter to system compact designing requirement.

Here a miniaturized millimeter wave high pass filter is designed, design objective: free transmission range: 30GHz-35GHz according to above analysis; Stopband range: 2GHz-10GHz; Along signal transmission direction size: 3mm; Insertion loss :≤0.5dB; Frequency degree of suppression: >=30dB.

The present invention adopts and determines substrate integral wave guide filter broadside initial length with the following method.

Suppose W _rfor the broadside of rectangular waveguide, W _sfor the broadside (being the lateral separation between two metallization via holes in corresponding diagram) of substrate integration wave-guide, d is metal throuth hole diameter, and p is metal throuth hole distance, and the corresponding relation of substrate integration wave-guide and traditional rectangular waveguide can show with following formula table:

$\stackrel{\‾}{a}=\frac{W_R}{W_S}={\mathrm{\ξ}}_1+\frac{{\mathrm{\ξ}}_2}{\frac{p}{d}+\frac{{\mathrm{\ξ}}_1+{\mathrm{\ξ}}_2-{\mathrm{\ξ}}_3}{{\mathrm{\ξ}}_3-{\mathrm{\ξ}}_1}}$ Formula 1

${\mathrm{\ξ}}_1=1.0198+\frac{0.3465}{\frac{W_S}{p}-1.0684}$ Formula 2

${\mathrm{\ξ}}_2=-0.1183-\frac{1.2729}{\frac{W_S}{p}-1.2010}$ Formula 3

${\mathrm{\ξ}}_3=1.0082-\frac{0.9163}{\frac{W_S}{p}+0.2152}$ Formula 4

Use electromagnetic simulation software to W _sinitial length is optimized adjustment, finally obtains result as shown in Figure 4.

As can be seen from simulation result, insertion loss < 0.5dB in free transmission range, frequency degree of suppression > 30dB in stopband range, filter equals 3mm along length of transmission line after tested, this shows: the design that this patent proposes has: volume is little, cost is low, structure is simple, the convenient and system integration, low differential loss, high degree of suppression.

Those of ordinary skill in the art will appreciate that, embodiment described here is to help reader understanding's principle of the present invention, should be understood to that protection scope of the present invention is not limited to so special statement and embodiment.Those of ordinary skill in the art can inspire according to these technology disclosed by the invention and make various other distortion and the combination that do not depart from essence of the present invention, and these distortion and combination are still in protection scope of the present invention.

Claims (3)

1. a miniaturized substrate integrated waveguide high pass filter, is characterized in that comprising dielectric substrate (5), is covered in the upper metal level (3) on dielectric substrate (5) two sides and lower metal layer (6), multiple metallization via holes (4) through dielectric substrate; Upper metal level (3) comprises 50 ohm of input microstrip lines, inputs micro-substrate integration wave-guide changeover portion, substrate integration wave-guide, substrate integration wave-guide of taking to output microstrip transition section and 50 ohm of output microstrip lines, metallization via hole (4) is positioned at substrate integration wave-guide, and lower metal layer (6) is metal ground; The broadside W of described substrate integration wave-guide _swith the broadside W of rectangular waveguide _rconversion formula as follows:

$\stackrel{\&OverBar;}{a}=\frac{W_R}{W_S}={\mathrm{\&xi;}}_1+\frac{{\mathrm{\&xi;}}_2}{\frac{p}{d}+\frac{{\mathrm{\&xi;}}_1+{\mathrm{\&xi;}}_2-{\mathrm{\&xi;}}_3}{{\mathrm{\&xi;}}_3-{\mathrm{\&xi;}}_1}}$

${\mathrm{\&xi;}}_1=1.0198+\frac{0.3465}{\frac{W_S}{p}-1.0684}$

${\mathrm{\&xi;}}_2=-0.1183-\frac{1.2729}{\frac{w_S}{p}-1.2010}$

${\mathrm{\&xi;}}_3=1.0082-\frac{0.9163}{\frac{w_S}{p}+0.2152}$

Wherein, d is metallic vias diameter, and p is metallic vias distance.

2. a kind of miniaturized substrate integrated waveguide high pass filter according to claim 1, is characterized in that described metallization via hole (4) is 14, and crossing pore radius is 0.3 millimeter.

3. a kind of miniaturized substrate integrated waveguide high pass filter according to claim 1, is characterized in that described dielectric substrate (5) is Rogers5880.