CN105789742A - Coplanar waveguide wide-stop-band filter - Google Patents

Abstract

The invention discloses a coplanar waveguide wide stopband filter, which is formed by nesting a coplanar waveguide λg/4 type SIR short-circuit branch unit structure and a coplanar waveguide defect structure. This structure is a nested structure of coplanar waveguide SIR and coplanar waveguide DGS, which can generate multiple adjacent resonance zeros, because this structure is essentially a SIR structure, which has the advantages of the SIR structure, so it can also be changed by changing the SIR The ratio of the characteristic impedance of the structural transmission line is used to realize the frequency change, which is very suitable for designing a miniaturized wide stopband filter. The present invention solves the contradiction between the performance and the volume when designing the wide stop band filter currently, the insertion loss is small, the frequency selectivity is better, and the volume is small, which satisfies the filtering performance and reduces the volume at the same time .

Description

A Coplanar Waveguide Wide Band Stop Filter

technical field

The invention relates to the technical field of communication equipment, in particular to a coplanar waveguide wide stopband filter.

Background technique

After the coplanar waveguide (CPW) structure was proposed by C.P.Wen in 1969, the use of the coplanar waveguide structure to realize microwave filters also came into being. The coplanar waveguide is a structure in which the conductor strip and the ground plane are on the same plane. As shown in Figure 2, the structure includes a dielectric substrate and a coplanar waveguide signal line laid in the middle of the upper surface of the dielectric substrate. The coplanar waveguide ground is laid on both sides of the coplanar waveguide signal line. This structure is convenient for connecting external components in parallel, and it is easy to form a hybrid integrated circuit. Due to its many advantages such as very convenient connection with active devices and passive devices, and the rapid development of microwave and millimeter wave integrated circuits, especially monolithic integrated circuits, recent In recent years, the coplanar waveguide structure has attracted more and more scholars' attention, and the use of this structure to design microwave filters has become more widespread.

With the development of microwave technology, the design of microwave filters has become relatively mature. Nowadays, people have paid more attention to the realization of wide stopband when meeting the passband performance requirements of filters.

At present, the coplanar waveguide wide stopband filter usually adopts one of the following two structures:

1. Using a stepped impedance resonator (SIR) and a deformed structure of the SIR, as shown in Figure 3, the structure includes the λg/4-type SIR unit structure shown in Figure 1 and the coplanar waveguide structure shown in Figure 2 , one end of the SIR structure is connected to the coplanar waveguide ground to form a short circuit, and the other end is open circuit;

2. Defective ground structure (DGS), as shown in Figure 4, the structure includes the coplanar waveguide structure shown in Figure 2, and two symmetrical rectangular defect grounds with relatively small openings are formed on the coplanar waveguide ground;

At present, many designers only use DGS structure or SIR structure for cascading, and the number of cascading is about 4 or 5. Generally, the more cascading times, the greater the insertion loss will be. Therefore, although the obtained Good wide stopband performance, but at the same time it also brings the disadvantages of increased insertion loss in the bandpass part and increased device volume.

Contents of the invention

The purpose of the embodiments of the present invention is to provide a coplanar waveguide wide stopband filter, which solves the problems of large insertion loss in the bandpass part and large filter volume in the prior art.

In order to achieve the above object, the embodiment of the present invention discloses:

A coplanar waveguide wide stop band filter, comprising a coplanar waveguide λg/4 type SIR short-circuit stub unit structure, and at least one layer nested in the coplanar waveguide λg/4 type SIR short-circuit stub unit structure The defect structure of the coplanar waveguide,

The coplanar waveguide λg/4-type SIR short-circuit branch unit structure includes a coplanar waveguide structure and a λg/4-type SIR unit structure nested in the coplanar waveguide structure,

The coplanar waveguide structure includes a dielectric substrate, a coplanar waveguide signal line is laid at the middle position on the upper surface of the dielectric substrate, and a coplanar waveguide ground is laid on both sides of the coplanar waveguide signal line. The coplanar waveguide There is a gap between the signal line and the coplanar waveguide ground,

The λg/4-type SIR unit structure includes a thicker transmission line and a thinner transmission line connected to each other, and the coplanar waveguide structure and the λg/4-type SIR unit structure are nested into When the coplanar waveguide λg/4 type SIR short-circuit branch unit structure, one end of the thinner transmission line is connected to the coplanar waveguide ground to form a short circuit, and one end of the thicker transmission line is connected to the coplanar waveguide ground, common The surface waveguide signal lines are not connected, forming an open circuit,

The defect structure of the coplanar waveguide includes the coplanar waveguide structure, and rectangular defect grounds are respectively opened on the coplanar waveguide ground, and the defect ground faces the side of the coplanar waveguide signal line, and communicates with the common plane through an opening. The gap between the planar waveguide signal line and the coplanar waveguide ground is connected,

When the coplanar waveguide λg/4 type SIR short-circuit branch unit structure and the coplanar waveguide defect structure are nested into a coplanar waveguide wide stopband filter, the defect ground of the coplanar waveguide defect structure Partially nested in the thicker transmission line in the SIR short-circuit stub unit structure of the coplanar waveguide λg/4 type.

Preferably, the coplanar waveguide λg/4 type SIR short-circuit branch unit structure is nested with a layer of coplanar waveguide defect structure, and the defect ground of the coplanar waveguide defect structure is partially nested in the coplanar waveguide In the thicker transmission line in the waveguide λg/4-type SIR short-circuit stub unit structure, the opening of the defective ground portion of the defect structure of the coplanar waveguide faces to the side of the coplanar waveguide signal line.

Preferably, the defective part of the defective structure of the coplanar waveguide is a rectangular ring.

Preferably, the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type is embedded with defect structures of two layers of coplanar waveguides, and the defects of the defect structures of the first layer of coplanar waveguides are partially embedded Set in the thicker transmission line in the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type, the opening of the defective ground part of the defect structure of the first layer of coplanar waveguide faces the coplanar waveguide λg/4 type The SIR short-circuit branch unit structure is on the side of the coplanar waveguide signal line, and the defective part of the defect structure of the first layer of coplanar waveguide is a rectangular ring, and the coplanar waveguide in the rectangular ring is not completely hollowed out. The second layer The defective ground portion of the defect structure of the coplanar waveguide is nested in the coplanar waveguide ground within the defective ground portion of the defect structure of the first layer of coplanar waveguide, and the opening of the defective ground portion of the defect structure of the second layer of coplanar waveguide faces The coplanar waveguide λg/4 type SIR short-circuit branch unit structure is one side of the coplanar waveguide signal line.

Preferably, the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type is embedded with defect structures of two layers of coplanar waveguides, and the defects of the defect structures of the first layer of coplanar waveguides are partially embedded Set in the thicker transmission line in the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type, the opening of the defective ground part of the defect structure of the first layer of coplanar waveguide faces the coplanar waveguide λg/4 type The SIR short-circuit branch unit structure is on the side of the coplanar waveguide signal line, and the defective part of the defect structure of the first layer of coplanar waveguide is a rectangular ring, and the coplanar waveguide in the rectangular ring is not completely hollowed out. The second layer The defective ground portion of the defect structure of the coplanar waveguide is nested in the coplanar waveguide ground within the defective ground portion of the defect structure of the first layer of coplanar waveguide, and the opening of the defective ground portion of the defect structure of the second layer of coplanar waveguide faces The side relatively parallel to the signal line of the coplanar waveguide in the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type.

Preferably, the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type is embedded with defect structures of two layers of coplanar waveguides, and the defects of the defect structures of the first layer of coplanar waveguides are partially embedded Set in the thicker transmission line in the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type, the opening of the defective ground part of the defect structure of the first layer of coplanar waveguide faces the coplanar waveguide λg/4 type The SIR short-circuit branch unit structure is on the side of the coplanar waveguide signal line, and the defective part of the defect structure of the first layer of coplanar waveguide is a rectangular ring, and the coplanar waveguide in the rectangular ring is not completely hollowed out. The second layer The defective ground portion of the defect structure of the coplanar waveguide is nested in the coplanar waveguide ground within the defective ground portion of the defect structure of the first layer of coplanar waveguide, and the opening of the defective ground portion of the defect structure of the second layer of coplanar waveguide faces The side perpendicular to the signal line of the coplanar waveguide in the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type.

Preferably, the defective part of the defective structure of the second-layer coplanar waveguide is a rectangular ring.

It can be seen from the above technical solution that the embodiment of the present invention solves the problem by nesting the coplanar waveguide λg/4-type SIR short-circuit branch unit structure with the coplanar waveguide defect structure to obtain a miniaturized coplanar waveguide wide stopband filter. When designing a wide stopband filter, there is a contradiction between performance and volume, because the present invention does not obtain multiple resonance points by using DGS or SIR structure to perform simple multi-stage cascading, but designs a nested structure, so its insertion loss is small, and its volume is small, which satisfies the filtering performance and reduces the volume.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the structural representation of the SIR unit structure of λg/4 type;

Fig. 2 is a schematic diagram of a coplanar waveguide structure;

Fig. 3 is a schematic diagram of the structure of the SIR short-circuit branch unit of the coplanar waveguide λg/4 type;

Fig. 4 is a structural schematic diagram of the first embodiment of the defect structure of the coplanar waveguide;

Fig. 5 is a structural schematic diagram of a second embodiment of a defect structure of a coplanar waveguide;

Fig. 6 is the structural representation of the first embodiment of the coplanar waveguide wide stopband filter of the present invention;

Fig. 7 is the structural representation of the second embodiment of the coplanar waveguide wide stopband filter of the present invention;

Fig. 8 is a structural schematic diagram of a third embodiment of the coplanar waveguide wide stopband filter of the present invention;

Fig. 9 is a schematic structural view of a fourth embodiment of the coplanar waveguide wide stopband filter of the present invention;

Fig. 10 is a schematic structural view of a fifth embodiment of the coplanar waveguide wide stopband filter of the present invention;

Fig. 11 is a schematic structural view of the sixth embodiment of the coplanar waveguide wide stopband filter of the present invention;

Fig. 12 is a structural schematic diagram of the seventh embodiment of the coplanar waveguide wide stopband filter of the present invention;

Fig. 13 is a structural schematic diagram of the eighth embodiment of the coplanar waveguide wide stopband filter of the present invention;

Fig. 14 is a structural schematic diagram of the ninth embodiment of the coplanar waveguide wide stopband filter of the present invention;

Fig. 15 is a schematic structural diagram of the tenth embodiment of the coplanar waveguide wide stopband filter of the present invention;

Fig. 16 is a schematic diagram of S21 parameters of the coplanar waveguide SIR structure;

Fig. 17 is a schematic diagram of S21 parameters of a coplanar waveguide defect ground structure;

Fig. 18 is a schematic diagram of S21 parameters of coplanar waveguide SIR and defect ground nesting structure.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Figure 1 is a λg/4-type SIR unit structure, which includes a thicker transmission line and a thinner transmission line connected to each other. The thicker transmission line and the thinner transmission line have different characteristic impedances. By changing the impedance ratio between them R _Z can adjust the length of the resonator and the corresponding spurious resonant frequency, it is a kind of resonator that can generate double resonant point of transverse electromagnetic field or quasi transverse electromagnetic field mode.

Figure 2 is a coplanar waveguide structure, including a dielectric substrate, a coplanar waveguide signal line is laid at the middle position on the upper surface of the dielectric substrate, a coplanar waveguide ground is laid on both sides of the coplanar waveguide signal line, the coplanar waveguide signal line and A gap is left between the coplanar waveguide grounds.

Figure 3 is the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type, which includes the coplanar waveguide structure and the λg/4 type SIR unit structure nested in the coplanar waveguide structure, and the λg/4 type SIR One end of the thinner transmission line in the unit structure is connected to the coplanar waveguide ground of the coplanar waveguide structure to form a short circuit, and one end of the thicker transmission line is not connected to the coplanar waveguide ground or the coplanar waveguide signal line, forming an open circuit.

Fig. 4 is the first embodiment of the defective ground structure of the coplanar waveguide. This structure also includes the coplanar waveguide structure in Fig. 2. There are rectangular defective grounds respectively opened on the coplanar waveguide ground, and the defective ground faces the coplanar waveguide signal. One side of the line communicates with the gap between the coplanar waveguide signal line and the coplanar waveguide ground through an opening.

Fig. 5 is the second embodiment of the defective ground structure of the coplanar waveguide. The difference from Fig. 4 is that the defective ground is partly a rectangular ring, and the metal sheet in the rectangular ring is not completely hollowed out in the coplanar waveguide, so that the filtering The filter has a larger equivalent capacitance and a smaller equivalent inductance at higher frequencies, which helps to increase the insertion loss of the filter and reduce the return loss of the filter at high frequencies.

Fig. 6 is the structure of the first embodiment of the coplanar waveguide wide stopband filter of the present invention, the structure is based on Fig. 3 and the structure of Fig. 4 is nested, and the SIR short-circuit branch of the coplanar waveguide λg/4 type A defect structure of a coplanar waveguide is nested in the unit structure, and the defect ground of the defect structure of the coplanar waveguide is partially nested in the thicker transmission line in the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type, coplanar The opening of the defective ground part of the defective structure of the waveguide faces to the signal line side of the coplanar waveguide of the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type.

According to the structure of the first embodiment, a layer of defective ground is set. The characteristic of the filter of this structure is that the second harmonic generated by the DGS structure nested in the SIR structure is farther away from the first harmonic, so the second Harmonics will have less impact on filter stopband performance.

The structure of the second embodiment of the present invention, as shown in Figure 7, is also a defect structure of a layer of coplanar waveguide nested in the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type, which includes the first implementation All the structures in the example are not described here again. In addition, the defective part of the defect structure of the coplanar waveguide is a rectangular ring, and the metal sheet in the rectangular ring is not completely hollowed out.

According to the structure of the second embodiment, a layer of defective ground is set, and the defective ground part is a rectangular ring, and the coplanar waveguide ground of the metal sheet in the rectangular ring is not completely hollowed out. The filter with this structure has a larger The equivalent capacitance and smaller equivalent inductance help to increase the insertion loss of the filter and reduce the return loss of the filter in the high frequency band.

In the structure of the third embodiment of the present invention, as shown in Figure 8, the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type is nested with two layers of coplanar waveguide defect structures, and the first layer of coplanar waveguide The defect ground part of the defect structure is nested in the thicker transmission line in the SIR short-circuit stub unit structure of the coplanar waveguide λg/4 type, and the opening of the defect part of the defect structure of the first layer of coplanar waveguide faces the coplanar waveguide λg /4 type SIR short-circuit branch unit structure on the side of the coplanar waveguide signal line, the defective part of the defect structure of the first layer of coplanar waveguide is divided into a rectangular ring, and the metal sheet coplanar waveguide in the rectangular ring is not completely hollowed out. The defective ground portion of the defective structure of the second coplanar waveguide is nested in the coplanar waveguide ground within the defective ground portion of the defective structure of the first layer coplanar waveguide, and the defective ground portion of the defective structure of the second layer coplanar waveguide The opening of the coplanar waveguide λg/4 type SIR short-circuit branch unit structure faces the side of the coplanar waveguide signal line.

According to the structure of the third embodiment, two layers of defect grounds are provided, and the openings of the two layers of defect grounds are the same. The characteristic of the filter of this structure is that compared with setting one layer of defect grounds, more resonance points are generated, so the corresponding The stopband bandwidth is wider.

The structure of the fourth embodiment of the present invention, as shown in Figure 9, is also a defect structure with two layers of coplanar waveguides nested in the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type, which includes the third All the structures in the embodiment will not be described in detail here. In addition, the defective structure of the coplanar waveguide in the second layer is a rectangular ring, and the metal sheets in the rectangular ring share the same The surface waveguide is not completely hollowed out.

According to the structure of the fourth embodiment, two layers of defective ground are set, the openings of the two layers of defective ground are the same, and the second layer of defective ground is a rectangular ring, and the metal sheet coplanar waveguide in the rectangular ring is not completely hollowed out. This structure Compared with the third embodiment, the filter has larger equivalent capacitance and smaller equivalent inductance at higher frequencies, which helps to increase the insertion loss of the filter and reduce the return loss of the filter in the high frequency band .

The structure of the fifth embodiment of the present invention, as shown in Figure 10, has two layers of coplanar waveguide defect structures nested in the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type, and the first layer of coplanar waveguide The defect ground part of the defect structure is nested in the thicker transmission line in the SIR short-circuit stub unit structure of the coplanar waveguide λg/4 type, and the opening of the defect part of the defect structure of the first layer of coplanar waveguide faces the coplanar waveguide λg /4 type SIR short-circuit branch unit structure on the side of the coplanar waveguide signal line, the defective part of the defect structure of the first layer of coplanar waveguide is divided into a rectangular ring, and the metal sheet coplanar waveguide in the rectangular ring is not completely hollowed out. The defective ground of the defect structure of the second layer coplanar waveguide is partially nested in the metal sheet coplanar waveguide ground within the defective ground portion of the defect structure of the first layer coplanar waveguide, and the defect of the defect structure of the second layer coplanar waveguide The opening of the ground part faces the side relatively parallel to the signal line of the coplanar waveguide in the SIR short-circuit stub unit structure of the coplanar waveguide λg/4 type.

According to the structure of the fifth embodiment, the metal sheet coplanar waveguide in the defect ground introduces a small defect, but the opening is opposite to the opening of the large defect ground. Compared with the third embodiment, the two-layer defect ground When the opening directions are the same, it is equivalent to a parallel relationship, and when the opening directions of the two layers of defects are different, it is equivalent to a series relationship. Parallel defective ground can introduce more resonance points, so that the filter has a larger stop band range; serial defective ground has a longer electrical length, thereby changing the value of the resonant frequency point _f4 , making _f4 have a wider variable range.

The structure of the sixth embodiment of the present invention, as shown in Figure 11, is also a defect structure with two layers of coplanar waveguides nested in the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type, and the openings of the two layers of defects On the contrary, it includes all the structures in the fifth embodiment, which will not be repeated here. In addition, the defective part of the second layer is a rectangular ring, and the metal sheet coplanar waveguide in the rectangular ring is not completely hollowed out.

Compared with the fifth embodiment, the filter structure of the sixth embodiment has larger equivalent capacitance and smaller equivalent inductance at higher frequencies, which helps to increase the insertion loss and Reduce filter return loss.

The structures of the seventh and eighth embodiments of the present invention are shown in Fig. 12 and Fig. 13 respectively. The SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type is nested with defect structures of two layers of coplanar waveguides. , the defect ground of the defect structure of the coplanar waveguide in the first layer is partially embedded in the thicker transmission line in the SIR short-circuit stub unit structure of the coplanar waveguide λg/4 type, and the defect ground of the defect structure of the first layer of coplanar waveguide Part of the opening faces the coplanar waveguide signal line side of the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type, and the defective part of the defect structure of the first layer of coplanar waveguide is a rectangular ring, and the metal sheet in the rectangular ring The ground of the coplanar waveguide is not completely hollowed out, and the defect ground of the defect structure of the second layer of coplanar waveguide is partially nested in the metal sheet coplanar waveguide ground of the defect structure of the defect structure of the first layer of coplanar waveguide, and the second layer of coplanar waveguide The opening of the defective ground portion of the defect structure of the coplanar waveguide faces the side perpendicular to the signal line of the coplanar waveguide in the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type.

According to the structures of the seventh and eighth embodiments, the performance of the filter refers to the performance of the filter in the fifth embodiment.

The structure of the ninth and tenth embodiments of the present invention, as shown in Figures 14 and 15, is also a defect structure in which two layers of coplanar waveguides are nested in the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type , the opening of the defective ground portion of the defect structure of the coplanar waveguide on the second layer faces the side perpendicular to the signal line of the coplanar waveguide in the SIR short-circuit branch unit structure of the coplanar waveguide λg/4 type. It includes all the structures in the seventh and eighth embodiments, and will not be repeated here. In addition, the defective part of the defect structure of the second-layer coplanar waveguide is a rectangular ring, and the metal sheets in the rectangular ring share the same The surface waveguide is not completely hollowed out.

According to the structures of the ninth and tenth embodiments, the performance of the filter refers to the performance of the filter in the sixth embodiment.

It should be noted that the total number of nested layers of the coplanar waveguide λg/4 type SIR short-circuit branch unit structure and the coplanar waveguide defect structure should not exceed 3 layers, because too many layers will cause a relatively large passband loss.

Those skilled in the art can understand that when the DGS-SIR structure is nested, the frequency relationship between the resonance zero point of the coplanar waveguide SIR structure and the resonance zero point of the coplanar waveguide DGS should be considered, as shown in Figure 16, Figure 17 and As shown in Figure 18, the resonance zero point _f4 of the coplanar waveguide defect ground should be between the higher resonance zero point f2 of the coplanar waveguide SIR structure and the lower cutoff frequency _f3 , thereby forming a continuous multi _- resonance zero point filter. The lower resonance zero point f1 _of the coplanar waveguide SIR structure is mainly affected by the width f of the thinner transmission line. As the width _f increases, the lower resonance zero point f1 will increase, while the resonance zero point _f2 remains basically unchanged ; The higher resonance zero point f ₂ is mainly affected by the length c of the thick transmission line, the increase of the length c, the higher resonance zero point f ₂ will decrease, and at this time the lower cut-off frequency f ₃ will also decrease, and its decrease The small range is the same as the reduction range of f ₂ , which means that the two frequency points of f ₂ and f ₃ are shifted by Δf together, while the resonance zero point f ₁ remains basically unchanged. The resonance zero point f ₄ of the coplanar waveguide defect ground is mainly related to the perimeter of the defect ground. When the perimeter increases, the resonance zero point f ₄ will decrease. Therefore, in the process of adjusting the frequency, two of the resonance zero points can be kept unchanged first, and the adjustment Another resonance zero point finally makes the frequency relationship of the three resonance zero points reach f ₃ >f ₄ >f ₂ .

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a relationship between these entities or operations. any such actual relationship or order exists between them. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

Each embodiment in this specification is described in a related manner, the same and similar parts of each embodiment can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and for relevant parts, refer to part of the description of the method embodiment.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present invention are included in the protection scope of the present invention.

Claims (7)

1. a co-planar waveguide Wide stop bands wave filter, it is characterised in that include the SIR short branch cellular construction of co-planar waveguide λ g/4 type and the defect sturcture of at least one of which co-planar waveguide being nested in the SIR short branch cellular construction of co-planar waveguide λ g/4 type,

The SIR short branch cellular construction of described co-planar waveguide λ g/4 type, including the SIR cellular construction of coplanar waveguide structure and the λ g/4 type that is nested in coplanar waveguide structure,

Described coplanar waveguide structure, including dielectric substrate, it is laid with co-planar waveguide holding wire in dielectric substrate upper surface middle position, is laid with co-planar waveguide ground in co-planar waveguide holding wire both sides, gap is left between described co-planar waveguide holding wire and co-planar waveguide ground

The SIR cellular construction of described λ g/4 type, including the thicker transmission line being connected and a thinner transmission line, the SIR cellular construction of described coplanar waveguide structure and λ g/4 type is when being nested into the SIR short branch cellular construction of co-planar waveguide λ g/4 type, described thinner transmission line one end is connected formation short circuit with described co-planar waveguide ground, described thicker transmission line one end is all not connected to co-planar waveguide ground, co-planar waveguide holding wire, form open circuit

The defect sturcture of described co-planar waveguide, including described coplanar waveguide structure, having the defect ground of rectangle on the ground at described co-planar waveguide, defect ground is towards co-planar waveguide holding wire side, it is connected by the gap between an opening with coplanar waveguide signal line and co-planar waveguide ground

The SIR short branch cellular construction of described co-planar waveguide λ g/4 type and the defect sturcture of co-planar waveguide are when being nested into co-planar waveguide Wide stop bands wave filter, and the defect ground part of the defect sturcture of described co-planar waveguide is nested in transmission line thicker in the SIR short branch cellular construction of co-planar waveguide λ g/4 type.

2. co-planar waveguide Wide stop bands wave filter according to claim 1, it is characterized in that, the SIR short branch cellular construction of described co-planar waveguide λ g/4 type is nested with the defect sturcture of one layer of co-planar waveguide, the defect ground part of the defect sturcture of described co-planar waveguide is nested in transmission line thicker in the SIR short branch cellular construction of co-planar waveguide λ g/4 type, and the opening of the defect ground part of the defect sturcture of co-planar waveguide is towards described co-planar waveguide holding wire side.

3. co-planar waveguide Wide stop bands wave filter according to claim 2, it is characterised in that the defect ground part of the defect sturcture of described co-planar waveguide is a straight-flanked ring.

null4. co-planar waveguide Wide stop bands wave filter according to claim 1，It is characterized in that，The SIR short branch cellular construction of described co-planar waveguide λ g/4 type is nested with the defect sturcture of two-layer co-planar waveguide，The defect ground part of the defect sturcture of described ground floor co-planar waveguide is nested in transmission line thicker in the SIR short branch cellular construction of co-planar waveguide λ g/4 type，The opening of the defect ground part of the defect sturcture of ground floor co-planar waveguide is towards co-planar waveguide holding wire side in the SIR short branch cellular construction of described co-planar waveguide λ g/4 type，The defect ground part of the defect sturcture of ground floor co-planar waveguide is a straight-flanked ring，Co-planar waveguide ground not exclusively hollow out in straight-flanked ring，The defect ground part of the defect sturcture of described second layer co-planar waveguide is nested in the co-planar waveguide ground in the defect ground part of the defect sturcture of ground floor co-planar waveguide，The opening of the defect ground part of the defect sturcture of second layer co-planar waveguide is towards co-planar waveguide holding wire side in the SIR short branch cellular construction of described co-planar waveguide λ g/4 type.

null5. co-planar waveguide Wide stop bands wave filter according to claim 1，It is characterized in that，The SIR short branch cellular construction of described co-planar waveguide λ g/4 type is nested with the defect sturcture of two-layer co-planar waveguide，The defect ground part of the defect sturcture of described ground floor co-planar waveguide is nested in transmission line thicker in the SIR short branch cellular construction of co-planar waveguide λ g/4 type，The opening of the defect ground part of the defect sturcture of ground floor co-planar waveguide is towards co-planar waveguide holding wire side in the SIR short branch cellular construction of described co-planar waveguide λ g/4 type，The defect ground part of the defect sturcture of ground floor co-planar waveguide is a straight-flanked ring，Co-planar waveguide ground not exclusively hollow out in straight-flanked ring，The defect ground part of the defect sturcture of described second layer co-planar waveguide is nested in the co-planar waveguide ground in the defect ground part of the defect sturcture of ground floor co-planar waveguide，The side that opening is in the SIR short branch cellular construction of described co-planar waveguide λ g/4 type and co-planar waveguide holding wire is opposing parallel of the defect ground part of the defect sturcture of second layer co-planar waveguide.

null6. co-planar waveguide Wide stop bands wave filter according to claim 1，It is characterized in that，The SIR short branch cellular construction of described co-planar waveguide λ g/4 type is nested with the defect sturcture of two-layer co-planar waveguide，The defect ground part of the defect sturcture of described ground floor co-planar waveguide is nested in transmission line thicker in the SIR short branch cellular construction of co-planar waveguide λ g/4 type，The opening of the defect ground part of the defect sturcture of ground floor co-planar waveguide is towards co-planar waveguide holding wire side in the SIR short branch cellular construction of described co-planar waveguide λ g/4 type，The defect ground part of the defect sturcture of ground floor co-planar waveguide is a straight-flanked ring，Co-planar waveguide ground not exclusively hollow out in straight-flanked ring，The defect ground part of the defect sturcture of described second layer co-planar waveguide is nested in the co-planar waveguide ground in the defect ground part of the defect sturcture of ground floor co-planar waveguide，The side that opening is in the SIR short branch cellular construction of described co-planar waveguide λ g/4 type and co-planar waveguide holding wire is perpendicular of the defect ground part of the defect sturcture of second layer co-planar waveguide.

7. the co-planar waveguide Wide stop bands wave filter according to claim 4-6 any one, it is characterised in that the defect ground part of the defect sturcture of described second layer co-planar waveguide is a straight-flanked ring.