CN202564511U

CN202564511U - K-wave band broadband band-pass filter

Info

Publication number: CN202564511U
Application number: CN2012201562356U
Authority: CN
Inventors: 袁贵兰; 殷兴辉
Original assignee: Hohai University HHU
Current assignee: Hohai University HHU
Priority date: 2012-04-13
Filing date: 2012-04-13
Publication date: 2012-11-28
Anticipated expiration: 2022-04-13

Abstract

The utility model discloses a K-wave band broadband band-pass filter. The K-wave band broadband band-pass filter comprises a rectangular waveguide and a metal inserting piece, wherein the metal inserting piece is longitudinally inserted in the inner cavity of the rectangular waveguide to divide the inner cavity of the rectangular waveguide into two asymmetric parts, and the metal inserting piece is parallel to the direction of the electric field of the waveguide; a plurality of rectangular openings and metal diaphragms are staggerly arranged on the metal inserting piece, the rectangular openings and the rectangular waveguide form resonant cavities and the metal diaphragms among the resonant cavities form a coupling structure; and when the number of the resonant cavities is an odd number, the metal inserting piece is symmetric with the central rectangular opening as the center of symmetry, and when the number of the resonant cavities is an even number, the metal inserting piece is symmetric with the central metal diaphragm as the center of symmetry. By adopting the waveguide structure and the offset longitudinal metal inserting piece structure, a broader broadband can be realized corresponding to a traditional filter whose metal inserting piece arranged symmetrically on the center.

Description

A kind of K wave band broadband band-pass filter

Technical field

The utility model relates to a kind of broadband waveguide filter, relates in particular to a kind of K wave band broadband band-pass filter.

Background technology

Microwave filter is the critical elements that is used for separating or making up various different frequency signals in the microwave system, and it all has in microwave relay communication, satellite communication, radar, electronic countermeasures and microwave measurement instrument extremely widely uses.E face metallic membrane waveguide filter causes extensive attention after being proposed by konishi in 1974, because its quality factor are high, simple in structure, Insertion Loss is low, is easy to advantages such as batch process, thereby has obtained application in a plurality of waveguide frequency ranges.

All symmetry placements in waveguide broadside center of metal insert in the existing rectangle E ground roll waveguide filter, this modes of emplacement is not only simple in structure, and because TE only occurs _N0Mould, calculating also has very big convenience, and relative bandwidth is between 1%-6%.When requiring broader bandwidth; Can suitably reduce the width of metal insert coupled structure; But when the coupled structure width was narrow, the little and prior art of diaphragm support strength was (it has been generally acknowledged that attainable minimum widith is 0.1mm) that is difficult to even can't realizes.So realize that filter is broadband, can not reduce the coupled structure width simply, need look for method in addition.Because of machining or when install producing error, the asymmetric placement of metal insert also possibly occur in addition, and how the asymmetric placement of this metal insert also is the problem that people generally are concerned about to the influence of filter.

The utility model content

The utility model purpose: the purpose of the utility model is the deficiency to prior art, provides a kind of relative bandwidth can reach 8.8% K wave band broadband band-pass filter.

Technical scheme: the described K wave band of the utility model broadband band-pass filter; Comprise rectangular waveguide and metal insert; The inner chamber that said metal insert vertically is inserted in the inner chamber of said rectangular waveguide said rectangular waveguide is divided into asymmetric two parts, and said metal insert is parallel with the direction of waveguide electric field; Be staggeredly equipped with some rectangular opening and metallic membrane on the said metal insert, the number of rectangular opening is the exponent number of filter.Said rectangular opening and said rectangular waveguide constitute resonant cavity, and the metallic membrane between the resonant cavity forms coupled structure; Distance on the change metal insert between the rectangular opening is the width of diaphragm width and rectangular opening, can change the performance of filter.When the quantity of said resonant cavity was odd number, said metal insert was the symmetrical centre symmetry with the rectangular opening of centre, and when the quantity of said resonant cavity was even number, said metal insert was the symmetrical centre symmetry with the metallic membrane of centre.The utility model rectangular waveguide adopts the rectangular waveguide of standard; Metal insert departs from waveguide broadside center certain distance; The principle that the biasing metal insert can increase bandwidth is that the equivalent parallel inductance of biasing metal insert is big when placing than symmetry, and equivalent series inductance is constant basically, and the required K transformation factor of derived filter is also bigger thus; Broadband filter is needed just for this, and therefore certain bias structure can reach the frequency band of broad.

Said metal insert reduces from the rectangular opening of symmetrical centre outward direction and the width of metallic membrane successively, is minimum from the nearest coupled structure resonant cavity of interface.

Metal insert thickness is selected according to international standard and combination experience.Metal insert is thin more, and the performance of filter is good more, but processing technology is proposed higher requirement, and in order to guarantee the structural strength of metal insert, the thickness of metal insert is not less than 0.3mm.

The two ends of said rectangular waveguide are respectively arranged with the ring flange interface.

Beneficial effect: the utility model adopts waveguiding structure and biasing longitudinal metal inserted sheet structure; Place filter with respect to traditional metal insert center symmetry and can realize bigger bandwidth; For the filter of symmetric design, metal insert is thin more, and the possibility of asymmetric placement is big more in machining and installation process; And also big more to the filter bandwidht influence, the biasing inserted sheet can reduce this error relatively.More than big 1 one magnitude of power capacity of waveguiding structure power capacity that adopts than employed coaxial cable in the filter of pectinate line structure of the prior art, and have that volume is little, in light weight, advantages such as convenient processing and manufacture, reliability height and good stability.

Description of drawings

The structural representation of Fig. 1 the utility model.

Fig. 2 is the utility model metal insert structural representation.

The metal insert structural representation of the

enforcement

1,2 of Fig. 3 the utility model.

The enforcement of Fig. 4 the utility model is 1 ring flange visual angle figure for example.

The enforcement of Fig. 5 the utility model is 2 ring flange visual angle figure for example.

The simulation architecture sketch map of Fig. 6 the utility model.

The enforcement of Fig. 7 the utility model is 1 simulation result figure for example.

The enforcement of Fig. 8 the utility model is 2 simulation result figure for example.

The simulation result figure that Fig. 9 the utility model metal insert is not setovered.

Embodiment

Be elaborated in the face of the utility model technical scheme down, but the protection range of the utility model is not limited to said embodiment.

Embodiment 1:The utility model K wave band broadband band-pass filter; Form by rectangular waveguide 1 and metal insert 2; The two ends of rectangular waveguide 1 are designed with the ring flange interface, and metal insert 2 is installed in rectangular waveguide 1 inner chamber broadside the inside and vertical with broadside, and metal insert 2 is parallel with the direction of waveguide electric field; Be the convenient metal insert 2 of installing, rectangular waveguide 1 separated into two parts and two parts width are different, and metal insert 2 is installed between two parts, forms the biasing inserted sheet.Have the rectangular opening 3 of some on the

metal insert

2,1 one-tenth resonant cavity of rectangular opening 3 and rectangular waveguide shape, the metallic membrane 4 of certain-length forms coupled structure between the resonant cavity.Rectangular waveguide 1 is combined with metal insert 2 and is the flanged dish standard waveguide in two ends in appearance.When resonant cavity quantity is odd number, be symmetrical centre with middle resonant cavity; When resonant cavity is even number, be symmetrical centre with middle coupled structure.Rectangular waveguide and ring flange are an integral body, produce with the mode of milling, and metal insert 2 is with the placement production of line cutting processing.

Metal insert 2 is thin more, and the performance of filter is good more, but processing technology is proposed higher requirement, and in order to guarantee the structural strength of metal insert 2, the thickness of metal insert 2 should be not less than 0.3mm.Present embodiment is selected the BJ220 standard waveguide for use, and in conjunction with processing technology and waveguide dimensions, metal insert thickness is got 0.5mm.The difference of metal insert rectangular opening quantity can realize the outer filter that suppresses of different bands.In the utility model, select eight rank filters for use, promptly metal insert is opened the rectangular opening of eight certain-lengths and width, structure as shown in Figure 3; Eight rectangular opening are arranged in the metal insert 2, and promptly eight resonant cavitys are numbered 202,204,206,208,210,212,214,216; The length of rectangular opening is identical, but the width ecto-entad once increases, and the width of rectangular opening is symmetry equivalent; Be that rectangular opening 202 and 2016 width equate;

Rectangular opening

204 and 214 width equate that

rectangular opening

206 and 212 width equate that

rectangular opening

208 and 210 width equate.202 and 216 width is minimum, maximum during 208 and 210 width.Eight resonant cavitys form nine coupled structures altogether, and the length that numbering is respectively 201,203,205,207,209,211,213,215,217, nine coupled structures is identical; Width once increases from outside to inside, and wherein coupled structure 201 is identical with 217 width, and coupled structure 203 is identical with 215 width; Coupled structure 205 is identical with 213 width; Coupled structure 207 is identical with 211 width, and the width of coupled structure 209 is maximum, and 201 and 217 width is minimum.Wherein the length of each coupled structure resonant cavity of metal insert is the same with the length of standard waveguide; Their width all calculates through formulae design and simulation software optimization obtains at last, and design process can list of references " modern Filter Structures and design " [M].The width numerical value of the coupled structure in the metal insert depends on the degree of coupling between the filter, and the width of resonant cavity depends on the operating frequency of filter, generally a little bit smaller than half guide wavelength of operating frequency.The selected metal insert offset position of present embodiment is selected 0.5mm for use, and is as shown in Figure 4.Shown in Figure 6 is the simulation model of K waveguide rectangular waveguide biasing metal insert broadband band-pass filter, and machining accuracy reaches the product that 0.01mm just can obtain meeting index request.When Fig. 7 is 20.7GHz for the centre frequency of K wave band rectangular waveguide filter, the bandwidth during metal insert biasing 0.5mm, relative bandwidth can reach 7% respectively.Fig. 9 is that filter construction is all identical, the filter parameter when symmetry is placed in the middle of the metal insert, and relative bandwidth can only reach 6%.

Embodiment 1:Present embodiment K wave band broadband band-pass filter, its basic structure are with embodiment 1, and difference is that the metal insert offset position is selected 1mm for use, and is as shown in Figure 5.Shown in Figure 8 when being 20.7GHz for the centre frequency of K wave band rectangular waveguide filter, the bandwidth during metal insert biasing 0.1mm, relative bandwidth can reach 8.8% respectively.

As stated, although represented and explained the utility model that with reference to specific preferred embodiment it shall not be construed as the restriction to the utility model self.Under the spirit and scope prerequisite of the utility model that does not break away from the accompanying claims definition, can make various variations in form with on the details to it.

Claims

1. K wave band broadband band-pass filter; It is characterized in that: comprise rectangular waveguide (1) and metal insert (2); The inner chamber that said metal insert (2) vertically is inserted in the inner chamber of said rectangular waveguide (1) said rectangular waveguide (1) is divided into asymmetric two parts, and said metal insert (2) is parallel with the direction of waveguide electric field; Be staggeredly equipped with some rectangular opening (3) and metallic membrane (4) on the said metal insert (2), said rectangular opening (3) constitutes resonant cavity with said rectangular waveguide (1), and the metallic membrane between the resonant cavity (4) forms coupled structure; When the quantity of said resonant cavity was odd number, said metal insert (2) was the symmetrical centre symmetry with the rectangular opening (3) of centre, and when the quantity of said resonant cavity was even number, said metal insert (2) was the symmetrical centre symmetry with the metallic membrane (4) of centre.

2. K wave band broadband band-pass filter according to claim 1 is characterized in that: said metal insert (2) reduces from the rectangular opening (3) of symmetrical centre outward direction and the width of metallic membrane (4) successively.

3. K wave band broadband band-pass filter according to claim 1 is characterized in that: the thickness of said metal insert (2) is not less than 0.3mm.

4. K wave band broadband band-pass filter according to claim 1 is characterized in that: the two ends of said rectangular waveguide (1) are respectively arranged with the ring flange interface.