CN201689958U

CN201689958U - Microwave filter

Info

Publication number: CN201689958U
Application number: CN2009201045358U
Authority: CN
Inventors: 陈熙; 鲁国林; 许悦; 李丰
Original assignee: BOWEI INTEGRATED CIRCUITS Co Ltd
Current assignee: BOWEI INTEGRATED CIRCUITS Co Ltd
Priority date: 2009-09-18
Filing date: 2009-09-18
Publication date: 2010-12-29
Anticipated expiration: 2019-09-18

Abstract

The utility model discloses a microwave filter, which comprises a metal shielding box and a three-layer filter arranged in the metal shielding box. The upper layer of the three-layer filter is a microstrip resonator, the middle layer thereof is a coplanar waveguide resonator, the lower layer thereof is a suspended microstrip resonator, an insulating layer is respectively arranged between the upper layer and the middle layer and between the middle layer and the lower layer, the upper layer and the lower layer are connected with the middle lay through metal holes, the middle layer is connected with the metal shielding box through metal holes, and the upper layer and the lower layer are a certain distance away from the inner surface of the metal shielding box. With the structure, the utility model has the advantages that: the microstrip resonator, the coplanar waveguide resonator and the suspended microstrip resonator are integrated on the three-layer structure, thereby forming the microwave filter with the three-layer filter, which has the advantages of small size, high Q value, low loss and good frequency selectivity, and under the condition with the identical center frequency and frequency selectivity, the size is only around 40 percent of the single-layer microstrip structure, and the Q value is increased by about 200 percent.

Description

Microwave filter

Technical field

The utility model relates to a kind of filter, and is especially a kind of with little band, the microwave filter that the co-planar waveguide and the micro-strip resonantor that suspends are made with three-decker.

Background technology

In recent years, microwave filter develops into little band and co-planar waveguide structure combining by simple microstrip structure gradually.The advantage of this structure is integrated little band and co-planar waveguide forms co-planar waveguide by etching bath line on ground plate, utilizes the coupling between little band and the co-planar waveguide, can obtain than littler volume of simple microstrip filter and the Q value of Geng Gao.But this structure is very limited to the performance boost of filter, and volume is relatively large, and the develop rapidly of modern short-wave communication tedhnology has proposed more and more higher requirement to the performance index of filter, need volume littler, logical in-band insertion loss is lower, the better filter of frequency selectivity.

The utility model content

The utility model technical issues that need to address provide little, the high Q value of a kind of volume, loss is low, frequency selectivity is good microwave filter.

For addressing the above problem, technical solution adopted in the utility model is: a kind of microwave filter, comprise the three-decker filter in metallic shield box and the metallic shield box, wherein the upper strata of three-decker filter is a micro-strip resonantor, the middle level is the co-planar waveguide resonator, lower floor is the micro-strip resonantor that suspends, be provided with insulating barrier between upper strata and middle level and middle level and the lower floor, the upper and lower are connected with the middle level by metal aperture, the middle level is connected with the metallic shield box by metal aperture, and there is a segment distance the upper and lower apart from metallic shield box inner surface.

Described upper strata micro-strip resonantor is 2, middle level co-planar waveguide resonator is 2, lower floor's micro-strip resonantor that suspends is 2, input signal is coupled to output through micro-strip resonantor, co-planar waveguide resonator, the micro-strip resonantor that suspends, the micro-strip resonantor that suspends, co-planar waveguide resonator, micro-strip resonantor successively, the micro-strip resonantor cross-couplings connects, and co-planar waveguide resonator cross-couplings connects.

Adopt the beneficial effect that technique scheme produced to be: basis is novel to be integrated in micro-strip resonantor, co-planar waveguide resonator, the micro-strip resonantor that suspends on the three-decker, formation has the microwave filter of three-decker filter, it has the advantages that volume is little, the Q value high, loss is low, frequency selectivity is good, under the condition of same centre frequency and frequency selectivity, its volume has only about 40% of single layer microstrip structure, and the Q value improves about 200%.

Description of drawings

Fig. 1 is the utility model structural representation;

Fig. 2 is the utility model equivalent circuit theory block diagram;

Fig. 3 is the specific embodiment structure chart of the utility model three-decker filter.

Embodiment

Below in conjunction with accompanying drawing the utility model is done and to be described in further detail:

As shown in Figure 1, this novel three-decker filter that comprises in metallic shield box 3 and the metallic shield box 3, wherein metallic shield box 3 is made of last shielding box and following shielding box, the three-decker filter is fixed on up and down in the middle of the shielding box, there are a segment distance in upper strata 1 and lower floor 5 apart from metallic shield box 3 inner surfaces, and the co-planar waveguide in middle level 7 closely links to each other with metallic shield box 3 by number of metal hole 4 and is grounded.The upper strata 1 of three-decker filter is a micro-strip resonantor, and middle level 7 is the co-planar waveguide resonator, and lower floor 5 is the micro-strip resonantor that suspends, and is provided with insulating barrier 6 between upper strata 1 and middle level 7 and middle level 7 and the lower floor 5, and the upper and lower are connected with middle level 7 by metal aperture 2.

This novel specific embodiment as shown in Figure 3, with micro-band technique, the co-planar waveguide technology and the micro-band technique that suspends combine, make a kind of three layers structure with up-to-date technology, the superiors adopt common microstrip structure, and the input and output of filter are also at this one deck, and the middle level adds coplanar waveguide structure, this one deck utilizes via hole to be connected with levels and ground, and lower floor then adopts the microstrip structure that suspends.In its manufacturing process, at first need a medium substrate (insulating barrier), surface etching goes out metallic pattern thereon, form coplanar waveguide structure at lower surface by the etching line of rabbet joint 17 again, with metal aperture 2 the double layer of metal figure is coupled together again, and then look for an onesize substrate, the metal of this upper surface of base plate is all etched away, lower surface at it etches metallic pattern again, utilizes adhesive or other technology that two substrates are sticked together, and promptly can be made into the three-decker filter.It is

micro-strip resonantor

11 and 12 at the middle and upper levels, the middle level is

co-planar waveguide resonator

13 and 14, lower floor is the

micro-strip resonantor

15,16 that suspends, levels is separated by the intermediate layer, therefore the resonator between the levels is less than coupling, can form cross-couplings between the

resonator

11 and 12, also form cross-couplings between the

resonator

13 and 14, two groups of cross-couplings have formed the outer transmission zero of a pair of passband.The metallic pattern that upper, middle and lower is three layers is realized the connection of electrical property by four metal aperture 2.The equivalent circuit theory block diagram of its formation as shown in Figure 3, its set specific frequency signal enters micro-strip resonantor 11 by input port, pass through co-planar waveguide resonator 13 successively by coupling,

micro-strip resonantor

15,16 suspends, co-planar waveguide resonator 14, micro-strip resonantor 12 is obtained at last the signal of this frequency by output, the signal of other frequency all has been filtered.It is little that this resonator has a volume, the characteristics that parasitic passband is far away.

Claims

1. microwave filter, it is characterized in that: comprise the three-decker filter in metallic shield box (3) and the metallic shield box (3), wherein the upper strata of three-decker filter (1) is micro-strip resonantor, middle level (7) is the co-planar waveguide resonator, lower floor (5) is the micro-strip resonantor that suspends, be provided with insulating barrier (6) between upper strata (1) and middle level (7) and middle level (7) and the lower floor (5), upper strata (1) is connected with middle level (7) by metal aperture (2) with lower floor (5), middle level (7) is connected with metallic shield box (3) by metal aperture (4), and there are a segment distance in upper strata (1) and lower floor (5) apart from metallic shield box (3) inner surface.

2. microwave filter according to claim 1, it is characterized in that the upper strata micro-strip resonantor is 2, middle level co-planar waveguide resonator is 2, lower floor's micro-strip resonantor that suspends is 2, input signal is coupled to output through micro-strip resonantor (11), co-planar waveguide resonator (13), the micro-strip resonantor that suspends (15), the micro-strip resonantor that suspends (16), co-planar waveguide resonator (14), micro-strip resonantor (12) successively, micro-strip resonantor (11), (12) cross-couplings connect, and co-planar waveguide resonator (13), (14) cross-couplings connect.