CN202455321U

CN202455321U - LTCC (Low Temperature Co-Fired Ceramic) band-pass filter with C frequency band

Info

Publication number: CN202455321U
Application number: CN 201220076783
Authority: CN
Inventors: 姜立伟; 杨毅民; 张燚; 任志鹏; 林浩佳
Original assignee: Xian Institute of Space Radio Technology
Current assignee: Xian Institute of Space Radio Technology
Priority date: 2012-02-29
Filing date: 2012-02-29
Publication date: 2012-09-26
Anticipated expiration: 2022-02-28

Abstract

The utility model discloses an LTCC (Low Temperature Co-Fired Ceramic) band-pass filter with a C frequency band. The LTCC band-pass filter with the C frequency band comprises four resonators and three resonator partition plates, wherein each resonator comprises a capacitor and an inductor; the fourth resonator, the third resonator partition plate, the third resonator, the second resonator partition plate, the second resonator, the first resonator partition plate and the first resonator are arranged sequentially from upside to downside; the position of the inductor of the first resonator corresponds to the position of the inductor of the fourth resonator; three resonator partition plates are respectively provided with coupling holes at the positions corresponding to the position where the inductor of the first resonator exists; the position where the inductor of the second resonator exists is far away from the projection position of the inductor of the first resonator on the second resonator; the position where the inductor of the third resonator exists is far away from the projection position of the inductor of the first resonator on the third resonator; and one end of the inductor of the first resonator and one end of the inductor of the fourth resonator are respectively led out through tapping lines to serve as an input end and an output end of a filter.

Description

A kind of C frequency range LTCC band pass filter

Technical field

The utility model relates to a kind of band pass filter.

Background technology

Microwave band-pass filter is a critical component of microwave radio system; Along with the development of microwave circuits emulation technology and technology in recent years; Miniaturization demand to radio system is also increasingly high; And the miniaturization of filter stands in the breach especially, how to guarantee that the volume that reduces filter under the certain performance index as much as possible becomes the major issue that the compact radio frequency system need solve.Simultaneously, along with the growing tension of frequency spectrum resource, guarantee that the requirement to other signal suppressing was also more and more stricter when available signal passed through.

LTCC (LTCC) technology is the multi-layer ceramics technology that developed recently gets up, and utilizes this technology can realize the three-dimensional structure that the traditional ceramics substrate process can't be realized.Use LTCC art designs microwave passive component to have very large flexibility.How to make full use of the advantage of LTCC technology; Pass through rational deployment; Confirm Filter Structures, and make design have certain stability, the success rate that in the mismachining tolerance scope of necessity, still can guarantee product is a key issue of LTCC Design of Filter.

At present based on the most of lumped parameter form that adopts of the band pass filter of LTCC technology; Adopting the resonator of resonant mode generally all is planar alignment; The size of filter inevitably strengthens like this; And zero point is transmitted in all increasing of resonator vertical arrangement outside the band, the reduction that the frequency selectivity of filter is relative again.

The utility model content

The technology of the utility model is dealt with problems and is: overcome the deficiency of prior art, a kind of compact conformation, size is little, performance is good C frequency range LTCC band pass filter are provided.

The technical solution of the utility model is: a kind of C frequency range LTCC band pass filter; Comprise four resonators and three resonator dividing plates; Each resonator includes electric capacity and inductance; The 4th resonator, the 3rd resonator dividing plate, the 3rd resonator, the second resonator dividing plate, second resonator, the first resonator dividing plate, first resonator be sequence arrangement from top to bottom; The inductance of first resonator is corresponding consistent with the inductance position of the 4th resonator, and position corresponding with the inductance position of first resonator on three resonator dividing plates has coupling aperture; The inductance position of second resonator is away from the projected position of inductance on second resonator of first resonator, and the inductance position of the 3rd resonator is away from the projected position of inductance on the 3rd resonator of first resonator; Inductance one end of first resonator is drawn the input as C frequency range LTCC band pass filter through tap line, and inductance one end of the 4th resonator is drawn the output as C frequency range LTCC band pass filter through tap line.The baseplate material of filter is a Dupont951 type ceramic substrate, and the material of conductor is a silver.

The utility model advantage compared with prior art is: the utility model has adopted the notion of resonator filter; Start with from the angle that is coupled between the design of resonator and chamber, improved design efficiency greatly, simultaneously; Cross-linked way of realization makes four resonators of filter can vertical arrangement; Effectively controlled the size of filter, and filter increases a pair of band and transmitted zero point outward, improved the frequency selectivity of filter.Therefore to have size little for the utility model filter, and performance is good, compact conformation, and rate of finished products is high, is convenient to the advantage of mass production, can be widely used in the wireless radiofrequency system.

Description of drawings

Fig. 1 is the circuit theory diagrams of the utility model C frequency range LTCC band pass filter;

Fig. 2 is the structure chart of the utility model C frequency range LTCC band pass filter;

Fig. 3 is the simulated effect figure of the utility model C frequency range LTCC band pass filter.

Embodiment

The C frequency range LTCC band pass filter of the utility model adopts quadravalence broad sense Chebyshev prototype, has a pair of band and transmits zero point outward, lays respectively at the high-end and low side of filter passband.The utility model has adopted the notion of resonator filter, starts with from the angle that is coupled between the design of resonator and chamber, has improved design efficiency greatly, and simultaneously, the arrangement mode of this resonator has also effectively been controlled the size of filter.Under the small dimensions limit of filter, how can realize that the introducing that cross-couplings reduces parasitic couplings simultaneously is crucial.The utility model carries out Design of Filter from above-described several angles just.

As shown in Figure 1, the utility model C frequency range LTCC band pass filter is the fourth-order band-pass filter with a pair of transmission zero, and each resonator is made up of capacitive part and inductive part.Input and output are the port of filter among Fig. 1; J01 is the coupling of source to first resonator, and J12, J23, J34 are coupled between resonator, and J4L is the coupling of the 4th resonator to load; J14 is the cross-couplings between first, fourth resonator, and each LC loop constitutes a resonator.

The physical structure of the utility model C frequency range LTCC band pass filter is as shown in Figure 2; Four four LC resonant tanks that

resonator

1,2,3,4 is distinguished in the corresponding diagram 1; Realize coupling through coupling aperture between the resonator; Correspondence J converter in Fig. 1, the form of tap line is all adopted in the input and output of filter, the J converter that is connected with input and output in the corresponding diagram 1.Main coupling (between first resonator 1 and second resonator 2, between second resonator 2 and the 3rd resonator 3, between the 3rd resonator 3 and the 4th resonator 4) realizes through the coupling of electric capacity disc; Be field coupled; Cross-couplings (between first resonator 1 and the 4th resonator 4) realizes through the coupling of inductance, is the magnetic field coupling.In order to realize the cross-couplings between first resonator 1 and the 4th resonator 4; On middle three

resonator dividing plates

5,6,7, open three same coupling apertures over against the position of the inductance of the inductance of first resonator 1 and the 4th resonator 4 in large area; Move on to the inductance of the inductance of second resonator 2 and the 3rd resonator 3 the submarginal position of trying one's best of its place resonator simultaneously, can effectively reduce between first resonator 1 and the 3rd resonator 3 like this and the parasitic couplings between second resonator 2 and the 4th resonator 4.The size of input and output coupling realizes through regulating the tap position that is connected with inductance.Like this; The utility model has just utilized the notion of resonator filter fully, starts with from coupling between resonator, chamber, input and output coupling, is applied to the method for designing of coupling matrix in the Filter Design; Get up with the Design of Filter theory and combining of maturation; Improve design efficiency greatly, practiced thrift design time, reduced design cost.

The filter medium baseplate material uses Dupont951 type LTCC ceramic substrate material, relative dielectric constant 7.8, the substrate thickness 0.096mm behind the sintering.The conductor layer materials used is a silver, 8 microns of thickness.Whole filter is of a size of 7mm*8mm*1.5mm.

Fig. 3 can find out from simulation result for using the simulation result of ansoft HFSS software, and the return loss of filter produces a transmission zero respectively with low side in that passband is high-end, with accord with theoretical analysis less than-20dB in the frequency range of needs.

The content of not doing to describe in detail in the utility model specification belongs to those skilled in the art's known technology.

Claims

1. C frequency range LTCC band pass filter; It is characterized in that comprising: four resonators (1,2,3,4) and three resonator dividing plates (5,6,7); Each resonator includes electric capacity and inductance; The 4th resonator (4), the 3rd resonator dividing plate (7), the 3rd resonator (3), the second resonator dividing plate (6), second resonator (2), the first resonator dividing plate (5), first resonator (1) be sequence arrangement from top to bottom; The inductance of first resonator (1) is corresponding consistent with the inductance position of the 4th resonator (4), goes up at three resonator dividing plates (5,6,7) and has coupling aperture with the corresponding position, inductance position of first resonator (1); The inductance position of second resonator (2) is away from the projected position of inductance on second resonator (2) of first resonator (1), and the inductance position of the 3rd resonator (3) is away from the projected position of inductance on the 3rd resonator (3) of first resonator (1); Inductance one end of first resonator (1) is drawn the input as C frequency range LTCC band pass filter through tap line, and inductance one end of the 4th resonator (4) is drawn the output as C frequency range LTCC band pass filter through tap line.

2. a kind of C frequency range LTCC band pass filter according to claim 1, it is characterized in that: the baseplate material of filter is a Dupont951 type ceramic substrate, the material of conductor is a silver.