CN109150130A

CN109150130A - A kind of inductive type bandpass filter

Info

Publication number: CN109150130A
Application number: CN201810883004.7A
Authority: CN
Inventors: 石玉; 皮晖帆; 尉旭波
Original assignee: University of Electronic Science and Technology of China
Current assignee: University of Electronic Science and Technology of China
Priority date: 2018-08-06
Filing date: 2018-08-06
Publication date: 2019-01-04

Abstract

The invention discloses an inductive coupling type bandpass filter, belonging to the technical field of filters, comprising a grounding plate G1, an input port P1, a capacitor C1, a coupled inductor L1, a parasitic capacitor C2, a coupled inductor L2, a capacitor C3 and an output port P2 . The unique feature of the present invention is that it uses a new structure based on LTCC technology, and realizes a band-pass filter with high reliability, excellent electrical performance, simple structure, high yield, good batch consistency and low cost for the extremely low center frequency of 80M. . It solves the problem that the existing band-pass filter needs a large capacitance and a large inductance to form a resonator when working at a frequency of tens of megahertz, but the traditional process technology cannot effectively reduce the size and area of the device.

Description

A kind of inductive type bandpass filter

Technical field

The present invention relates to short wave filter technical field, in particular to a kind of inductive type bandpass filter.

Background technique

In recent years, the micromation of mobile communication, satellite communication and Defensive Avionics System rapidly develops, high-performance, low cost Have become microwave current/RF application developing direction with miniaturization, and filter is then the critical electronic received and dispatched in branch Component describes this component capabilities and refers mainly to indicate: passband operating frequency range, stop band frequency range, pass band insertion loss, Stopband attenuation, passband input/output voltage standing-wave ratio, insertion phase shift and delay/frequency characteristic, temperature stability, volume, weight, Reliability etc..

Bandpass filter need of work bulky capacitor and big inductance under tens mhz frequencies constitute resonator.In order to meet The small form factor requirements of device, initial method are reduced using high dielectric constant, high quality factor, low-loss dielectric material The size of resonator, and then reduce the volume of device.But traditional technology can not effectively reduce the size of device Area.

Summary of the invention

It is an object of the invention to: a kind of inductive type bandpass filter is provided, by inductance it is three-dimensionally integrated and coupling, Reduce the area of plane of filter.

The technical solution adopted by the invention is as follows:

A kind of inductive type bandpass filter including the laminated body being made of multilayer dielectric substrate stacking and is arranged in layer Filter circuit in stack is mutually connected conducting between adjacent media substrate by metal conduction band and via hole, the medium substrate Using LTCC ceramic substrate, there is one layer of ground plane in medium substrate, ground connection layer surface is provided with input terminal P1 and output end P2.

The filter circuit includes capacitor C1, C2, C3 and inductance L1, L2, and the one end capacitor C1 is connected with input port P1, and one End is connected with coupling inductance L1；Coupling inductance L1 other end ground connection；Coupling inductance L2 intercouples with coupling inductance L1, and generates Parasitic capacitance C2；One end coupling inductance L2 to ground, the other end are connected with capacitor C3, the capacitor C3 other end and output port P2 phase Even.

The inductance L1 and L2 is the three-dimensional spiral inductance formed by the metal conduction band being set on medium substrate.

The capacitor C2 is the parasitic capacitance that three-dimensional spiral inductance L1, the L2 to intercouple is generated.

Using interdigital capacitor structure, the substrate by being located at different layers is realized by described capacitor C1, C3.

The input port P1 and output port P2 is the port of 50 ohmages of coplanar waveguide structure.

Above-mentioned inductive type bandpass filter includes vertical capacitor and three-dimensional spiral inductance, it is characterised in that filter In two three-dimensional spiral inductance use coupled structure, series connection vertical capacitor and three-dimensional spiral inductance are logical in the top of filter Microstrip line connection is crossed, shunt capacitance is in the filter bottom after terminating three-dimensional spiral inductance.

Including earth plate G1, input port P1, capacitor C1, coupling inductance L1, parasitic capacitance C2, coupling inductance L2, capacitor C3 and output port P2.A kind of inductive type bandpass filter lower left is equipped with the input port P1, described one kind Inductive type bandpass filter upper right side is equipped with the output port P2, a kind of inductive type bandpass filter bottom right Side is equipped with the earth plate G1, and the earth plate G1 is horizontally disposed；The one end the capacitor C1 is connected with the input port P1, One end is connected with the coupling inductance L1；The coupling inductance L1 other end to ground；The coupling inductance L2 couples electricity with described Sense L1 intercouples, and generates the parasitic capacitance C2；The one end the coupling inductance L2 is to ground, one end and the capacitor C3 phase Even, the capacitor C3 other end is connected with the output port P2.

The input port P1 and output port P2 is the port of 50 ohmages.

The medium substrate is all made of LTCC ceramic substrate.

The middle layer of the medium substrate is equipped with metal ground plane, which is connected to ground by side plate.

In conclusion by adopting the above-described technical solution, the beneficial effects of the present invention are:

1. a kind of inductive type bandpass filter of the present invention, small in size, light-weight, superior performance is at low cost, is suitble to criticize Amount production

2. a kind of inductive type bandpass filter of the present invention, can be processed into the form of patch, convenient in microwave system It is integrated in system.

Detailed description of the invention

Examples of the present invention will be described by way of reference to the accompanying drawings, in which:

Fig. 1 is equivalence filter schematic diagram of the invention；

Fig. 2 is structural schematic diagram of the invention；

Specific embodiment

All features disclosed in this specification or disclosed all methods or in the process the step of, in addition to mutually exclusive Feature and/or step other than, can combine in any way.

It elaborates below with reference to Fig. 1, Fig. 2 to the present invention.

Embodiment 1

A kind of inductive type bandpass filter, including the laminated body constituted, adjacent media is laminated by multilayer dielectric substrate Mutually it is connected between substrate by conduction band and via hole and is connected, surface is equipped with input terminal P1, output end P2.Filter circuit includes electricity Hold C1, C2, C3 and inductance L1, L2, the one end capacitor C1 are connected with input port P1, one end is connected with coupling inductance L1；Coupling electricity The L1 other end is felt to ground；Coupling inductance L2 intercouples with coupling inductance L1, parallel to generate parasitic capacitance C2；Coupling inductance L2 mono- It holds to ground, one end is connected with capacitor C3, and the capacitor C3 other end is connected with output port P2.

The present embodiment is all made of LTCC ceramic substrate using medium substrate, is equipped with metallic ground in the middle layer of medium substrate Layer GND, metal ground plane GND is connected to ground by side plate.Inductance L1 and L2 are the metal by being set on medium substrate The three-dimensional spiral inductance that conduction band is formed.Capacitor C1, C3 are real by the substrate for being located at different layers using interdigital capacitor structure It is existing.Capacitor C2 is the parasitic capacitance that the three-dimensional spiral inductance to intercouple generates.

In the present embodiment constitute spiral inductance each layer be all the rectangle being coiled by the metal conduction band of 0.1mm width or 3/4 rectangle is linked together the metal conduction band of adjacent layer by via hole；Wherein, the spiral inductance in left side is L1, the spiral shell on right side Rotation inductance is L2, and two spiral inductance structures are completely the same.

A kind of inductive type bandpass filter of the present invention is made of multilayer low-temperature co-fired ceramics technique.

The working principle of the invention/the course of work are as follows:

A kind of inductive type bandpass filter of the present invention is realized using multilayer low-temperature co-fired ceramics technique, Its low-temperature co-burning ceramic material and metallic pattern sinter at a temperature of about 900 DEG C, thus have extreme high reliability and Temperature stability, be grounded using three-dimensional integration and multilayer folding structure and outer surface metallic shield due to structure and Encapsulation, so that volume be made substantially to reduce.

A kind of inductive type bandpass filter of the present invention, is realized using LTCC technology, has light-weight, volume Small, high reliablity, good electrical property, temperature stability are good, electrical property batch consistency is good, it is at low cost, can be mass-produced etc. it is excellent Point, suitable for satellite communication etc. to volume, electrical property, temperature stability and reliability have rigors occasion and corresponding system In system.

The above, only the preferred embodiment of the present invention, but scope of protection of the present invention is not limited thereto, it is any Those skilled in the art within the technical scope disclosed by the invention, can without the variation that creative work is expected or Replacement, should be covered by the protection scope of the present invention.Therefore, protection scope of the present invention should be limited with claims Subject to fixed protection scope.

Claims

1. An inductively coupled band-pass filter, comprising a laminate composed of multilayer dielectric substrates and a filter circuit arranged on the laminate, and adjacent dielectric substrates are connected to each other through metal conduction strips and vias. , which is characterized in that: the dielectric substrate is an LTCC ceramic substrate, the dielectric substrate has a ground layer, and the surface of the ground layer is provided with an input end P1 and an output end P2.

2 . The inductively coupled bandpass filter according to claim 1 , wherein the filter circuit comprises capacitors C1 , C2 , C3 and inductors L1 and L2 ; one end of the capacitor C1 is connected to the input port P1 , and one end is connected to the input port P1 . Connected to the coupled inductor L1, the other end of the coupled inductor L1 is grounded, the coupled inductor L2 and the coupled inductor L1 are coupled to each other, and generate a parasitic capacitance C2, one end of the coupled inductor L2 is connected to the ground, the other end is connected to the capacitor C3, and the other end of the capacitor C3 is connected to the output port P2 is connected.

3 . The inductively coupled bandpass filter according to claim 2 , wherein the inductances L1 and L2 are three-dimensional spiral inductances formed by metal conduction strips disposed on the dielectric substrate. 4 .

4 . The inductively coupled bandpass filter according to claim 3 , wherein the capacitor C2 is a parasitic capacitor generated by the three-dimensional spiral inductors L1 and L2 coupled with each other. 5 .

5 . The inductively coupled bandpass filter according to claim 2 , wherein the capacitors C1 and C3 adopt an interdigital capacitor structure, which is realized by substrates located on different layers. 6 .

6 . The inductively coupled bandpass filter according to claim 1 , wherein the input port P1 and the output port P2 are both ports of a coplanar waveguide structure with an impedance of 50 ohms. 7 .