CN213717941U

CN213717941U - Compact on-chip band-pass filter

Info

Publication number: CN213717941U
Application number: CN202120006390.9U
Authority: CN
Inventors: 胡善文
Original assignee: Anhui Xixin Microelectronic Technology Co ltd
Current assignee: Anhui Xixin Microelectronic Technology Co ltd
Priority date: 2021-01-04
Filing date: 2021-01-04
Publication date: 2021-07-16
Anticipated expiration: 2031-01-04

Abstract

The utility model relates to a band pass filter, concretely relates to band pass filter on compact piece, including input port P1 that connects gradually, first resonance unit, the second resonance unit, the third resonance unit, the fourth resonance unit, output port P2, and central microstrip line L, first resonance unit includes parallelly connected first electric capacity C1, first inductance L1, the second resonance unit includes parallelly connected second electric capacity C2, second inductance L2, the third resonance unit includes parallelly connected third electric capacity C3, third inductance L3, the fourth resonance unit includes parallelly connected fourth electric capacity C4, fourth inductance L4, input port P1, first electric capacity C1, second electric capacity C2, third electric capacity C3, fourth inductance L4 connects gradually the microstrip line through central L; the utility model provides a technical scheme can effectively overcome the size that prior art exists great, between the adjacent inductance mutual crosstalk, the relatively poor defect of outband inhibition performance.

Description

Compact on-chip band-pass filter

Technical Field

The utility model relates to a band pass filter, concretely relates to band pass filter on compact piece.

Background

The rf microwave band-pass filter is one of the important modules in modern wireless communication systems, and with the rapid development of rf integrated circuits, the miniaturization trend of communication equipment terminals and the shortage of spectrum resources, higher requirements are put forward on the performance and size of the filter. Miniaturization of communication equipment places higher demands on miniaturization of filters with a larger number in the equipment, and the shortage of spectrum resources requires that the filters have good out-of-band rejection and low insertion loss, otherwise, signals of adjacent channels cause interference. In order to meet the requirements of system miniaturization and high integration level, the trend of miniaturization and high performance of the filter is more and more obvious.

In the design of the filter, a passive device capacitance-inductance resonance mode is adopted, the size of the passive device inductance is usually larger, the mutual inductance between adjacent inductances can reduce the inductance value of the inductance, and additional parasitic effects can be introduced to seriously influence the performance of the filter. Therefore, the distance requirement between adjacent inductors in practical design results in a larger filter size, which cannot meet the miniaturization requirement in modern communication equipment.

SUMMERY OF THE UTILITY MODEL

Technical problem to be solved

To the above-mentioned shortcoming that prior art exists, the utility model provides a band pass filter on compact piece can effectively overcome the size that prior art exists great, between the adjacent inductance mutual crosstalk, the relatively poor defect of outband rejection performance.

(II) technical scheme

In order to achieve the above purpose, the utility model discloses a following technical scheme realizes:

the utility model provides a compact band-pass filter on chip, includes input port P1, first resonance unit, second resonance unit, third resonance unit, fourth resonance unit, output port P2 that connect gradually to and central microstrip line L, first resonance unit includes parallelly connected first electric capacity C1, first inductance L1, the second resonance unit includes parallelly connected second electric capacity C2, second inductance L2, the third resonance unit includes parallelly connected third electric capacity C3, third inductance L3, the fourth resonance unit includes parallelly connected fourth electric capacity C4, fourth inductance L4, input port P1, first electric capacity C1, second electric capacity C2, third electric capacity C3, fourth inductance L4 connect gradually through central microstrip line L, first electric capacity L1, second inductance L2, third inductance L3, fourth inductance L4 divide and locate central inductance L both sides and set up crisscross.

Preferably, the input port P1 is connected to one end of a first resonant unit, the other end of the first resonant unit is grounded, and the output end of the first resonant unit is connected to the input end of a second resonant unit.

Preferably, the output terminal of the second resonance unit is connected to the input terminal of the third resonance unit.

Preferably, the output end of the third resonant unit is connected to the input end of a fourth resonant unit, one end of the fourth resonant unit is connected to the output port P2, and the other end of the fourth resonant unit is grounded.

Preferably, the antenna further comprises a gallium arsenide substrate, and the input port P1, the first resonant unit, the second resonant unit, the third resonant unit, the fourth resonant unit, the output port P2, and the central microstrip line L are all disposed on the gallium arsenide substrate.

Preferably, GSG pads are adopted for the input port P1 and the output port P2.

(III) advantageous effects

Compared with the prior art, the utility model provides a band-pass filter on compact piece, because first inductance L1, second inductance L2, third inductance L3, fourth inductance L4 divide and locate central microstrip line L both sides and crisscross setting, can effectively avoid the great inductance of size to the waste of area and the crosstalk between the adjacent inductance, avoided the influence of coupling between the device to the filter performance when reducing the filter size; the second resonance unit presents a trap characteristic, determines a transmission zero on the left side of a passband, the third resonance unit presents a trap characteristic, determines a transmission zero on the right side of the passband, and the transmission zeros on the two sides of the passband can greatly improve the out-of-band rejection performance of the filter and obtain better selectivity.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the invention, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.

Fig. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic circuit diagram of FIG. 1 according to the present invention;

fig. 3 is a working characteristic curve of the band pass filter of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the drawings in the embodiments of the present invention are combined below to clearly and completely describe the technical solutions in the embodiments of the present invention. It is to be understood that the embodiments described are only some of the embodiments of the present invention, and not all of them. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

A compact on-chip band-pass filter is disclosed, as shown in fig. 1 and fig. 2, and includes an input port P1, a first resonance unit, a second resonance unit, a third resonance unit, a fourth resonance unit, an output port P2, and a central microstrip line L, which are connected in sequence, wherein the first resonance unit includes a first capacitor C1 and a first inductor L1 which are connected in parallel, the second resonance unit includes a second capacitor C2 and a second inductor L2 which are connected in parallel, the third resonance unit includes a third capacitor C3 and a third inductor L3 which are connected in parallel, the fourth resonance unit includes a fourth capacitor C4 and a fourth inductor L4 which are connected in parallel, the input port P1, the first capacitor C1, the second capacitor C2, the third capacitor C3, and the fourth inductor L4 are connected in sequence through the central microstrip line L, and the first inductor L1, the second inductor L2, the third inductor L3, and the fourth inductor L4 are respectively disposed on two sides of the central microstrip line L and are staggered.

The input port P1 is connected with one end of the first resonance unit, the other end of the first resonance unit is grounded, and the output end of the first resonance unit is connected with the input end of the second resonance unit; the output end of the second resonance unit is connected with the input end of the third resonance unit; the output end of the third resonant unit is connected with the input end of the fourth resonant unit, one end of the fourth resonant unit is connected with the output port P2, and the other end of the fourth resonant unit is grounded.

In the technical scheme of the application, the first resonance unit and the fourth resonance unit determine the center frequency of the filter, the second resonance unit presents a notch characteristic, the transmission zero on the left side of the passband is determined, the third resonance unit presents a notch characteristic, the transmission zero on the right side of the passband is determined, the transmission zero on the two sides of the passband can greatly improve the out-of-band rejection performance of the filter, and better selectivity is obtained.

In the technical scheme of the application, the device further comprises a gallium arsenide substrate, wherein the input port P1, the first resonance unit, the second resonance unit, the third resonance unit, the fourth resonance unit, the output port P2 and the central microstrip line L are all arranged on the gallium arsenide substrate. The capacitor, the inductor, the input port P1 and the output port P2 are integrated on the gallium arsenide substrate by adopting an integrated circuit semiconductor process and through the process flows of photoetching, metal deposition, dry etching, oxidation etching and the like.

GSG pads are adopted for the input port P1 and the output port P2, so that a good grounding effect is achieved. In addition, the embodiment adopts a 0.35um GaAs HBT process, and the technical scheme of the present application is also applicable to radio frequency circuits of other processes.

As shown in fig. 3, the operating frequency of the technical scheme of the present application is 3.4GHz-4.2GHz, the insertion loss is 2dB, the out-of-band rejection at 3GHz is-19 dB, the out-of-band rejection at 4.9GHz is-20 dB, the chip size is only 750um × 540um, and the performance indexes of miniaturization, interference resistance and high rejection are realized.

In the technical scheme of the application, each electrical component can be configured according to the following parameter ranges:

C1:1.2-1.31pF；C2:0.36-0.43pF；C3:2.15-2.21pF；C4:0.65-0.71pF；

L1:1.58-1.61nH；L2:0.9-0.98nH；L3:5.2-5.25nH；L4:3.25-3.28nH。

the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention in its corresponding aspects.

Claims

1. A compact on-chip bandpass filter, characterized by: the resonant circuit comprises an input port P1, a first resonant unit, a second resonant unit, a third resonant unit, a fourth resonant unit, an output port P2 and a central microstrip line L which are sequentially connected, wherein the first resonant unit comprises a first capacitor C1 and a first inductor L1 which are connected in parallel, the second resonant unit comprises a second capacitor C2 and a second inductor L2 which are connected in parallel, the third resonant unit comprises a third capacitor C3 and a third inductor L3 which are connected in parallel, the fourth resonant unit comprises a fourth capacitor C4 and a fourth inductor L4 which are connected in parallel, the input port P1, the first capacitor C1, the second capacitor C2, the third capacitor C3 and the fourth inductor L4 are sequentially connected through the central microstrip line L, and the first inductor L1, the second inductor L2, the third inductor L3 and the fourth inductor L4 are respectively arranged on two sides of the central microstrip line L and are arranged in a staggered manner.

2. The compact on-chip bandpass filter of claim 1 wherein: the input port P1 is connected to one end of a first resonant unit, the other end of the first resonant unit is grounded, and the output end of the first resonant unit is connected to the input end of a second resonant unit.

3. The compact on-chip bandpass filter of claim 2 wherein: and the output end of the second resonance unit is connected with the input end of the third resonance unit.

4. The compact on-chip band-pass filter of claim 3, wherein: the output end of the third resonance unit is connected with the input end of the fourth resonance unit, one end of the fourth resonance unit is connected with the output port P2, and the other end of the fourth resonance unit is grounded.

5. The compact on-chip band-pass filter according to any one of claims 1 to 4, characterized in that: the antenna further comprises a gallium arsenide substrate, wherein the input port P1, the first resonance unit, the second resonance unit, the third resonance unit, the fourth resonance unit, the output port P2 and the central microstrip line L are all arranged on the gallium arsenide substrate.

6. The compact on-chip band-pass filter according to any one of claims 1 to 4, characterized in that: GSG pads are adopted for the input port P1 and the output port P2.