CN213717940U

CN213717940U - IPD absorption type high-pass filter

Info

Publication number: CN213717940U
Application number: CN202022717723.7U
Authority: CN
Inventors: 李小珍; 代传相; 邢孟江; 刘永红; 张志刚; 侯明
Original assignee: Kunming University
Current assignee: Kunming University
Priority date: 2020-11-23
Filing date: 2020-11-23
Publication date: 2021-07-16
Anticipated expiration: 2030-11-23

Abstract

The utility model relates to an IPD absorption formula high pass filter belongs to wave filter technical field. Including the metal level of base member layer and its upper surface, be formed with circuit structure on the metal level, circuit structure includes high pass path unit and signal absorption unit, and high pass path unit is including establishing ties the first electric capacity between input port and output port, is connected with first inductance between first electric capacity and the input port, and first inductance is connected with first ground capacitor, is connected with the second inductance between first electric capacity and the output port, and the second inductance is connected with second ground capacitor, and the signal absorption unit is the pi type attenuator that three resistance formed, the utility model discloses based on IPD technology and novel circuit topology form, reach the effect that the size is little and outband does not have the reflection. The first capacitor is formed by connecting two sub-capacitors in series, the process tolerance is increased in a capacitor series connection mode, the withstand voltage value of the capacitor is increased, and finally the filter which is miniaturized and convenient to integrate is realized.

Description

IPD absorption type high-pass filter

Technical Field

The utility model relates to an IPD absorption formula high pass filter belongs to wave filter technical field.

Background

Conventional filter design circuits achieve the filtering goal by reflecting unwanted signals back to the source. In most applications, the signal reflected back to the source can have a significant impact on the performance of the circuit. For example, filters are often used in front of and behind the mixer, and the stop band signals reflected by conventional filters create some unwanted harmonics in the mixer; in high gain amplifier circuits, the reflected stop band signal back to the source may cause the amplifier to become unstable and oscillate. Designing filters that approach or meet the circuit requirements is a significant challenge.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome the above-mentioned defect that current wave filter exists, provide an IPD absorption formula high pass filter, form based on IPD technology and novel circuit topology, reach the effect that the size is little and outband does not have the reflection.

The utility model discloses an adopt following technical scheme to realize:

an IPD absorption type high-pass filter comprises a substrate layer and a metal layer on the upper surface of the substrate layer, wherein a circuit structure is formed on the metal layer and comprises a high-pass path unit and a signal absorption unit, the high-pass path unit comprises a first capacitor connected in series between an input port and an output port, a first inductor is connected between the first capacitor and the input port, the first inductor is connected with a first grounding capacitor, a second inductor is connected between the first capacitor and the output port, the second inductor is connected with a second grounding capacitor, and the signal absorption unit is a pi-type attenuator formed by three resistors.

Further, the first capacitor is formed by two sub-capacitors connected in series.

Further, the first inductor and the second inductor adopt a planar spiral structure.

Furthermore, the first capacitor, the first grounding capacitor and the second grounding capacitor are all thin film parallel plate capacitors.

Further, the resistance of the signal absorbing unit is composed of 82% Ni and 18% Cr.

Further, the resistor obtains an accurate resistance value through a magnetron sputtering codeposition method.

Furthermore, the inductance value of the first inductor is equal to the inductance value of the second inductor, and the capacitance value of the first grounded capacitor is equal to the capacitance value of the second grounded capacitor.

Further, the substrate layer is gallium arsenide, silicon nitride or silicon.

Further, the high-pass path unit and the signal absorbing unit may be cascaded in multiple stages as sub-units.

The utility model has the advantages that:

(1) the first capacitor of the utility model is formed by connecting two sub-capacitors in series, the process tolerance is increased by connecting the capacitors in series, and the withstand voltage value of the capacitor is increased;

(2) the utility model realizes the non-reflection characteristic of the filter by absorbing the stop band signal through the signal absorbing unit and preventing the reflection signal from returning to the signal source, thereby preventing the influence of the signal reflected back to the source on the circuit performance;

(3) the utility model has good expandability, can be directly cascaded according to the requirement, and provides higher out-of-band attenuation by sacrificing the insertion loss;

(4) the utility model discloses based on IPD technology and novel circuit topology form, finally reach the effect that the size is little and the outband does not have the reflection.

Drawings

Fig. 1 is a circuit topology diagram of the present invention;

FIG. 2 is a schematic view of the internal structure of the present invention;

FIG. 3 is a schematic view of the structure of the package housing of the present invention;

fig. 4 is a schematic diagram of a three-dimensional circuit structure of the present invention;

FIG. 5 shows the simulation result of S parameter of the present invention

The labels in the figure are: 1 encapsulating a housing; 11 input port; 12 output ports.

Detailed Description

The present invention will be further explained with reference to the accompanying drawings.

As shown in fig. 1, the absorption-type high-pass filter of this embodiment includes a substrate layer and a ground layer, a metal layer is disposed on an upper surface of the substrate layer, a circuit structure is formed on the metal layer, the circuit structure includes a high-pass path unit and a signal absorption unit, the high-pass path includes an input end, an output end, a port ground, a first capacitor C1, a first inductor L1, a second inductor L2, a first ground capacitor C2, and a second ground capacitor C3; the input end of the first inductor L1 is connected with the first capacitor C1, the other end of the first capacitor C1 is connected with the output end, a first inductor L1 is connected between the input end and the first capacitor C1, the other end of the first inductor L1 is connected with the signal absorption unit, a second inductor L2 is connected between the output end and the first capacitor C1, the other end of the second inductor L2 is connected with the signal absorption unit, a first grounding capacitor C2 is connected between the first inductor L1 and the signal absorption unit, the other end of the first grounding capacitor C2 is grounded, a second grounding capacitor C3 is connected between the second inductor L2 and the signal absorption unit, and the other end of the second capacitor C3 is grounded; the signal absorbing unit comprises a resistor R1, a resistor R2, a resistor R3 and a port ground, wherein three resistors form a pi-type attenuator.

As shown in fig. 2, fig. 3, and fig. 4, the absorption-type high-pass filter of this embodiment includes a package housing 1 and an IPD filter body, the package housing 1 may be made of aluminum metal or alloy, the package housing 1 is used as a mounting base of the filter, the overall package size of this embodiment is (1.1mm × 1.0mm × 0.5mm), the thickness of the package housing 1 is 100um, and the filter is opened corresponding to the input port 11 and the output port 12 as shown in fig. 11 and 12, so as to implement the leading-out of the input end and the output end of the filter, and the package housing 1 is used as a ground end of the circuit; the IPD filter body is prepared by an IPD silicon process through the working procedures of photoetching, metal deposition, dry etching, high-temperature oxidation etching and the like, and the equivalent inductor adopts a planar spiral structure; the equivalent capacitance adopts a thin film parallel plate capacitor; the equivalent resistance is composed of 82% Ni and 18% Cr, and the size of the IPD filter is (0.9mm multiplied by 0.8mm multiplied by 0.25mm) by a magnetron sputtering codeposition method.

As shown in fig. 5, the 3dB cut-off frequency of the absorption high-pass filter of the present embodiment is 3.0GHz, and the insertion loss in the pass band of 4GHz to 8GHz is less than 1.0 dB; the DC-6 GHz standing wave is less than 15 dB; within the stopband, the rejection is greater than 20dB over the DC to 1.5GHz range.

The basic principles and the main features of the invention and the advantages of the invention have been shown and described above. It will be understood by those skilled in the art that the present invention is not limited to the above embodiments, and that the foregoing embodiments and descriptions are provided only to illustrate the principles of the present invention without departing from the spirit and scope of the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. An IPD absorption type high-pass filter comprises a substrate layer and a metal layer on the upper surface of the substrate layer, and is characterized in that a circuit structure is formed on the metal layer and comprises a high-pass path unit and a signal absorption unit, the high-pass path unit comprises a first capacitor connected between an input port and an output port in series, a first inductor is connected between the first capacitor and the input port and connected with a first grounding capacitor, a second inductor is connected between the first capacitor and the output port and connected with a second grounding capacitor, the signal absorption unit is a pi-type attenuator formed by three resistors, and the first capacitor is formed by connecting two sub-capacitors in series.

2. The IPD absorptive high-pass filter according to claim 1, characterized in that: the first inductor and the second inductor adopt a planar spiral structure.

3. The IPD absorptive high-pass filter according to claim 1, characterized in that: and the first capacitor, the first grounding capacitor and the second grounding capacitor are all thin film parallel plate capacitors.

4. The IPD absorptive high-pass filter according to claim 1, characterized in that: and the resistance of the signal absorption unit obtains an accurate resistance value by a magnetron sputtering codeposition method.

5. The IPD absorptive high-pass filter according to claim 1, characterized in that: the inductance value of the first inductor is equal to that of the second inductor, and the capacitance value of the first grounding capacitor is equal to that of the second grounding capacitor.

6. The IPD absorptive high-pass filter according to claim 1, characterized in that: the substrate layer is gallium arsenide, silicon nitride or silicon.

7. The IPD absorptive high-pass filter according to claim 1, characterized in that: the high-pass path unit and the signal absorption unit are used as subunits to carry out multistage cascade connection.