CN218217315U

CN218217315U - AWR-LC hybrid filter based on IPD process

Info

Publication number: CN218217315U
Application number: CN202220205325.3U
Authority: CN
Inventors: 盖广洪; 冯铭昆; 刘兆年; 黄一
Original assignee: Suzhou Hangkai Microelectronics Technology Co ltd
Current assignee: Suzhou Hangkai Microelectronics Technology Co ltd
Priority date: 2022-01-25
Filing date: 2022-01-25
Publication date: 2023-01-03
Anticipated expiration: 2032-01-25

Abstract

The embodiment of the application discloses an AWR-LC hybrid filter based on an IPD process, which is used for improving the Q value of the AWR-LC hybrid filter through an AW resonator. The method in the embodiment of the application comprises the following steps: a first resonant module, a second resonant module, and an AW resonator circuit; the input end of the AW resonator circuit is connected with the first resonance module, the output end of the AW resonator circuit is connected with the second resonance module, and the AW resonator circuit, the first resonance module and the second resonance module are connected in series and integrated in the same integrated circuit through an IPD (integrated phase delay) process; the AW resonator circuit is formed by connecting an AW resonator, a first lumped element and a second lumped element in parallel, and the Q value of the AW resonator is far higher than those of the first lumped element and the second lumped element, so that the Q value of the AW resonator circuit is improved.

Description

AWR-LC hybrid filter based on IPD process

Technical Field

The embodiment of the application relates to the field of electronics, in particular to an AWR-LC hybrid filter based on an IPD process.

Background

The market of mobile terminals has expanded and the 5G network has covered a large range, and meanwhile people pursue miniaturization and convenience of smart phones and control industrial cost, so that the Circuit part in the PCB (Printed Circuit Board) of the mobile device is developed in the direction of integration. With the development of CMOS technology, the problem of low Q value and large area of the inductor in the filter is still not solved, and in the prior art, when the Q value is limited, the loss of the passband increases, the ripple phenomenon disappears, and the additional loss is proportional to 1/Q and the group delay. The group delay is large for the edges of the filter passband, which results in poor selectivity.

Disclosure of Invention

The application provides an AWR-LC hybrid filter based on IPD technology, which is used for improving the Q value of the AWR-LC hybrid filter through an AW resonator, so that the passband of the filter is narrower than that of a traditional LC filter, and meanwhile, the transition band of the filter can realize rapid attenuation.

The application provides an AWR-LC hybrid filter based on IPD process, which comprises:

a first resonant module, a second resonant module, and an AW resonator circuit;

the input end of the AW resonator circuit is connected with the first resonance module, the output end of the AW resonator circuit is connected with the second resonance module, and the AW resonator circuit, the first resonance module and the second resonance module are connected in series and integrated in the same integrated circuit through an IPD (integrated phase delay) process;

the AW resonator circuit is formed by connecting an AW resonator, a first lumped element and a second lumped element in parallel, and the Q value of the AW resonator is far higher than those of the first lumped element and the second lumped element, so that the Q value of the AW resonator circuit is improved.

Optionally, the AW resonator circuit is equivalent to an LC series resonant tank and an LC parallel resonant tank connected in parallel.

Optionally, an MIM (metal-insulator-metal) capacitor is formed between the LC series resonant tank and the LC parallel resonant tank.

Optionally, the calculation formula of the MIM capacitor is:

wherein epsilon _r And epsilon ₀ S is the area of the circuit board in the integrated circuit, and d is the distance between the circuit board and the circuit board in the integrated circuit.

Optionally, the LC parallel resonant tank includes a first capacitor and a first inductor, and a capacitive reactance of the first capacitor is variable.

Optionally, the resonant frequencies of the first resonant module and the second resonant module are the same as the center frequency of the AW resonator circuit, and the first resonant module and the second resonant module are configured to increase out-of-band rejection of the AW resonator circuit.

Optionally, the first resonance module includes a second inductor and a second capacitor, the second inductor is connected in parallel with the second capacitor, an output end of the first resonance module is grounded, and the first resonance module is an LC parallel resonance loop.

Optionally, the second resonance module includes a third inductor and a third capacitor, the third inductor is connected in parallel with the third capacitor, an output end of the second resonance module is grounded, and the second resonance module is an LC parallel resonance loop.

Optionally, more than one planar spiral inductor is provided around the AW resonator circuit.

Alternatively, the planar spiral inductor may be shaped as a quadrangle, a hexagon, or an octagon.

According to the technical scheme, the equivalent AWR-LC filter with the higher Q value is obtained by using the AW resonator with the higher Q value in a specified circuit connection mode, and the AWR-LC filter is integrated on a chip through an IPD (offset digital) process, so that the integration level of the AWR-LC filter is further improved.

Drawings

FIG. 1 is a schematic circuit diagram of an AWR-LC hybrid filter based on IPD process in the embodiment of the present application;

FIG. 2 is a schematic diagram of an equivalent circuit of an AWR-LC hybrid filter based on IPD process in the embodiment of the application;

FIG. 3 is a schematic diagram of a side view structure of an AWR-LC hybrid filter based on IPD process in the embodiment of the present application;

FIG. 4 is a schematic diagram of a top view structure of an AWR-LC hybrid filter based on IPD process in the embodiment of the present application;

fig. 5 is a frequency response graph of an AWR-LC hybrid filter based on IPD process in the embodiment of the present application.

Detailed Description

In the present invention, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "transverse", "longitudinal", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are used only for explaining relative positional relationships between the respective components or constituent parts, and do not particularly limit the specific mounting orientations of the respective components or constituent parts.

Moreover, some of the above terms may be used in other meanings besides orientation or positional relationship, for example, the term "upper" may also be used in some cases to indicate a certain attaching or connecting relationship. The specific meaning of these terms in the present invention can be understood by those of ordinary skill in the art as appropriate.

Furthermore, the terms "mounted," "disposed," "provided," "connected," and "connected" are to be construed broadly. For example, it may be a fixed connection, a removable connection, or a unitary construction; can be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements or components. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

In addition, the structure, proportion, size, etc. drawn by the drawings attached to the present invention are only used for matching with the content disclosed in the specification, so as to be known and read by those skilled in the art, and are not used for limiting the limit conditions that the present invention can be implemented, so that the present invention has no technical essential meaning, and any modification of the structure, change of the proportion relation or adjustment of the size should still fall within the scope covered by the technical content disclosed in the present invention without affecting the function and the achievable purpose of the present invention.

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The embodiment of the application provides an AWR-LC hybrid filter based on IPD technology, which is used for improving the Q value of the AWR-LC hybrid filter through an AW resonator, so that the passband of the filter is narrower than that of a traditional LC filter, and meanwhile, the transition band of the filter can realize rapid attenuation.

The AWR-LC hybrid filter based on IPD process proposed by the embodiment of the application is collectively called as a hybrid filter in the following description of the application embodiment.

Referring to fig. 1 to 5, an embodiment of the application provides an AWR-LC hybrid filter based on IPD process, including:

a first resonant module 1, a second resonant module 2 and an AW resonator circuit 3;

the input end of the AW resonator circuit 3 is connected with the first resonance module 1, the output end of the AW resonator circuit 3 is connected with the second resonance module 2, and the AW resonator circuit 3, the first resonance module 1 and the second resonance module 2 are connected in series and integrated in the same integrated circuit through an IPD (integrated phase delay) process;

the AW resonator circuit 3 is formed by connecting an AW resonator 31, a first lumped element 32 and a second lumped element 33 in parallel, and the Q value of the AW resonator 31 is much higher than the Q values of the first lumped element 32 and the second lumped element 33, so that the Q value of the AW resonator circuit 3 is improved.

Specifically, the hybrid filter has an AW resonator circuit as a main body, and the AW resonator circuit includes an AW resonator, a first lumped element and a second lumped element, where the first lumped element is a capacitor and the second lumped element is an inductor.

In practical situations, the AW resonator has a characteristic of high Q value, and when the AW resonator is combined with lumped elements, i.e. capacitors and inductors, a Q value far larger than that of a conventional LC resonant circuit is obtained, so that a quasi-elliptic function filter can be flexibly introduced, a high-quality transition bandwidth and a narrower passband bandwidth compared with the lumped element filter are flexibly introduced, and the bandwidth of the hybrid filter is no longer influenced by the quality factor of the AW resonator due to the introduction of the lumped elements in the hybrid filter.

According to the embodiment of the application, the IPD process is utilized, the hybrid filter is connected to the substrate 6 in a mode of welding the passive IPD device 5 and the welding spot 7, the hybrid filter can be processed on different substrates, the passive devices consuming the area in the active circuit are allowed to be stacked, the number of components of the matching circuit is reduced, the space on the board is saved, and the system area is reduced. Compared with the standard integrated circuit technology, the IPD technology can use more flexible materials and process flows, reduce the influence of stray capacitance and improve the performance of passive devices. The IPD process can also provide an inductor with a higher Q value than a core-mounted inductor, and a high-density capacitor and a large-value inductor are manufactured; the IPD process also simplifies assembly, reduces the number of purchased components, compresses inventory, and saves labor, thereby reducing overall system cost and increasing manufacturer profits.

Referring specifically to fig. 2, the AW resonator circuit 3 is equivalent to an LC series resonant tank 34 and an LC parallel resonant tank 35 in parallel.

The AW resonator circuit can generate an equivalent circuit through a BVD model, the equivalent circuit is a lumped element circuit and consists of an LC series resonance loop and an LC parallel resonance loop, wherein the resonance frequency of the LC series resonance loop is the center frequency of the hybrid filter and is also the pole of the hybrid filter, and when the frequency of the LC series resonance sink rate is equal to the frequency of the LC parallel resonance loop, the transmission zeros of the hybrid filter are symmetrical to each other.

Specifically, the specification of the capacitor in the LC parallel resonant tank may need to be changed, so that when the capacitance specification is changed, the resonant frequency of the LC parallel resonant tank changes, and the hybrid filter at this time becomes a hybrid filter with asymmetric passband, and the bandwidth sum changes along with the change of the capacitance reactance of the capacitor.

Optionally, an MIM (metal-insulator-metal) capacitor 36 is formed between the LC series resonant tank and the LC parallel resonant tank.

The capacitance value of the MIM capacitor is accurate and can not change along with the change of bias voltage, because of the capacitance of an IPD process, a MIN capacitor on a silicon substrate has a parasitic resistance and a parasitic inductance, the MIM capacitor is positioned between an LC series resonant circuit and an LC parallel resonant circuit, in practical situations, the arrival and departure of the MIM capacitor is in direct proportion to frequency in a low-frequency state, but when the MIM capacitor is in a high-frequency state, the admittance of the MIM capacitor is rapidly reduced due to the existence of the parasitic inductance, so that the admittance of the MIM capacitor firstly rises along with the rise of the frequency until the frequency reaches a SRF self-resonant frequency point, the admittance of the MIM capacitor reaches the maximum value, then along with the increase of the frequency, the admittance of the MIM capacitor can be rapidly reduced to 0, and if the frequency continues to rise at the moment, the MIM capacitor can present the inductance.

Optionally, the calculation formula of the MIM capacitor 36 is:

wherein epsilon _r And epsilon ₀ Is the dielectric constant, S is the electric constant in the integrated circuitAnd d is the distance between the circuit boards in the integrated circuit.

Specifically, the MIM capacitor is an electrical parallel plate capacitor, and the parallel plate capacitor is a capacitor generated in production by an actual integrated circuit fabrication process, and the MIM capacitor is not directly present in the circuit until the hybrid filter is produced, so that in order to ensure the capacitance of the MIM capacitor, the parallel plate capacitor needs to be calculated by an actual production size, that is, the capacitance of the MIM capacitor needs to be calculated. The calculation is as described above, wherein the parameters affecting the capacity of the MIM capacitor, in addition to the two dielectric constants, are the area of the plates of the circuit board and the distance between the two plates that create the MIM capacitor.

Optionally, the LC parallel resonant tank 35 includes a first capacitor 351 and a first inductor 352. The capacitance reactance of the first capacitor 351 is variable.

In practical applications, the first lumped element in parallel with the AW resonator in the circuit of the AW resonator is a first capacitor, and the specification of the first capacitor may be replaced if necessary, by changing the specification of the first capacitor. Therefore, when the capacitive reactance of the first capacitor is changed, the resonance frequency of the LC parallel resonance circuit is changed, so that the passband of the filter is asymmetric, and the bandwidth of the filter is changed. The first lumped element and the second lumped element are combined into an LC parallel resonant circuit, so that the resonant frequency of the LC parallel resonant circuit can be changed through the capacitance reactance change of a capacitor, in practical situations, an AW resonator can be equivalent to an LC series resonant circuit, when the resonant frequency of the LC parallel resonant circuit is the same as the resonant frequency of the LC series resonant circuit, transmission zeros of the hybrid filter are stacked mutually, and therefore when the LC series resonant circuit changes the frequency of the LC parallel resonant circuit through changing the capacitance reactance of the capacitor, the frequency of the AW resonator and the frequency of the LC parallel resonant circuit are different, so that the transmission zeros of the hybrid filter are changed, and the bandwidth of the filter is changed.

Optionally, the resonant frequency of the first resonant module 1 and the resonant frequency of the second resonant module 2 are the same as the center frequency of the AW resonator circuit 3, and the first resonant module 1 and the second resonant module 2 are configured to increase out-of-band rejection of the AW resonator circuit.

The input end and/or the output end of the round filter are/is connected with a first resonance module and/or a second resonance module, an LC resonance circuit of the first resonance module and/or the second resonance module has the same central frequency as that of the hybrid filter, when the signal input frequency is the central frequency of the hybrid filter, the first resonance module and/or the second resonance module resonates, namely, is open circuit and has no influence on the signal passing through the filter, and when the signal input frequency is not equal to the central frequency, part of the signal can pass through the finger of the first resonance module and/or the second resonance module to the ground, so that the signal received by the receiving end of the hybrid filter is reduced, and the effect of increasing out-of-band rejection is achieved.

Optionally, the first resonance module 1 includes a second inductor 11 and a second capacitor 12, the second inductor 11 is connected in parallel with the second capacitor 12, an output end of the first resonance module 1 is grounded, and the first resonance module 1 is an LC parallel resonance loop.

Optionally, the second resonance module 2 includes a third inductor 21 and a third capacitor 22, the third inductor 21 and the third capacitor 22 are connected in parallel, an output end of the second resonance module 2 is grounded, and the second resonance module 2 is an LC parallel resonance loop.

The impedance of the LC parallel resonant circuit can be equivalent to a resistor, which is a special resistor, the resistance of which changes with the frequency, and the equivalence can facilitate the understanding of the working principle of the circuit, which is an important characteristic of the LC parallel circuit: the impedance of the circuit reaches a maximum at parallel resonance. After the frequency of the input signal is higher than the resonance frequency, the LC parallel resonance loop is equivalent to a capacitor.

Thus, the first and second resonator modules are used to increase the out-of-band rejection of the filter.

Optionally, more than one planar spiral inductor 4 is provided around the AW resonator circuit 3.

In the embodiment of the present application, the planar spiral inductor based on the IPD process has a significant influence on the overall performance of many rf circuits. Because improving the quality factor of the inductor is very critical to reducing the phase noise of the oscillation circuit, the low-loss passive filter circuit and the matching circuit of the oscillator, there are many parameters that are affected during design, including the shape of the spiral line (quadrilateral, hexagon, octagon, etc.), the number of inductor layers, the number of inductor turns, the inner diameter of the coil, the line width, the line spacing, the line thickness, etc., and the specific details are not limited herein.

In practical cases, the inductance value and geometry of the planar spiral inductor are closely related, and for quadrilateral, hexagonal and octagonal planar spiral inductors, the inductance value can be calculated using the following empirical formula:

where k1 and k2 can be found in a table lookup and are constants associated with different spiral shaped lines. μ 0 represents the permeability, davg the average of the inner and outer diameters, n represents the number of turns, and ρ represents the filling value of the coil.

The embodiment of the application completes the index simulation by using the equivalent circuit in the ADS, and the result is shown in figure 5. It can be seen that the filter provided by the invention has excellent performance, the bandwidth of 10M at 2.21GHz (-3 dB) is realized, the maximum return loss is-16.51 dB, the out-of-band rejection at the frequency of 10M reaches-79 dB, an extremely narrow-band-pass filter with excellent performance is obtained, and the IPD process is utilized to ensure that the performance of the filter is more stable. It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one type of logical functional division, and other divisions may be realized in practice, for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

Claims

1. An AWR-LC hybrid filter based on IPD process, comprising:

a first resonant module, a second resonant module, and an AW resonator circuit;

the AW resonator circuit is formed by connecting an AW resonator, a first lumped element and a second lumped element in parallel, and the Q value of the AW resonator is higher than the Q values of the first lumped element and the second lumped element, so that the Q value of the AW resonator circuit is improved.

2. The IPD process based AWR-LC hybrid filter of claim 1, wherein said AW resonator circuit is equivalent to parallel LC series and LC parallel resonant tanks.

3. The IPD process based AWR-LC hybrid filter of claim 2, wherein a MIM metal-insulator-metal capacitor is formed between said LC series resonant tank and said LC parallel resonant tank.

4. The IPD process based AWR-LC hybrid filter of claim 3, wherein the MIM metal-insulator-metal capacitance is calculated by the formula:

wherein epsilon _r And ε ₀ Is the dielectric constant, S is the area of the circuit board in the integrated circuit, and d is the distance between the circuit board and the circuit board in the integrated circuit.

5. The IPD process based AWR-LC hybrid filter of claim 2, wherein said LC parallel resonant tank comprises a first capacitance and a first inductance, the capacitance reactance of said first capacitance being variable.

6. The IPD process based AWR-LC hybrid filter of any of claims 1 to 5, wherein the resonant frequency of the first and second resonant modules is the same as the center frequency of the AW resonator circuit, the first and second resonant modules being configured to increase the out-of-band rejection of the AW resonator circuit.

7. An IPD process based AWR-LC hybrid filter according to any one of claims 1 to 5, characterized in that the first resonance module comprises a second inductor and a second capacitor, the second inductor and the second capacitor are connected in parallel, the output end of the first resonance module is connected to ground, and the first resonance module is an LC parallel resonance loop.

8. The IPD process based AWR-LC hybrid filter of any one of claims 1 to 5, wherein the second resonance module comprises a third inductor and a third capacitor, the third inductor and the third capacitor are connected in parallel, the output terminal of the second resonance module is connected to ground, and the second resonance module is an LC parallel resonance loop.

9. The IPD process based AWR-LC hybrid filter according to any of the claims 1 to 5, characterized in that more than one planar spiral inductor is arranged around the AW resonator circuit.

10. The IPD process based AWR-LC hybrid filter according to claim 9, wherein said planar spiral inductor can be shaped as a quadrilateral, a hexagon or an octagon.