Electric tuning frequency hopping filter

Abstract

The utility model provides an electric tuning frequency hopping filter, which comprises a first welding pad, a second welding pad, a first coupling structure and a second coupling structure, and the first coupling structure and the second coupling structure are three-dimensional graphic structures which are formed on the surface of a chip substrate and are symmetrical by rotating 180 degrees. The first end of the first coupling structure, the first welding pad, the first end of the second coupling structure and the second welding pad are arranged on the same metal layer farthest from the surface of the chip substrate, and the second end of the first coupling structure and the second end of the second coupling structure are arranged on the same metal layer closest to the surface of the chip substrate; a first interval is formed between the first end of the first coupling structure and the first welding pad, and the first end is electrically connected with the first welding pad through the first variable capacitor; a second interval is formed between the first end of the second coupling structure and the second welding pad, and the first end and the second welding pad are electrically connected through a second variable capacitor; the first welding pad, the second end of the first coupling structure, the second end of the second coupling structure and the second welding pad are all grounded.

Description

Technical Field

[0001] The utility model relates to a filter, in particular to an electrically tunable frequency hopping filter. Background Art

[0002] An electrically tunable frequency hopping filter is a filter that can quickly change its center frequency within a relatively wide frequency range, and is mainly used in frequency hopping communication systems. Frequency hopping communication is an anti-jamming and secure communication technology that transmits signals by quickly and randomly hopping the carrier frequency among multiple preset frequencies to combat interference and eavesdropping. The electrically tunable frequency hopping filter is one of the key components to implement this technology, and it can automatically adjust the center frequency of its passband according to the frequency hopping pattern to match the currently used carrier frequency.

[0003] Existing electrically tunable filters mainly filter out harmonic signals through components such as capacitors and inductors, and only transmit the required fundamental signals, thereby ensuring the normal operation of the circuit and helping the radio communication system improve its anti-jamming ability. Existing electrically tunable filters usually use varactor diodes and hand-wound inductors to achieve. This type of filter requires manual debugging, and has poor reliability and consistency. Moreover, the structure is fixed and cannot meet some specific requirements. Content of the Utility Model

[0004] Aiming at the defects of the existing technology, on the one hand, the utility model provides an electrically tunable frequency hopping filter.

[0005] The electrically tunable frequency hopping filter includes: a first variable capacitor, a second variable capacitor, an input terminal, an input inductor, a first coupling structure, a second coupling structure, an output inductor, a first pad, a second pad, and an output terminal provided on a chip substrate; the first coupling structure and the second coupling structure are three-dimensional graphic structures formed by alternating multiple dielectric layers and metal layers on the surface of the chip substrate, and the first coupling structure and the second coupling structure are symmetric with a 180-degree rotation; the first coupling structure has a first end and a second end, the second coupling structure has a first end and a second end, the first end of the first coupling structure, the first pad, the first end of the second coupling structure, and the second pad are arranged on the same-layer metal layer farthest from the surface of the chip substrate, and the second end of the first coupling structure and the second end of the second coupling structure are arranged on the same-layer metal layer closest to the surface of the chip substrate; there is a first gap between the first end of the first coupling structure and the first pad and they are electrically connected through the first variable capacitor; there is a second gap between the first end of the second coupling structure and the second pad and they are electrically connected through the second variable capacitor; the first pad, the second end of the first coupling structure, the second end of the second coupling structure, and the second pad are all grounded.

[0006] Further, the first variable capacitor or the second variable capacitor is a chip variable capacitor, and the first coupling structure and the second coupling structure include microstrip lines.

[0007] Furthermore, the first variable capacitor or the second variable capacitor is a controlled varactor diode.

[0008] Furthermore, the capacitance value change range of the controlled varactor diode is from 0.05 to 10 pF.

[0009] Furthermore, the multi-layer metal layers of the first coupling structure are electrically connected through conductive vias, and the multi-layer metal layers of the second coupling structure are electrically connected through conductive vias; the patterns between the first coupling structure and the second coupling structure on the same layer are parallel to each other.

[0010] Furthermore, the inductance values of the input inductor and the output inductor are from 0.5 to 100 nH, and the wiring width is from 0.05 to 0.6 mm.

[0011] Furthermore, the input inductor and the output inductor are two-dimensional structures or three-dimensional structures.

[0012] Furthermore, both the first coupling structure and the second coupling structure are three-dimensional coil structures or three-dimensional resonator structures.

[0013] Furthermore, when both the first coupling structure and the second coupling structure are three-dimensional coil structures, the width of the coil is set to be from 0.1 to 2 mm, and the total length of the coil is from 0.5 to 10 mm.

[0014] On the other hand, the present utility model provides a communication device, including the filter according to any one of the foregoing items.

[0015] The beneficial effects of the present utility model are as follows:

[0016] 1. For the filter provided by the present utility model, by using the IPD process, compared with the PCB process and the LTCC process, the processing accuracy is higher, the consistency is better, and inductors with higher Q values can be realized to reduce losses. Compared with the LTCC process, this product can fabricate capacitors with high precision and high density.

[0017] 2. The filter provided by the present utility model can provide thick copper and fabricate a 3D coupler through the packaged RDL process, and can increase the inductance and Q value under a limited area.

[0018] 3. The filter provided by the present utility model uses high-resistance silicon as the substrate, which realizes low losses of radio frequency devices while ensuring compatibility with the silicon process, and meets the transmission of high-frequency microwave signals. Description of the Drawings

[0019] The specific content of the present utility model will be described below with reference to the drawings, which will help to more easily understand the above and other objects, features and advantages of the present utility model. The drawings are only for showing the principle of the present utility model. The dimensions and relative positions of the units do not have to be drawn to scale in the drawings.

[0020] Figure 1 is a schematic structural diagram of the filter in Embodiment 1;

[0021] Figure 2A is the bandwidth diagram of the filter in Embodiment 1 at 1 GHz;

[0022] Figure 2B is the bandwidth diagram of the filter in Embodiment 1 at 1.5 GHz;

[0023] Figure 2C is the bandwidth diagram of the filter in Embodiment 1 at 2 GHz;

[0024] Description of Reference Numerals

[0025] 1. First coupling structure; 2. Second coupling structure; 3. Input end; 4. Output end; 5. Input inductor; 6. Output inductor; 7. First pad; 8. Second pad; 9. First interval; 10. Second interval; 11. Second end of the second coupling structure; 12. Conductive via; 13. Second end of the first coupling structure; 14. Conductive via. Detailed Embodiment

[0026] To make the above objects, features, and advantages of the present utility model more obvious and understandable, the following will describe in detail the specific embodiments of the present utility model with reference to the accompanying drawings, so that the above and other objects, features, and advantages of the present utility model will be clearer. The same reference numerals indicate the same parts in all the drawings. The drawings are not deliberately drawn to scale, and the focus is on showing the gist of the present utility model.

[0027] The terms and words used in the following description and claims are not limited to their written meanings, but are only used by the inventor to clearly and consistently understand the present utility model. Therefore, it is obvious to those skilled in the art that the following description of the various embodiments of the present utility model is only for the purpose of illustration, rather than for the purpose of limiting the present utility model defined by the appended claims and their equivalents.

[0028] It should be understood that the singular forms of "a", "an", and "the" include plural objects unless the context clearly indicates otherwise. Thus, for example, reference to "a module" includes reference to one or more such modules. The advantages and features of the present utility model and the method for implementing the present utility model can be more easily understood by referring to the detailed description of the following embodiments and the accompanying drawings. However, the present utility model can be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that the present utility model will be thorough and complete and will fully convey the concept of the present utility model to those skilled in the art.

[0029] This embodiment provides a filter, including:

[0030] An input terminal 3, an input inductor 5, a first pad 7, a first coupling structure 1, a second coupling structure 2, a second pad 8, an output inductor 6, and an output terminal 4. The first coupling structure 1 and the second coupling structure 2 are coupled to each other.

[0031] The filter in this embodiment is fabricated on a chip substrate by an IPD (Integrated Passive Device) process compatible with the chip substrate. Compared with the PCB process and the LTCC process, the IPD process has higher processing accuracy, better consistency, and can realize inductors with higher Q values to reduce losses. The chip substrate in this embodiment can exemplarily adopt a high-resistance silicon substrate with a resistivity higher than 2500 Ω·cm obtained by the zone melting method or the epitaxial process. The above high-resistance silicon substrate is compatible with microelectronic manufacturing processes and microelectromechanical system manufacturing processes, and can meet the transmission of high-frequency microwave signals, realizing low losses of radio frequency devices.

[0032] As Figure 1 shown, the first coupling structure 1 of the filter is disposed on the left side of the substrate surface (not shown in the figure), the second coupling structure 2 is disposed on the right side of the substrate surface, and the first coupling structure and the second coupling structure are symmetric with a 180-degree rotation. The first coupling structure 1 and the second coupling structure 2 transfer signals through the coupling resonance principle. The coupling resonance principle means that when two or more oscillating systems are coupled to each other, when their oscillation frequencies are close and the energy transfer efficiency is the highest, the system will exhibit a resonant state.

[0033] More specifically, in this embodiment, electromagnetic coupling is adopted between the first coupling structure 1 and the second coupling structure 2. Electromagnetic coupling resonance refers to the resonance phenomenon that occurs when two electromagnetic systems are connected through electrical components such as capacitors and inductors. When the frequencies of the two systems are close, their impedances match each other, and energy can be transferred efficiently. This interaction leads to the exchange of system energy, making the system in a resonant state.

[0034] The input terminal 3 of the filter is connected to the first coupling structure 1 through the input inductor 5, and the output terminal 4 of the filter is connected to the second coupling structure 2 through the output inductor 6. Further, the inductance values of the input inductor 5 and the output inductor 6 can be 0.5 - 100 nH, and the wiring width is 0.05 - 0.6 mm. It can be understood that the input inductor 5 and the output inductor 6 can also be arranged in the form of chip inductors on the chip substrate surface.

[0035] Specifically, the first coupling structure 1 and the second coupling structure 2 can use microstrip lines or stripline. The specific choice between microstrip lines and stripline depends on the requirements of specific applications, including factors such as operating frequency, cost budget, space constraints, signal integrity, and shielding requirements for comprehensive consideration. Based on the structural characteristics of microstrip lines and stripline, they can be well compatible with the chip substrate. In this embodiment, the first coupling structure 1 and the second coupling structure 2 can be formed on the chip substrate through the RDL process. The first coupling structure 1 and the second coupling structure 2 can be deposited on the surface of the chip substrate using thick copper material.

[0036] Exemplarily, a copper metal layer can be deposited on the chip surface, and the copper metal is made into a part of the first coupling structure 1 and the second coupling structure 2; then a layer of dielectric material (such as polyimide PI) is deposited on the metal layer for insulation and isolation. The etching process is used to remove the unnecessary metal or dielectric material. Further, the above process can be repeated to form a multi-layer structure. When there are multiple metal layers, the metals between different layers in the first coupling structure 1 are electrically connected through the conductive vias 12, and the metals between different layers in the second coupling structure 2 are electrically connected through the conductive vias 14. The patterns between the first coupling structure 1 and the second coupling structure 2 on the same layer are parallel to each other, such as Figure 1 shown in the first coupling structure 1 and the second coupling structure with a predetermined pattern. Although Figure 1 the first coupling structure 1 and the second coupling structure 2 are shown as a predetermined pattern of a broken-line spiral type in the figure, the present invention does not specifically limit the predetermined pattern of the first coupling structure 1 and the second coupling structure 2.

[0037] It should be noted that in this embodiment, the first coupling structure 1 and the second coupling structure 2 can be set as a multi-layer three-dimensional coil structure, such as a two-layer coil structure, a three-layer coil structure, etc. Specifically, when the three-dimensional structure of the first coupling structure 1 and the second coupling structure 2 is a two-layer coil structure, it will be formed from bottom to top as: substrate - dielectric layer - metal layer - dielectric layer - metal layer. Similarly, when the three-dimensional structure of the first coupling structure 1 and the second coupling structure 2 is a three-layer coil structure, the following structure will be formed from bottom to top: substrate - dielectric layer - metal layer - dielectric layer - metal layer - dielectric layer - metal layer. By forming the first coupling structure 1 and the second coupling structure 2 into a three-dimensional inductance structure, the inductance and Q value can be increased under a limited area. When both the first coupling structure and the second coupling structure are three-dimensional coil structures, the width of the coil is set to 0.1 - 2 mm, and the total length of the coil is 0.5 - 10 mm.

[0038] It should be understood that although the first coupling structure 1 and the second coupling structure 2 are implemented in the form of inductors by means of metal coils in this specific embodiment, it is only necessary that the first coupling structure and the second coupling structure can produce a coupling function. Therefore, in addition to being presented in the form of inductors, the first coupling structure and the second coupling structure can also be other structures, such as resonators.

[0039] There is a first gap 9 between the first end of the first coupling structure 1 and the first pad 7, and a second gap 10 between the first end of the second coupling structure 2 and the second pad 8. The first pad 7, the second pad 8, the first end of the first coupling structure 1 and the first end of the second coupling structure 2 are arranged on the metal layer farthest from the substrate in the same layer, and the first pad 7 and the second pad 8 are respectively connected to the ground GND through conductive vias. A first variable capacitor (not shown in the figure) is connected across the first gap 9. The first variable capacitor can be any form of chip capacitor or a capacitor formed by a metal layer - dielectric layer - metal layer on the chip substrate, such as a varactor diode, a varactor triode, etc. A second variable capacitor (not shown in the figure) is connected across the second gap 10. The second variable capacitor can be any form of chip capacitor or a capacitor formed by a metal layer - dielectric layer - metal layer on the chip substrate, such as a varactor diode, and the capacitance value of the varactor diode varies in the range of 0.05 - 10 pF. The second end 13 of the first coupling structure 1 and the second end 11 of the second coupling structure 2 are arranged on the metal layer closest to the substrate in the same layer.

[0040] A third gap is formed between the first end of the first coupling structure 1 and the first end of the second coupling structure 2, and a fourth gap is formed between the second end 13 of the first coupling structure 1 and the second end 11 of the second coupling structure 2. The third gap is larger than the fourth gap.

[0041] In the present utility model, a signal enters from the input terminal 3 of the filter, is transmitted to the first coupling structure 1 through the input inductor 5, then the signal is coupled from the first coupling structure 1 to the second coupling structure 2, and then is output from the output terminal 4 through the output inductor 6. The first end of the first coupling structure 1 is connected to the first pad 7 through the first variable capacitor and then grounded, the second end of the first coupling structure 1 is grounded, the first end of the second coupling structure 2 is connected to the second pad 8 through the second variable capacitor and then grounded, and the second end of the second coupling structure 2 is grounded. The first variable capacitor and the second variable capacitor can be controllable varactor diodes. The capacitance value of the varactor diode can be changed through a control circuit. The specific structure of the control circuit can be any structure that can achieve the above specific control function, and no specific limitation is imposed on it. The control circuit can also be arranged on the chip substrate, and the part that originally required manual debugging can be directly integrated on the surface of the chip substrate.

[0042] By adjusting the capacitance values of the first variable capacitor and / or the second variable capacitor, the bandwidth of the filter can be adjusted. For example, by selecting varactor diodes of different models, which have different capacitance change ranges, or by adjusting the capacitance value of the varactor diode. In addition to adjusting the capacitance value, the input inductor 5 and the output inductor 6 also have a significant impact on the signal. Therefore, by adjusting the input inductor 5 and the output inductor 6, more flexible and broader signal processing can be achieved. It can be further understood that the input inductor 5 and the output inductor 6 can be fabricated into a two-dimensional structure or a three-dimensional structure on the chip substrate to further improve the Q value and reduce the loss.

[0043] In addition, in the present utility model, the connection from the first end of the first coupling structure 1 to its connection with the input inductor 5, and the connection from the first end of the second coupling structure to its connection with the output inductor 6 can be regarded as the electrical part; the connection from the connection of the first coupling structure 1 and the input inductor 5 to the second end, and the connection from the connection of the second coupling structure 2 and the output inductor 6 to the second end can be regarded as the magnetic part. When the distance between the magnetic parts becomes smaller, the relative bandwidth becomes larger; when the distance between the magnetic parts becomes larger, the relative bandwidth becomes smaller. Therefore, the bandwidth can be adjusted by adjusting the relative distance between the microstrip lines or strip lines.

[0044] Through the above structure, a frequency hopping filter can be realized in which the relative bandwidth (for example, it can increase from 5% to 6%, or from 10% to 15%) increases as the center frequency increases within different frequency ranges (such as within 500 - 1500 MHz, within 1000 - 2000 MHz, etc.).

[0045] The filter provided in this embodiment is tested as Figure 2A shown. At 1 GHz, the 3 dB bandwidth is approximately 136 MHz, and the relative bandwidth is 13.6%; at 1.5 GHz, as Figure 2B shown, the 3 dB bandwidth is approximately 224 MHz, and the relative bandwidth is 14.9%; as Figure 2C shown, at 2 GHz, the 3 dB bandwidth is approximately 332 MHz, and the relative bandwidth is 16.6%.

[0046] It can be seen that for the electrically tunable frequency hopping filter of the present invention, within the frequency hopping range covered by the filter, as the center frequency changes from 1 GHz to 2 GHz, the relative bandwidth increases from 13.6% to 16.6%.

[0047] While the technology has been described and illustrated with respect to one or more embodiments, changes and / or modifications may be made to the illustrated examples without departing from the spirit and scope of the appended claims. In particular, with respect to the various functions performed by the above-described components or structures (assemblies, devices, circuits, systems, etc.), the terms used to describe such components (including references to "means") are intended to correspond to any component or structure that performs the specified function of the described component (e.g., functionally equivalent), even if not structurally equivalent to the disclosed structure that performs the functions in the exemplary embodiments described herein, unless otherwise indicated. Additionally, while a particular feature may have been disclosed with respect to one of several embodiments, such feature may be combined with one or more other features of one or more other embodiments as may be desired and advantageous for any given or particular application. Further, with respect to the use of the terms "comprising", "comprises", "having", "has", "containing", or variants thereof in the detailed description or claims, such terms are intended to be inclusive in a manner similar to the term "including".

[0048] In the above description, many specific details are set forth in order to provide a thorough understanding of the present utility model. However, the above description is only a preferred embodiment of the present utility model, and the present utility model can be implemented in many other ways different from those described herein. Therefore, the present utility model is not limited by the specific embodiments disclosed above. At the same time, any person skilled in the art can, without departing from the scope of the technical solution of the present utility model, make many possible changes and modifications to the technical solution of the present utility model by using the methods and technical contents disclosed above, or modify it into equivalent embodiments with equivalent changes. All simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present utility model without departing from the content of the technical solution of the present utility model still fall within the scope of protection of the technical solution of the present utility model.

Claims

1. An electrically tunable frequency hopping filter, characterized in that, Comprising: A first variable capacitor, a second variable capacitor, an input terminal, an input inductor, a first coupling structure, a second coupling structure, an output inductor, a first pad, a second pad, and an output terminal provided on a chip substrate; The first coupling structure and the second coupling structure are three-dimensional graphic structures formed by alternating multi-layer dielectric layers and metal layers on the surface of the chip substrate, and the first coupling structure and the second coupling structure are symmetric with a 180-degree rotation; The first coupling structure has a first end and a second end, the second coupling structure has a first end and a second end, the first end of the first coupling structure, the first pad, the first end of the second coupling structure, and the second pad are provided on the same metal layer farthest from the surface of the chip substrate, and the second end of the first coupling structure and the second end of the second coupling structure are provided on the same metal layer closest to the surface of the chip substrate; There is a first gap between the first end of the first coupling structure and the first pad and they are electrically connected through the first variable capacitor; There is a second gap between the first end of the second coupling structure and the second pad and they are electrically connected through the second variable capacitor; The first pad, the second end of the first coupling structure, the second end of the second coupling structure, and the second pad are all grounded.

2. The filter according to claim 1, wherein: The first variable capacitor or the second variable capacitor is a chip variable capacitor, and the first coupling structure and the second coupling structure include microstrip lines.

3. The filter according to claim 2, characterized in that: The first variable capacitor or the second variable capacitor is a controlled varactor diode.

4. The filter according to claim 3, wherein: The capacitance value change range of the controlled varactor diode is 0.05 - 10 pF.

5. The filter according to claim 4, wherein: The multi-layer metal layers of the first coupling structure are electrically connected through conductive vias, and the multi-layer metal layers of the second coupling structure are electrically connected through conductive vias; the patterns between the first coupling structure and the second coupling structure of the same layer are parallel to each other.

6. The filter according to claim 5, characterized in that: The inductance values of the input inductor and the output inductor are 0.5 - 100 nH, and the wiring width is 0.05 - 0.6 mm.

7. The filter according to claim 6, characterized in that: The input inductor and the output inductor are two-dimensional structures or three-dimensional structures.

8. The filter according to any one of claims 1-7, characterized in that: Both the first coupling structure and the second coupling structure are three-dimensional coil structures or three-dimensional resonator structures.

9. The filter according to claim 8, wherein: When both the first coupling structure and the second coupling structure are three-dimensional coil structures, the width of the coil is set to 0.1 - 2 mm, and the total length of the coil is 0.5 - 10 mm.

10. A communication device, characterized in that: A filter comprising any one of claims 1 - 9.

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