A miniaturized substrate-integrated waveguide fully tunable filter

Abstract

The present invention discloses a miniaturized substrate integrated waveguide fully tunable filter, comprising an upper dielectric layer, an upper metal layer, an intermediate dielectric layer, an intermediate metal layer, a lower dielectric layer and a lower metal layer stacked in sequence from top to bottom, a metal through hole array penetrates the edge of the intermediate metal layer from top to bottom to form a cascade resonant cavity, and the cascade resonant cavity is coupled by two double folded quarter-mode substrate integrated waveguide resonant cavities through the coupling window of the intermediate metal layer; a plurality of pairs of PIN diodes, a first varactor diode and a second varactor diode are arranged on the upper dielectric layer. The present invention realizes the adjustable center frequency by controlling the magnitude of the external loading voltage of the PIN diode; the adjustment of the transmission zero point of the broadband filter is controlled by changing the cross coupling by adjusting the external loading voltage of the first varactor diode; the adjustment of the bandwidth of the broadband filter is controlled by changing the interstage coupling by adjusting the external loading voltage of the second varactor diode; and the bandwidth is kept stable when adjusting the frequency and the transmission zero point.

Description

Technical Field

[0001] The invention belongs to the technical field of filters, and in particular relates to a miniaturized substrate integrated waveguide fully tunable filter. Background Art

[0002] Both military and civilian communication systems require miniaturization and generalization of communication equipment. In order to improve the utilization of spectrum resources, technologies such as spread spectrum, frequency hopping and dynamic frequency allocation are widely used. The wide application of these technologies meets the needs of fast adjustable or reconfigurable filters, so the research on adjustable filters is becoming more and more important.

[0003] Fully tunable filters can integrate multiple adjustable functions, flexibly change their parameters, and better adapt to complex and changing communication environments. In today's highly scarce spectrum resources and the uneven standards of existing communication equipment, fully tunable filters undoubtedly have extremely high research significance and application value. Domestic and foreign scholars have conducted extensive research on fully tunable filters in multi-band communication systems, and have achieved good results in achieving adjustable parameters such as the center frequency, bandwidth, transmission zero point, order, Q value, group delay, etc. of the filter. Its significance lies in the ability to select the required signals in real time in a complex and changing spectrum environment, flexibly suppress various interferences, realize adaptive control of the system, reduce filter costs, and effectively adapt to the development needs of broadband technology in future communication systems.

[0004] However, full tunability, as the development goal of the ideal tunable filter, has not yet truly achieved the simultaneous integration of multiple adjustable functions. There are still shortcomings such as fewer adjustable parameters, narrow adjustment range, single cavity mode, and unstable adjustment. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a miniaturized substrate integrated waveguide fully tunable filter in view of the deficiencies in the above-mentioned prior art, which realizes the adjustable center frequency by controlling the size of the external loading voltage of the PIN diode; the adjustment of the transmission zero point of the broadband filter is controlled by changing the cross coupling by adjusting the external loading voltage of the first varactor diode; the adjustment of the bandwidth of the broadband filter is controlled by changing the inter-stage coupling by adjusting the external loading voltage of the second varactor diode; thereby, multiple parameter adjustments are integrated together, and the parameter adjustments do not affect or interfere with each other, and when adjusting the frequency and the transmission zero point, the bandwidth is kept stable, and a double-folded quarter-mode substrate integrated waveguide resonant cavity is adopted, and its area is reduced by 93.5% compared with the full-mode resonant cavity, thereby realizing miniaturization.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a miniaturized substrate integrated waveguide fully tunable filter, characterized in that: it comprises an upper dielectric layer, an upper metal layer, an intermediate dielectric layer, an intermediate metal layer, a lower dielectric layer and a lower metal layer stacked in sequence from top to bottom, a metal through hole array penetrates the edge of the intermediate metal layer from top to bottom to form a cascade resonant cavity, and the cascade resonant cavity is coupled by two double folded quarter-mode substrate integrated waveguide resonant cavities through a coupling window of the intermediate metal layer; a plurality of pairs of PIN diodes and a plurality of varactor diodes are arranged on the upper dielectric layer, the cathode of the PIN diode is connected to the upper metal layer, the anode of the PIN diode is connected to the intermediate metal layer, and the plurality of pairs of PIN diodes are symmetrically arranged along the coupling window of the intermediate metal layer; the cathode of the varactor diode is connected to the upper metal layer, the anode of the varactor diode is connected to the intermediate metal layer, and the plurality of varactor diodes include a first varactor diode arranged at the top of the coupling window at a corresponding position of the upper dielectric layer and a second varactor diode arranged at the middle of the coupling window at a corresponding position of the upper dielectric layer.

[0007] The above-mentioned miniaturized substrate integrated waveguide fully tunable filter is characterized in that the double folded quarter-mode substrate integrated waveguide resonant cavity is obtained by dividing the full-mode resonant cavity twice along the equivalent magnetic wall and then folding it twice along the length and width directions.

[0008] The above-mentioned miniaturized substrate integrated waveguide fully tunable filter is characterized in that a gap is provided above the coupling window of the intermediate metal layer.

[0009] The above-mentioned miniaturized substrate integrated waveguide fully tunable filter is characterized in that the size of the gap is adjustable.

[0010] The above-mentioned miniaturized substrate integrated waveguide fully tunable filter is characterized in that the slot is in an inverted U shape.

[0011] The above-mentioned miniaturized substrate integrated waveguide fully tunable filter is characterized in that two ends of the PIN diode and the varactor diode are respectively led out to the edge of the upper dielectric layer through fine strip lines, and the fine strip lines are connected with wires.

[0012] The above-mentioned miniaturized substrate integrated waveguide fully tunable filter is characterized in that: the PIN diode is connected to the intermediate metal layer through a first metallized tuning column, the PIN diode is connected to the intermediate metal layer through a second metallized tuning column, the upper dielectric layer is provided with a through hole for the first metallized tuning column and the second metallized tuning column to pass through, and the upper metal layer is provided with a gap for the first metallized tuning column to pass through.

[0013] The above-mentioned miniaturized substrate integrated waveguide fully tunable filter is characterized in that the PIN diode is arranged in the area enclosed by the metal through hole array and the coupling window at the corresponding position of the upper dielectric layer.

[0014] The above-mentioned miniaturized substrate integrated waveguide fully tunable filter is characterized in that: the number of the second varactor diodes is multiple.

[0015] The above-mentioned miniaturized substrate integrated waveguide fully tunable filter is characterized in that the number of the first variable capacitance diode is at least one.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. The invention has a simple structure, reasonable design, and is easy to implement and operate.

[0018] 2. The present invention adopts two double folded quarter mode substrate integrated waveguide resonant cavities DFQMSIW in cascade. The double folded quarter mode substrate integrated waveguide resonant cavity DFQMSIW reduces the area to 6.25%, greatly reducing the size of the original full mode resonant cavity SIW, and can equivalently realize the function of the original full mode resonant cavity SIW, meeting the higher power and higher quality factor of the fully adjustable filter.

[0019] 3. In the present invention, the two ends of the PIN diode are connected to the middle metal layer and the upper metal layer respectively. When the PIN diode is connected, the middle metal layer and the upper metal layer are connected to each other, causing electromagnetic field disturbance at that position, thereby achieving the effect of adjusting the frequency. At the same time, the present invention is provided with multiple pairs of PIN diodes, and various changes in the center frequency are realized by controlling the on-off combinations of different pairs of PIN diodes.

[0020] 4. The present invention changes the cross-coupling by adjusting the external loading voltage of the first varactor diode to achieve a change in the transmission zero point, wherein the smaller the external loading voltage of the first varactor diode is, the closer the transmission zero point is to the passband; the larger the external loading voltage of the first varactor diode is, the farther the transmission zero point is from the passband.

[0021] 5. The present invention changes the inter-stage coupling by adjusting the external loading voltage of the second varactor diode to achieve bandwidth adjustment. The smaller the external loading voltage of the second varactor diode, the narrower the bandwidth; the larger the external loading voltage of the second varactor diode, the wider the bandwidth.

[0022] 6. When adjusting the frequency and the transmission zero point, the present invention dynamically changes the coupling coefficient by adjusting the external loading voltage of the second varactor diode, thereby maintaining the stability of the bandwidth and achieving good use effect.

[0023] 7. The number of PIN diodes and varactor diodes in the present invention is adjustable, thus avoiding the huge volume and large insertion loss caused by too many components, and achieving good use effect.

[0024] In summary, the present invention realizes the adjustable center frequency by controlling the size of the external loading voltage of the PIN diode; the adjustment of the transmission zero point of the broadband filter is controlled by changing the cross-coupling by adjusting the external loading voltage of the first varactor diode; the adjustment of the bandwidth of the broadband filter is controlled by changing the inter-stage coupling by adjusting the external loading voltage of the second varactor diode; thereby, multiple parameter adjustments are integrated together, and the parameter adjustments do not affect or interfere with each other, and when adjusting the frequency and the transmission zero point, the bandwidth is kept stable, and a double-folded quarter-mode substrate integrated waveguide resonant cavity is adopted, and its area is reduced by 93.5% compared with a full-mode resonant cavity, thereby realizing miniaturization.

[0025] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a structural schematic diagram of the present invention.

[0027] Figure 2 for Figure 1 Top view of the .

[0028] Figure 3 It is a schematic diagram of the structure of the intermediate metal layer of the present invention.

[0029] Figure 4 for Figure 1 Side view of.

[0030] Figure 5 This is a simulation diagram of the effect of the change in the gap length on the inter-stage coupling effect of the present invention.

[0031] Figure 6 This is a simulation diagram of the effect of the change of the external loading voltage of the varactor diode on the transmission zero point of the present invention.

[0032] Figure 7 This is a simulation diagram of the effect of the change of the external loading voltage on the bandwidth of the second varactor diode of the present invention.

[0033] Figure 8 This is a simulation diagram of the effect of changes in the external loading voltage of the PIN diode of the present invention on the center frequency.

[0034] Description of reference numerals:

[0035] 1—upper dielectric layer; 2—upper metal layer; 3—middle dielectric layer;

[0036] 4—middle metal layer; 41—coupling window; 5—lower dielectric layer;

[0037] 6—lower metal layer; 7—metal through hole array; 8—through hole;

[0038] 91—first varactor diode; 92—second varactor diode; 10—PIN diode;

[0039] 11—slot; 12—fine strip line; 13—first metalized tuning column;

[0040] 14—Second metalized tuning column. DETAILED DESCRIPTION

[0041] The method of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments of the present invention.

[0042] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0043] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0044] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0045] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0046] like Figures 1 to 4 As shown, the present invention includes an upper dielectric layer 1, an upper metal layer 2, an intermediate dielectric layer 3, an intermediate metal layer 4, a lower dielectric layer 5 and a lower metal layer 6 which are stacked in sequence from top to bottom.

[0047] In actual use, the upper metal layer 2 is plated on the lower surface of the upper dielectric layer 1, the middle metal layer 4 is plated on the lower surface of the middle dielectric layer 3, and the lower metal layer 6 is plated on the lower surface of the lower dielectric layer 5. The thickness of the upper dielectric layer 1, the middle dielectric layer 3 and the lower dielectric layer 5 are all 1 mm. The metal through hole array 7 penetrates from the upper dielectric layer 1 at the top to the lower metal layer 6 at the bottom. The metal through hole array 7 is arranged along the edge of the middle metal layer 4, and the metal through hole array 7 is inverted U-shaped, with its opening facing the coupling window 41 of the middle metal layer 4.

[0048] The metal through hole array 7 penetrates the edge of the middle metal layer 4 from top to bottom to form a cascade resonant cavity. The cascade resonant cavity is coupled by two double-folded quarter-mode substrate integrated waveguide resonant cavities through the coupling window 41 of the middle metal layer 4.

[0049] In actual use, according to the electromagnetic field distribution inside the full-mode resonant cavity SIW, the full-mode resonant cavity SIW is divided into two parts along the symmetrical position of its electric field to obtain a half-mode substrate integrated waveguide resonant cavity HMSIW, and the half-mode substrate integrated waveguide resonant cavity HMSIW is further divided into two halves along the equivalent magnetic wall to obtain a quarter-mode substrate integrated waveguide resonant cavity QMSIW, and then the quarter-mode substrate integrated waveguide resonant cavity QMSIW is folded twice along the length and width directions to obtain a double-folded quarter-mode substrate integrated waveguide resonant cavity DFQMSIW. Compared with the full-mode resonant cavity SIW, the double-folded quarter-mode substrate integrated waveguide resonant cavity DFQMSIW reduces the area to 6.25%, greatly reduces the size of the original full-mode resonant cavity SIW, and can equivalently realize the function of the original full-mode resonant cavity SIW, and has a good use effect.

[0050] A plurality of pairs of PIN diodes 10 and a plurality of varactor diodes are arranged on the upper dielectric layer 1 , the cathode of the PIN diode 10 is connected to the upper metal layer 2 , the anode of the PIN diode 10 is connected to the middle metal layer 4 , and the plurality of pairs of PIN diodes 10 are symmetrically arranged along the coupling window 41 of the middle metal layer 4 .

[0051] In actual use, the PIN diode 10 is arranged in the area enclosed by the metal through hole array 7 on the upper dielectric layer 1 and the coupling window 41 at the corresponding position of the upper dielectric layer 1. And multiple pairs of PIN diodes 10 are symmetrically arranged along the coupling windows 41 of the middle metal layer 4. The coupling window 41 is a regular rectangular notch, and its length direction is parallel to the opening direction of the metal through hole array 7, and the opening direction of the coupling window 41 is the same as the opening direction of the metal through hole array 7.

[0052] In actual use, when the PIN diode 10 is connected, the upper metal layer 2 and the middle metal layer 4 are connected to each other through the through hole 8, causing electromagnetic field disturbance at that position, thereby achieving the effect of adjusting the frequency. Assuming that there are n pairs of PIN diodes 10, and the n pairs of PIN diodes 10 are not turned on and off at the same time, then by controlling the on and off combination of the n pairs of PIN diodes 10, 2 n Frequency changes.

[0053] like Figure 1 As shown, in this embodiment, there are five pairs of PIN diodes 10, including a first pair consisting of diodes A1 and A2, a second pair consisting of diodes B1 and B2, a third pair consisting of diodes C1 and C2, a fourth pair consisting of diodes D1 and D2, and a fifth pair consisting of diodes E1 and E2. The five pairs of PIN diodes 10 are arranged at different positions of the upper dielectric layer 1, but each pair of PIN diodes 10 is symmetrical along the longitudinal axis of the coupling window 41, wherein diodes A1 and A2 are arranged at two corner positions of the metal through hole array 7, diodes B1 and B2 are arranged at both sides of the top of the coupling window 41, diodes C1 and C2 are arranged at both sides of the opening of the metal through hole array 7, diodes D1 and D2 are arranged at both sides of the middle section of the coupling window 41, and diodes E1 and E2 are arranged at both sides of the bottom of the coupling window 41. In this embodiment, since the five pairs of PIN diodes 10 can be controlled to be turned on and off respectively by wires, the five pairs of PIN diodes 10 are not turned on and off at the same time. Therefore, the on-off combination of the five pairs of PIN diodes 10 can achieve 2 5 This frequency change has the effect of adjusting the frequency.

[0054] like Figure 8As shown, the simulation curve is obtained by simulation calculation using three-dimensional electromagnetic simulation software, and the measurement curve is obtained by measurement after processing. The simulation curve and the measurement curve are superimposed to obtain the following Figure 8 The filter transmission response curve shown in the figure shows that the horizontal axis represents the frequency of the fully adjustable filter and the vertical axis represents the transmission characteristics. Figure 8 It can be seen that the center frequency of the passband changes with the magnitude of the external loading voltage of the PIN diode 10. The center frequency changes from top to bottom to 1.1 GHz, 1.29 GHz, 1.48 GHz, 1.6 GHz, and 1.9 GHz. By adjusting the magnitude of the external loading voltage of the PIN diode 10, the fully tunable filter is adjusted in the frequency range of 1.1 GHz to 1.9 GHz.

[0055] The cathode of the varactor is connected to the upper metal layer 2, and the anode of the varactor is connected to the middle metal layer 4. The multiple varactor diodes include a first varactor diode 91 arranged at the top of the coupling window 41 at a corresponding position on the upper dielectric layer 1 and a second varactor diode 92 arranged in the middle of the coupling window 41 at a corresponding position on the upper dielectric layer 1.

[0056] In actual use, the first varactor diode 91 is used to adjust the cross coupling to achieve a change in the transmission zero point, wherein the smaller the external loading voltage of the first varactor diode 91 is, the closer the transmission zero point is to the passband; the larger the external loading voltage of the first varactor diode 91 is, the farther the transmission zero point is from the passband.

[0057] like Figure 6 As shown, the horizontal axis represents the bandwidth of the fully tunable filter, the vertical axis represents the return loss, V1 represents the external loading voltage of the first varactor diode 91, V2 represents the external loading voltage of the first second varactor diode 92, and V3 represents the external loading voltage of the second second varactor diode 92. Figure 6 As known, when the voltage V1 = 3.8V, the transmission zero point is located at 1.54GHz; when the voltage V1 = 2.8V, the transmission zero point is located at 1.45GHz; when the voltage V1 = 2.1V, the transmission zero point is located at 1.41GHz. In summary, the smaller the voltage V1, the closer the transmission zero point is to the passband, so the transmission zero point can be adjusted by changing the external loading voltage of the first varactor diode 91.

[0058] It should be noted that while reducing the external loading voltage of the first varactor diode 91, the external loading voltage value of the second varactor diode 92 is increased, so that the bandwidth is kept stable and the use effect is good. Figure 6 As shown, while reducing the voltage V1, increasing the voltages V2 and V3, the bandwidth is kept stable.

[0059] In this embodiment, the number of the first varactor diode 91 is 1, and the number of the second varactor diode 92 is 2. The two second varactor diodes 92 are respectively arranged in the middle part of the coupling window 41 from top to bottom, and are used to adjust the inter-stage coupling to achieve bandwidth adjustment. The smaller the external loading voltage of the second varactor diode 92, the narrower the bandwidth; the larger the external loading voltage of the second varactor diode 92, the wider the bandwidth.

[0060] The bandwidth can be adjusted by adjusting the external loading voltage of the second varactor diode 92. Figure 7 As shown, the horizontal axis represents the bandwidth of the fully adjustable filter, and the vertical axis represents the transmission characteristics. In this embodiment, V2 and V3 are of the same size. When the external loading voltages V2 and V3 are both reduced from 11.5V to 5.6V, the absolute bandwidth will drop from 200MHz to 120MHz.

[0061] In this embodiment, a gap 11 is provided above the coupling window 41 of the intermediate metal layer 4. The gap 11 is in an inverted U shape.

[0062] In actual use, the cascade resonant cavity is coupled by two double folded quarter-mode substrate integrated waveguide resonant cavities through the coupling window 41 and the slot 11 of the intermediate metal layer 4. The width of the coupling window 41 and the length of the slot 11 will jointly determine the inter-stage coupling, which increases with the increase of the width of the coupling window 41, and increases with the increase of the length of the slot 11. Since the coupling window 41 is loaded with multiple PIN diodes 10 and varactor diodes, the width adjustment of the coupling window 41 is relatively complicated, so the slot 11 is provided to cooperate with the coupling window 41 to play the role of auxiliary coupling, so that the inter-stage coupling adjustment is flexible.

[0063] like Figure 5 As shown, the horizontal axis represents the length w of the gap 11, and the vertical axis represents the main coupling K of the cascade resonant cavity. 12 , interstage coupling K 12 The length w of the inverted U-shaped gap 11 increases. The horizontal length of the inverted U-shaped gap 11 is w, and the vertical length is w1. The size of the gap 11 can be adjusted according to actual conditions. In this embodiment, w1=1mm, and the width of the gap 11 is 0.1mm.

[0064] In this embodiment, both ends of the PIN diode 10 and the varactor diode are led out to the edge of the upper dielectric layer 1 through a fine strip line 12, and the fine strip line 12 is connected with a wire. In actual use, an external loading voltage is applied to the PIN diode 10 and the varactor diode through the wire, which makes the control simple.

[0065] In this embodiment, the PIN diode 10 is connected to the middle metal layer 4 through the first metallized tuning column 13, and the PIN diode 10 is connected to the upper metal layer 2 through the second metallized tuning column 14. The upper dielectric layer 1 is provided with a through hole 8 for the first metallized tuning column 13 and the second metallized tuning column 14 to pass through, and the upper metal layer 2 is provided with a gap for the first metallized tuning column 13 to pass through.

[0066] In this embodiment, the upper dielectric layer 1 is made of FR4-xpoxy material layer. The middle dielectric layer 3 and the lower dielectric layer 5 are made of RogersRT / duroid588 material layer. The varactor diode is SMV2020-079 series produced by Skyworks.

[0067] The above description is only an embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A miniaturized substrate integrated waveguide fully tunable filter, characterized in that: The invention comprises an upper dielectric layer (1), an upper metal layer (2), an intermediate dielectric layer (3), an intermediate metal layer (4), a lower dielectric layer (5) and a lower metal layer (6) which are stacked in sequence from top to bottom. A metal through-hole array (7) penetrates the edge of the intermediate metal layer (4) from top to bottom to form a cascade resonant cavity. The cascade resonant cavity is coupled by two double-folded quarter-mode substrate integrated waveguide resonant cavities through a coupling window (41) of the intermediate metal layer (4). A plurality of pairs of PIN diodes (10) and a plurality of variable capacitance diodes are arranged on the upper dielectric layer (1). The cathode of the PIN diode (10) is connected to the upper metal layer (2), the anode of the PIN diode (10) is connected to the middle metal layer (4), and a plurality of pairs of PIN diodes (10) are symmetrically arranged along the coupling windows (41) of the middle metal layer (4); The cathode of the varactor diode is connected to the upper metal layer (2), and the anode of the varactor diode is connected to the middle metal layer (4). The plurality of varactor diodes include a first varactor diode (91) arranged at the top of the coupling window (41) at a position corresponding to the upper dielectric layer (1), and a second varactor diode (92) arranged at the middle of the coupling window (41) at a position corresponding to the upper dielectric layer (1). The double-folded quarter-mode substrate integrated waveguide resonant cavity is obtained by bisecting the full-mode resonant cavity twice along the equivalent magnetic wall and then folding it twice along the length and width directions. A gap (11) is provided above the coupling window (41) of the middle metal layer (4).

2. A miniaturized substrate integrated waveguide fully tunable filter according to claim 1, characterized in that: The size of the gap (11) is adjustable.

3. A miniaturized substrate integrated waveguide fully tunable filter according to claim 1, characterized in that: The gap (11) is in an inverted U shape.

4. A miniaturized substrate integrated waveguide fully tunable filter according to claim 1, characterized in that: Two ends of the PIN diode (10) and the varactor diode are respectively led out to the edge of the upper dielectric layer (1) through fine strip lines (12), and the fine strip lines (12) are connected to wires.

5. A miniaturized substrate integrated waveguide fully tunable filter according to claim 1, characterized in that: The PIN diode (10) is connected to the middle metal layer (4) via a first metallized tuning column (13), and the PIN diode (10) is connected to the middle metal layer (4) via a second metallized tuning column (14). The upper dielectric layer (1) is provided with a through hole (8) for the first metallized tuning column (13) and the second metallized tuning column (14) to pass through, and the upper metal layer (2) is provided with a gap for the first metallized tuning column (13) to pass through.

6. A miniaturized substrate integrated waveguide fully tunable filter according to claim 1, characterized in that: The PIN diode (10) is arranged in an area enclosed by the metal through hole array (7) and the coupling window (41) at corresponding positions on the upper dielectric layer (1).

7. A miniaturized substrate integrated waveguide fully tunable filter according to claim 1, characterized in that: The number of the second variable capacitance diodes (92) is plural.

8. A miniaturized substrate integrated waveguide fully tunable filter according to claim 1, characterized in that: The number of the first variable capacitance diode (91) is at least one.

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