KU wave band band-pass waveguide filter

Abstract

The utility model discloses a KU wave band band-pass waveguide filter comprising a lower seat which is internally provided with a ripple filtering groove penetrating through two sides; the upper cover is buckled at the top of the lower seat and is fixed, so that the corrugated filtering grooves are encircled to form a single filtering channel; the input end is arranged at one end of the filtering channel; the output end is arranged at the other end of the filtering channel, and the filtering channel can be communicated end to end under the action of the input end and the output end; the impedance transformer is arranged at the input end of the filtering channel; the impedance transformer comprises at least two right-angle bosses formed on one side wall of the lower seat. According to the KU wave band band-pass waveguide filter provided by the utility model, through the arrangement of the lower seat and the upper cover, a single filtering channel can be formed between the input end and the output end, and the inner side plane of the upper cover is attached to the top of the lower seat for assembly, so that the filtering channel can be formed, and meanwhile, the overall size can be reduced.

Description

Technical Field

[0001] This utility model relates to the field of KU-band bandpass waveguide filter technology, and in particular to a KU-band bandpass waveguide filter. Background Technology

[0002] A waveguide filter is a type of filter based on waveguide transmission lines. Its basic principle is to utilize the transmission characteristics of waveguides by arranging structures such as metal plates and spirals inside the waveguide to filter signals. Compared to other filters, waveguide filters offer advantages such as good isolation performance, high power handling capability, and high reliability.

[0003] Suppose a signal with a uniform power spectrum is input from one port. After passing through a network, the power spectrum absorbed by the signal at the load at the other port is no longer uniform. In other words, the network output has frequency selectivity, which is a filter. Filter specifications include operating frequency, insertion loss, passband ripple, out-of-band rejection, etc.

[0004] Filters can be classified according to their frequency band as follows: low-pass filter (LPF), high-pass filter (HPF), band-pass filter (BPF), and band-stop filter (BEF). Among them, band-pass filter (BPF) is mainly used in the field of radio frequency antennas.

[0005] 1. A high-pass filter (HPF) allows high-frequency signals to pass through while suppressing low-frequency signals.

[0006] 2. Low-pass filter (LPF), as a key component in signal processing, allows low-frequency signals to pass through while blocking or attenuating high-frequency signals.

[0007] 3. The characteristic of a bandpass filter (BPF) is that the amplitude and frequency of the signal within its passband remain independent, while the output signal attenuates rapidly when the frequency is lower than fp1 or higher than fp2.

[0008] 4. The characteristics of a band-stop filter (BEF) are exactly the opposite of those of a band-pass filter. In the frequency range of fp1 to fp2, a band-stop filter can effectively suppress the passage of signals, and is therefore mainly used for signal suppression within a specific frequency band.

[0009] With the development of microwave communication technology, the requirements for microwave devices are becoming increasingly stringent. For filters, reducing size and improving frequency selectivity are two very important aspects. To address these issues, a Ku-band bandpass waveguide filter is proposed. Utility Model Content

[0010] Therefore, it is necessary to provide a KU-band bandpass waveguide filter to address the aforementioned technical problems. This filter converts a conventional dual-channel filter cavity into a single filter channel, which can reduce the overall size while meeting the actual filtering requirements, reducing insertion loss, and enhancing noise suppression.

[0011] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0012] A KU-band bandpass waveguide filter, comprising:

[0013] The lower part has a corrugated filter groove that runs through both sides;

[0014] The upper cover is fastened to the top of the lower seat and fixed, so that the corrugated filter grooves surround and form a single filter channel.

[0015] The input terminal is located at one end of the filter channel;

[0016] The output terminal is located at the other end of the filter channel and can connect the beginning and end of the filter channel under the action of the input terminal and the output terminal.

[0017] An impedance transformer is configured at the input of the filter channel;

[0018] The impedance transformer includes a right-angled boss formed on one side wall of the lower seat. There are at least two right-angled bosses, and multiple right-angled bosses are progressively arranged in the direction of the input end toward the filter channel.

[0019] Furthermore, the impedance transformer contains two right-angled bosses.

[0020] Furthermore, the input terminal is located at the bottom of the lower seat, and the output terminal is located on the outside of the lower seat.

[0021] Furthermore, the filtering channel includes a filtering cavity, and a partition wall is provided inside the filtering cavity.

[0022] Furthermore, the two ends of the filter cavity correspond to the input end and the output end, respectively.

[0023] Furthermore, the partition walls are longitudinally distributed within the filter cavity, and a height gap is left between their tops and the top cover.

[0024] Furthermore, the partition wall has multiple partition walls, and a width gap is left between the multiple partition walls, so that a filter chamber is formed between adjacent partition walls through the width gap.

[0025] Furthermore, the number of partition walls is six, and the six partition walls form five filter chambers.

[0026] Furthermore, the six partition walls are divided into three groups, which are respectively called the inner partition wall group, the middle partition wall group, and the outer partition wall group;

[0027] The heights of the internal partition wall group, the middle partition wall group, and the external partition wall group decrease sequentially, and the partition walls in each group have the same height.

[0028] Furthermore, the width of the five filter chambers increases sequentially from the center outwards.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The KU-band bandpass waveguide filter provided by this utility model can form a single filtering channel between the input and output ends by setting up a lower base and a top cover. The inner plane of the top cover is attached to the top of the lower base for assembly. This allows the filtering channel to be formed while reducing the overall size. Therefore, compared with conventional filters that splice two cavity parts together, it can reduce the interruption of the current path, reduce insertion loss, and improve frequency selectivity.

[0031] Meanwhile, since the gaps at the joints of the single channel in this application are reduced compared to the conventional method of assembling two cavities together, the overall electromagnetic leakage can be reduced, which can be used to enhance noise suppression and make it more practical.

[0032] Impedance matching can be achieved using impedance transformers. When the load or source impedance is mismatched with the transmission waveguide, or when there is a discontinuity at the connection point of two transmission waveguides, electromagnetic waves will be reflected, affecting the effective transmission of microwave power. In such cases, impedance transition devices, i.e., impedance transformers, are inserted at the discontinuity or other suitable locations to eliminate reflections and achieve matching. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the KU-band bandpass waveguide filter provided by this utility model;

[0034] Figure 2 A schematic diagram of the disassembled structure of the KU-band bandpass waveguide filter provided by this utility model;

[0035] Figure 3 A schematic diagram of the filter channel structure of the KU-band bandpass waveguide filter provided by this utility model;

[0036] Figure 4 A top view of the KU-band bandpass waveguide filter provided by this utility model;

[0037] Figure 5A cross-sectional view of the KU-band bandpass waveguide filter provided by this utility model.

[0038] The markings in the diagram are explained as follows:

[0039] Lower seat 1, corrugated filter groove 11;

[0040] Top cover 2;

[0041] Filter channel 3, filter cavity 31, partition wall 32, input end 33, output end 34, filter chamber 35;

[0042] Partition wall assembly 320, central partition wall assembly 321, external partition wall assembly 322;

[0043] Impedance transformer 4, right-angle boss 41. Detailed Implementation

[0044] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0045] As described in the background section, with the development of microwave communication technology, the requirements for microwave devices are becoming increasingly stringent. For filters, reducing size and improving frequency selectivity are two very important aspects.

[0046] To address this technical problem, this invention provides a KU-band bandpass waveguide filter, which is applied to KU-band bandpass waveguide filters.

[0047] For details, please refer to Figures 1-5 As shown, the KU-band bandpass waveguide filter specifically includes:

[0048] The lower seat 1 has a corrugated filter groove 11 that runs through both sides;

[0049] The upper cover 2 is fastened to the top of the lower seat 1 and fixed, so that the corrugated filter groove 11 surrounds and forms a single filter channel 3;

[0050] Input terminal 33 is located at one end of the filter channel 3;

[0051] The output terminal 34 is located at the other end of the filter channel 3, and the filter channel 3 can be connected end to end by the input terminal 33 and the output terminal 34.

[0052] Impedance transformer 4 is configured at the input terminal 33 of the filter channel 3;

[0053] The impedance transformer 4 includes a right-angled boss 41 formed on one side wall of the lower seat 1. There are at least two right-angled bosses 41, and multiple right-angled bosses 41 are progressively arranged in the direction of the input end 33 toward the filter channel 3.

[0054] The KU-band bandpass waveguide filter provided by this utility model can form a single filter channel 3 between the input end 33 and the output end 34 by setting the lower base 1 and the upper cover 2. The inner plane of the upper cover 2 is attached to the top of the lower base 1 for assembly. At the same time, the filter channel 3 can be formed and the overall volume can be reduced. Therefore, compared with the conventional filter that splices two cavity parts together, it can reduce the interruption of the current path, reduce the insertion loss, and improve the frequency selectivity.

[0055] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0056] It should be noted that, unless otherwise specified, the embodiments and features and technical solutions in the present invention can be combined with each other.

[0057] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0058] Example 1

[0059] Please refer to Figures 1-5 As shown, a KU-band bandpass waveguide filter includes:

[0060] The lower seat 1 has a corrugated filter groove 11 that runs through both sides;

[0061] The upper cover 2 is fastened to the top of the lower seat 1 and fixed, so that the corrugated filter groove 11 surrounds and forms a single filter channel 3;

[0062] Input terminal 33 is located at one end of the filter channel 3;

[0063] Output terminal 34 is located at the other end of the filter channel 3. It can connect the beginning and end of the filter channel 3 under the action of input terminal 33 and output terminal 34. Output terminal 34 (BJ120 waveguide port) is connected to WR-75 standard waveguide port.

[0064] Impedance transformer 4 is configured at the input terminal 33 of the filter channel 3;

[0065] The impedance transformer 4 includes a right-angled boss 41 formed on one side wall of the lower seat 1. There are at least two right-angled bosses 41, and multiple right-angled bosses 41 are progressively arranged in the direction of the input end 33 toward the filter channel 3.

[0066] The impedance transformer 4 contains two right-angled bosses 41. The impedance transformer 4 is a device used to achieve impedance matching. When the load or source impedance is mismatched with the transmission waveguide, or when a discontinuity occurs at the connection point of two transmission waveguides, electromagnetic waves will be reflected, affecting the effective transmission of microwave power. In this case, an impedance transition device, i.e., an impedance transformer, can be inserted at the discontinuity or other suitable location to eliminate reflection and achieve matching.

[0067] The input terminal 33 is located at the bottom of the lower seat 1, and the output terminal 34 is located on the outside of the lower seat 1;

[0068] like Figure 2 As shown, in this embodiment, by setting a corrugated filter groove 11 on a single lower seat 1, and then attaching a single flat upper cover 2 to the top of the lower seat 1, the corrugated filter groove 11 can be enclosed to form a filter channel 3. Therefore, compared with the conventional dual-channel filter that splices two cavities together, the single filter channel 3 in this embodiment can reduce the overall volume, reduce the interruption of the current path, and reduce the insertion loss.

[0069] Meanwhile, the contact surfaces of the upper cover 2 and the lower seat 1 are in a planar state. Therefore, after using external bolts for fastening, the sealing effect of the contact surfaces can be improved. Moreover, the overall joint only has the gap between the contact surfaces of the upper cover 2 and the lower seat 1, so the overall gap will be reduced, thereby reducing the overall electromagnetic leakage and enhancing suppression (57dB).

[0070] Example 2

[0071] The KU-band bandpass waveguide filter provided in Example 1 is further optimized, specifically, as follows: Figure 4 As shown, the filter channel 3 includes a filter cavity 31, and a partition wall 32 is provided inside the filter cavity 31;

[0072] The two ends of the filter cavity 31 correspond to the input end 33 and the output end 34, respectively;

[0073] The partition wall 32 is longitudinally distributed within the filter cavity 31, and a height gap is left between its top and the upper cover 2;

[0074] The partition wall 32 has multiple partition walls 32, and a width gap is left between the multiple partition walls 32, so that a filter chamber 35 is formed between adjacent partition walls 32 through the width gap;

[0075] In this embodiment, multiple filter chambers 35 are connected in series to form the core resonant unit of the filter, and the multiple filter chambers 35 allow electromagnetic field energy to be transferred between adjacent chambers.

[0076] When the signal to be processed is input into the impedance transformer 4 through input terminal 33 (BJ120 waveguide port), it will first be processed by the impedance transformer 4. The processed signal will then enter the input circuit as follows: Figure 5 In the leftmost filter chamber 35 shown, signal energy excites a specific mode of electromagnetic oscillation within the first filter chamber 35. Then, the electromagnetic energy leaks / couples into the second filter chamber 35 according to a specific intensity (determined by the dimensions of the partition walls 32 and the filter chamber 35) and phase relationship. The energy coupled into the second filter chamber 35 excites the resonant mode of that cavity. This process continues in this manner, with signal energy propagating backward through a series of filter chambers 35 and the coupling windows between them. This is because only signal energy within the passband frequency range where all filter chambers 35 work together can effectively and with minimal loss (insertion loss) propagate through the entire cavity chain to the output terminal 33. Finally, the signal energy passes through the output filter at the output terminal 33 (BJ120 waveguide port), completing the filtering operation for the entire signal.

[0077] In the above filtering process, since the signal enters through input terminal 33 and is output through output terminal 34, the overall filtering process of the signal is performed by only a single filtering channel 3. Compared with conventional dual-channel cavity filters, the overall insertion loss is lower.

[0078] This embodiment has the following parameter requirements regarding signal input and frequency conversion:

[0079] 1.1 Clock signal input parameters:

[0080] a) Reference signal input frequency: 10MHz;

[0081] b) Reference signal input power: 0dBm±5dBm;

[0082] c) Reference signal input phase noise; 1) ≤-130dBc / Hz@100Hz; 2) ≤-140dBc / Hz@1kHz; 3) ≤-145dBc / Hz@10kHz; 4) ≤-155dBc / Hz@100kHz.

[0083] 1.2 Down-conversion performance requirements

[0084] a) Radio frequency input frequency: 10.7 GHz ~ 12.75 GHz;

[0085] b) Local oscillator frequency: 9.75GHz / 10.6GHz;

[0086] c) Intermediate frequency output frequency: 0.95GHz~2.15GHz;

[0087] d) Noise figure: <1.0dB (including the cutoff filter);

[0088] e) Gain: >55d76%;

[0089] f) Gain flatness: <5dB;

[0090] g) Output P1dB: > 1dBm;

[0091] h) Intermediate frequency output noise suppression: ≥55dBc;

[0092] i) Phase noise of intermediate frequency output signal: 1) ≤-60dBc / Hz@100Hz; 2) ≤-70dBc / Hz@1kHz; 3) ≤-80dBc / Hz@10kHz; 4) ≤-90dBc / Hz@100kHz.

[0093] j) Input standing wave ratio: ≤1.5;

[0094] k) Output VSWR: ≤2.0;

[0095] L) Power requirements: Input voltage: 10~20V; Power consumption: <1.5W.

[0096] Example 3

[0097] The KU-band bandpass waveguide filter provided in Embodiment 1 or 2 is further optimized, such as... Figure 4 and Figure 5 As shown, there are six partition walls 32, and the six partition walls 32 form five filter chambers 35;

[0098] The six partition walls 32 are divided into three groups, which are respectively called the inner partition wall group 320, the middle partition wall group 321 and the outer partition wall group 322;

[0099] The heights of the inner partition wall group 320, the middle partition wall group 321, and the outer partition wall group 322 decrease sequentially, and the partition walls 32 in each group have the same height.

[0100] The width of the five filter chambers 35 increases sequentially from the center outwards;

[0101] Furthermore, the actual number of partitions 32 in this embodiment can be set according to the actual signal being processed. Therefore, the actual number of partitions 32 is not limited in this embodiment. The inductance and capacitance can be changed by adjusting the structure and size of these partitions 32, and the filtering characteristics can be adjusted.

[0102] Meanwhile, the shape, height, and width gap between adjacent partition walls 32 can be adaptively adjusted according to the corresponding processed signals. For example, by adjusting the size, shape, and position of partition walls 32, the size of the top window of partition walls 32 can be adjusted simultaneously. The window plays a decisive role in the electromagnetic coupling strength between two adjacent filter chambers 35. The larger the window size, the stronger the coupling, and the faster the signal energy is transferred from one filter chamber 35 to the next filter chamber 35. Conversely, the smaller the window size, the weaker the coupling and the slower the energy transfer. Partition walls 32 and filter chambers 35 are equivalent to an inductor and capacitor connected in series, with partition walls 32 acting as an inductor. Electromagnetic waves are propagated through coupling. Since the specific structural features and principles of filtering are well-known technical knowledge to those skilled in the art, no further elaboration is required in this embodiment.

[0103] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0104] Obviously, the embodiments described above are only some embodiments of this utility model, not all embodiments. The accompanying drawings show preferred embodiments of this utility model, but do not limit the patent scope of this utility model. This utility model can be implemented in many different forms; rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of this utility model. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing specific embodiments, or make equivalent substitutions for some of the technical features. Any equivalent structures made using the content of this utility model specification and drawings, directly or indirectly applied to other related technical fields, are similarly within the patent protection scope of this utility model.

Claims

1. A KU-band bandpass waveguide filter, characterized in that, It includes: The lower seat (1) has a corrugated filter groove (11) that runs through both sides. The upper cover (2) is fastened to the top of the lower seat (1) and fixed, so that the corrugated filter groove (11) surrounds and forms a single filter channel (3). The input terminal (33) is located at one end of the filter channel (3); The output terminal (34) is located at the other end of the filter channel (3), and the filter channel (3) can be connected end to end by the input terminal (33) and the output terminal (34); An impedance transformer (4) is configured at the input (33) of the filter channel (3); The impedance transformer (4) includes a right-angle boss (41) formed on one side wall of the lower seat (1). There are at least two right-angle bosses (41), and multiple right-angle bosses (41) are progressively arranged in the direction of the input end (33) toward the filter channel (3).

2. The KU-band bandpass waveguide filter according to claim 1, characterized in that, The impedance transformer (4) has two right-angle bosses (41).

3. The KU-band bandpass waveguide filter according to claim 1, characterized in that, The input terminal (33) is located at the bottom of the lower seat (1), and the output terminal (34) is located on the outside of the lower seat (1).

4. The KU-band bandpass waveguide filter according to claim 3, characterized in that, The filtering channel (3) includes a filtering cavity (31), and a partition wall (32) is provided inside the filtering cavity (31).

5. The KU-band bandpass waveguide filter according to claim 4, characterized in that, The two ends of the filter cavity (31) correspond to the input end (33) and the output end (34) respectively.

6. The KU-band bandpass waveguide filter according to claim 4, characterized in that, The partition wall (32) is longitudinally distributed within the filter cavity (31), and a height gap is left between its top and the upper cover (2).

7. The KU-band bandpass waveguide filter according to claim 5, characterized in that, The partition wall (32) has multiple partition walls (32) with a width gap between them, and the width gap allows the adjacent partition walls (32) to form a filter chamber (35).

8. The KU-band bandpass waveguide filter according to claim 6, characterized in that, The number of partition walls (32) is six, and the six partition walls (32) form five filter chambers (35).

9. The KU-band bandpass waveguide filter according to claim 6, characterized in that, The six partition walls (32) are divided into three groups, which are respectively the inner partition wall group (320), the middle partition wall group (321) and the outer partition wall group (322). The heights of the internal partition wall group (320), the middle partition wall group (321), and the external partition wall group (322) decrease sequentially, and the partition walls (32) in each group have the same height.

10. The KU-band bandpass waveguide filter according to claim 8, characterized in that, The width of the five filter chambers (35) increases sequentially from the center outwards.

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