Coaxial Resonator Duplexer for In-Building Distributed Antenna System

Abstract

A coaxial resonator duplexer for in-building distribution systems provided by the present application includes a first waveguide cavity, a second waveguide cavity, and a third waveguide cavity; wherein, a first resonant metal module is disposed in the first waveguide cavity, a second resonant metal module is disposed in the second waveguide cavity, and a third resonant metal module is disposed in the third waveguide cavity; the first resonant metal module includes a first resonant metal unit and a second resonant metal unit, the first resonant metal unit and the second resonant metal module resonate to form a first passband, and the second resonant metal unit and the third resonant metal module resonate to form a second passband; a common signal transmission port is further disposed on the first surface of the first waveguide cavity, a first signal output port is disposed on the first surface of the second waveguide cavity, and a second signal output port is disposed on the first surface of the third waveguide cavity. Through the optimized waveguide cavity and resonant metal module, efficient frequency separation and mode coupling are achieved, and at the same time, the volume and weight are effectively reduced.

Description

Technical Field

[0001] This application relates to the field of microwave technology, and in particular, to a coaxial resonator duplexer for in-building distribution systems. Background Art

[0002] With the rapid development of wireless communication technology, new requirements for high performance, miniaturization, low cost, and easy integration have been put forward for microwave passive devices. To meet these standards, duplexers have emerged. By integrating two-channel filters and sharing an input port and an antenna, it simplifies the radio frequency front-end system architecture, realizes the orderly transmission of signals, reduces the cost and volume of the device, and at the same time avoids the mutual interference between received and transmitted signals.

[0003] Currently, the design of duplexers mainly adopts traditional structures and uses two independent band-pass filters and coupling junctions, or eliminates the coupling junctions and uses two independent filters.

[0004] However, the duplexer using band-pass filters occupies a large size and cannot meet the structural requirements of lightweight duplexers. Summary of the Invention

[0005] This application provides a coaxial resonator duplexer for in-building distribution systems to solve the problems of insufficient miniaturization and lightweight of existing duplexers.

[0006] This application provides a coaxial resonator duplexer for in-building distribution systems, including:

[0007] A first waveguide cavity, a second waveguide cavity, and a third waveguide cavity;

[0008] Wherein, a first resonant metal module is arranged in the first waveguide cavity, a second resonant metal module is arranged in the second waveguide cavity, and a third resonant metal module is arranged in the third waveguide cavity;

[0009] The first resonant metal module includes a first resonant metal unit and a second resonant metal unit. The first resonant metal unit resonates with the second resonant metal module to form a first passband, and the second resonant metal unit resonates with the third resonant metal module to form a second passband;

[0010] A common signal transmission port is further arranged on the first surface of the first waveguide cavity, a first signal output port is arranged on the first surface of the second waveguide cavity, and a second signal output port is arranged on the first surface of the third waveguide cavity.

[0011] Optionally, the common signal transmission port is the common signal port of the first waveguide cavity, the second waveguide cavity, and the third waveguide cavity in the coaxial resonator duplexer;

[0012] The first signal output port is the signal output port of the second waveguide cavity;

[0013] The second signal output port is the signal output port of the third waveguide cavity.

[0014] Optionally, the second resonant metal unit is sleeved on the first resonant metal unit.

[0015] Optionally, the second surface of the first waveguide cavity is coupled and communicated with the second surface of the second waveguide cavity through a first coupling window;

[0016] The third surface of the first waveguide cavity is coupled and communicated with the second surface of the third waveguide cavity through a second coupling window;

[0017] The second surface of the first waveguide cavity and the third surface of the first waveguide cavity are opposite to each other.

[0018] Optionally, both the first coupling window and the second coupling window are rectangular, and the sizes of the first coupling window and the second coupling window are different.

[0019] Optionally, SMA connector feeding probes are provided on the common signal transmission port, the first signal output port, and the second signal output port;

[0020] Among them, the lengths of the respective SMA connector feeding probes are different.

[0021] Optionally, a third resonant metal unit is provided in the second resonant metal module;

[0022] A fourth resonant metal unit is provided in the third resonant metal module.

[0023] Optionally, an L-shaped coupling probe is provided in the second coupling window.

[0024] Optionally, the L-shaped coupling probe includes two metal cylinders;

[0025] The two metal cylinders are vertically connected.

[0026] Optionally, the distance from the first signal output port to the bottom surface of the coaxial resonant cavity duplexer is lower than the distance from the common signal transmission port to the bottom surface of the coaxial resonant cavity duplexer;

[0027] The distance from the common signal transmission port to the bottom surface of the coaxial resonant cavity duplexer is lower than the distance from the second signal output port to the bottom surface of the coaxial resonant cavity duplexer.

[0028] A coaxial resonator duplexer for in-building distribution systems provided by the present application includes a first waveguide cavity, a second waveguide cavity, and a third waveguide cavity. Among them, a first resonant metal module is arranged in the first waveguide cavity, a second resonant metal module is arranged in the second waveguide cavity, and a third resonant metal module is arranged in the third waveguide cavity. The first resonant metal module includes a first resonant metal unit and a second resonant metal unit. The first resonant metal unit and the second resonant metal module resonate to form a first passband, and the second resonant metal unit and the third resonant metal module resonate to form a second passband. A common signal transmission port is further arranged on the first surface of the first waveguide cavity, a first signal output port is arranged on the first surface of the second waveguide cavity, and a second signal output port is arranged on the first surface of the third waveguide cavity. Through the precisely optimized waveguide cavities and resonant metal modules, efficient frequency separation and mode coupling are achieved, while effectively reducing the volume and weight. Description of the Drawings

[0029] The drawings herein are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application, and are used together with the specification to explain the principles of the present application.

[0030] Figure 1 It is a schematic structural diagram of Embodiment 1 of the coaxial resonator duplexer for in-building distribution systems provided by the present application;

[0031] Figure 2 It is a schematic structural diagram of Embodiment 2 of the coaxial resonator duplexer for in-building distribution systems provided by the present application;

[0032] Figure 3 It is a schematic structural diagram of Embodiment 3 of the coaxial resonator duplexer for in-building distribution systems provided by the present application;

[0033] Figure 4 It is a topology diagram of the coaxial resonator duplexer for in-building distribution systems provided by the present application;

[0034] Figure 5 It is a diagram showing the variation of the frequency of the coaxial resonator duplexer for in-building distribution systems provided by the present application with the size r2;

[0035] Figure 6 It is a diagram of the simulation and test of the filtering characteristics of the coaxial resonator duplexer for in-building distribution systems provided by the present application;

[0036] Figure 7 It is a diagram of the simulation and test of the isolation parameters of the coaxial resonator duplexer for in-building distribution systems provided by the present application.

[0037] Reference Signs:

[0038] 100 - Coaxial Resonator Duplexer for In - building Distribution System; 101 - First Waveguide Cavity; 102 - Second Waveguide Cavity; 103 - Third Waveguide Cavity; 201 - First Resonant Metal Unit; 202 - Second Resonant Metal Unit; 203 - Third Resonant Metal Unit; 204 - Fourth Resonant Metal Unit; 301 - Common Signal Transmission Port; 302 - First Signal Output Port; 303 - Second Signal Output Port; 401 - First Coupling Window; 402 - Second Coupling Window.

[0039] Through the above - mentioned drawings, specific embodiments of the present application have been shown, and there will be more detailed descriptions hereinafter. These drawings and written descriptions are not intended to limit the scope of the concept of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. Detailed Embodiment

[0040] Here, the exemplary embodiments will be described in detail, and the examples are shown in the drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present application. On the contrary, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0041] The duplexers in the prior art are difficult to meet the requirements of lightweight and miniaturization of equipment in in - building distribution systems due to their complex design, large volume, and heavy weight. At the same time, the signal coupling efficiency between waveguide cavities of existing duplexers is relatively low, the mode matching is not precise enough, and there are high losses and interferences in signal transmission, resulting in the inability to fully exert the system performance and limiting their application in high - frequency communication scenarios.

[0042] To address the above problems, this solution realizes efficient signal coupling and low - loss transmission in terms of structure and materials by designing rectangular coupling windows, L - shaped coupling probes, and optimized SMA feeding probes. At the same time, through a compact nested structure and modular design, the volume and weight of the duplexer are significantly reduced, providing a new technical path for high - efficiency miniaturized duplexers in in - building distribution systems.

[0043] The technical solutions of the present application and how the technical solutions of the present application solve the above - mentioned technical problems will be described in detail below with specific embodiments. These several specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below with reference to the drawings.

[0044] Figure 1 It is a schematic structural diagram of the first embodiment of the coaxial resonator duplexer for in - building distribution system provided by the present application. As Figure 1As shown in the figure, the coaxial resonator duplexer 100 for in-building distribution system includes:

[0045] The first waveguide cavity 101, the second waveguide cavity 102 and the third waveguide cavity 103.

[0046] Among them, the first waveguide cavity 101 can be a rectangular metal cavity, made of lightweight metal material to reduce the weight of the entire duplexer. A first resonant metal module is arranged in the first waveguide cavity 101. The first resonant metal module includes a first resonant metal unit 201 and a second resonant metal unit 202. The second resonant metal unit 202 is sleeved on the first resonant metal unit 201 and tightly combined together in a nested manner, so that the first resonant metal unit 201 and the second resonant metal unit 202 form an effective electromagnetic coupling, and at the same time, redundant space can be reduced, the space utilization rate of the duplexer is improved, and thus the overall volume of the duplexer is reduced.

[0047] In addition, the first resonant metal unit 201 and the second resonant metal unit 202 jointly generate two different modes TEM1 and TEM2 in the first waveguide cavity 101. This structure enables the duplexer to achieve efficient mode separation and signal transmission, and at the same time avoids the disadvantages of multiple large metal parts or complex circuits in traditional designs, thus greatly reducing the volume and weight of the device.

[0048] On the other hand, a second resonant metal module is arranged in the second waveguide cavity 102. The second waveguide cavity 102 is a cylindrical metal cavity. Its cylindrical design can effectively utilize space, reduce unnecessary structural volume, and improve the transmission efficiency of electromagnetic waves through optimized design.

[0049] A second resonant metal module is arranged at the central position of the second waveguide cavity 102. A third resonant metal unit 203 is arranged in the second resonant metal module. The design of the third resonant metal unit 203 enables it to generate a single mode Mode1 in the second waveguide cavity 102. Since the wavelength and resonant frequency of the electromagnetic wave in the Mode1 mode are precisely matched, the space requirement can be minimized and good signal quality can be maintained.

[0050] Secondly, the third waveguide cavity 103 is also a cylindrical metal cavity, and its size and shape are the same as those of the second waveguide cavity 102. Through reasonable design of size and proportion, this waveguide cavity can effectively carry the required electromagnetic waves and reduce unnecessary space waste. A third resonant metal module is arranged at the central position of the third waveguide cavity 103. A fourth resonant metal unit 204 is arranged in the third resonant metal module for generating a single mode Mode2.

[0051] In the coaxial resonator duplexer for in-building distribution systems proposed in this application, a common signal transmission port 301 is further provided on the first surface of the first waveguide cavity 101. This common signal transmission port 301 can serve as the signal input port for the first waveguide cavity 101, the second waveguide cavity 102, and the third waveguide cavity 103. As the core signal input port of the coaxial resonator duplexer, this common signal transmission port 301 can support signal coupling and transmission between different waveguide cavities, enabling the duplexer to process multiple signal frequency bands. By optimizing the position and design of this common signal transmission port 301, signal loss and intermodulation interference can be significantly reduced, thereby improving the performance of the duplexer in high-frequency transmission.

[0052] Secondly, a first signal output port 302 is further provided on the first surface of the second waveguide cavity 102. As the signal output port of the second waveguide cavity 102, it is used to transmit the Mode1 signal generated by the second waveguide cavity 102 and output it outside the duplexer, ensuring the stability and effectiveness of signal transmission and having a low reflection loss.

[0053] A second signal output port 303 is provided on the first surface of the third waveguide cavity 103. As the signal output port of the third waveguide cavity, it is used to transmit the Mode2 signal generated by the third waveguide cavity 103 and transmit it to external devices through the port, avoiding mutual interference between signals and enabling the duplexer to achieve precise frequency separation and signal processing.

[0054] Furthermore, SMA connector feeding probes are provided on the common signal transmission port 301, the first signal output port 302, and the second signal output port 303. The SMA connector is a standard RF connection method commonly used for high-frequency signal transmission, and it has good signal stability and low insertion loss characteristics.

[0055] Among them, the lengths of the respective SMA connector feeding probes are different. The length of the SMA connector feeding probe of the common signal transmission port 301 is adjusted according to the design of the first waveguide cavity 101 to ensure stable signal transmission and proper matching. The lengths of the SMA connector feeding probes of the first signal output port 302 and the second signal output port 303 are also adjusted according to the operating frequencies of the respective waveguide cavities and the propagation characteristics of electromagnetic waves. By adjusting the lengths of these probes, the output power and bandwidth of the signal can be precisely controlled, while unnecessary signal loss is reduced.

[0056] Through the differential design of the lengths of the SMA connector feeding probes, the signal transmission path is further optimized, enabling the entire coaxial resonator duplexer to efficiently transmit signals under high-frequency operating conditions, while avoiding signal interference, distortion, and attenuation problems, ensuring the stable operation of the coaxial resonator duplexer in complex in-building distribution systems.

[0057] Furthermore, the coaxial resonator duplexer provided by the embodiment of the present application for the in-building distribution system realizes efficient electromagnetic signal coupling between the first waveguide cavity 101, the second waveguide cavity 102, and the third waveguide cavity 103 by setting the first coupling window 401, the second coupling window 402, and the L-shaped probe, so as to further improve the performance of the coaxial resonator duplexer.

[0058] Specifically, the second surface of the first waveguide cavity 101 is coupled and communicated with the second surface of the second waveguide cavity 102 through the first coupling window 401. Among them, the first coupling window 401 adopts a rectangular design, and its size can be adjusted according to the actual application scenario to match the coupling requirements between TEM1 generated by the first waveguide cavity and the single mode Mode1 generated by the second waveguide cavity 102, so that the transmission efficiency of the signal between the first waveguide cavity 101 and the second waveguide cavity 102 reaches the maximum, while reducing the reflection loss and improving the overall performance.

[0059] The third surface of the first waveguide cavity 101 is coupled and communicated with the second surface of the third waveguide cavity 103 through the second coupling window 402, which is used to realize the signal coupling between the first waveguide cavity 101 and the third waveguide cavity 103. Among them, the second coupling window 402 also adopts a rectangular design, and its size is different from that of the first coupling window 401 to adapt to the coupling characteristics of the single mode Mode2 generated by the third waveguide cavity 103 and the TEM2 mode of the first waveguide cavity 101. By adjusting the size ratio, the effective transfer of signal energy is ensured, and at the same time, mode interference is reduced.

[0060] It should be noted that the second surface of the first waveguide cavity 101 and the third surface of the first waveguide cavity 101 are oppositely arranged, forming good structural symmetry, which helps to evenly distribute the electromagnetic field and further improve the signal transmission stability.

[0061] In addition, an L-shaped coupling probe is arranged in the second coupling window 402, which is used to realize more efficient signal coupling between the first waveguide cavity 101 and the third waveguide cavity 103. Specifically, the L-shaped coupling probe includes two metal cylinders, and the two metal cylinders are vertically connected to form an L-shaped structure. Among them, the first cylinder (metal arm) is arranged horizontally and is used to couple with the electric field in the first waveguide cavity 101, and the second cylinder (metal leg) is arranged vertically and is used to couple with the electric field in the third waveguide cavity 103. It should be noted that the L-shaped coupling probe is made of a metal material with high conductivity to ensure the efficient transmission and low loss of electromagnetic signals.

[0062] The coaxial resonator duplexer for in-building distribution systems provided by the embodiments of the present application realizes the high efficiency and flexibility of signal transmission by designing multiple waveguide cavities, a common signal transmission port 301, and multiple signal output ports, as well as the SMA connector feeding probes with targeted adjustment. It improves the signal stability, accuracy, and bandwidth utilization rate. Moreover, by optimizing the structure and streamlining components, the coaxial resonator duplexer achieves the goals of miniaturization and light weight, and is particularly suitable for application environments with strict requirements for space and weight in modern in-building distribution systems.

[0063] Figure 2 FIG. 4 is a schematic structural diagram of Embodiment 2 of the coaxial resonator duplexer for in-building distribution systems provided by the present application. As Figure 2 shown, on the basis of Figure 1 the embodiment, a top view of the coaxial resonator duplexer for in-building distribution systems is shown, and the information of each parameter includes:

[0064] r1 represents the radius of the first resonant metal unit 201, which determines the layout position of the metal unit in the first waveguide cavity 101. The setting of its size affects the adjustment of the resonant frequency and the coupling relationship with other cavities. The second resonant metal unit 202 is a hollow metal cylinder, and r2 represents the radius of the hollow part in the metal cylinder where the second resonant metal unit 202 is located, and r3 represents the radius of the second resonant metal unit 202 itself. r4 represents the radius of the fourth resonant metal unit 204, r5 represents the radius of the hollow part of the metal cylinder where the third resonant metal unit 203 is located, and r6 represents the radius of the third resonant metal unit 203 itself.

[0065] Exemplarily, if r1 is too large, the metal unit will deviate from the expected position, thus affecting the resonant mode of the entire duplexer. If it is too small, it may lead to poor coupling or impedance mismatch. Therefore, the reasonable setting of r1 helps to improve the efficiency and stability of the coaxial resonator duplexer.

[0066] w_w1 represents the width of the first coupling window 401, thus affecting the coupling strength of the signal. A larger coupling window width can improve the coupling efficiency, but if it is too large, it will introduce unnecessary signal interference or affect the system stability.

[0067] w_w2 represents the width of the second coupling window 402. Adjusting the size of w_w2 helps to control the coupling strength between the third resonant cavity and other parts, and optimize the frequency response and signal isolation.

[0068] w_t1 represents the thickness of the first coupling window 401 between the first waveguide cavity 101 and the second waveguide cavity 102. w_t1 controls the coupling region between the first waveguide cavity 101 and the second waveguide cavity 102. The magnitude of this parameter determines the coupling strength between the waveguides, thereby affecting the operating bandwidth and signal transmission efficiency of the duplexer. Appropriate w_t1 can ensure good coupling between the waveguides while avoiding signal loss caused by overly strong coupling.

[0069] w_t2 represents the thickness of the second coupling window 402 between the first waveguide cavity 101 and the third waveguide cavity 103. Similar to w_t1, w_t2 controls the coupling situation between the first waveguide cavity 101 and the third waveguide cavity 103. Adjustment of this parameter also affects the signal isolation effect and the performance of the duplexer at different frequency bands. A reasonable setting of w_t2 can help optimize the operating frequency response of the duplexer, ensuring that signals can be effectively separated between different channels.

[0070] Exemplarily, in the coaxial resonator duplexer for in-building distribution systems proposed in the application embodiments, the parameters of each part can be r1 = 2.3, r2 = 8.3, r3 = 9.8, r4 = 2.2, r5 = 3.3, r6 = 5.4, w_w1 = 17, w_w2 = 10, w_t1 = 2.4, w_t2 = 2.4, where the unit of each parameter is mm.

[0071] The coaxial resonator duplexer for in-building distribution systems provided in the application embodiments, with the set parameters, ensures its operating efficiency and signal separation ability in the in-building distribution system. By reasonably adjusting the values of each parameter, the resonant frequency, bandwidth, coupling strength, and signal isolation effect can be controlled, thereby improving the overall performance of the duplexer and enabling it to operate stably in a multi-band system.

[0072] Figure 3 This is a schematic structural diagram of Embodiment 3 of the coaxial resonator duplexer for in-building distribution systems provided in the present application. As Figure 3 shown, on the basis of the Figure 1 embodiment, a front view of the coaxial resonator duplexer for in-building distribution systems is shown. The information of each parameter includes:

[0073] H1 represents the height of the first resonant metal unit 201. The parameter H1 determines the vertical dimension (height) of the first resonant cavity. Changes in the height directly affect the resonant frequency and the volume of the cavity. A reasonable setting of H1 can ensure that the first resonant cavity can effectively operate within a predetermined frequency band and maintain a good coupling relationship with other resonant cavities.

[0074] H2 represents the height of the second resonant unit. By adjusting H2, the resonant frequency of the second resonant unit can be made to match the design requirements of the coaxial cavity duplexer, optimizing the signal isolation and frequency response of the duplexer.

[0075] H3 represents the height of the third resonant unit, and H4 represents the height of the fourth resonant unit. Usually used to adjust the heights of the third and fourth resonant units, the bandwidth and signal isolation ability of the entire coaxial cavity duplexer can be adjusted.

[0076] h1 represents the distance from the center of the common signal port to the bottom surface, h2 represents the distance from the center of the first signal output port 302 to the bottom surface, and h3 represents the distance from the center of the second signal output port 303 to the bottom surface. Adjusting each height can affect the port matching and signal transmission quality. Appropriate settings of h1, h2, and h3 can ensure that the coupling effect between the signal port and the resonant cavity is maximized, avoiding unnecessary signal loss or reflection.

[0077] Among them, the distance from the first signal output port 302 to the bottom surface of the coaxial cavity duplexer is lower than the distance from the common signal transmission port 301 to the bottom surface of the coaxial cavity duplexer; the distance from the common signal transmission port 301 to the bottom surface of the coaxial cavity duplexer is lower than the distance from the second signal output port 303 to the bottom surface of the coaxial cavity duplexer.

[0078] Cl1 represents the length of the first metal cylinder of the L-shaped coupling probe, and Cl2 represents the length of the second metal cylinder of the L-shaped coupling probe. Adjusting Cl1 and Cl2 affects the coupling strength between the first waveguide cavity 101 and the third waveguide cavity 103, thereby affecting the performance of the coaxial cavity duplexer.

[0079] Exemplarily, in the embodiments of the present application, the above various parameters can be set as H1 = 23, H2 = 25, H3 = 25.5, H4 = 18, h1 = 10.2, h2 = 6, h3 = 23, where the units of all parameters are mm.

[0080] The parameter settings provided in the embodiments of the present application are crucial for the design of the coaxial resonant duplexer for in-building distribution systems. They not only affect the physical size of the duplexer but also determine the performance of the coaxial resonant duplexer in different frequency bands, including signal transmission, isolation, and coupling efficiency, etc. By precisely controlling these parameters, designers can optimize the overall performance of the duplexer to ensure its stable and efficient operation in a complex wireless communication environment.

[0081] Figure 4 This is the topology diagram of the coaxial cavity duplexer for in-building distribution systems provided by the present application. The topology uses the cascade of a dual-mode cavity and a single-mode cavity to construct the coaxial cavity duplexer, and this structure has been widely used in many wireless communication and radio frequency devices.

[0082] Among them, the dual-mode cavity is used to support the signal transmission of two different frequency bands, while the single-mode cavity plays the role of filtering and separating. Through this cascaded design, frequency separation can be achieved to ensure that signals of each frequency band can be transmitted without mutual interference. In addition, by adopting this optimized topology, the design can greatly reduce the volume while maintaining the performance, making the duplexer suitable for installation in application scenarios with limited space, such as in-building distribution systems or miniaturized communication devices.

[0083] Figure 5 It is a graph showing the variation of the frequency of the coaxial resonator duplexer for in-building distribution systems provided in this application with respect to the size r2. As Figure 5 shown, it presents the graphs of the frequency curves of the two modes of the resonator with respect to the variation of r2 under the simulation of the high-frequency electromagnetic simulation software (English: High Frequency Structure Simulator, abbreviated as: HFSS) for the coaxial resonator duplexer, as well as the variation of the frequency ratio of the two modes.

[0084] By adjusting r2, the frequencies of the two different channels can be adjusted, enabling the duplexer to operate within a specific frequency range. Among them, as the r2 parameter changes, the operating frequencies of the two channels also change accordingly. As shown in the figure, a frequency shift is shown, indicating the fine-tuning effect of r2 on the resonant frequency. By precisely controlling this parameter, the operating performance of the coaxial resonator duplexer within the target frequency band can be optimized.

[0085] Figure 6 It is a graph of the filtering characteristic simulation and test of the coaxial resonator duplexer for in-building distribution systems provided in this application.

[0086] Among them, the return loss is an index to measure the degree of signal reflection. Generally, the larger the return loss, the less the signal reflection, indicating better matching performance of the device. In the figure, the return losses of Channel 1 and Channel 2 are both higher than 20 dB, which means that the duplexer can effectively eliminate signal reflection, thereby reducing signal loss and improving communication quality.

[0087] The insertion loss represents the power loss when the signal passes through the duplexer. The insertion loss values in the figure show that the duplexer has very low losses on both channels, indicating high signal transmission efficiency. This is very crucial for wireless communication devices because the lower the insertion loss, the higher the overall efficiency.

[0088] According to the data in the figure, the center frequency of Channel 1 is 1.8 GHz, and the bandwidth is about 6%. The center frequency of Channel 2 is 3.4 GHz, and the bandwidth is 5.8%. This means that the duplexer has a wide operating bandwidth and can support the transmission of more communication signals, thereby increasing the system capacity.

[0089] Figure 7 It is the simulation and test diagram of the isolation parameter of the coaxial resonator duplexer for the in-building distribution system provided by this application.

[0090] Among them, port isolation means that the signal of one channel will not interfere with that of another channel. The data in the figure shows that the isolation degree between the two channels is greater than 30 dB, which indicates that in actual operation, the two channels are almost completely independent and do not interfere with each other. This is a very important performance index in the design of the duplexer, ensuring that the duplexer can transmit signals of two frequency bands simultaneously without mutual influence.

[0091] The isolation parameter can be expressed as S, which is an important tool for describing the characteristics of radio frequency devices. S 11 represents the reflection characteristic of the input port. The S-parameter results in the figure show that the duplexer achieves efficient signal transmission and low loss between the two channels, while ensuring good isolation performance.

[0092] Specifically, an isolation degree higher than 30 dB indicates that the duplexer effectively isolates the signals of the two channels, enabling signals of different frequencies to operate in parallel in the same system without interfering with each other. This is a very important performance in radio frequency communication, especially important in multi-band and multi-channel systems.

[0093] After considering the specification and the invention disclosed herein in practice, those skilled in the art will readily think of other embodiments of this application. This application is intended to cover any variations, uses, or adaptations of this application, which follow the general principles of this application and include the common general knowledge or conventional technical means in this technical field not disclosed in this application. The specification and examples are only regarded as exemplary, and the true scope and spirit of this application are pointed out by the following claims.

[0094] It should be understood that this application is not limited to the exact structure already described and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is only limited by the appended claims.

Claims

1. A coaxial resonator duplexer for indoor distributed antenna system, characterized in that Comprising: A first waveguide cavity, a second waveguide cavity, and a third waveguide cavity, wherein the second surface of the first waveguide cavity is coupled and communicated with the third surface of the second waveguide cavity through a first coupling window; the third surface of the first waveguide cavity is coupled and communicated with the second surface of the third waveguide cavity through a second coupling window; the second surface and the third surface of the first waveguide cavity are opposite to each other. Wherein, a first resonant metal module is arranged in the first waveguide cavity, a second resonant metal module is arranged in the second waveguide cavity, and a third resonant metal module is arranged in the third waveguide cavity. The first resonant metal module includes a first resonant metal unit and a second resonant metal unit. The second resonant metal unit is sleeved on the first resonant metal unit. The first resonant metal unit and the second resonant metal module resonate to form a first passband. The second resonant metal unit and the third resonant metal module resonate to form a second passband. The first resonant metal unit and the second resonant metal unit jointly generate two different modes TEM1 and TEM2 in the first waveguide cavity. A common signal transmission port is further arranged on the first surface of the first waveguide cavity, a first signal output port is arranged on the second surface of the second waveguide cavity, and a second signal output port is arranged on the third surface of the third waveguide cavity.

2. The coaxial resonator duplexer according to claim 1, wherein The common signal transmission port is the common signal port of the first waveguide cavity, the second waveguide cavity, and the third waveguide cavity in the coaxial resonant cavity duplexer. The first signal output port is the signal output port of the second waveguide cavity. The second signal output port is the signal output port of the third waveguide cavity.

3. The coaxial resonator duplexer according to claim 1, wherein Both the first coupling window and the second coupling window are rectangular, and the sizes of the first coupling window and the second coupling window are different.

4. The coaxial resonator duplexer according to claim 1 or 2, characterized in that, SMA connector feeding probes are arranged on the common signal transmission port, the first signal output port, and the second signal output port. Wherein, the lengths of the respective SMA connector feeding probes are different.

5. The coaxial resonator duplexer according to claim 1 or 2, characterized in that, The second resonant metal module is a third resonant metal unit. The third resonant metal module is a fourth resonant metal unit.

6. The coaxial resonator duplexer according to claim 3, characterized in that, An L-shaped coupling probe is arranged in the second coupling window.

7. The coaxial resonator duplexer according to claim 6, wherein The L-shaped coupling probe includes two metal cylinders. The two metal cylinders are vertically connected.

8. The coaxial resonator duplexer according to claim 1 or 2, characterized in that, The distance from the first signal output port to the bottom surface of the coaxial resonant cavity duplexer is lower than the distance from the common signal transmission port to the bottom surface of the coaxial resonant cavity duplexer. The distance from the common signal transmission port to the bottom surface of the coaxial resonant cavity duplexer is lower than the distance from the second signal output port to the bottom surface of the coaxial resonant cavity duplexer.

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