Terahertz multistage coupling type duplexer easy to realize by CNC (computer numerical control)

Abstract

The utility model relates to the technical field of terahertz radio frequency circuits, solves the technical problems of narrow relative bandwidth and complex processing of a terahertz frequency band waveguide duplexer, and particularly relates to a terahertz multistage coupling type duplexer easy to realize by CNC (computer numerical control). Comprising a duplexer main body structure which is formed by separably combining an E-plane slotted waveguide structural body A and an E-plane slotted waveguide structural body B. The duplexer main body structure is formed by cascading an E-plane Y-type junction with two filters and is provided with an input waveguide, a low-frequency output waveguide and a high-frequency output waveguide. Compared with a traditional T-shaped junction, the T-shaped junction is more suitable for the design of a broadband waveguide duplexer, and the compactness and simplicity of the structure are kept. Actual measurement shows that 24% of total working bandwidth is obtained, and the overall performance of a terahertz communication system is further improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of terahertz radio frequency circuit technology, specifically to a duplex module applied to a terahertz wireless communication system. BACKGROUND

[0002] The terahertz frequency band generally refers to a frequency range of 0.1-10THz, covering short millimeter waves, sub-millimeter waves to far infrared waves, and showing excellent characteristics such as high rate, large capacity and high penetration, and is widely used in radar detection, high-speed communication, safety detection and other fields. Especially in the field of communication, terahertz waves are good broadband information carriers, have abundant spectrum resources, and effectively improve the data transmission rate, which is of great significance to the realization of ultra-wideband and ultra-high-speed wireless communication systems.

[0003] The duplex is one of the key devices in the receiver system, which has the performance of separating or combining different frequency band signals. With the continuous deepening of the research on high frequency band communication systems, the development of the duplex is put on the agenda. According to the duplex reported so far, based on different circuit implementation methods, the duplex structure can be roughly divided into four types: hybrid network coupling type duplex, multi-stage coupling type duplex, ring coupling type duplex and directional filtering duplex.

[0004] Among them, the ring coupling type and the directional filtering type duplex can only be realized in the low frequency microwave band due to the particularity of the circulator and the directional filter, and are limited to narrowband applications; while the hybrid network coupling type duplex can realize wideband performance in high frequency band, but this structure is bulky and not conducive to miniaturization and integration, and the repeated use of multiple units introduces additional loss, resulting in too high loss in the channel.

[0005] In contrast, the multi-stage coupling type duplex structure is compact and simple, can realize miniaturization and low insertion loss, and allows multiple channels to work, which is another best choice to realize wideband performance. In addition, in the terahertz frequency band, rectangular waveguide has the characteristics of high Q value, low loss, high power capacity and easy cascading, and becomes the best choice for the transmission line structure of the terahertz system. Therefore, the terahertz multi-stage coupling type waveguide duplex is the current research hotspot.

[0006] The current terahertz multi-stage coupling type duplex is usually composed of T-shaped junction cascaded filters, which has superiorities in compactness, low loss and other performances, but has inherent limitations of complex design and difficult debugging, and the relative bandwidth in the channel is narrow, about 3%, which limits their application in wideband communication, detection and other systems. Although the characteristics of ridge waveguide can realize ultra-wideband, the use of micro-process preparation will bring high loss disadvantage, and is not suitable for terahertz high-speed communication systems. UTILITY MODEL CONTENT

[0007] The utility model discloses a purpose is to solve the relative bandwidth of terahertz frequency band waveguide diplexer is narrow, the processing is complicated and other problems, provide a kind of wideband easy processing multistage coupling type diplexer, to improve the overall performance of terahertz communication system further.

[0008] To solve the above technical problems, the utility model provides technical scheme as follows: a kind of terahertz multistage coupling type diplexer easy to realize CNC, including the diplexer main body structure of separable combination of E face crack waveguide structure A and E face crack waveguide structure B, the diplexer main body structure is made of E face Y type knot cascaded two filters, has input waveguide, low-frequency output waveguide, high-frequency output waveguide;

[0009] The E face Y type knot includes waveguide input branch, low-frequency band output branch and high-frequency band output branch three parts arranged on the diplexer main body structure, and the low-frequency band output branch and high-frequency band output branch are respectively connected with low-frequency band cavity filter and high-frequency band cavity filter.

[0010] Further, the waveguide input branch, low-frequency band output branch and high-frequency band output branch all adopt standard WR-3 waveguide, and the included angle between the three branches is 120 °.

[0011] Further, the low-frequency band cavity filter is composed of six first resonant cavities by magnetic coupling;

[0012] The first resonant cavity is six half-wave resonant cavities, and the wide side of the first resonant cavity is much larger than the standard rectangular wide side of WR-3.

[0013] Further, the magnetic coupling structure is realized by a first H-face inductive diaphragm, and there are seven magnetic coupling structures in the low-frequency band cavity filter.

[0014] Further, the high-frequency band cavity filter is composed of four second resonant cavities by magnetic coupling;

[0015] The second resonant cavity is four half-wave resonant cavities, and the wide side of the second resonant cavity is consistent with the standard rectangular wide side of WR-3.

[0016] Further, the magnetic coupling structure is realized by a second H-face inductive diaphragm, and there are five magnetic coupling structures in the high-frequency band cavity filter.

[0017] Further, the low-frequency output waveguide is composed of a 150 ° waveguide elbow loaded on the output port of the low-frequency band filter, and adopts WR-3 standard rectangular waveguide.

[0018] Further, the high-frequency output waveguide is composed of a 150 ° waveguide elbow loaded on the output port of the high-frequency band filter, and adopts WR-3 standard rectangular waveguide.

[0019] By the above technical scheme, the utility model provides a kind of terahertz multistage coupling type diplexer of easy CNC implementation, at least have following beneficial effects:

[0020] 1, the terahertz multistage coupling type waveguide diplexer proposed in the utility model adopts E face Y type knot, compared with traditional T type knot, it is more suitable for the design of wideband waveguide diplexer, and compactness and simplicity of structure are maintained.It is proved by actual measurement that it obtains 24% total operating bandwidth.

[0021] 2, the multistage coupling type waveguide diplexer proposed in the utility model is applicable to computer numerical control technology processing, has the advantages of low loss, miniaturization, wide bandwidth, and extremely high engineering practical value;At the same time, it plays a promoting role for the development and application of ultra-wideband high-speed wireless communication system.

[0022] 3, the terahertz multistage coupling type waveguide diplexer proposed in the utility model adopts traditional chebyshev filter of simple structure and easy to process, wherein low-frequency band filter improves out-of-band rejection by increasing resonant cavity wide side, and it is proved by actual measurement that it obtains 50dB high isolation characteristic.

[0023] 4, the E face split processing mode adopted in the utility model is applicable to the realization of most E face waveguide diplexer at present stage, and is easy to integrate with terahertz band E face split type circuit.

[0024] 5, the three ports adopted in the utility model are standard UG-387 flange joints, which can be directly measured and applied in wireless communication system, without other conversion and transition structure. BRIEF DESCRIPTION OF DRAWINGS

[0025] The drawings described herein are used to provide further understanding of the present application, constitute a part of the present application, and the illustrative embodiments of the present application and their description are used to explain the present application, and do not constitute improper limitation on the present application.In the drawings:

[0026] Figure 1 It is the structure schematic view of the utility model diplexer;

[0027] Figure 2 It is the two-part structure expansion schematic view of the utility model diplexer;

[0028] Figure 3 It is the top view of the E face structure of the utility model;

[0029] Figure 4 It is the structure schematic view of the E face Y type knot of the utility model;

[0030] Figure 5 It is the dimension marking drawing of the E face Y type knot of the utility model;

[0031] Figure 6 The S-parameter test result chart of the diplexer.

[0032] In the figure,

[0033] 1, E-plane crack waveguide structure A; 2, E-plane crack waveguide structure B; 3, E-plane Y junction;

[0034] 31, waveguide input branch; 32, low-frequency band output branch; 33, high-frequency band output branch; 34, low-frequency band cavity filter; 341, first resonant cavity; 342, first H-plane inductive diaphragm;

[0035] 35, high-frequency band cavity filter; 351, second resonant cavity; 352, second H-plane inductive diaphragm;

[0036] 4, low-frequency band filter output port; 5, high-frequency band filter output port; 6, waveguide input port. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the utility model.

[0038] In view of the fact that the current terahertz multi-stage coupling type diplexer is usually composed of T-type junction cascaded filters, and thus has the problems of narrow relative bandwidth, complex processing and the like, the embodiment proposes and designs a multi-stage coupling type waveguide diplexer suitable for computer numerical control (CNC) processing, low loss, miniaturization and wide bandwidth in the atmospheric transmission window frequency band of 220GHz, which has extremely high engineering practical value. Meanwhile, the embodiment plays a promoting role in the development and application of the ultra-wideband high-speed wireless communication system.

[0039] Please refer to Figures 1-6The embodiment provides a terahertz multi-stage coupling type diplexer which is easy to be realized by CNC and can be applied to computer numerical control (CNC) machining, has the advantages of low loss, miniaturization, wide bandwidth and extremely high engineering practical value, and promotes the development and application of an ultra-wideband high-speed wireless communication system. Specifically, the terahertz multi-stage coupling type diplexer is composed of an E-plane slit waveguide structure A1 and an E-plane slit waveguide structure B2 which are separable and fixedly combined to form a diplexer main body structure, the diplexer main body structure is composed of an E-plane Y junction 3 connected with two filters, has an input waveguide, a low-frequency output waveguide and a high-frequency output waveguide, and has a simple structure which is easy to be realized by CNC process. The low-frequency output waveguide is composed of a low-frequency filter output port 4 loaded with a 150° waveguide elbow, adopts a WR-3 standard rectangular waveguide, the high-frequency output waveguide is composed of a high-frequency filter output port 5 loaded with a 150° waveguide elbow, adopts a WR-3 standard rectangular waveguide, and the input waveguide is composed of a waveguide input port 6.

[0040] As shown in Figure 1 and Figure 2 , the terahertz multi-stage coupling type diplexer adopts an E-plane split machining mode and an E-plane slit waveguide structure, that is, the whole cavity structure is split into two symmetrical structures, and the whole structure is divided into the E-plane slit waveguide structure A1 and the E-plane slit waveguide structure B2, so that the terahertz multi-stage coupling type diplexer is easy to be integrated with an E-plane split type circuit in the terahertz frequency band, and the whole structure is simple and easy to realize, and all cavity right angles in the diplexer are rounded, with a minimum radius of 0.1 mm.

[0041] When the CNC process is adopted, the two metal blocks can be machined respectively, and the closed cavity can be formed by combining the two metal blocks. First, the whole structure of the diplexer and the assembly auxiliary structure are symmetrically milled in the two aluminum blocks by using the traditional CNC technology, then gold plating is performed after completion, and finally the physical size of the assembled diplexer is 21 mm*22 mm*21 mm. Figure 1 The waveguide port surface is provided with a standard UG-387 flange structure, that is, a ring-shaped groove part which is coplanar with the input port and the two output ports, and an internal thread hole is arranged on the waveguide port surface, which is beneficial to the close cooperation of the screw during assembly and avoids the generation of a gap when the two modules are fixed.

[0042] The E-plane Y junction 3 includes a waveguide input branch 31, a low-frequency output branch 32 and a high-frequency output branch 33 which are arranged on the diplexer main body structure, and the low-frequency output branch 32 and the high-frequency output branch 33 are respectively connected with a low-frequency cavity filter 34 and a high-frequency cavity filter 35.

[0043] As shown in Figure 3 and Figure 4As shown, the waveguide input branch 31, the low-frequency output branch 32 and the high-frequency output branch 33 all adopt standard WR-3 waveguides, and the included angle between the three branches is 120°, wherein the waveguide input branch 31 is an input waveguide, and the remaining low-frequency output branch 32 and high-frequency output branch 33 are connected to two filters, which are a low-frequency cavity filter 34 and a high-frequency cavity filter 35 respectively. The low-frequency output branch 32 is connected to the low-frequency cavity filter 34, and the high-frequency output branch 33 is connected to the high-frequency cavity filter 35.

[0044] The low-frequency cavity filter 34 is composed of 6 first resonant cavities 341 through magnetic coupling, with a passband of 250GHz-275GHz; the first resonant cavity 341 is a half-wavelength resonant cavity, and the wide side of the first resonant cavity 341 is much larger than the standard rectangular wide side of WR-3, thereby improving the out-of-band suppression. The magnetic coupling structure is realized by a first H-plane inductive diaphragm 342, and the interval between two first resonant cavities 341 is a first H-plane inductive diaphragm with a thickness of 0.15mm. There are 7 magnetic coupling structures in the low-frequency cavity filter 34.

[0045] The high-frequency cavity filter 35 is composed of 4 second resonant cavities 351 through magnetic coupling, with a passband of 300GHz-320GHz; the second resonant cavity 351 is a half-wavelength resonant cavity, and the wide side of the second resonant cavity 351 is consistent with the standard rectangular wide side of WR-3; the magnetic coupling structure is realized by a second H-plane inductive diaphragm 352, and the interval between two second resonant cavities 341 is a second H-plane inductive diaphragm with a thickness of 0.15mm. There are 5 magnetic coupling structures in the high-frequency cavity filter 35.

[0046] As shown in Figure 2 The duplexer includes an E-plane Y-junction 3, a low-frequency cavity filter 34 and a high-frequency cavity filter 35, and the included angle between the low-frequency cavity filter 34 and the high-frequency cavity filter 35 is 120°, and the included angle with the waveguide input port 6 is 120°. The low-frequency cavity filter 34 adopts 6 waveguide resonant cavities, and 7 magnetic coupling structures are introduced through linear arrangement; the high-frequency cavity filter 35 adopts 4 waveguide resonant cavities, and 5 magnetic coupling structures are introduced through linear arrangement; wherein the magnetic coupling structure is composed of an H-plane inductive diaphragm. The output waveguides of the low-frequency cavity filter 34 and the high-frequency cavity filter 35 are both loaded with a section of 150° waveguide elbow, which is convenient for subsequent testing. The specific dimensions are shown in Figure 5 .

[0047] The proposed terahertz multi-stage coupling diplexer is tested for S-parameter, which is used to describe the performance of radio frequency network in frequency domain. It represents the electrical performance change of radio frequency signal in the transmission process from port to port in radio frequency network at a certain frequency. S-parameter is a complex number containing amplitude and phase information, which can fully reflect the transmission and reflection characteristics of the network.

[0048] wherein |S 11 |(input reflection coefficient): represents the reflection loss measured at the transmitting port. The closer the value to 0, the smaller the reflection at the transmitting port, and the better the matching performance. |S 21 |(forward transmission coefficient): represents the transmission coefficient from the transmitting port to the receiving port. Since the purpose of the diplexer design is to isolate the transmitting and receiving signals, the value of |S 21 should be very small to avoid the leakage of the transmitting signal to the receiving port. |S 23 |(insertion loss of the receiving port): represents the transmission coefficient from the antenna port to the receiving port. It is a key parameter for measuring how much the received signal is lost after passing through the diplexer. The closer the value to 1, the better, indicating that the received signal can be efficiently transmitted to the receiving port. |S 31 |(insertion loss of the transmitting port): represents the transmission coefficient from the transmitting port to the antenna port. It is a parameter for measuring how much the transmitting signal is lost after passing through the diplexer. Similarly, the closer the value to 1, the better, to ensure that the transmitting signal can be efficiently transmitted to the antenna.

[0049] As Figure 6 shown in the test results, the diplexer works in the WR-3 frequency band, with a low-frequency passband of 249.7-279.8 GHz, a 3dB bandwidth of 11.4%, and an in-band insertion loss of 1.7dB; a high-frequency passband of 299.2-318.5 GHz, a 3dB bandwidth of 6.2%, and an in-band insertion loss of 1.4dB; echo loss in both passbands is better than 15dB, and channel isolation is better than 50dB. Applied to a terahertz communication system, it can realize wideband wireless communication with a total working bandwidth of 24% in the 220GHz frequency band.

[0050] It should be noted that in this document, relational terms such as first and second and the like can only be used to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying that there is any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising", or any other variations thereof are intended to cover non-exclusive inclusions, so that a process, method, article, or apparatus including a list of elements does not only include those elements, but also includes other elements not explicitly listed, or inherent to such a process, method, article, or apparatus.

[0051] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A terahertz multi-stage coupled duplexer that is easily implemented by CNC, comprising a duplexer main structure composed of an E-plane slotted waveguide structure A (1) and an E-plane slotted waveguide structure B (2) that can be separably combined, characterized in that, The duplexer's main structure consists of two filters cascaded together in an E-plane Y-type junction (3), and includes an input waveguide, a low-frequency output waveguide, and a high-frequency output waveguide. The E-plane Y-junction (3) consists of three parts: a waveguide input branch (31), a low-frequency output branch (32), and a high-frequency output branch (33) disposed on the main structure of the duplexer. The low-frequency output branch (32) and the high-frequency output branch (33) are respectively connected to a low-frequency cavity filter (34) and a high-frequency cavity filter (35).

2. The terahertz multi-stage coupled duplexer according to claim 1, characterized in that: The waveguide input branch (31), low-frequency output branch (32), and high-frequency output branch (33) all adopt the standard WR-3 waveguide, and the included angle between the three branches is 120°.

3. The terahertz multi-stage coupled duplexer according to claim 1, characterized in that: The low-frequency cavity filter (34) is composed of six first resonant cavities (341) connected by magnetic coupling; The first resonant cavity (341) consists of six half-wavelength resonant cavities, and the width of the first resonant cavity (341) is much larger than the width of the WR-3 standard rectangle.

4. The terahertz multi-stage coupled duplexer according to claim 3, characterized in that: The magnetic coupling is achieved by the first H-plane sensitive diaphragm (342), and there are a total of 7 structures in the low-frequency cavity filter (34) that are formed by magnetic coupling.

5. The terahertz multi-stage coupled duplexer according to claim 1, characterized in that: The high-frequency cavity filter (35) is composed of four second resonant cavities (351) connected by magnetic coupling; The second resonant cavity (351) consists of four half-wavelength resonant cavities, and the width of the second resonant cavity (351) is consistent with the width of the WR-3 standard rectangle.

6. The terahertz multi-stage coupled duplexer according to claim 5, characterized in that: The magnetic coupling is achieved by the second H-plane sensitive diaphragm (352), and there are a total of 5 structures in the high-frequency cavity filter (35) that are formed by magnetic coupling.

7. The terahertz multi-stage coupled duplexer according to claim 1, characterized in that: The low-frequency output waveguide is composed of a 150° waveguide bend loaded on the output port (4) of the low-frequency filter, and adopts the WR-3 standard rectangular waveguide.

8. The terahertz multi-stage coupled duplexer according to claim 1, characterized in that: The high-frequency output waveguide is composed of a 150° waveguide bend loaded at the output port (5) of the high-frequency filter and adopts the WR-3 standard rectangular waveguide.

Images