Broadband low-loss airtight switching structure

Abstract

The invention provides a broadband low-loss airtight switching structure, and relates to the technical field of microwaves, the structure comprises a flat waveguide, a micro-strip cavity is arranged above the surface of the flat waveguide, and a micro-strip line is mounted on one side, close to the flat waveguide, in the micro-strip cavity; a glass insulator is installed between the flat waveguide and the micro-strip cavity, one end of the glass insulator is connected with the micro-strip line, and the other end of the glass insulator extends into the flat waveguide but is not connected with the cavity of the flat waveguide. According to the technical scheme of the invention, through the arrangement of the flat waveguide, the glass insulator and the microstrip line, airtightness is realized while signal transmission between the waveguide and the microstrip is realized, the overall structure is convenient to install, the cost is low, and the loss is low.

Description

Technical Field

[0001] The invention relates to the field of microwave technology, and in particular to a broadband low-loss airtight switching structure. Background Art

[0002] Phased array technology is widely used in communications, imaging, target search and tracking. As an important component of the phased array antenna system, the transceiver component (T / R component) mainly shifts the phase of the input signal, amplifies it, and then outputs it to the antenna for radiation, or amplifies, shifts the phase of the signal received by the antenna, and filters it. The transceiver module contains many active devices and control chips, which account for a high proportion of the system's value and are easily affected by environmental factors such as water vapor, so the transceiver component is often required to be hermetically sealed.

[0003] Traditional waveguide-to-microstrip transitions often use microstrip probes or antennas to penetrate deep into the waveguide for mode conversion. However, existing waveguide-to-microstrip transition solutions have problems such as not being airtight, insufficient bandwidth, inconvenient installation, electromagnetic wave leakage, high loss, and requiring a thicker waveguide. Summary of the invention

[0004] The embodiments of the present invention provide a broadband low-loss airtight switching structure to solve the technical problems existing in the prior art.

[0005] Other features and advantages of the present invention will become apparent from the following detailed description, or may be learned in part by practice of the present invention.

[0006] According to a first aspect of an embodiment of the present invention, there is provided a broadband low-loss airtight switching structure, comprising:

[0007] A flat waveguide, wherein a microstrip cavity is arranged above the surface of the flat waveguide, and a microstrip line is installed on a side of the microstrip cavity close to the flat waveguide;

[0008] A glass insulator is installed between the flat waveguide and the microstrip cavity, one end of the glass insulator is connected to the microstrip line, and the other end extends into the interior of the flat waveguide but is not connected to the cavity of the flat waveguide.

[0009] In some embodiments of the present invention, based on the above solution, the microstrip line includes:

[0010] A dielectric plate, wherein a microstrip signal line is arranged on the dielectric plate;

[0011] A microstrip probe hole is provided at one end of the microstrip signal line, and the glass insulator passes through the microstrip probe hole and is welded to the microstrip signal line;

[0012] A microstrip high-resistance matching section and a microstrip low-resistance matching section of specific sizes are arranged on the microstrip signal line, and the microstrip high-resistance matching section and the microstrip low-resistance matching section are close to the microstrip probe hole.

[0013] In some embodiments of the present invention, based on the above solution, the dielectric board is further provided with a microstrip upper surface ground and a grounding metal hole;

[0014] The upper surface of the microstrip is connected to the grounding metal hole.

[0015] In some embodiments of the present invention, based on the aforementioned solution, the glass insulator comprises: an insulator inner conductor and an insulator glass cylinder;

[0016] The inner conductor of the insulator is divided into a small diameter section and a large diameter section;

[0017] The small diameter section passes through the insulator glass cylinder to form air coaxiality and then passes through the microstrip probe hole to be welded to the microstrip signal line;

[0018] The large diameter section extends into the interior of the flat waveguide and is not connected to the cavity of the flat waveguide.

[0019] In some embodiments of the present invention, based on the above solution, an insulator metal shell is provided on the outer surface of the insulator glass cylinder.

[0020] In some embodiments of the present invention, based on the above solution, a metal layer is provided on one side of the microstrip cavity close to the flat waveguide;

[0021] The grounding metal hole is connected to the metal layer;

[0022] The insulator metal shell is connected to the metal layer.

[0023] In some embodiments of the present invention, based on the aforementioned solution, the flat waveguide includes a waveguide matching step, a waveguide matching section and a waveguide transition section which are connected in sequence.

[0024] In some embodiments of the present invention, based on the above-mentioned solution, semicircular ears for clamping the microstrip line are symmetrically arranged on the microstrip cavity.

[0025] In some embodiments of the present invention, based on the above solution, the microstrip line is installed in the microstrip cavity by bonding or welding.

[0026] The technical solution of the present invention realizes airtightness while realizing signal transmission between the waveguide and the microstrip through the provision of a flat waveguide, a glass insulator and a microstrip line; the overall structure is easy to install, and has low cost and low loss.

[0027] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings herein are incorporated into and constitute a part of the specification, showing embodiments consistent with the present invention, and together with the specification, are used to explain the principles of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0029] Figure 1 A top view of a broadband low-loss airtight transition structure according to an embodiment of the present invention is shown;

[0030] Figure 2 A side view of a broadband low-loss airtight transition structure according to an embodiment of the present invention is shown;

[0031] Figure 3 A schematic diagram of a microstrip line structure according to an embodiment of the present invention is shown;

[0032] Figure 4 A schematic structural diagram of a glass insulator according to an embodiment of the present invention is shown;

[0033] Figure 5 A schematic diagram showing reflection and transmission coefficients of a broadband low-loss airtight switching structure according to an embodiment of the present invention is shown;

[0034] Figure 6 A side view showing the electric field distribution of a transition portion of a broadband low-loss airtight transition structure according to an embodiment of the present invention is shown;

[0035] Figure 7 A top view of the electric field distribution of the transition part of a broadband low-loss airtight transition structure according to an embodiment of the present invention is shown.

[0036] Description of Reference Numerals

[0037] 1- flat waveguide, 2- microstrip line, 3- microstrip cavity, 4- glass insulator, 5- solder, 6- air coaxial, 11- waveguide matching section, 12- waveguide transition section, 13- waveguide matching step, 21- dielectric plate, 22- grounding metal hole, 23- microstrip upper surface ground, 24- microstrip probe hole, 25- microstrip high resistance matching section, 26- microstrip low resistance matching section, 27- microstrip signal line, 31- semicircular ear, 41- insulator inner conductor, 42- insulator glass cylinder, 43- insulator metal shell. DETAILED DESCRIPTION

[0038] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the present invention will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0039] In addition, the described features, structures or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present invention. However, those skilled in the art will appreciate that the technical solution of the present invention can be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. may be adopted. In other cases, known methods, devices, implementations or operations are not shown or described in detail to avoid blurring various aspects of the present invention.

[0040] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all the embodiments. Based on the embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Some embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0042] In order to solve the technical problems existing in the prior art, an embodiment of the present invention provides a broadband low-loss airtight switching structure, including:

[0043] A flat waveguide, wherein a microstrip cavity is arranged above the surface of the flat waveguide, and a microstrip line is installed on a side of the microstrip cavity close to the flat waveguide;

[0044] A glass insulator is installed between the flat waveguide and the microstrip cavity, one end of the glass insulator is connected to the microstrip line, and the other end extends into the interior of the flat waveguide but is not connected to the cavity of the flat waveguide.

[0045] It should be noted that in order to enable the glass insulator to be connected to the microstrip line in the microstrip cavity, a through hole is opened on the side of the microstrip cavity close to the flat waveguide, so that the glass insulator can enter the microstrip cavity and connect to the microstrip line, and the contact point between the glass insulator and the microstrip cavity is welded to ensure airtightness.

[0046] It can be understood that the switching structure provided by the present invention can realize the transmission of signals between the waveguide and the microstrip while also having airtightness.

[0047] For example, see Figure 1 , showing a top view of a broadband, low-loss, airtight transition structure.

[0048] See also Figure 2 , showing a side view of a broadband, low-loss, airtight transition structure.

[0049] like Figure 1 and Figure 2 As shown, the microstrip cavity 3 is arranged above the flat waveguide 1, the microstrip line 2 is arranged inside the microstrip cavity 3 and close to the flat waveguide 1, the upper end of the glass insulator 4 enters the microstrip cavity 3 from the bottom of the microstrip cavity 3 and is soldered to the microstrip line 2 by solder 5, and the lower end of the glass insulator 4 extends into the interior of the flat waveguide 1, but the lower end of the glass insulator 4 is not connected to the cavity of the flat waveguide 1. The glass insulator 4 is not connected to the cavity of the flat waveguide 1 to prevent the insulator from being damaged by deformation and cracking caused by vibration and temperature changes.

[0050] In some feasible embodiments, based on the above-mentioned solution, semicircular ears for clamping the microstrip line are symmetrically arranged on the microstrip cavity.

[0051] For example, Figure 1 As shown, the microstrip line 2 is loaded in the microstrip cavity 3 by bottom welding or bonding. The microstrip cavity 3 has two symmetrical semicircular ears 31, which are used to facilitate clamping when welding or bonding the microstrip line 2.

[0052] In some feasible embodiments, based on the above solution, the microstrip line includes:

[0053] A dielectric plate, wherein a microstrip signal line is arranged on the dielectric plate;

[0054] A microstrip probe hole is provided at one end of the microstrip signal line, and the glass insulator passes through the microstrip probe hole and is welded to the microstrip signal line;

[0055] A microstrip high-resistance matching section and a microstrip low-resistance matching section of specific sizes are arranged on the microstrip signal line, and the microstrip high-resistance matching section and the microstrip low-resistance matching section are close to the microstrip probe hole.

[0056] In some feasible embodiments, based on the above solution, the dielectric board is further provided with a microstrip upper surface ground and a grounding metal hole;

[0057] The upper surface of the microstrip is connected to the grounding metal hole.

[0058] For example, see Figure 3, showing a schematic structural diagram of a microstrip line.

[0059] like Figure 3 As shown, the microstrip line is made of a radio frequency PCB board through etching and drilling processes. It includes a dielectric plate 21, on which a microstrip signal line 27 is arranged. The area near the left side of the microstrip signal line 27 has a microstrip high-impedance matching section 25 and a microstrip low-impedance matching section 26 of a specific size, through which impedance matching can be performed. 23 is the ground on the upper surface of the microstrip, which is connected to the metal layer on the lower surface of the microstrip cavity through the grounding metal hole 22. Its function is to reduce the radiation loss caused by the discontinuity at the connection between the microstrip line and the inner conductor of the insulator. 24 is a microstrip probe hole, through which the inner conductor of the glass insulator 4 passes through this hole and is welded to the signal transmission line 27 of the microstrip line 2, and 5 is the solder for welding the microstrip line.

[0060] In some feasible embodiments, based on the above solution, the glass insulator comprises: an insulator inner conductor and an insulator glass cylinder;

[0061] The inner conductor of the insulator is divided into a small diameter section and a large diameter section;

[0062] The small diameter section passes through the insulator glass cylinder to form air coaxiality and then passes through the microstrip probe hole to be welded to the microstrip signal line;

[0063] The large diameter section extends into the interior of the flat waveguide and is not connected to the cavity of the flat waveguide.

[0064] In some feasible embodiments, based on the above-mentioned solution, an insulator metal shell is provided on the outer surface of the insulator glass cylinder.

[0065] In some feasible embodiments, based on the above solution, a metal layer is provided on one side of the microstrip cavity close to the flat waveguide;

[0066] The grounding metal hole is connected to the metal layer;

[0067] The insulator metal shell is connected to the metal layer.

[0068] For example, see Figure 4 , showing a schematic structural diagram of a glass insulator.

[0069] like Figure 4As shown, 4 is a glass insulator, which includes an insulator inner conductor 41, an insulator glass cylinder 42, and an insulator metal shell 43. The diameters of the insulator inner conductor 41 are different. The small diameter end passes through the insulator glass cylinder 42, penetrates into the columnar hole to form an air coaxial 6, and continues to pass through the microstrip probe hole 24 and is welded together with the microstrip signal line 27. The glass insulator 4 is inserted into the metal layer on the lower surface of the microstrip cavity 3 from the direction of the flat waveguide 1, and the insulator metal shell 43 is welded to the metal layer by welding. The large diameter end of the insulator inner conductor 41 penetrates into the flat waveguide 1 and is not connected to the cavity of the flat waveguide 1. The inner conductor diameter and penetration depth as well as the insertion position can be adjusted to match. The inner conductor is not connected to the flat waveguide cavity to prevent deformation and cracking caused by vibration and temperature changes from damaging the insulator.

[0070] In some feasible embodiments, based on the aforementioned solution, the flat waveguide includes a waveguide matching step, a waveguide matching section and a waveguide transition section which are connected in sequence.

[0071] For example, Figure 1 and Figure 2 As shown, the flat waveguide 1 has a waveguide matching section 11 and a waveguide matching step 13, which work together to adjust the matching. The function of the waveguide switching section 12 is to switch the flat waveguide to a position at the same height as the metal of the microstrip cavity.

[0072] Figure 5 The figure shows the reflection transmission coefficient of the switching structure provided by the present invention, the -10dB impedance bandwidth is greater than 40% (12.2-21.5GHz), and the in-band switching loss is less than 0.1dB. The switching bandwidth is limited by the flat waveguide 1. If the output port is a ridge waveguide, it will have a wider working bandwidth.

[0073] The transition from insulator to waveguide is achieved by the simultaneous action of magnetic field coupling and electric field coupling, such as Figure 6 and Figure 7 As shown, the waveguide matching step 13 structure is introduced into the flat waveguide, and then the electric coupling is introduced to increase the coupling strength and bandwidth. There is a strong electric field coupling effect at the tip of the insulator inner conductor 41 near the waveguide matching step 13 (the solid line represents the electric field, and the dotted line represents the magnetic field); at the same time, the magnetic field gradually transitions from the insulator glass cylinder 42 surrounding the insulator inner conductor 41 to the typical TE 10 Mode magnetic field (magnetic field parallel to the broadside).

[0074] In summary, the switching structure provided by the present invention has the following advantages:

[0075] 1. Glass insulator is used as the transition bridge from microstrip to waveguide. The transition size is compact, the loss is small, the performance is stable, and the airtight transition can be achieved;

[0076] 2. The conductor inside the insulator does not contact the flat waveguide to prevent the insulator from being cracked due to temperature changes or vibrations;

[0077] 3. The diameters of the inner conductors of the insulators vary. The inner conductor that goes deep into the waveguide has a larger diameter to increase the coupling strength from the insulator to the waveguide.

[0078] 4. Introduce waveguide matching steps and then introduce electrical coupling to increase coupling strength and transfer bandwidth;

[0079] 5. The combination of high and low impedance of microstrip lines increases the matching bandwidth;

[0080] 6. Introduce grounding holes and surface metal near the connection between the microstrip line and the inner conductor of the insulator to reduce the radiation at the discontinuity and thus reduce the switching loss.

[0081] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the embodiments disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A broadband low-loss airtight switching structure, characterized in that: include: A flat waveguide, wherein a microstrip cavity is arranged above the surface of the flat waveguide, and a microstrip line is installed on a side of the microstrip cavity close to the flat waveguide; A glass insulator is installed between the flat waveguide and the microstrip cavity, one end of the glass insulator is connected to the microstrip line, and the other end extends into the interior of the flat waveguide but is not connected to the cavity of the flat waveguide.

2. The structure according to claim 1, characterized in that: The microstrip line comprises: A dielectric plate, wherein a microstrip signal line is arranged on the dielectric plate; A microstrip probe hole is provided at one end of the microstrip signal line, and the glass insulator passes through the microstrip probe hole and is welded to the microstrip signal line; A microstrip high-resistance matching section and a microstrip low-resistance matching section of specific sizes are arranged on the microstrip signal line, and the microstrip high-resistance matching section and the microstrip low-resistance matching section are close to the microstrip probe hole.

3. The structure according to claim 2, characterized in that: The dielectric plate is also provided with a microstrip upper surface ground and a grounding metal hole; The upper surface of the microstrip is connected to the grounding metal hole.

4. The structure according to claim 3, characterized in that: The glass insulator comprises: an insulator inner conductor and an insulator glass cylinder; The inner conductor of the insulator is divided into a small diameter section and a large diameter section; The small diameter section passes through the insulator glass cylinder to form air coaxiality and then passes through the microstrip probe hole to be welded to the microstrip signal line; The large diameter section extends into the interior of the flat waveguide and is not connected to the cavity of the flat waveguide.

5. The structure according to claim 4, characterized in that: An insulator metal shell is arranged on the outer surface of the insulator glass cylinder.

6. The structure according to claim 5, characterized in that A metal layer is provided on one side of the microstrip cavity close to the flat waveguide; The grounding metal hole is connected to the metal layer; The insulator metal shell is connected to the metal layer.

7. The structure according to any one of claims 1 to 6, characterized in that: The flat waveguide comprises a waveguide matching step, a waveguide matching section and a waveguide transition section which are connected in sequence.

8. The structure according to any one of claims 1 to 6, characterized in that: Semicircular ears for clamping the microstrip line are symmetrically arranged on the microstrip cavity.

9. The structure according to any one of claims 1 to 6, characterized in that: The microstrip line is installed in the microstrip cavity by bonding or welding.

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