Ka-band double-layer substrate integrated waveguide directional coupler

Abstract

A Ka-band double-layer substrate integrated waveguide directional coupler belongs to the technical field of communication and comprises two layers of laminated dielectric substrates, a plurality of mounting holes are formed in the surfaces of the dielectric substrates and used for mounting waveguides; after the two layers of dielectric substrates are laminated, the surface between the outer surface and the dielectric substrates is coated with copper, and the wide wall part of the outer surface is provided with a mounting hole matched with the mounting hole of the dielectric substrate, a butt joint groove used for being in butt joint with the waveguide port, and a metalized through hole penetrating through the two layers of dielectric substrates. Coupling grooves which are regularly arranged are formed in the wide wall between the two layers of dielectric substrates in the electromagnetic wave transmission direction and used for coupling electromagnetic waves of one layer of dielectric substrate to the other layer of dielectric substrate. The feed structure adopts a waveguide-substrate integrated waveguide transition structure, the bandwidth is relatively wide, the waveguide joint is used as a feed end interface, and the transmission loss is relatively small. The two substrate integrated waveguide wide-wall coupling structures improve the miniaturization degree of the product.

Description

Technical Field

[0001] The invention relates to a Ka-band double-layer substrate integrated waveguide directional coupler, belonging to the technical field of communications. Background Art

[0002] The Ka-band is widely used in satellite communications, radar systems, and 5G communications due to its wider bandwidth and smaller antenna size. As the frequency increases, the design difficulty of RF components also increases. In modern communication systems, a high-performance RF transceiver front-end is a prerequisite for ensuring the normal operation of the communication system. Among them, the directional coupler has functions including signal distribution, power detection, signal isolation, etc., and is one of the core components of the RF transceiver front-end. Traditional waveguide directional couplers have problems such as large size, narrow bandwidth, and high loss, which seriously restrict the performance indicators of the communication system. In addition, higher frequencies have more stringent requirements on the size of the waveguide, and the roughness of the waveguide wall has a more obvious impact on the transmission loss. Summary of the Invention

[0003] The technical problem solved by the present invention is to overcome the shortcomings of the existing technology and provide a Ka-band double-layer substrate integrated waveguide directional coupler to solve the problem that traditional waveguide directional couplers do not have the performance of miniaturization, low loss, high isolation and ultra-wideband.

[0004] The technical solution of the present invention is: a Ka-band double-layer substrate integrated waveguide directional coupler, comprising two stacked dielectric substrates, each having a plurality of mounting holes on its surface for mounting a waveguide. After the two dielectric substrates are stacked, copper is clad on the outer surface and the surface between the dielectric substrates. The wide wall portion of the outer surface is provided with mounting holes that match the mounting holes of the dielectric substrates, a docking groove for docking the waveguide ports, and a metallized through-hole that penetrates the two dielectric substrates. The wide wall between the two dielectric substrates is provided with regularly arranged coupling grooves along the direction of electromagnetic wave transmission, for coupling electromagnetic waves from one dielectric substrate to the other.

[0005] Furthermore, the regularly arranged coupling grooves are T-shaped and inverted T-shaped coupling grooves arranged at equal intervals.

[0006] Furthermore, in the T-shaped and inverted T-shaped coupling slots, a gap is provided between the transverse coupling slot and the longitudinal coupling slot, the transverse coupling slot is equivalent to impedance, and the longitudinal coupling slot is equivalent to parallel admittance; the transverse direction is the direction of electromagnetic wave transmission, and the longitudinal direction is the direction perpendicular to the transverse direction on the plane of the dielectric substrate.

[0007] Furthermore, the distance between adjacent T-shaped coupling slots is one quarter of the waveguide wavelength, and the signal energies transmitted by different coupling slots in the coupling waveguide are superimposed in the same phase, thereby achieving the preset coupling degree requirement.

[0008] Furthermore, a broadband impedance matching effect can be achieved by adjusting the length and width of the coupling slot.

[0009] Furthermore, the waveguide port is a rectangular waveguide port; the metallized through holes are located at a distance of one quarter of the waveguide wavelength from the rectangular waveguide port, and the metallized through holes are arranged in a row.

[0010] Furthermore, the dielectric substrate is a hard dielectric substrate, including Rogers 4350 or Rogers 6002.

[0011] Furthermore, the metallized through-hole is filled with a conductive metal column.

[0012] Furthermore, by adjusting the position and size of the docking groove, the high-order modes excited from the waveguide opening into the dielectric substrate are suppressed.

[0013] The advantages of the present invention compared with the prior art are:

[0014] The feed structure of this invention utilizes a waveguide-substrate integrated waveguide transition structure, resulting in a wide bandwidth. A waveguide connector serves as the feed interface, minimizing transmission loss. The wide-wall coupling of two substrate integrated waveguides improves product miniaturization. The alternating arrangement of T-slots achieves 3dB coupling strength over a wide frequency range. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0016] Figure 1 This is the wide wall diagram of this patent;

[0017] Figure 2 is the common broad wall diagram of the through waveguide and the coupled waveguide;

[0018] Figure 3 It is the overall structure. DETAILED DESCRIPTION

[0019] In order to better understand the above technical solution, the technical solution of the present invention is described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present invention and the specific features in the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. In the absence of conflict, the embodiments of the present invention and the technical features in the embodiments can be combined with each other.

[0020] The following is a further detailed description of a Ka-band double-layer substrate integrated waveguide directional coupler provided by an embodiment of the present invention, in conjunction with the accompanying drawings. A specific implementation method may include two stacked dielectric substrates with a plurality of mounting holes formed on their surfaces for mounting the waveguides. After the two dielectric substrates are stacked, copper is clad on the outer surfaces and the surface between the dielectric substrates. The wide wall portion of the outer surface is provided with mounting holes that mate with the mounting holes of the dielectric substrates, a docking groove for docking the waveguide ports, and a metallized through-hole that extends through the two dielectric substrates. The wide wall between the two dielectric substrates is provided with regularly arranged coupling grooves along the direction of electromagnetic wave transmission, for coupling electromagnetic waves from one dielectric substrate to the other.

[0021] In the solution provided in the embodiment of the present invention, the waveguide-substrate integrated waveguide transition structure consists of a rectangular waveguide and a dielectric substrate. The two ends of the dielectric substrate are copper-clad, two rows of metallized through holes are opened in the dielectric base, and a groove is opened at the top of the dielectric substrate to directly connect to the waveguide port.

[0022] The principle of the above scheme is: the feeding port is a rectangular waveguide, the quasi-TE10 mode in the substrate integrated waveguide and the TE10 mode in the rectangular waveguide are very similar, and the two can obtain a good physical match. A row of metallized through holes is opened at a quarter wavelength (waveguide wavelength) away from the rectangular waveguide port to reduce field leakage, reduce reflection loss, and improve transmission efficiency.

[0023] like Figure 1 Rectangular grooves 5 are opened at both ends of the two dielectric substrates 1, the waveguide is fixed in the mounting hole 2, the waveguide port is aligned 4, and regularly arranged metal through holes 3 are opened on the wide wall of the dielectric substrate along the Z direction.

[0024] The H-plane waveguide directional coupler consists of two layers of dielectric substrates with copper cladding at both ends. Two rows of metallized through-holes are opened in the dielectric base to form a substrate-integrated waveguide structure. The common wide wall of the straight-through and coupled substrate-integrated waveguides is etched with corresponding equally spaced "T" and inverted "T" coupling slots using the printed circuit board process.

[0025] The principle behind this scheme is that a T-coupling slot, created in the common wide wall of the through-waveguide and coupled waveguide, cuts off the surface current in the wide wall. This causes the electric field to undergo a sudden change on either side of the slot, radiating from the through-waveguide to the coupled waveguide, completing the coupling of the RF signal. The transverse coupling slot is equivalent to an impedance, while the longitudinal coupling slot is equivalent to a parallel admittance. The arrangement of the coupling slots is similar to a linear arrangement of coupling holes. The length and number of the coupling slots affect the coupling degree. The distance between adjacent "T"-shaped coupling slots is a quarter of a wavelength. The signal energies transmitted by different coupling slots within the coupled waveguide are superimposed in phase, ultimately achieving a 3dB coupling degree.

[0026] like Figure 2On the common wide wall of the two-layer dielectric substrate, there are alternately arranged "T" grooves 6 and inverted "T" grooves 7.

[0027] like Figure 3 , stack two dielectric substrates together, install a standard rectangular waveguide on the dielectric substrate, and the electromagnetic wave can be coupled from the waveguide port to the substrate integrated waveguide. The T-rectangular gap intercepts the transmission current on the common wide wall, and the electromagnetic wave can be coupled to the coupling waveguide below, thereby achieving the purpose of power distribution / synthesis.

[0028] The dielectric substrate in the above solution should be a hard dielectric substrate such as Rogers4350, Rogers6002, etc. In addition to the metallized through holes, the three locations can also be filled with metal pillars with good conductive properties.

[0029] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

[0030] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A Ka-band double-layer substrate integrated waveguide directional coupler, characterized in that: The invention comprises two stacked dielectric substrates, each having a plurality of mounting holes on its surface for mounting a waveguide. After the two dielectric substrates are stacked, the outer surface and the surface between the dielectric substrates are clad with copper, and the wide wall portion of the outer surface is provided with mounting holes that match the mounting holes of the dielectric substrates, a docking groove for docking the waveguide ports, and a metallized through-hole that penetrates the two dielectric substrates. The wide wall between the two dielectric substrates is provided with regularly arranged coupling grooves along the direction of electromagnetic wave transmission, for coupling the electromagnetic waves of one dielectric substrate to the other.

2. The Ka-band double-layer substrate integrated waveguide directional coupler according to claim 1, characterized in that: The regularly arranged coupling grooves are T-shaped and inverted T-shaped coupling grooves arranged at equal intervals.

3. The Ka-band double-layer substrate integrated waveguide directional coupler according to claim 2, characterized in that: In the T-shaped and inverted T-shaped coupling slots, a gap is provided between the transverse coupling slot and the longitudinal coupling slot. The transverse coupling slot is equivalent to impedance, and the longitudinal coupling slot is equivalent to parallel admittance. The transverse direction is the direction of electromagnetic wave transmission, and the longitudinal direction is the direction perpendicular to the transverse direction on the plane of the dielectric substrate.

4. The Ka-band double-layer substrate integrated waveguide directional coupler according to claim 2, characterized in that: The distance between adjacent T-shaped coupling slots is one-quarter of the waveguide wavelength. The signal energies transmitted by different coupling slots in the coupling waveguide are superimposed in the same phase to achieve the preset coupling degree requirements.

5. The Ka-band double-layer substrate integrated waveguide directional coupler according to claim 1, characterized in that: The broadband impedance matching effect can be achieved by adjusting the length and width of the coupling slot.

6. The Ka-band double-layer substrate integrated waveguide directional coupler according to claim 1, characterized in that: The waveguide port is a rectangular waveguide port; the metallized through holes are located at a distance of one quarter of the waveguide wavelength from the rectangular waveguide port, and the metallized through holes are arranged in a row.

7. The Ka-band double-layer substrate integrated waveguide directional coupler according to claim 1, characterized in that: The dielectric substrate is a hard dielectric substrate, including Rogers 4350 or Rogers 6002.

8. The Ka-band double-layer substrate integrated waveguide directional coupler according to claim 1, characterized in that: The metallized through-holes are filled with conductive metal pillars.

9. The Ka-band double-layer substrate integrated waveguide directional coupler according to claim 1, characterized in that: By adjusting the position and size of the docking groove, the high-order modes excited from the waveguide port into the dielectric substrate are suppressed.

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