Stacked miniaturized broadband circulator

Abstract

The invention discloses a stacked miniaturized broadband circulator, and belongs to the technical field of microwave passive radio frequency device engineering. The problems that an existing circulator is narrow in working bandwidth, large in size, large in insertion loss and the like are solved. Through the vertical interconnection technology, the matching line circuit and the central junction circuit are designed on different layers of dielectric substrates, so that the size of the circulator is greatly reduced, and the size under the relative center frequency is only 0.14 lambda0 * 0.14 lambda0. And the metal ground is designed between the two substrates, so that the two layers of microstrip circuits share one layer of metal ground, and the structure is simplified. And according to a simulation result, the performance is very excellent, the insertion loss is kept within 1dB in a broadband, and the return loss is kept below-15dB. Compared with an existing circulator, the circulator provided by the invention effectively overcomes the technical problems of antenna receiving and transmitting integration, inter-stage isolation and the like, and has the remarkable advantages of small size, simple design scheme and excellent performance.

Description

Technical Field

[0001] The invention relates to a stacked miniaturized broadband circulator, belonging to the technical field of microwave passive radio frequency device engineering. Background Art

[0002] With the rapid development of modern communication technology and the continuous progress of domestic core components, circulators, as key components of the transceiver front end in phased array radar systems, are facing more stringent performance requirements. Existing circulators mainly include lumped element circulators, self-biased circulators, and spatiotemporal modulation circulators. Among them, integrated lumped elements have made outstanding contributions to the miniaturization design of circulators, but the working bandwidth is usually narrow. Self-biased circulators use self-biased magnetic materials. Although this can avoid the use of external bias magnets and greatly reduce the longitudinal volume of the circulator, most of these materials are still in the development stage, and the preparation process and performance are not mature enough to achieve commercialization. Circulators based on spatiotemporal modulation of electromagnetic signal propagation and without external magnetic bias, although small in size, require quite complex modulation circuits. In addition, they have high levels of insertion loss and poor linearity and can only handle low-power electromagnetic signals.

[0003] Based on this, the industry currently mainly uses the classic method of using magnets to bias ferrites and combine them with conductive metal patterns to design circulators. This classic circulator has very mature design theory and technology, and has the advantage of low insertion loss. In order to achieve impedance matching with the center junction, the classic circulator usually requires a longer matching line, which undoubtedly increases the size of the circulator. Summary of the invention

[0004] The present invention aims at the problems of narrow working bandwidth, large size, large insertion loss and the like of existing circulators, and provides a stacked miniaturized wide-band circulator.

[0005] The technical solution of the present invention:

[0006] One of the purposes of the present invention is to provide a stacked miniaturized broadband circulator, which specifically consists of an iron carrier, a lower ceramic gasket, a center junction circuit, a lower ceramic dielectric, a ferrite, a metal grounding layer, an upper ceramic dielectric, a matching line circuit, an upper ceramic gasket and a magnet stacked in sequence.

[0007] It is further defined that the upper ceramic dielectric, the metal grounding layer and the lower ceramic dielectric are all provided with metallized vias to achieve electrical connection between the matching line circuit and the center junction circuit.

[0008] It is further defined that the matching line circuit includes a central matching line and two side matching lines, the ports connected to the central matching line and the side matching lines are respectively located on opposite sides of the upper ceramic dielectric, and the central matching line is located in the middle position of the upper ceramic dielectric, and the two side matching lines are symmetrically arranged on both sides of the central matching line.

[0009] It is further defined that the central matching line and the side matching line adopt a three-section structure, the first section is connected to the port, and the first section of the central matching line and the side matching line has different lengths, the second section and the third section of the central matching line and the side matching line have the same shape and size, and the terminal of the third section is a pad of a metallized via.

[0010] It is further defined that the center junction circuit is composed of a large Y junction and a small Y junction with 120° rotational symmetry, and the large Y junction is provided with a pad of an arc matching line and a metallized via.

[0011] It is further defined that the magnet is a cylinder with a thickness of h1 and a diameter of d1, and the material is a samarium cobalt magnet with a nickel-plated surface.

[0012] It is further defined that the upper ceramic gasket has a thickness of h2, a diameter of d2, and a relative dielectric constant of 6.5.

[0013] It is further defined that the upper ceramic medium, the lower ceramic medium, the lower ceramic gasket and the iron carrier are all square plates with a side length of P, and the thicknesses are h3, h4, h5 and h6 respectively.

[0014] It is further defined that the ferrite is a disc with a radius of r4, located on the lower ceramic dielectric and not connected to the metallized via.

[0015] It is further defined that a circular hole with a radius of r3 is opened at the location of the metallized via hole of the metal grounding layer.

[0016] It is further defined that the length of the first section of the central matching line is l1 and the width is w1, the length of the second section is l2 and the width is w2, and the length of the third section is l3 and the width is w3.

[0017] It is further defined that the first segment of the edge matching line has a length of l4 and a width of w1, the second segment has a length of l2 and a width of w2, and the third segment has a length of l3 and a width of w3.

[0018] It is further defined that the large Y junction has a length of l5 and a width of l3.

[0019] It is further defined that the length of the small Y junction is ly and the width is wy.

[0020] It is further defined that the angle of the arc matching line relative to the center is α, the radius of the outer arc is r5, and the radius of the inner arc is r6.

[0021] It is further defined that the radius of the metallized via hole is r2, and the radius of the pad is r1.

[0022] It is further defined that the circulator has an operating frequency band of 2.5-6 GHz, the length and width of the circulator are 10 mm × 10 mm, the size at the relative center frequency is 0.14λ0 × 0.14λ0, specifically d1 is 7 mm, h1 is 0.5 mm, d2 is 3 mm, h2 is 0.5 mm, h3 is 0.5 mm, h4 is 0.5 mm, h5 is 0.5 mm, h6 is 0.5 mm, p is 10 mm, l1 is 2 .82mm, l2 is 4.25mm, l3 is 1.8mm, l4 is 1.63mm, w1 is 0.2mm, w2 is 0.49mm, w3 is 1.62mm, r1 is 0.4mm, r2 is 0.2mm, r3 is 0.8mm, r4 is 3.45mm, l5 is 4.37mm, ly is 3.9mm, wy is 1.4mm, r5 is 3.67mm, r6 is 2.5mm, and α is 70°.

[0023] It is further defined that the remanence Br of the magnet is 1 T, and the magnetic coercive force Hcb = 785 kA / m.

[0024] It is further defined that the relative dielectric constant of the upper ceramic gasket and the lower ceramic gasket is 6.5.

[0025] It is further defined that the matching line circuit and the center junction circuit are copper, gold, silver or platinum thin films with a thickness t of 0.005 mm.

[0026] It is further defined that the relative dielectric constant of the upper ceramic dielectric and the lower ceramic dielectric is 20.3.

[0027] It is further defined that the relative dielectric constant of the ferrite is 15.5, the saturation magnetization is 1400 gauss, and the ferromagnetic resonance linewidth is 110 Oe.

[0028] A second object of the present invention is to provide an application of the above-mentioned stacked miniaturized wideband circulator, specifically for use in the transceiver front end of a phased array radar system.

[0029] Beneficial effects:

[0030] The present invention uses vertical interconnection technology to design the matching line circuit and the center junction circuit on different layers of dielectric substrates, which greatly reduces the size of the circulator. The overall size is only 10mm×10mm, and the size at the relative center frequency is only 0.14λ0×0.14λ0. The metal ground is designed in the middle of the two substrates, so that the two layers of microstrip circuits share a layer of metal ground, simplifying the structure. And through simulation results, it can be seen that the performance is also very excellent. The insertion loss is kept within 1dB in a wide band, and the return loss is kept below -15dB. In addition, the circulator structure provided by the present invention has been configured with a bias magnet and an iron carrier, and it can be used by adding a metal packaging shell and a probe connector. Compared with existing circulators, the circulator provided by the present invention effectively overcomes the technical difficulties such as antenna reception and transmission integration and inter-stage isolation in modern mobile communication and radar communication systems, and has the significant advantages of small size, simple design and excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of the three-dimensional structure of the circulator provided by the present invention;

[0032] Figure 2 A side view of a circulator provided by the present invention;

[0033] Figure 3 is a schematic diagram of the matching line circuit;

[0034] Figure 4 It is a schematic diagram of the metal grounding layer;

[0035] Figure 5 is a schematic diagram of ferrite;

[0036] Figure 6 The schematic diagram of the central junction circuit is shown in Figure 2.

[0037] Figure 7 This is a diagram of S parameter simulation results of the circulator provided in Example 1;

[0038] In the figure, 1-magnet, 2-upper ceramic gasket, 3-matching line circuit, 3-1-central matching line, 3-2-side matching line, 4-upper ceramic dielectric, 5-metal ground layer, 6-metal via, 7-ferrite, 8-lower ceramic dielectric, 9-center junction circuit, 9-1-large Y junction, 9-2-small Y junction, 10-lower ceramic gasket, 11-iron carrier, 12-hole. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0040] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, methods and instruments used are conventional materials, reagents, methods and instruments in the art unless otherwise specified, and can be obtained through commercial channels by those skilled in the art.

[0041] Embodiment 1:

[0042] This embodiment provides a circulator operating in the 2.5-6 GHz frequency band.

[0043] like Figure 1-Figure 6 As shown, the circulator is composed of an iron carrier 11, a lower ceramic gasket 10, a center junction circuit 9, a lower ceramic dielectric 8, a ferrite 7, a metal grounding layer 5, an upper ceramic dielectric 4, a matching line circuit 3, an upper ceramic gasket 2 and a magnet 1 which are stacked in sequence.

[0044] The upper ceramic dielectric 4, the metal grounding layer 5 and the lower ceramic dielectric 8 are all provided with metallized vias 6 to realize the electrical connection between the matching line circuit 3 and the center junction circuit 9. A hole 12 with a radius of r3 is also opened around the metallized via 6 of the metal grounding layer 5, in order to enable the signal to be well transmitted between layers. In addition, the metal grounding layer 5 is shared by the matching line circuit 3 and the center junction circuit 9, that is, a very simple structure is used to vertically interconnect the circuits, greatly reducing the size of the device.

[0045] The matching line circuit 3 includes a central matching line 3-1 and two side matching lines 3-2. The ports connected to the central matching line 3-1 and the side matching line 3-2 are respectively located on opposite sides of the upper ceramic dielectric 4, and the central matching line 3-1 is located in the middle of the upper ceramic dielectric 4. The two side matching lines 3-2 are symmetrically arranged on both sides of the central matching line 3-1. The central matching line 3-1 and the side matching line 3-2 adopt a three-section structure, the first section is connected to the port, and the first section of the central matching line 3-1 and the side matching line 3-2 has different lengths, the second section and the third section of the central matching line 3-1 and the side matching line 3-2 have the same shape and size, and the terminal of the third section is the pad of the metallized via 6. The first segment of the central matching line 3-1 has a length of l1 and a width of w1, a length of l2 and a width of w2, and a length of l3 and a width of w3. The first segment of the edge matching line 3-2 has a length of l4 and a width of w1, a length of l2 and a width of w2, and a length of l3 and a width of w3.

[0046] The center junction circuit 9 is composed of a large Y junction 9-1 and a small Y junction 9-2 with 120° rotational symmetry, and the large Y junction 9-1 is provided with a pad for an arc matching line and a metallized via 6, and the arc matching line further compensates the reactance in the junction of the circulator. The large Y junction 9-1 has a length of l5 and a width of l3; the small Y junction 9-2 has a length of ly and a width of wy, which can play a role in reactance compensation. The angle of the arc matching line relative to the center is α, the outer arc radius is r5, and the inner arc radius is r6. The radius of the metallized via 6 is r2, and the radius of the pad is r1.

[0047] The matching line circuit 3 and the center junction circuit 9 are both made of a copper film with a thickness t of 0.005 mm. Other good conductors such as gold, silver, platinum, etc. may also be used.

[0048] The magnet 1 is a cylinder with a thickness of h1 and a diameter of d1. The material is a samarium cobalt magnet with a nickel-plated surface. The remanence Br is 1T and the magnetic coercive force Hcb=785kA / m. It is used to generate a static magnetic field and magnetize the ferrite 7 to make the magnetization of the ferrite 7 more uniform. Other magnetic materials can also be used, but the thickness of the upper ceramic gasket 2 needs to be adjusted accordingly to ensure that the ferrite 7 is saturated and magnetized.

[0049] The upper ceramic gasket 2 has a thickness of h2, a diameter of d2, and a relative dielectric constant of 6.5, and is used to support the magnet 1 to prevent short circuit caused by contact with the circuit.

[0050] The upper ceramic medium 4, the lower ceramic medium 8, the lower ceramic gasket 10 and the iron carrier 11 are all square plates with a side length of P, and the thicknesses are h3, h4, h5 and h6 respectively. The relative dielectric constants of the upper ceramic medium 4 and the lower ceramic medium 10 are consistent and are both 20.3. The relative dielectric constant of the lower ceramic gasket 10 is 6.5, which is used to isolate the center junction circuit 9 from the iron carrier 11 at the bottom to prevent short circuit. The thickness of the iron carrier 11 is h1, which is used to improve the magnetic circuit and make the ferrite magnetization more uniform.

[0051] The ferrite 7 is a disc with a radius of r4, located on the lower ceramic medium 8 and not connected to the metallized via 6. Its relative dielectric constant is 15.5, saturation magnetization intensity is 1400 gauss, and ferromagnetic resonance line width is 110 Oe.

[0052] The structural parameters of the above circulator are set as follows:

[0053] d1=7、h1=0.5、d2=3、h2=0.5、h3=0.5、h4=0.5、h5=0.5、h6=0.5、p=10、l1=2.82、l2=4.25、l3=1.8、l4=1.63、w1=0.2、w2=0.49、w3=1.62、r1=0.4、r2=0.2、r3=0.8、r4=3.45、l5=4.37、ly=3.9、wy=1.4、r5=3.67、r6=2.5、α=70°(unit is mm). The overall size of the circulator is only 10mm×10mm, and the size at the relative center frequency is only 0.14λ0×0.14λ0.

[0054] Based on the above structural parameters and material properties, the simulation results of the circulator are as follows: Figure 7 As shown. Figure 7 It can be seen that within the wide bandwidth range of 2.5-6G, the insertion loss of the circulator is kept within 1dB and the return loss is kept within -15dB. The relative working bandwidth is as high as 82%, and the performance is also very superior. The above results prove that the circulator design method proposed in this patent can bring very considerable beneficial effects.

[0055] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A stacked miniaturized broadband circulator, characterized in that: It consists of an iron carrier, a lower ceramic gasket, a center junction circuit, a lower ceramic dielectric, a ferrite, a metal grounding layer, an upper ceramic dielectric, a matching line circuit, an upper ceramic gasket and a magnet which are stacked in sequence; The upper ceramic dielectric, the metal grounding layer and the lower ceramic dielectric are all provided with metallized vias to achieve electrical connection between the matching line circuit and the center junction circuit; The matching line circuit comprises a central matching line and two side matching lines, the ports connected to the central matching line and the side matching line are respectively located on two opposite sides of the upper ceramic medium, and the central matching line is located in the middle of the upper ceramic medium, and the two side matching lines are symmetrically arranged on both sides of the central matching line; the central matching line and the side matching line adopt a three-section structure, the first section is connected to the port, and the first section of the central matching line and the side matching line has different lengths, the second section and the third section of the central matching line and the side matching line have the same shape and size, and the terminal of the third section is a pad of a metallized via; The central junction circuit is composed of a large Y junction and a small Y junction with 120° rotational symmetry, and the large Y junction is provided with a circular arc matching line and a pad of a metallized via hole.

2. The circulator according to claim 1, characterized in that: The magnet is a cylinder with a thickness of h1 and a diameter of d1. The material is samarium cobalt magnet and the surface is nickel-plated.

3. The circulator according to claim 1, characterized in that: The upper ceramic gasket has a thickness of h2, a diameter of d2, and a relative dielectric constant of 6.

5.

4. The circulator according to claim 1, characterized in that: The upper ceramic medium, the lower ceramic medium, the lower ceramic gasket and the iron carrier are all square plates with a side length of P, and the thicknesses are h3, h4, h5 and h6 respectively.

5. The circulator according to claim 1, characterized in that: The ferrite is a disc with a radius of r4, located on the lower ceramic dielectric and not connected to the metallized vias.

6. The circulator according to claim 1, characterized in that: A circular hole with a radius of r3 is opened at the location of the metallized via hole of the metal grounding layer.

7. The circulator according to claim 1, characterized in that: The length of the first segment of the central matching line is l1, the width is w1, the length of the second segment is l2, the width is w2, and the length of the third segment is l3, the width is w3; the length of the first segment of the edge matching line is l4, the width is w1, the length of the second segment is l2, the width is w2, and the length of the third segment is l3, the width is w3.

8. The circulator according to claim 1, characterized in that: The length of the large Y knot is l5 and the width is l3; the length of the small Y knot is ly and the width is wy; the angle of the arc matching line relative to the center is α, the outer arc radius is r5, and the inner arc radius is r6.

9. The circulator according to claim 1, characterized in that: The radius of the metalized via is r2, and the radius of the pad is r1.

10. Application of the stacked miniaturized broadband circulator according to any one of claims 1 to 9, characterized in that: Used in the transceiver front end of phased array radar system.

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