Millimeter wave packaged antenna array

Abstract

The present invention discloses a millimeter wave packaged antenna array in the field of antennas, including a bare chip pin structure, a printed circuit board, a waveguide transmission line structure and a rectangular horn antenna array, wherein the rectangular horn antenna array is located directly above the bare chip, and an extended transmission line connecting the bare chip pin structure and the waveguide transmission line structure is provided on the printed circuit board, wherein the extended transmission line includes a coplanar waveguide CPW transmission line segment, a substrate integrated waveguide SIW transmission line segment and a rectangular waveguide transmission interface. The antenna array adopts 2P2M packaging and plastic metallization processing technology to integrate the bare chip and the antenna in an integrated manner, with a short transmission path, thus achieving higher transmission efficiency and lower power consumption; the antenna adopts Z-shaped rectangular waveguide feeding, so that the antenna is located directly above the chip, reducing the area occupied by the antenna in the package; the antenna has stable matching and radiation performance, and the integrated design of the bare chip and the antenna provides convenience for applications such as millimeter wave vehicle-mounted radar.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a millimeter wave packaged antenna array. Background Art

[0002] The transmission and reception of traditional radar sensors are usually implemented on PCB boards, but to achieve high antenna performance, high-frequency substrate materials such as Rogers' RO3003 are required, which requires an integrated design of antenna and chip, which is not conducive to the widespread application of antenna and chip. With the continuous development of millimeter wave technology, the integrated packaging of antenna and chip can reduce the size of antenna and chip, improve overall efficiency, reduce transmission loss, and especially facilitate its widespread application. In addition, since the path from chip to antenna is shorter, higher transmission efficiency and lower power consumption can be achieved. Millimeter wave antennas are limited by processing accuracy and are prone to processing errors. This invention proposes an integrated antenna array that integrates antenna and bare chip, which has stable radiation performance and engineering application value. Summary of the invention

[0003] The purpose of the present invention is to provide a millimeter wave packaged antenna array, which solves the problems of low transmission efficiency and high power consumption of traditional antennas and improves the stability of radiation performance.

[0004] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0005] A millimeter wave packaged antenna array comprises a bare chip pin structure, a printed circuit board, a waveguide transmission line structure and a rectangular horn antenna array fed by the waveguide transmission line structure, wherein the rectangular horn antenna array is located directly above the bare chip, and an extended transmission line connecting the bare chip pin structure and the waveguide transmission line structure is provided on the printed circuit board, wherein the extended transmission line comprises a coplanar waveguide CPW transmission line segment, a substrate integrated waveguide SIW transmission line segment and a rectangular waveguide transmission interface which are connected in sequence.

[0006] A further improvement is that the chip package of the printed circuit board adopts a 2P2M packaging structure, and the 2P2M packaging structure includes a first PI layer, an RDL layer, and a second PI layer arranged in sequence from top to bottom. The bare chip pin structure is located above the printed circuit board, and the bare chip pin structure is connected to the RDL layer through the metallized vias of the first PI layer. The RDL layer serves as an extended transmission line wiring layer, and the middle dielectric layer and the lower layer of the printed circuit board are the second PI layer and the bottom metal layer respectively.

[0007] A further improvement is that there are N antenna units in the rectangular horn antenna array, N is a positive integer, and the corresponding N bare chip pin structures are connected to N substrate integrated waveguide SIW transmission line segments through N coplanar waveguide CPW transmission line segments in a one-to-one correspondence, and then connected to N rectangular waveguide transmission interfaces. There are N waveguide transmission line structures, the lower part of which is connected to the rectangular waveguide transmission interface, and the upper part serves as the feeding end of the rectangular horn antenna array.

[0008] A further improvement is that the rectangular horn antenna array is composed of three-order rectangular horn antennas, and the steps of the horn antennas are gradually expanded from bottom to top, and the horn antenna apertures are alternately distributed in a zigzag shape.

[0009] A further improvement is that the waveguide transmission line structure and the rectangular horn antenna array are integrally formed using the same plastic packaging material, and both are subjected to surface metallization treatment.

[0010] A further improvement is that the waveguide transmission line structure adopts a Z-shaped structure with double right-angle bends, and transition steps are provided on the outer sides of the right-angle bends.

[0011] A further improvement is that the rectangular waveguide transmission interface is composed of a rectangular back cavity surrounded by a number of metallized vias, a rectangular radiation port located inside the rectangular back cavity and a rectangular patch located inside the rectangular radiation port, and a gap is left on the side of the rectangular back cavity close to the substrate integrated waveguide SIW transmission line segment.

[0012] The beneficial effects of the present invention are as follows: the millimeter wave packaged antenna array adopts 2P2M packaging and plastic metallization processing technology, adopts different transition designs to integrate the bare chip and the antenna, and the transmission path from the bare chip pin structure to the antenna is short, which can achieve higher transmission efficiency and lower power consumption; the antenna adopts Z-shaped rectangular waveguide feeding, and realizes two 90° conversions through two steps, so that the antenna is located directly above the bare chip, reducing the area occupied by the antenna in the package. The millimeter wave packaged antenna has stable matching and radiation performance, and the integrated design of the bare chip and the antenna provides convenience for applications such as millimeter wave vehicle-mounted radar. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 An exploded perspective view of the structure of a millimeter wave packaged antenna array;

[0014] Figure 2 A side view of a package stackup of a millimeter wave packaged antenna array;

[0015] Figure 3 It is a partial schematic diagram of the extended transmission line of the millimeter wave packaged antenna array;

[0016] Figure 4 A side view of an antenna array for a millimeter wave packaged antenna array;

[0017] Figure 5 is a standing wave diagram of four horn antennas in the structure of an embodiment of the present invention;

[0018] Figure 6 is a gain diagram of the antenna unit in the structure of an embodiment of the present invention at 76 GHz;

[0019] Figure 7 is a gain diagram of the antenna unit in the structure of an embodiment of the present invention at 78 GHz;

[0020] Figure 8 is a gain diagram of the antenna unit in the structure of an embodiment of the present invention at 80 GHz;

[0021] In the figure: 1. Bare chip pin structure; 2. Printed circuit board; 3. Waveguide transmission line structure; 4. Rectangular horn antenna array; 5. Coplanar waveguide CPW transmission line segment; 6. Substrate integrated waveguide SIW transmission line segment; 7. Rectangular waveguide transmission interface; 8. First PI layer; 9. RDL layer; 10. Second PI layer; 11. Metallized via; 12. Bottom metal layer; 13. Rectangular back cavity; 14. Rectangular radiation port; 15. Rectangular patch; 16. Transition step. DETAILED DESCRIPTION

[0022] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0023] Combination Figure 1-4 As shown, a millimeter wave packaged antenna array includes a bare chip pin structure 1, a printed circuit board 2, a waveguide transmission line structure 3 and a rectangular horn antenna array 4 fed by the waveguide transmission line structure 3, wherein the rectangular horn antenna array 4 is located directly above the bare chip, and an extended transmission line connecting the bare chip pin structure 1 and the waveguide transmission line structure 3 is provided on the printed circuit board 2, wherein the extended transmission line includes a coplanar waveguide CPW transmission line segment 5 (Coplanarwaveguide), a substrate integrated waveguide SIW transmission line segment 6 (Substrate integrated waveguide) and a rectangular waveguide transmission interface 7 which are connected in sequence.

[0024] Preferably, the chip package of the printed circuit board 2 in the present invention adopts a 2P2M packaging structure (i.e., two passivation layers and two metal layers), and the 2P2M packaging structure includes a first PI layer 8 (i.e., a dielectric insulation layer), an RDL layer 9 (i.e., a redistribution layer) and a second PI layer 10 arranged in sequence from top to bottom. The bare chip pin structure 1 is located above the printed circuit board 2, and the bare chip pin structure 1 is connected to the RDL layer 9 through the metallized vias 11 of the first PI layer 8. The RDL layer 9 serves as an extended transmission line wiring layer, and the middle dielectric layer and the lower layer of the printed circuit board 2 are the second PI layer 10 and the bottom metal layer 12, respectively.

[0025] Preferably, there are N antenna units in the rectangular horn antenna array 4 of the present invention, N is a positive integer, and the number can be increased or decreased. The corresponding N bare chip pin structures 1 are connected to N substrate integrated waveguide SIW transmission line segments 6 through N coplanar waveguide CPW transmission line segments 5, and then connected to N rectangular waveguide transmission interfaces 7. There are N waveguide transmission line structures 3, the lower part of which is connected to the rectangular waveguide transmission interface 7, and the upper part serves as the feeding end of the rectangular horn antenna array 4.

[0026] Preferably, the rectangular horn antenna array 4 in the present invention is composed of three-order rectangular horn antennas, and the steps of the horn antennas are gradually expanded from bottom to top, and the horn antenna apertures are alternately distributed in a sawtooth shape.

[0027] Preferably, the waveguide transmission line structure 3 and the rectangular horn antenna array 4 in the present invention are integrally formed using the same plastic packaging material, and both are subjected to surface metallization treatment.

[0028] Preferably, the waveguide transmission line structure 3 of the present invention adopts a Z-shaped structure with double right-angle bends, and transition steps 16 are provided on the outside of the right-angle bends. The Z-shaped structure allows the vertically propagating feeding waveguide to transition to horizontal propagation through two steps, and then to transition to vertical propagation through two steps, so that the antenna is located directly above the chip.

[0029] Preferably, the rectangular waveguide transmission interface 7 in the present invention is composed of a rectangular back cavity 13 surrounded by a plurality of metallized vias, a rectangular radiation port 14 located inside the rectangular back cavity 13, and a rectangular patch 15 located inside the rectangular radiation port 14, and a gap is left on the side of the rectangular back cavity 13 close to the substrate integrated waveguide SIW transmission line segment 6.

[0030] A specific embodiment structure is provided below:

[0031] The present embodiment provides a millimeter wave packaged antenna array operating at 73-82 GHz, including a bare chip pin structure 1, a printed circuit board 2, a waveguide transmission line structure 3 and a third-order rectangular horn antenna array 4 located above the bare chip, the extended transmission line located on the printed circuit board 2 connects the bare chip pin structure 1 and the waveguide transmission line structure 3, and the extended transmission line on the printed circuit board 2 includes a coplanar waveguide CPW transmission line segment 5, a substrate integrated waveguide SIW transmission line segment 6 and a rectangular waveguide transmission interface 7.

[0032] The antenna array has four third-order rectangular horn antenna units. Correspondingly, one end of the four coplanar waveguide CPW transmission line segments 5 is connected to four bare chip pin structures 1, and the other end is converted into a substrate integrated waveguide SIW transmission line segment 6, and then further converted into a rectangular waveguide transmission interface 7. The line width of the coplanar waveguide CPW transmission line segment 5 is 0.07mm, the gap is 0.026mm, and the width of the substrate integrated waveguide SIW transmission line 6 is 1.6mm. The waveguide transmission line structure 3 and the third-order rectangular horn antenna array 4 are integrally formed using the same plastic packaging material. The lower part of the waveguide transmission line structure 3 is connected to the rectangular waveguide transmission interface 7 located on the printed circuit board 2, and the other end is used as the feeding end of the third-order rectangular horn antenna array 4. The size of the waveguide transmission line structure 3 is 2.4mm×1.2mm. The rectangular waveguide transmission interface 7 is composed of a rectangular back cavity 13 surrounded by a plurality of metallized vias, a 1.914mm×1.073mm rectangular radiation port 14 and an inner 1.067mm×0.915mm rectangular patch 15. The rectangular back cavity 13 surrounded by metallized vias has a gap on the side close to the substrate integrated waveguide SIW transmission line segment 6.

[0033] The waveguide transmission line structure 3 is a Z-shaped rectangular band transmission structure, and a transition step 16 is provided at the right-angle turn. The transition step 16 is a second-order step, and the step heights are 0.49 mm and 0.4 mm from top to bottom. The steps of the third-order rectangular horn antenna unit are gradually enlarged from bottom to top, and the sizes are 2.4 mm × 1.2 mm, 3.4 mm × 1.8 mm, and 3.8 mm × 2.5 mm, respectively. The heights of adjacent steps are 0.5 mm, and the horn antenna mouth surface is serrated and alternately distributed. The horizontal distance between adjacent units is 4 mm, and the vertical distance is 3 mm. The waveguide transmission line structure 3 and the third-order rectangular horn antenna unit are both processed by plastic packaging materials, and the surfaces of the waveguide transmission line structure 3 and the rectangular horn antenna unit are metallized.

[0034] The millimeter wave packaged antenna array in this embodiment realizes the integration of bare chip and antenna. After simulation calculation, the standing wave of its antenna unit is as follows: Figure 5 As shown in Figure 2, within 73-82 GHz, the standing waves of the four antenna units are all less than 2; the gain diagrams of the antenna units at 76, 78, and 80 GHz are as follows: Figure 6-8As shown in sequence, the peak gains are all greater than 8.5dBi.

[0035] To summarize, the millimeter-wave packaged antenna array of the above embodiment integrates the bare chip and the antenna array in one, and the antenna array is located directly above the chip, which reduces the package area; the antenna adopts a third-order horn antenna, and the unit adopts a zigzag array; the antenna operating bandwidth reaches 73-82GHz, with stable matching and radiation performance, and the integrated design of the bare chip and the antenna provides convenience for applications such as millimeter-wave vehicle-mounted radar.

[0036] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A millimeter wave packaged antenna array, characterized in that: It includes a bare chip pin structure, a printed circuit board, a waveguide transmission line structure and a rectangular horn antenna array fed by the waveguide transmission line structure, wherein the rectangular horn antenna array is located directly above the bare chip, and an extended transmission line connecting the bare chip pin structure and the waveguide transmission line structure is provided on the printed circuit board, wherein the extended transmission line includes a coplanar waveguide CPW transmission line segment, a substrate integrated waveguide SIW transmission line segment and a rectangular waveguide transmission interface connected in sequence; The waveguide transmission line structure and the rectangular horn antenna array are integrally formed using the same plastic packaging material, and both are subjected to surface metallization treatment; The waveguide transmission line structure adopts a Z-shaped structure with double right-angle bends, and transition steps are arranged on the outer sides of the right-angle bends.

2. The millimeter wave packaged antenna array according to claim 1, characterized in that: The chip package of the printed circuit board adopts a 2P2M packaging structure, and the 2P2M packaging structure includes a first PI layer, an RDL layer, and a second PI layer arranged in sequence from top to bottom. The bare chip pin structure is located above the printed circuit board, and the bare chip pin structure is connected to the RDL layer through the metallized vias of the first PI layer. The RDL layer serves as an extended transmission line wiring layer. The middle dielectric layer and the lower layer of the printed circuit board are the second PI layer and the bottom metal layer, respectively.

3. The millimeter wave packaged antenna array according to claim 1, characterized in that: There are N antenna units in the rectangular horn antenna array, N is a positive integer, and the corresponding N bare chip pin structures are connected to N substrate integrated waveguide SIW transmission line segments through N coplanar waveguide CPW transmission line segments in a one-to-one correspondence, and then connected to N rectangular waveguide transmission interfaces. There are N waveguide transmission line structures, the lower part of which is connected to the rectangular waveguide transmission interface, and the upper part serves as the feeding end of the rectangular horn antenna array.

4. The millimeter wave packaged antenna array according to claim 1, characterized in that: The rectangular horn antenna array is composed of three-order rectangular horn antennas, and the steps of the horn antennas are gradually expanded from bottom to top, and the horn antenna surfaces are alternately distributed in a sawtooth shape.

5. The millimeter wave packaged antenna array according to claim 1, characterized in that: The rectangular waveguide transmission interface is composed of a rectangular back cavity surrounded by a plurality of metallized vias, a rectangular radiation port located inside the rectangular back cavity, and a rectangular patch located inside the rectangular radiation port. A gap is left on the side of the rectangular back cavity close to the substrate integrated waveguide SIW transmission line segment.

Images