CN217881908U

CN217881908U - Back feed structure for millimeter wave automobile radar board

Info

Publication number: CN217881908U
Application number: CN202221797384.0U
Authority: CN
Inventors: 刘冬; 胡玮
Original assignee: KUNSHAN HULI MICROELECTRONICS CO Ltd
Current assignee: KUNSHAN HULI MICROELECTRONICS CO Ltd
Priority date: 2022-07-13
Filing date: 2022-07-13
Publication date: 2022-11-22
Anticipated expiration: 2032-07-13

Abstract

The utility model discloses a back feed structure that can be used to millimeter wave car radar board of radar board feed technical field aims at solving the problem that transmission efficiency is poor when radio frequency chip and millimeter wave antenna pass through ordinary metal through-hole and connect among the prior art. It includes multilayer PCB board, distributes in millimeter wave antenna feeder and the radio frequency chip feeder of multilayer PCB board both sides, be equipped with metallization waist shape hole on the multilayer PCB board, millimeter wave antenna feeder and radio frequency chip feeder all do not contact with metallization dish face, two isolation holes have been seted up on the lateral wall in metallization waist shape hole, two the isolation hole is used for forming the perpendicular guided wave strip of metallization, the perpendicular guided wave strip of metallization is used for millimeter wave antenna feeder and radio frequency chip feeder electric connection. The utility model is used for reduce chip and millimeter wave antenna mutual interference's when connecting problem, transmission mode is stable, the impedance continuity is good, can effectively promote the work bandwidth.

Description

Back feed structure for millimeter wave automobile radar board

Technical Field

The utility model relates to a back feed structure that can be used to millimeter wave car radar board belongs to radar board antenna design technical field.

Background

In the design of the antenna of the millimeter wave automobile radar, an antenna array surface and a radio frequency chip are usually placed on the same surface together and are connected through a coplanar waveguide, a microstrip line or other types of feeder lines, in the actual use process, electromagnetic waves transmitted and received by the antenna easily interfere with the radio frequency chip, and meanwhile, the bent feeder lines can also generate radiation to influence the use of the antenna.

The radio frequency chip and the antenna array surface are respectively arranged on the upper surface and the lower surface, and the interference of the antenna with the chip can be well solved by adopting a back feed mode. At present, a back feed structure is realized by a common metallized through hole mode, the structure is mostly applied below a millimeter wave frequency band, and the working frequency of an automobile radar mainly belongs to the millimeter wave frequency band of 24GHz and 77 GHz; under a millimeter wave frequency band, the back feed structure of the metalized through hole has the defects of high insertion loss, narrow bandwidth, poor impedance continuity, parasitic inductance and capacitance generated by a hole ring and the like, and the performance of the radar antenna is influenced.

Disclosure of Invention

An object of the utility model is to overcome not enough among the prior art, provide a back feed structure that can be used to millimeter wave car radar board for reduce chip and millimeter wave antenna mutual interference's when connecting problem, transmission mode is stable, the impedance continuity is good, can effectively promote the work bandwidth.

In order to achieve the above purpose, the utility model is realized by adopting the following technical scheme:

the utility model provides a pair of back feed structure that can be used to millimeter wave car radar board, including multilayer PCB board, distribute in millimeter wave antenna feeder and the radio frequency chip feeder of multilayer PCB board both sides, the upper and lower both sides of multilayer PCB board all are equipped with the metallization quotation, set up the waist shape hole that runs through two metallization quotations on the multilayer PCB board, the waist shape hole forms metallization waist shape hole through electroplating, millimeter wave antenna feeder and radio frequency chip feeder all do not contact with the metallization quotation, two isolation holes have been seted up on the lateral wall in metallization waist shape hole, two isolation holes are used for forming the perpendicular guided wave strip of metallization, the perpendicular guided wave strip of metallization is used for millimeter wave antenna feeder and radio frequency chip feeder electric connection, two from top to bottom still be equipped with a plurality of metallization intercommunicating pore between the metallization quotation.

Specifically, the multilayer PCB is formed by pressing copper foils and dielectric slabs, the surface dielectric slab is made of Rogers RO4835 and 0.127mm in thickness, and the middle dielectric slab is made of FR4 and 1.016mm in thickness.

Specifically, the multilayer PCB is formed by pressing copper foils and dielectric slabs, the surface dielectric slab is made of Rogers RO3003 and is 0.254mm thick, and the middle dielectric slab is made of FR4 and is 1.016mm thick.

Specifically, the material of millimeter wave antenna feeder and radio frequency chip feeder is the copper foil, and thickness is 30um.

Specifically, the copper layer that the thickness is 30um is electroplated on the metallization waist shape hole, and waist shape hole length 2mm is wide 0.8mm, keep apart the hole diameter and be 0.3mm, the wide 1.6mm of metallization dish face length 2.8 mm.

Specifically, a copper layer with the thickness of 30um is electroplated on the metalized waist-shaped hole, the waist-shaped hole is 1.5mm long and 0.55mm wide, the diameter of the isolation hole is 0.3mm, and the length of the metalized disc surface is 2.3mm and the width of the metalized disc surface is 1.35mm.

Specifically, the diameter of the metallized through hole is 0.3mm, and a copper layer is electroplated.

Specifically, the metallized vertical waveguide strip is 30um thick electroplated copper, 0.64mm wide and 1.524mm high.

Specifically, the perpendicular guided wave strip of metallization is 30um thick electro-coppering, and is wide 0.3mm high 1.27mm.

Specifically, two isolation strips are formed on the millimeter wave antenna feeder line, the radio frequency chip feeder line and the two metalized disc surfaces, and the width of each isolation strip is half of the width of the corresponding millimeter wave antenna feeder line or radio frequency chip feeder line.

Compared with the prior art, the utility model discloses the beneficial effect who reaches:

1. an object of the utility model is to provide a back feed structure that can be used to millimeter wave car radar, this structure is through doing benefit to common drilling, electroplating process on PCB, constructs a section of perpendicular guided wave structure and replaces the cylindrical guided wave structure of traditional metallized through-hole, this kind of perpendicular conductive structure is similar to the stripline in the microwave transmission line, and transmission mode is stable, and the impedance continuity is good, and insertion loss is low, can reduce insertion loss about 0.35dB with traditional metallized through-hole, and the bandwidth of working increases one time simultaneously;

2. the utility model provides the structure guidance size and material selection of the radar with the working frequency below 24GHz and 77GHz respectively, and can provide good guidance suggestion for the full implementation of the technical scheme;

3. the utility model discloses a reserve the isolation bandwidth width and be half of corresponding feeder width, outwards radiate the electromagnetic wave in order to restrain the junction of perpendicular guided wave strip of metallization and feeder through forming coplanar waveguide.

Drawings

Fig. 1 is a perspective view of a PCB board feeding structure provided in an embodiment of the present invention;

fig. 2 is an enlarged view of a metallized vertical guided wave strip structure provided by an embodiment of the present invention;

fig. 3 is a schematic level diagram of a multi-layer PCB board structure provided by an embodiment of the present invention;

reference numerals: 1. a multilayer PCB board; 2. a millimeter wave antenna feed line; 3. a radio frequency chip feeder line; 4. a metallized disk surface; 5. an isolation hole; 6. semi-fillet rectangular etching windowing; 7. metallized through holes; 8. the vertical waveguide strips are metallized.

Detailed Description

The present invention will be further described with reference to the accompanying drawings. The following examples are only used to illustrate the technical solutions of the present invention more clearly, and the protection scope of the present invention is not limited thereby.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, are not to be construed as limiting the present invention. In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art through specific situations.

The embodiment is as follows:

the embodiment of the utility model provides a pair of back feed structure that can be used to millimeter wave car radar board for reduce chip and millimeter wave antenna mutual interference's when connecting problem, transmission mode is stable, the impedance continuity is good, can effectively promote the work bandwidth. In order to realize the technical scheme, the arrangement structure comprises a multilayer PCB board 1 (the structure of the multilayer PCB board 1 can be shown in figure 3, wherein L1 and L4 are connecting layers, L2 and L3 are grounding layers), a millimeter wave antenna feeder 2 and a radio frequency chip feeder 3 which are distributed on two sides of the multilayer PCB board 1 (can be shown in figure 1, the millimeter wave antenna and the radio frequency chip are respectively arranged on two sides of the multilayer PCB board 1, the interference of electromagnetic waves transmitted and received by the antenna on the radio frequency chip is avoided in the actual use process), in order to reduce the defect of the conduction of the conventional metallized through hole under the millimeter wave frequency band, metallized disk surfaces 4 are arranged on the upper side and the lower side of the multilayer PCB board, waist-shaped holes penetrating through the two metallized disk surfaces 4 are arranged on the multilayer PCB board, and the waist-shaped holes are formed into the metallized waist-shaped holes through electroplating, the millimeter wave antenna feeder 2 and the radio frequency chip feeder 3 are not arranged to contact with a metallized disc surface 4 (refer to the figure 2 for forming an isolation slot), two isolation holes 5 are arranged on one side wall of a metallized waist-shaped hole, the two isolation holes 5 are used for forming a metallized vertical guided wave strip 8, so that the metallized vertical guided wave strip 8 can be used for electrically connecting the millimeter wave antenna feeder 2 with the radio frequency chip feeder 3, the vertical conductive structure is similar to a strip line in a microwave transmission line, the transmission mode is stable, the impedance continuity is good, the insertion loss is low, compared with the traditional metallized through hole, the insertion loss can be reduced by about 0.35dB, the application prospect is good, a plurality of metallized through holes 7 are also arranged between the upper metallized disc surface 4 and the lower metallized through hole 4, the metallized through holes 7 are used for inhibiting the transmission of electromagnetic waves between dielectric layers, the arrangement positions of the metallized through holes can be referred to the figure 1, the isolation holes can be arranged at the positions close to the feeder line and the corresponding isolation holes 5 as much as possible, and the number is not limited. For the solution, it is necessary to avoid short circuit contact between the metallized vertical waveguide strip 8 and the ground plane, and for this purpose, a semicircular rectangular etched window 6 is disposed on the ground plane of the multi-layer PCB 1 for isolating the metallized vertical waveguide strip 8, and the window can be set to have a length of 0.9mm and a width of 0.135mm, and the impedance continuity of the vertical waveguide strip can also be increased. According to the invention, a vertical guided wave structure is constructed on a multilayer PCB through drilling and electroplating and serves as an interlayer transmission part of a feeder system of a radio frequency chip and an antenna, so that the transmission of millimeter wave signals on the surface layer and the bottom layer of the multilayer PCB is realized, the back feed structure can be regarded as a part of a radar feeder system, and a stable strip line approximate structure is formed by a vertical metalized strip in a kidney-shaped groove, air and a multilayer medium of the PCB; the guided wave sent by the bottom radio frequency chip can realize the feed of the top antenna through the structure with lower insertion loss when the radar is transmitted, and the guided wave can also return to the receiving port of the radio frequency chip through the structure with lower insertion loss when the radar is received in the same way.

The embodiment of the utility model provides a pair of back feed structure that can be used to millimeter wave car radar board specifically provides a constitution of PCB board under the 24GHz operating frequency, sets up multilayer PCB board 1 here and forms by copper foil and dielectric-slab suppression, and top layer dielectric-slab material is Rogers RO4835, and thickness is 0.127mm, and the intermediate level dielectric-slab material is FR4, and thickness is 1.016mm.

The embodiment of the utility model provides a pair of back feed structure that can be used to millimeter wave automobile radar board specifically provides a constitution of PCB board under 77GHz operating frequency, and here multilayer PCB board 1 is formed by copper foil and dielectric slab suppression, and top layer dielectric slab material is Rogers RO3003, and thickness is 0.254mm, and intermediate level dielectric slab material is FR4, and thickness is 1.016mm.

The embodiment of the utility model provides a pair of back feed structure that can be used to millimeter wave car radar board makes millimeter wave antenna feeder 2 and radio frequency chip feeder 3 for being convenient for stably, can set up its material and be the copper foil (accessible etching directly makes), and thickness is 30um.

The embodiment of the utility model provides a pair of back feed structure that can be used to millimeter wave car radar board specifically provides a shape structure in metallization waist shape hole under 24GHz operating frequency, and the copper layer that has thickness for 30um is plated on the metallization waist shape hole, and waist shape hole length 2mm is wide 0.8mm, and isolation hole 5 diameter is 0.3mm, and the metallization quotation 4 is long 2.8mm wide 1.6mm.

The embodiment of the utility model provides a pair of back feed structure that can be used to millimeter wave car radar board specifically provides a shape structure in metallization waist shape hole under 77GHz operating frequency, and the copper layer that has thickness for 30um is plated on the metallization waist shape hole, and waist shape hole length 1.5mm is wide 0.55mm, and 5 diameters in isolation hole are 0.3mm, and the metallization quotation 4 is long 2.3mm wide 1.35mm.

The embodiment of the utility model provides a pair of back feed structure that can be used to millimeter wave car radar board, metallization intercommunicating pore 7 is used for preventing the electromagnetic wave at the dielectric layer transmission, and metallization intercommunicating pore 7's diameter is 0.3mm, the copper plate of electroplating.

The embodiment of the utility model provides a pair of back feed structure that can be used to millimeter wave car radar board specifically provides a guide characteristic of the perpendicular guided wave strip of metallization 8 under the 24GHz operating frequency, sets up the perpendicular guided wave strip of metallization 8 and is the thick electro-coppering of 30um, wide 0.64mm, high 1.524mm.

The embodiment of the utility model provides a pair of back feed structure that can be used to millimeter wave car radar board specifically provides a guide characteristic of the perpendicular guided wave strip of metallization 8 under 77GHz operating frequency, and the perpendicular guided wave strip of metallization 8 is the thick electro-coppering of 30um, and wide 0.3mm is high 1.27mm.

The embodiment of the utility model provides a pair of back feed structure that can be used to millimeter wave car radar board, because the junction of feeder part and the perpendicular guided wave strip of metallization 8 belongs to the impedance sudden change point, outwards radiate the electromagnetic wave easily in the millimeter wave frequency channel, it is shown for this reason to refer to figure 2, it is formed with two median respectively to set up millimeter wave antenna feeder 2 and radio frequency chip feeder 3 and two metallization quotations 4, and the width that sets up the median is half of corresponding millimeter wave antenna feeder 2 or radio frequency chip feeder 3 width, feeder and quotation can form coplanar waveguide and can restrain the radiation of junction part well this moment.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be considered as the protection scope of the present invention.

Claims

1. The utility model provides a back feed structure that can be used to millimeter wave car radar board, its characterized in that includes multilayer PCB board (1), distributes in millimeter wave antenna feeder (2) and radio frequency chip feeder (3) of multilayer PCB board (1) both sides, the upper and lower both sides of multilayer PCB board (1) all are equipped with metallization quotation (4), set up the waist shape hole that runs through two metallization quotations (4) on the multilayer PCB board, the waist shape hole forms metallization waist shape hole through electroplating, millimeter wave antenna feeder (2) and radio frequency chip feeder (3) all do not contact with metallization quotation (4), two isolation hole (5), two have been seted up on the lateral wall in metallization waist shape hole keep apart hole (5) and are used for forming perpendicular guided wave strip of metallization (8), perpendicular guided wave strip of metallization (8) are used for with millimeter wave antenna feeder (2) and radio frequency chip feeder (3) electric connection, two from top to bottom still be equipped with a plurality of metallization intercommunicating pore (7) between the metallization quotation.

2. The back feed structure of claim 1, wherein the multilayer PCB board (1) is formed by pressing copper foil and dielectric board, the surface dielectric board is Rogers RO4835 and has a thickness of 0.127mm, and the middle dielectric board is FR4 and has a thickness of 1.016mm.

3. The back feed structure of claim 1, wherein the multilayer PCB board (1) is formed by pressing copper foil and dielectric board, the surface dielectric board is Rogers RO3003 and has a thickness of 0.254mm, and the middle dielectric board is FR4 and has a thickness of 1.016mm.

4. The back feed structure of millimeter wave automobile radar panel as claimed in any one of claims 1 to 3, wherein the millimeter wave antenna feeder (2) and the RF chip feeder (3) are made of copper foil with a thickness of 30 μm.

5. The back feed structure of claim 1, wherein the metalized kidney-shaped hole is plated with a copper layer with a thickness of 30um, the kidney-shaped hole has a length of 2mm and a width of 0.8mm, the diameter of the isolation hole (5) is 0.3mm, and the length of the metalized disk surface (4) is 2.8mm and a width of 1.6mm.

6. The back feed structure of claim 1, wherein the metalized kidney-shaped hole is plated with a copper layer with a thickness of 30um, the kidney-shaped hole is 1.5mm long and 0.55mm wide, the diameter of the isolation hole (5) is 0.3mm, and the length of the metalized disk surface (4) is 2.3mm and 1.35mm wide.

7. The back feed structure applicable to millimeter wave automotive radar panels as claimed in claim 1, wherein said metallized through holes (7) have a diameter of 0.3mm and are plated with copper layers.

8. The back feed structure of claim 1, wherein the metallized vertical wave guide strip (8) is 30um thick plated copper, 0.64mm wide and 1.524mm high.

9. The back feed structure of claim 1, wherein the metallized vertical waveguide strip (8) is 30um thick plated copper, 0.3mm wide and 1.27mm high.

10. The back feed structure of claim 1, wherein the millimeter wave antenna feeder (2) and the radio frequency chip feeder (3) and the two metallized disk surfaces (4) are respectively formed with two isolation strips, and the width of each isolation strip is half of the width of the corresponding millimeter wave antenna feeder (2) or radio frequency chip feeder (3).