Millimeter wave differential antenna module and isolator thereof

Abstract

The utility model provides a millimeter wave differential antenna module, an isolator thereof and a millimeter wave differential antenna module. The millimeter wave differential antenna module comprises a differential antenna unit and a gold bonding wire. The differential antenna unit comprises a half-wave dipole antenna and a reflecting plate; the reflecting plate comprises an L1-layer ground and an L2-layer ground; the L1-layer ground and the L2-layer ground are stacked and are connected through a metal via hole; the half-wave dipole antenna is arranged on the layer where the L1 layer is located; the half-wave dipole antenna and the L1 layer ground are respectively connected with the same end of the gold bonding wire; particularly, a part of the L1 layer ground extends towards a radiation branch of the half-wave dipole antenna, and / or a part of the L2 layer ground extends towards the radiation branch of the half-wave dipole antenna. According to the utility model, good impedance matching can be formed between the gold bonding wire and the antenna, and a good packaging effect is obtained; furthermore, the millimeter wave differential isolator obtained based on the method can effectively suppress common-mode interference, and has the advantages of large bandwidth, high gain and low cost.

Description

Technical Field

[0001] The utility model relates to the technical field of antennas, and in particular to a millimeter wave differential antenna module and an isolator thereof. Background Art

[0002] Among the existing isolation devices, most use optocoupler isolation, electromagnetic isolation and capacitive isolation, and a few use antenna isolation. Compared with the first three isolation methods, antenna isolation can take into account both isolation and transmission rate, and has huge advantages in high-speed isolators. Most of the existing isolation devices using antenna isolation use a single-ended structure, and the single-ended structure is prone to interference or even breakdown of the front-end RF circuit due to the existence of common mode interference (CMTI) suppression; in addition, the antennas in many millimeter wave isolation devices have a narrow bandwidth, generally only a few hundred MHz, which is difficult to meet the needs of large bandwidth transmission scenarios; in addition, in the millimeter wave frequency band, due to the large inductance of the bonding wire (Wire Bonding), the antenna design is very difficult, and a flip chip packaging solution (Flip Chip Package) is generally used, which has a high cost.

[0003] Therefore, there is an urgent need for a millimeter-wave differential isolation solution that can effectively solve the above problems so that it can be better used in isolation scenarios that require DC isolation, high and low voltage module isolation, etc., while meeting the needs of large bandwidth transmission and lower packaging costs. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a millimeter wave differential antenna module and an isolator thereof, wherein the bonding gold wire and the antenna can form a good impedance match and obtain a good packaging effect.

[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0006] A millimeter wave differential antenna module, comprising: a differential antenna unit and a bonded gold wire; the differential antenna unit comprises a half-wave dipole antenna and a reflector; the reflector comprises an L1 layer ground and an L2 layer ground; the L1 layer ground and the L2 layer ground are stacked and connected through metal vias; the half-wave dipole antenna is arranged at the layer where the L1 layer ground is located; the half-wave dipole antenna and the L1 layer ground are respectively connected to the same end of the bonded gold wire;

[0007] A portion of the L1 layer ground extends toward the radiation branch of the half-wave dipole antenna, and / or a portion of the L2 layer ground extends toward the radiation branch of the half-wave dipole antenna.

[0008] Optionally, the L1 layer ground includes a left L1 layer ground and a right L1 layer ground which are spaced apart from each other; and the half-wave dipole antenna is disposed between the left L1 layer ground and the right L1 layer ground.

[0009] Optionally, part of the left L1 layer ground extends toward the radiating branch of the half-wave dipole antenna to form an L1 layer left extension arm, and / or part of the right L1 layer ground extends toward the radiating branch of the half-wave dipole antenna to form an L1 layer right extension arm.

[0010] Optionally, the L1 layer left extension arm and the L1 layer right extension arm are both spaced apart from the radiation branch by a preset distance.

[0011] Optionally, the half-wave dipole antenna includes a left array antenna and a right array antenna that are axially symmetrically arranged; the left array antenna is in an inverted L shape, and includes a feeding branch and a radiating branch; the feeding end of the feeding branch is connected to the bonding gold wire, and the other end is connected to the radiating branch; the feeding branches of the left array antenna and the right array antenna are arranged close to each other.

[0012] Optionally, the left L1 layer ground and the right L1 layer ground are both L-shaped; the left extension arm of the L1 layer corresponds to the radiating branch of the left array antenna and is far away from the feeding branch of the left array antenna; the right extension arm of the L1 layer corresponds to the radiating branch of the right array antenna and is far away from the feeding branch of the right array antenna.

[0013] Optionally, two sides of the L2 layer ground respectively extend toward the radiation branch of the left array antenna and the radiation branch of the right array antenna to form an L2 layer left extension arm and an L2 layer right extension arm.

[0014] Optionally, the L2 layer left extension arm and the L2 layer right extension arm are respectively spaced apart from their corresponding radiation branches by a preset distance, or the L2 layer left extension arm and the L2 layer right extension arm both exceed their corresponding radiation branches.

[0015] Optionally, the vertical height between one end of the bonding gold wire connected to the half-wave dipole antenna and the L1 layer ground and the L1 layer ground is Hum, where the value range of H is 100um-200um.

[0016] Another technical solution provided by the utility model is:

[0017] A millimeter wave differential isolator, comprising two millimeter wave differential antenna modules as described above, and two radio frequency chips; the two millimeter wave differential antenna modules are connected based on millimeter wave wireless communication to form an isolation zone; the other ends of the bonding gold wires in the two millimeter wave differential antennas are respectively connected to a radio frequency chip;

[0018] The two millimeter wave differential antenna modules and the two radio frequency chips are packaged as one.

[0019] The beneficial effect of the utility model is that for the millimeter wave antenna packaged with bonded gold wires, by extending the L1 layer ground and / or L2 layer ground part as the reflector toward the radiation branch direction of the antenna to strengthen the coupling between the antenna and the ground, the overall capacitance of the antenna and the bonded gold wire is greatly reduced, so that the Smith chart of the antenna module can only converge to the center position, the radiation characteristics of the antenna are significantly improved, the antenna gain is increased, and the return loss is reduced. In this way, the problem of poor impedance matching between the antenna and the bonded gold wire is solved, and a good packaging effect of the antenna and the bonded gold wire in the millimeter wave differential antenna module is achieved; further, the millimeter wave differential isolator obtained based on this can play its role in effectively suppressing common mode interference, and has the advantages of large bandwidth, high gain and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the structure of an antenna module encapsulated by bonding gold wire in the prior art;

[0021] Figure 2 Schematic diagram of the equivalent circuit model of gold wire bonding in the millimeter wave frequency band;

[0022] Figure 3 To adopt Figure 1 Smith chart of the antenna module of the structure;

[0023] Figure 4 To adopt Figure 1 Return loss curve of the antenna module of the structure;

[0024] Figure 5 To adopt Figure 1 Surface current distribution diagram of antenna in the antenna module of the structure;

[0025] Figure 6 A millimeter wave differential antenna module structure and a surface current distribution diagram of the antenna therein provided in an embodiment of the utility model;

[0026] Figure 7 A schematic diagram of the structure of a millimeter wave differential antenna module provided by an embodiment of the utility model in which only the L1 layer is lengthened;

[0027] Figure 8 To adopt Figure 6 Smith chart of antennas in the antenna module of the structure;

[0028] Fig. 9 A schematic diagram of the structure of the millimeter wave differential antenna module provided by the embodiment of the utility model in which only the L2 layer is lengthened;

[0029] Fig.10 A schematic diagram of the structure of the millimeter wave differential antenna module provided in an embodiment of the present utility model in which the L1 layer ground and the L2 layer ground are lengthened at the same time;

[0030] Fig.11 To adopt Fig.10 Smith chart of antennas in the antenna module of the structure;

[0031] Fig.12 To adopt Fig.10 Antenna patterns of antennas in antenna modules of the structure;

[0032] Fig.13 To adopt Fig.10 Antenna gain diagram of the antenna in the antenna module of the structure;

[0033] Fig.14 To adopt Fig.10 Return loss curve of the antenna in the antenna module of the structure;

[0034] Fig.15 It is a schematic structural diagram of a differential antenna unit in a millimeter wave differential antenna module in the prior art;

[0035] Fig.16 A schematic diagram of the height H of the bonding gold wire after packaging in the millimeter wave differential antenna module provided in the third embodiment of the present utility model;

[0036] Fig.17 The antenna gain diagram of the middle antenna of the millimeter wave differential antenna module provided in the third embodiment of the present utility model;

[0037] Fig.18 A schematic diagram of the structure of a millimeter wave differential isolator provided in Embodiment 4 of the present utility model;

[0038] Fig.19 for Fig.18 Return loss curve of the antenna in the antenna module of the structure;

[0039] Fig. 20 for Fig.18 Antenna gain diagram of the antenna in the antenna module of the structure;

[0040] Fig.21 for Fig.18 The E-plane and H-plane radiation patterns of the antenna in the antenna module of the structure.

[0041] Description of labels:

[0042] 10. Millimeter wave differential antenna module; 1. Differential antenna unit; 2. Bonding gold wire;

[0043] 11. Feeding point; 12. Half-wave dipole antenna; 13. Reflector; 14. Metal via;

[0044] 120, feeding branch; 121, radiating branch; 122, left array antenna; 123, right array antenna;

[0045] L1, L1 layer ground;

[0046] L1-L, left L1 floor; L1-R, right L1 floor;

[0047] 1-L, left extension arm of L1 layer; 1-R, right extension arm of L1 layer;

[0048] L2, L2 layer ground;

[0049] 2-L, left extension arm of L2 layer; 2-R, right extension arm of L2 layer. DETAILED DESCRIPTION

[0050] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in conjunction with the implementation modes and the accompanying drawings.

[0051] The differential antenna solution of the millimeter wave isolator can effectively suppress common mode interference, and has the advantages of high transmission rate, large bandwidth, extremely high anti-puncture performance, high gain and low cost. However, the differential antenna module in the existing millimeter wave antenna will be packaged in a flip chip manner if it is convenient for antenna design. The flip chip packaging method is to feed the antenna differentially directly or through a microstrip line, and then complete the antenna design by adjusting the antenna's length, width and other dimensional parameters. If the bonding wire packaging method is used for cost reduction, such as Figure 1 As shown in FIG. 1 , an antenna module encapsulated with bonding gold wires in the prior art is used. It is necessary to consider that in the millimeter wave frequency band, the equivalent model of the bonding gold wires is as follows: Figure 2 As shown in the figure, it is composed of an inductor and two capacitors in parallel. Among them, the inductance component is the main component, and as the frequency increases, the inductance value increases; especially in the millimeter wave frequency band, its inductance value will be even greater. Therefore, if no matching measures are taken, and it is simply connected through the bonding gold wire, the impedance matching effect between the antenna and the bonding gold wire will be poor due to its own large capacitance, the overall capacitance will be biased, and the Smith chart will deviate from the center (such as Figure 3 As shown), the return loss value is high (as shown Figure 4 At the same time, by analyzing the surface current of the antenna ( Figure 5 ) It can be seen that the current flow of the antenna is chaotic and does not conform to the current distribution of a half-wave dipole.

[0052] Therefore, for the millimeter-wave isolator solution using a differential antenna packaged with bonding gold wires, how to make the antenna and the bonding gold wires form an inductor-capacitor resonance within the working frequency band and achieve good impedance matching is a technical difficulty to be overcome in this case.

[0053] Embodiment 1

[0054] Please refer to Figures 6 to 15 This embodiment provides a millimeter wave differential antenna module, such as Figure 6 As shown, it includes a differential antenna unit 1 and a bonding gold wire 2; the feeding point 11 of the differential antenna unit 1 is connected to other components through the bonding gold wire 2.

[0055] The differential antenna unit 1 includes a half-wave dipole antenna 12 and a reflector 13; the reflector 13 includes an L1 layer ground and an L2 layer ground; the L1 layer ground and the L2 layer ground are stacked up and down, and the two are connected through a metal via 14; the half-wave dipole antenna 12 is arranged at the level where the L1 layer ground is located; the half-wave dipole antenna 12 and the L1 layer ground are respectively connected to the same end of the bonding gold wire 2;

[0056] In particular, a portion of the L1 layer ground extends toward the radiation branch 121 of the half-wave dipole antenna 12 , and / or a portion of the L2 layer ground extends toward the radiation branch 121 of the half-wave dipole antenna 12 .

[0057] Specifically, if Figure 7 As shown, the L1 layer ground portion can be optionally extended toward the radiation branch 121 of the half-wave dipole antenna 12 to shorten the distance between the radiation branch of the antenna and the ground by lengthening the L1 layer ground, thereby strengthening the coupling between the antenna and the ground and solving the impedance mismatch problem. Figure 6 As shown, due to the strong coupling between the half-wave dipole antenna 12 and the L1 layer ground, the current distribution on the antenna surface can be made to conform to the current distribution of the half-wave dipole; Figure 8 As shown, compared with the antenna before optimization, by lengthening the L1 layer ground, the overall capacitance of the antenna and the bonding gold wire will be greatly reduced, so that the Smith chart of the antenna module packaged with the bonding gold wire reaches near the center position.

[0058] like Fig. 9 As shown, it is also possible to optionally extend part of the L2 layer ground toward the radiating branch 121 of the half-wave dipole antenna 12 so as to shorten the distance between the radiating branch of the antenna and the ground by lengthening the L2 layer ground, thereby strengthening the coupling between the antenna and the ground and solving the impedance mismatch problem.

[0059] like Fig.10As shown, it is also possible to extend the L1 layer ground portion toward the radiation branch 121 of the half-wave dipole antenna 12, and extend the L2 layer ground portion toward the radiation branch 121 of the half-wave dipole antenna 12, so as to make the distance between the radiation branch of the antenna and the ground closer, and make the coupling between the antenna and the ground stronger, thereby solving the impedance mismatch problem. Compared with only lengthening the L1 layer ground or only lengthening the L2 layer ground, lengthening the L1 layer ground and the L2 layer ground at the same time, as shown in FIG. Fig.11 As shown in , the millimeter wave differential antenna can be made to converge more closely to the center of the Smith chart. Fig.12 and Fig.13 As shown in the figure, the solid line corresponds to the lengthening of both the L1 layer and the L2 layer, and the dotted line corresponds to the lengthening of only the L1 layer. It can be seen that the component of the optimized antenna radiating backward will be reduced, that is, the antenna's day-to-night ratio is also improved, and the antenna gain will be further improved; at the same time, Fig.14 As shown, the solid line corresponds to the lengthening of both the L1 layer and the L2 layer, the long dotted line corresponds to the lengthening of only the L1 layer, and the short dotted line corresponds to the lengthening before optimization. It can be seen that for the return loss, the antenna after optimization (whether only the L1 layer is lengthened or both the L1 layer and the L2 layer are lengthened) can reach below -10dB.

[0060] like Fig.15 As shown, it is a schematic diagram of the differential antenna unit structure in the millimeter wave differential antenna module in the prior art. It can be seen that the upper and lower layers of the ground that are stacked to form the reflector 13 are both long strips and are almost parallel to the radiation branch 121 of the half-wave dipole 12; at the same time, there is a large amount of space between the upper and lower layers of the reflector 13 and the antenna radiation branch 121, that is, from the perspective of the antenna radiation direction, the upper and lower layers of the reflector 13 are far away from the antenna radiation branch 121, and the distance between the two is relatively far.

[0061] In this embodiment, the coupling between the antenna and the ground is strengthened so that the coupling between the half-wave dipole antenna and the ground is strengthened. In this way, the surface current distribution of the antenna conforms to the current distribution of the half-wave dipole; at the same time, the overall capacitance of the antenna and the bonded gold wire can be greatly reduced; and the Smith chart of the antenna module using the bonded gold wire packaging method can be made to reach near the center position. In this way, the differential antenna unit and the bonded gold wire of this embodiment will form a good inductance-capacitance resonance within the working frequency band, complete good impedance matching, and effectively improve the antenna characteristics; thereby solving a series of problems caused by the poor impedance matching effect between the antenna and the bonded gold wire in the millimeter-wave differential antenna module using the bonded gold wire packaging method in the prior art, such as large overall partial capacitance, poor antenna radiation performance, and high return loss.

[0062] In some specific implementations of this embodiment, Figure 7 or Fig.10As shown, the L1 layer ground specifically includes a left L1 layer ground L1-L and a right L1 layer ground L1-R which are set at a distance; the half-wave dipole antenna 12 is set between the left L1 layer ground L1-L and the right L1 layer ground L1-R.

[0063] Specifically, when the length of the L1 layer is lengthened, that is, the portion of the L1 layer is extended toward the radiation branch 121 of the half-wave dipole antenna 12. Figure 7 As shown, part of the left L1 layer ground L1-L may be optionally extended toward the radiating branch 121 of the half-wave dipole antenna 12 to form the L1 layer left extension arm 1-L, or part of the right L1 layer ground L1-R may be extended toward the radiating branch 121 of the half-wave dipole antenna 12 to form the L1 layer right extension arm 1-R, or part of the left L1 layer ground L1-L may be extended toward the radiating branch 121 of the half-wave dipole antenna 12 to form the L1 layer left extension arm 1-L, and part of the right L1 layer ground L1-R may be extended toward the radiating branch 121 of the half-wave dipole antenna 12 to form the L1 layer right extension arm 1-R.

[0064] Here, the L1 layer is extended to a position where the radiation branch of the half-wave dipole antenna is spaced a preset distance apart. Figure 7 As shown, neither the left extension arm 1-L of the L1 layer nor the right extension arm 1-R of the L1 layer formed by lengthening and extending the L1 layer ground touches the radiation branch 121, that is, does not form a physical connection with the radiation branch 121, but is as close to the radiation branch 121 as possible. In this way, the coupling between the antenna and the ground is enhanced without affecting the performance of the antenna.

[0065] In some other specific implementations of this embodiment, Fig. 9 As shown, the L2 layer ground located at the bottom layer strengthens the ground coupling with the antenna by extending from its two sides respectively toward the radiation branch 121 of the half-wave dipole antenna 12 to form an L2 layer left extension arm 2-L and an L2 layer right extension arm 2-R.

[0066] Compared with the long strip L2 layer structure in the prior art, the L2 layer structure in the above specific embodiment is as follows: Fig. 9 As shown, it is designed into a "concave" shape, and the L2 layer left extension arm 2-L and the L2 layer right extension arm 2-R located on both sides thereof are as close to the antenna radiation branch 121 as possible to strengthen the ground coupling relationship between the two.

[0067] In the above specific implementation, since the L2 layer ground and the half-wave dipole antenna are not in the same layer, there is no need to worry that the extension arm of the L2 layer ground will form a physical connection with the antenna and affect the antenna performance. Therefore, the L2 layer left extension arm and the L2 layer right extension arm can be set at a preset distance from the radiation branch, or can extend beyond the radiation branch.

[0068] As a preferred example, Fig. 9 As shown, from a top perspective, the L2 layer left extension arm 2-L and the L2 layer right extension arm 2-R of the L2 layer ground both exceed the radiation branch 121 of the half-wave dipole antenna 12. In other words, there is an overlap between the L2 layer left extension arm 2-L and the L2 layer right extension arm 2-R of the L2 layer ground and the radiation branch 121 of the antenna located at the same level as the L1 layer ground.

[0069] In some other specific implementations of this embodiment, Figure 7 , Fig. 9 or Fig.10 As shown, the half-wave dipole antenna 12 is in a butterfly-wing shape as a whole, and specifically includes a left-element antenna 122 and a right-element antenna 123 that are axially symmetrically arranged; the left-element antenna 122 and the right-element antenna 123 are both in an inverted L shape, and each includes a feeding branch 120 and a radiating branch 121; the feeding end of the feeding branch is connected to one end of the bonding gold wire, and the other end of the feeding branch 120 is connected to one end of the radiating branch 121; the other end of the radiating branch 121 is suspended; the feeding branches 120 of the left-element antenna 122 and the right-element antenna 123 are arranged close to each other, that is, the suspended ends of the radiating branches 121 of the two are far away from each other.

[0070] As a preferred specific example of the above specific implementation, Figure 7 As shown, the left L1 layer L1-L and the right L1 layer L1-R of the L1 layer ground are both L-shaped; the left extension arm 1-L of the L1 layer corresponds to the radiation branch 121 of the left array antenna 122, and is far away from the feeding branch 120 of the left array antenna 122. In other words, the L-shaped left extension arm 1-L of the L1 layer and the L-shaped left array antenna 122 are arranged in a "mouth" shape. Correspondingly, the right extension arm 1-R of the L1 layer corresponds to the radiation branch 121 of the right array antenna 123, and is far away from the feeding branch 120 of the right array antenna 123. In other words, the L-shaped right extension arm 1-R of the L1 layer and the L-shaped right array antenna 123 are arranged in a "mouth" shape.

[0071] As another preferred specific example of the above specific implementation mode, Fig. 9 As shown, one side of the L2 layer ground extends toward the radiation branch 121 of the left array antenna 122 to form the L2 layer left extension arm 2-L; the other side opposite thereto extends toward the radiation branch 121 of the right array antenna 123 to form the L2 layer right extension arm 2-R. Here, the L2 layer ground is in a "concave" shape as a whole. Fig.10As shown, when the ground on the L1 layer is lengthened, the L2 layer left extension arm 2-L and the L2 layer right extension arm 2-R formed by the extension of the L2 layer ground respectively correspond to the L1 layer left extension arm 1-L and the L1 layer right extension arm 1-R of the L1 layer ground. Preferably, the arm widths of the L2 layer left extension arm 2-L and the L2 layer right extension arm 2-R are greater than those of the L1 layer left extension arm 1-L and the L1 layer right extension arm 1-R.

[0072] The millimeter-wave differential antenna module encapsulated with gold wire bonding provided in this embodiment, from the perspective of the antenna, on the premise that the overall area of the module remains unchanged, by increasing the size of the ground, strengthens the coupling relationship between the antenna and the ground, can greatly reduce the overall parasitic capacitance of the antenna module after encapsulation, and at the same time improves the radiation characteristics of the antenna, achieving a good encapsulation effect between the antenna and the gold wire bonding, thus solving the problem of poor impedance matching between the gold wire bonding and the antenna after encapsulation.

[0073] Embodiment 2

[0074] Please refer to Figures 10 to 14 , based on Embodiment 1, this embodiment provides a specific structure of a millimeter-wave differential antenna module, which can obtain the best impedance matching effect between the gold wire bonding and the antenna after encapsulation.

[0075] As Fig.10 shown, the millimeter-wave differential antenna module provided in this embodiment includes: a differential antenna unit 1 and a gold wire bonding 2; the differential antenna unit 1 includes a half-wave dipole antenna 12 and a reflector 13; the half-wave dipole antenna 12 is in the shape of "儿", and specifically includes a left dipole antenna 122 and a right dipole antenna 123 arranged axially symmetrically; both the left dipole antenna 122 and the right dipole antenna 123 are in an inverted L shape, and both include a feeding branch 120 and a radiation branch 121; the feeding end of the feeding branch 120 is connected to one end of the gold wire bonding 2, and the other end is connected to one end of the radiation branch 121, and the other end of the radiation branch 121 is suspended; the feeding branches 121 of the left dipole antenna 122 and the right dipole antenna 123 are arranged close to each other, while the suspended ends of the radiation branches 121 are far from each other. The reflector 13 includes an L1 layer ground and an L2 layer ground; the L1 layer ground and the L2 layer ground are stacked and connected through a metal via 14; the L1 layer ground includes a left L1 layer ground L1-L and a right L1 layer ground L1-R arranged at an interval; the half-wave dipole antenna 12 is arranged on the layer where the L1 layer ground is located; and is arranged between the left L1 layer ground L1-L and the right L1 layer ground L1-R; the L1 layer ground is connected to the same end of the gold wire bonding 2 that connects the half-wave dipole antenna 12.

[0076] Specifically, the left L1 ground layer L1-L and the right L1 ground layer L1-R in the L1 layer are both L-shaped; the left L1 ground layer L1-L in the L1 layer and the left dipole antenna 122 form a "square" shape; the right L1 ground layer L1-R in the L1 layer and the right dipole antenna 123 form a "square" shape. In particular, there is no physical connection between the left L1 ground layer L1-L and the left dipole antenna 122; at the same time, there is also no physical connection between the right L1 ground layer L1-R in the L1 layer and the right dipole antenna 123.

[0077] The L2 ground layer is "concave" in shape, and the extension arms on both sides thereof respectively correspond to the radiation branches 121 of the right dipole antenna 123 and the radiation branches 121 of the left dipole antenna 122. From the perspective of top-down perspective, the L1 ground layer is completely placed within the "range" of the L2 ground layer. At the same time, the extension arms on both sides of the L2 ground layer respectively have a spatial "overlap" with the corresponding radiation branches 121 of the right dipole antenna 123 and the left dipole antenna 122.

[0078] In the millimeter-wave differential antenna module provided in this embodiment, the L1 ground layer and the L2 ground layer serving as the reflector in the differential antenna unit are both lengthened at the same time, which will enable the coupling relationship between the antenna and the ground to reach the strongest. As Fig.11 shown, where the solid line corresponds to both the L1 ground layer and the L2 ground layer being lengthened, and the dashed line corresponds to only the L1 ground layer being lengthened. It can be seen that the optimized structure will enable the millimeter-wave differential antenna to converge more towards the center of the Smith chart; as Fig.12 and Fig.13 shown, where the solid line corresponds to both the L1 ground layer and the L2 ground layer being lengthened, and the dashed line corresponds to only the L1 ground layer being lengthened. It can be seen that the component of the antenna radiating backward in the optimized structure will be reduced, that is, the front-to-back ratio of the antenna is also improved, and the antenna gain will be further increased; at the same time, as Fig.14 shown, where the solid line corresponds to both the L1 ground layer and the L2 ground layer being lengthened, and the dashed line corresponds to only the L1 ground layer being lengthened. It can be seen that for the optimized antenna structure, the return loss will also reach below -10 dB.

[0079] Embodiment 3

[0080] Please refer to Fig.16 . This embodiment is a further expansion based on Embodiment 1 or Embodiment 2. This embodiment will further optimize the millimeter-wave differential antenna module encapsulated with gold wire bonding from the perspective of gold wire bonding.

[0081] As Fig.16As shown, in this embodiment, the millimeter wave differential antenna module based on the first or second embodiment is packaged, and the end 21 of the bonding gold wire 2 connected to the half-wave dipole antenna in the differential antenna unit 1 and the L1 layer ground has a vertical height of Hum with the L1 layer ground, and the value range of Hum is 100um-200um. In other words, the vertical distance H needs to be maintained between the end 21 of the bonding gold wire 2 and the level where the L1 layer ground is located.

[0082] For the bonding gold wire, when it is packaged together with the differential antenna unit, in the millimeter wave frequency band, the change in its length will not only affect the operating frequency of the antenna, but the height between it and the differential antenna unit will also have a relatively large impact on the characteristics of the antenna.

[0083] The longer the length of the bonding gold wire, the greater the loss on the wire. Therefore, in actual design, the length of the bonding gold wire is generally required to be as short as possible. In this embodiment, the length of the bonding gold wire connecting the millimeter-wave differential antenna module and the RF chip after packaging is set to be approximately 1 / 4 wavelength (in this case, the wavelength corresponds to the wavelength of the center frequency of 60GHz), which will be more conducive to impedance matching between the bonding gold wire and the antenna and reduce power reflection. Taking into account the process and errors in actual production, the length of the bonding gold wire is preferably in the range of 0.2λ to 0.3λ.

[0084] After the length of the bonding wire is fixed, the height H (such as Fig.16 As shown in the figure, the height H becomes the most important factor affecting the antenna characteristics. If the height H is too low, the bonding wire is difficult to connect; if the height H is too high, it is easy to deform and break during the packaging process. At the same time, from a technical point of view, the higher the height H of the bonding wire, the larger the reflector area, which is more conducive to improving the antenna gain. Fig.17 As shown in the figure, the horizontal axis is the working frequency band, and the vertical axis is the antenna gain; for the height H of the bonding gold wire, the solid line in the figure corresponds to H = 200um, the short dotted line corresponds to H = 150um, and the long dotted line corresponds to H = 100um. It can be seen from the figure that as H increases within the working frequency band, the antenna gain becomes higher. Therefore, during the packaging process, for the bonding gold wire of the selected length (the length is in the range of 0.2λ to 0.3λ), selecting the maximum allowable height will be able to maximize the characteristics of the middle antenna of the millimeter-wave differential antenna module from the perspective of the bonding gold wire. Specifically, the height H of the bonding gold wire in the millimeter-wave differential antenna module provided in this embodiment is controlled in the range of 100um to 200um, preferably 200um.

[0085] In this embodiment, regarding the issue of bonding gold wire and antenna packaging, from the perspective of the bonding gold wire, the wire length is within the range of 0.2λ to 0.3λ, and the optimal optional range of bonding gold wire height H that allows processing is selected, so as to reduce the overall loss and power reflection after packaging, and at the same time achieve the effect of improving the antenna gain.

[0086] Embodiment 4

[0087] See also Fig.18 This embodiment is based on any one of embodiments one to three, and provides a millimeter-wave differential isolator, which includes two millimeter-wave differential antenna modules as described in any one of embodiments one to three, and two radio frequency chips; the two millimeter-wave differential antenna modules are connected based on millimeter-wave wireless communication to form an isolation zone; the other ends of the bonding gold wires in the two millimeter-wave differential antennas are respectively connected to a radio frequency chip; the two millimeter-wave differential antenna modules and the two radio frequency chips are packaged as one.

[0088] In some specific implementations of this embodiment, the antennas in two millimeter-wave differential antenna modules are symmetrically arranged with the center line as the axis, and there is an isolation band with a width of 2 mm between the two antennas to physically isolate the two millimeter-wave differential antenna modules and ensure good isolation characteristics.

[0089] In some specific implementations of this embodiment, the antennas in the two millimeter-wave differential antenna modules are in the form of differential antennas. Compared with traditional single-ended fed antennas, differentially fed antennas can effectively suppress common-mode interference.

[0090] The working bandwidth of the conventional isolator is generally only tens of MHz or hundreds of MHz, while the millimeter wave differential isolator of this embodiment has Fig.19 and Fig. 20 The horizontal axis of the curve shows that the antenna works in the frequency band of 58-62 GHz and has a bandwidth of 4 GHz, which has the advantage of large bandwidth. Fig. 20 It can be seen that the minimum value of the antenna gain is 3.5dBi and the fluctuation is within 0.5dBi. It is high gain in the package antenna (Aip) and is within a relatively good fluctuation range, which can ensure that the antenna isolation zone can still maintain good high-speed communication characteristics after the distance increases. Fig.21 It can be seen that the 0° direction of the antenna is directly in front of the antenna, that is, the maximum direction of the antenna is the forward direction (that is, the end-fire mode), and the E-plane and H-plane radiation patterns of the antenna have good consistency in the frequency band of 58-62GHz, which means that the antenna has relatively stable radiation characteristics. It should be noted that the isolator of this embodiment is also applicable to other millimeter wave frequency bands (such as 70GHZ, 90GHZ, 110GHz, etc.).

[0091] It can be seen that the millimeter wave differential isolator provided by the present embodiment, which is obtained by the bonding gold wire packaging method, can form a good impedance match between the bonding gold wire and the antenna, and obtain a good packaging effect. Based on this, the millimeter wave differential isolator provided by the present embodiment can effectively suppress common mode interference, and has the advantages of large bandwidth, high gain and low cost.

[0092] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent transformations made using the contents of the specification and drawings of the present invention, or directly or indirectly applied in the relevant technical field, are also included in the patent protection scope of the present invention.

Claims

1. A millimeter wave differential antenna module, characterized in that: include: A differential antenna unit and a bonding gold wire; the differential antenna unit comprises a half-wave dipole antenna and a reflector; the reflector comprises an L1 layer ground and an L2 layer ground; the L1 layer ground and the L2 layer ground are stacked and connected through metal vias; the half-wave dipole antenna is arranged at the layer where the L1 layer ground is located; the half-wave dipole antenna and the L1 layer ground are respectively connected to the same end of the bonding gold wire; A portion of the L1 layer ground extends toward the radiation branch of the half-wave dipole antenna, and / or a portion of the L2 layer ground extends toward the radiation branch of the half-wave dipole antenna.

2. The millimeter wave differential antenna module according to claim 1, characterized in that: The L1 layer ground includes a left L1 layer ground and a right L1 layer ground which are arranged at a distance from each other; and the half-wave dipole antenna is arranged between the left L1 layer ground and the right L1 layer ground.

3. The millimeter wave differential antenna module according to claim 2, characterized in that: Part of the left L1 layer ground extends toward the radiating branch of the half-wave dipole antenna to form an L1 layer left extension arm, and / or part of the right L1 layer ground extends toward the radiating branch of the half-wave dipole antenna to form an L1 layer right extension arm.

4. The millimeter wave differential antenna module according to claim 3, characterized in that: The L1 layer left extension arm and the L1 layer right extension arm are both spaced apart from the radiation branch by a preset distance.

5. The millimeter wave differential antenna module according to claim 2, characterized in that: The half-wave dipole antenna includes a left array antenna and a right array antenna which are axially symmetrically arranged; the left array antenna is in an inverted L shape, and includes a feeding branch and a radiating branch; the feeding end of the feeding branch is connected to the bonding gold wire, and the other end is connected to the radiating branch; the feeding branches of the left array antenna and the right array antenna are arranged close to each other.

6. The millimeter wave differential antenna module according to claim 5, characterized in that: The left L1 layer ground and the right L1 layer ground are both L-shaped; the left extension arm of the L1 layer corresponds to the radiating branch of the left array antenna and is far away from the feeding branch of the left array antenna; the right extension arm of the L1 layer corresponds to the radiating branch of the right array antenna and is far away from the feeding branch of the right array antenna.

7. The millimeter wave differential antenna module according to claim 5, characterized in that: Both sides of the L2 layer ground extend toward the radiation branch of the left array antenna and the radiation branch of the right array antenna respectively to form an L2 layer left extension arm and an L2 layer right extension arm.

8. The millimeter wave differential antenna module according to claim 7, characterized in that: The L2 layer left extension arm and the L2 layer right extension arm are respectively spaced apart from their corresponding radiation branches by a preset distance, or the L2 layer left extension arm and the L2 layer right extension arm both exceed their corresponding radiation branches.

9. The millimeter wave differential antenna module according to claim 1, characterized in that: The vertical height of one end of the bonding gold wire connected to the half-wave dipole antenna and the L1 layer ground to the L1 layer ground is Hum, where the value range of H is 100um-200um.

10. A millimeter wave differential isolator, characterized in that: Comprising two millimeter wave differential antenna modules as claimed in any one of claims 1 to 9, and two radio frequency chips; the two millimeter wave differential antenna modules are connected based on millimeter wave wireless communication to form an isolation zone; the other ends of the bonding gold wires in the two millimeter wave differential antennas are respectively connected to a radio frequency chip; The two millimeter wave differential antenna modules and the two radio frequency chips are packaged as one.

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