CN215008531U

CN215008531U - Gold wire transition structure of Ka-band grounding coplanar waveguide

Info

Publication number: CN215008531U
Application number: CN202120962759.3U
Authority: CN
Inventors: 黎燕林; 肖倩; 刘季超; 周丽洁; 程桥; 王智会
Original assignee: Shenzhen Zhenhua Ferrite and Ceramic Electronics Co Ltd
Current assignee: Shenzhen Zhenhua Ferrite and Ceramic Electronics Co Ltd
Priority date: 2021-05-07
Filing date: 2021-05-07
Publication date: 2021-12-03
Anticipated expiration: 2031-05-07

Abstract

The utility model provides a Ka wave band ground connection coplanar waveguide spun gold transition structure, including ground connection coplanar waveguide, chip and spun gold, ground connection coplanar waveguide includes the base plate, the ground connection bottom, signal line and ground connection top layer, the impedance transformation minor matters is cascaded between the one end of signal line neighbouring chip and the spun gold, the impedance transformation minor matters includes the first impedance section that links to each other with the signal line, the second impedance section that links to each other with the spun gold and the third impedance section of connecting first impedance section and second impedance section, the impedance of first impedance section is greater than the impedance of third impedance section, the impedance of third impedance section is greater than the impedance of second impedance section. The utility model provides a Ka wave band ground connection coplanar waveguide gold wire transition structure, the impedance match between realization ground connection coplanar waveguide and the gold wire that both can be good effectively solves the problem that causes return loss and standing-wave ratio performance to worsen because of impedance mismatch, also can increase the operating band of impedance transformation stub to have good matching performance in the frequency band of broad.

Description

Gold wire transition structure of Ka-band grounding coplanar waveguide

Technical Field

The application belongs to the technical field of microwave radio, and particularly relates to a Ka-band grounding coplanar waveguide gold wire transition structure.

Background

The Ka band is a radio wave band with the frequency of 26.5-40 GHz. In a multi-Chip Module (MCM), a plurality of integrated circuit chips and other Chip components are assembled on a high-density multilayer interconnection substrate, which is the mainstream implementation scheme of a microwave/millimeter wave Module. The connection of the transmission line and the chip is a key link of the assembly process of the microwave/millimeter wave assembly. Common transmission line structures include microstrip lines, Coplanar waveguides (CPW), strip lines, and the like. The large-area grounding of the coplanar waveguide and the signal line are in the same plane, so that the radiation loss and the high-frequency dispersion can be effectively inhibited, the structural design is flexible, the grounded coplanar waveguide, the asymmetric coplanar waveguide and the like can be derived, and the grounded coplanar waveguide, the asymmetric coplanar waveguide and the like can be better integrated with other components in the multi-chip assembly. For a multi-chip module with a lower frequency band, the transmission line and the chip can be directly connected through gold wire bonding. However, since the impedance difference between the grounded coplanar waveguide and the gold wire is large, the gold wire is directly connected with the signal line in the grounded coplanar waveguide, and larger electromagnetic wave reflection is caused by impedance mismatch, so that the return loss and standing-wave ratio performance of the whole structure are deteriorated, and the deterioration is more serious as the frequency is higher.

SUMMERY OF THE UTILITY MODEL

An object of the embodiments of the present application is to provide a gold wire transition structure of a Ka-band grounded coplanar waveguide, so as to solve the technical problem in the prior art that return loss and standing-wave ratio performance are deteriorated due to impedance mismatch when a Ka-band grounded coplanar waveguide is connected to a gold wire.

In order to achieve the purpose, the technical scheme adopted by the application is as follows: providing a transition structure of a Ka-band grounded coplanar waveguide gold wire, which comprises a grounded coplanar waveguide, a chip and a gold wire connecting the chip and the grounded coplanar waveguide, wherein the grounded coplanar waveguide comprises a substrate, a grounded bottom layer arranged on the back surface of the substrate, a signal wire arranged on the front surface of the substrate and grounded surface layers respectively arranged on two sides of the signal wire, each grounded surface layer is arranged on the front surface of the substrate, the signal wire and each grounded surface layer are arranged at intervals, a containing groove is arranged on the front surface of the substrate, the chip is arranged in the containing groove, the signal wire extends to one end of the containing groove, the gold wire is connected with the chip, an impedance transformation branch which is used for impedance matching with the gold wire is cascaded between one end of the signal wire adjacent to the chip and the gold wire, and the impedance transformation branch is arranged on the front surface of the substrate, the impedance transformation branch is located between the two grounding surface layers and comprises a first impedance section connected with the signal line, a second impedance section connected with the gold wire and a third impedance section connected with the first impedance section and the second impedance section, the impedance of the first impedance section is greater than that of the third impedance section, and the impedance of the third impedance section is greater than that of the second impedance section.

In one embodiment, one end of the first impedance section is connected with the middle part of the signal line along the width direction of the signal line, the other end of the first impedance section is connected with the middle part of one end of the third impedance section along the width direction of the signal line, and the other end of the third impedance section is connected with the middle part of the second impedance section along the width direction of the signal line; along the signal line length direction: the length of the first impedance segment, the length of the second impedance segment and the length of the third impedance segment are all equal; along the signal line width direction: the width of the first impedance segment is less than the width of the third impedance segment, which is less than the width of the second impedance segment.

In one embodiment, the characteristic impedance of the grounded coplanar waveguide is 50 Ω, and the impedance transformation branch is a gold layer; the length of the first impedance section along the length direction of the signal wire is 0.2mm, and the width of the first impedance section along the width direction of the signal wire is 0.12 mm; the length of the third impedance section along the length direction of the signal wire is 0.2mm, and the width of the third impedance section along the width direction of the signal wire is 0.4 mm; the length of the second impedance section along the length direction of the signal wire is 0.2mm, and the width of the second impedance section along the width direction of the signal wire is 0.7 mm.

In one embodiment, one end of the signal line, which is far away from the chip, is provided with a transition section, the transition section is arranged along the length direction of the signal line, and the width of the transition section is gradually reduced from the end, connected with the signal line, of the transition section to the other end of the transition section.

In one embodiment, the signal lines and the grounding surface layers are all made of gold, the width of the signal lines is 0.38mm, and the gaps between the signal lines and the grounding surface layers are 0.4 mm.

In one embodiment, the length of the transition section is in the range of 0.8mm to 1.6mm, the width of one end of the transition section is equal to the width of the signal line, and the width of the other end of the transition section is in the range of 0.15mm to 0.5 mm.

In one embodiment, the transition section is in an isosceles trapezoid configuration.

In one embodiment, the impedance conversion branch is connected to the chip through two gold wires, the two gold wires are arranged in a splayed shape along the length direction of the signal wire, and the distance between the two gold wires and the end close to the chip is smaller than the distance between the two gold wires and the end close to the impedance conversion branch.

In one embodiment, the span of each gold wire is less than or equal to 300 μm, the arch height of each gold wire is in a range of 100 μm to 200 μm, the distance between two gold wires near one end of the chip is in a range of less than or equal to 50 μm, and the distance between two gold wires near one end of the impedance transformation stub is in a range of 100 μm to 250 μm.

In one embodiment, the signal line is divided into two sections, the two sections of signal lines are respectively located at two ends of the accommodating groove, one end of each signal line, which is adjacent to the chip, is respectively connected with the impedance transformation branches, and the two impedance transformation branches are respectively connected with two ends of the chip through the gold wire.

The application provides a Ka wave band ground connection coplanar waveguide gold wire transition structure's beneficial effect lies in: compared with the prior art, the Ka-band grounding coplanar waveguide gold wire transition structure has the advantages that the impedance conversion branches are added into the signal wire and the gold wire, so that impedance matching between the grounding coplanar waveguide and the gold wire can be well realized, the problems of return loss and standing-wave ratio performance deterioration caused by impedance mismatch are effectively solved, the manufacturing process requirements of a planar circuit are met, and the processing and manufacturing are easy; moreover, the impedances of the second impedance section, the third impedance section and the first impedance section are increased section by section, so that the working frequency band of the impedance transformation branch can be increased, and the impedance transformation branch has good matching performance in a wider frequency band.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic perspective view of a gold wire transition structure of a Ka-band grounded coplanar waveguide provided in an embodiment of the present application;

FIG. 2 is an enlarged view taken at A in FIG. 1;

FIG. 3 is an enlarged view at B of FIG. 1;

FIG. 4 is a top view of a portion of the chip, gold wire, impedance transformation stub, etc. of FIG. 1;

FIG. 5 is a cross-sectional view taken along line C-C of FIG. 4;

fig. 6 is an equivalent circuit diagram when the signal line of the grounded coplanar waveguide is directly connected to the chip through a gold wire.

FIG. 7 is an equivalent circuit diagram of an impedance transformation stub and a corresponding gold wire in a Ka-band grounded coplanar waveguide gold wire transition structure provided in an embodiment of the present application;

fig. 8 is an effect diagram of transmission performance simulation of a Ka-band grounded coplanar waveguide gold wire transition structure provided in an embodiment of the present application.

Wherein, in the figures, the respective reference numerals:

1-a grounded coplanar waveguide; 11-a substrate; 111-a receiving groove; 112-ground vias; 12-a ground floor; 13-a grounded surface layer; 14-a signal line; 141-transition section;

2-chip;

3-gold wire;

4-impedance transformation minor matters; 41-a first impedance segment; 42-a second impedance segment; 43-third impedance segment.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings that is solely for the purpose of facilitating the description and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be considered as limiting the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

Referring to fig. 1, for convenience of description, three coordinate axes that are spatially perpendicular to each other are defined as an X axis, a Y axis and a Z axis, wherein the X axis is along the length direction of the signal line, the Y axis is along the width direction of the signal line, and the Z axis is along the thickness direction of the signal line.

Referring to fig. 1, 2 and 5, a description will now be given of the gold transition structure of the Ka-band grounded coplanar waveguide provided in the present application. The Ka-band grounded coplanar waveguide gold wire transition structure comprises a grounded coplanar waveguide 1, a chip 2, a gold wire 3 and an impedance transformation branch 4. The grounded coplanar waveguide 1 comprises a substrate 11, a grounded bottom layer 12, a signal line 14 and two grounded surface layers 13, wherein the grounded bottom layer 12 is arranged on the back surface of the substrate 11, the signal line 14 and the two grounded surface layers 13 are arranged on the front surface of the substrate 11, the two grounded surface layers 13 are respectively arranged on two sides of the signal line 14, and the signal line 14 and each grounded surface layer 13 are arranged at intervals, so that the grounded coplanar waveguide 1 is formed. The front surface of the substrate 11 is provided with a receiving groove 111, the signal line 14 extends to one end of the receiving groove 111, that is, the receiving groove 111 is disposed at a position corresponding to the signal line 14, and the chip 2 is mounted in the receiving groove 111, so that the chip 2 is conveniently mounted, and the chip meets the requirements of a planar circuit manufacturing process, and is easy to process and manufacture. The gold wire 3 is connected with the chip 2, the impedance conversion branch 4 is arranged on the front surface of the substrate 11, the impedance conversion branch 4 is used for performing impedance matching with the gold wire 3, and the impedance conversion branch 4 is connected with one end, close to the chip 2, of the signal wire 14 and the gold wire 3, namely, the signal wire 14 and the gold wire 3 are connected through the impedance conversion branch 4 in an impedance matching mode, so that the problems of return loss and standing-wave ratio performance deterioration caused by impedance mismatch are effectively solved. Therefore, the impedance matching between the grounding coplanar waveguide 1 and the gold wire 3 can be well realized, the problems of return loss and the deterioration of standing-wave ratio performance caused by impedance mismatch are effectively solved, the requirements of the planar circuit manufacturing process are met, and the processing and the manufacturing are easy.

Further, the impedance transformation branch 4 includes a first impedance section 41, a second impedance section 42 and a third impedance section 43, the first impedance section 41 is connected with the signal line 14, the second impedance section 42 is connected with the gold wire 3, and the third impedance section 43 is connected with the first impedance section 41 and the second impedance section 42; the impedance of the first impedance segment 41 is greater than the impedance of the third impedance segment 43 and the impedance of the third impedance segment 43 is greater than the impedance of the second impedance segment 42. Thus, the impedances of the second impedance section 42, the third impedance section 43 and the first impedance section 41 are increased section by section, a plurality of sections with good impedance matching performance can be generated in the Ka band, so that the impedance matching performance in the Ka band is further improved, the operating frequency band of the impedance transformation stub 4 can be increased, and the good matching performance can be achieved in a wider frequency band.

In an embodiment of the present application, referring to fig. 2, 4 and 5, one end of the first impedance section 41 is connected to the middle of the signal line 14 along the width direction of the signal line 14, the other end of the first impedance section 41 is connected to the middle of the third impedance section 43 along the width direction of the signal line 14, and the other end of the third impedance section 43 is connected to the middle of the second impedance section 42 along the width direction of the signal line 14. Thus, a multi-section impedance transformation branch 4 with gradually changed impedance is formed, the impedance characteristic of the branch 4 can be equivalent to that of adding an L-shaped impedance matching network in an equivalent circuit of a gold wire, and impedance matching is well realized so as to increase the working frequency band of the impedance transformation branch 4. Moreover, the distribution of a plurality of intervals with high return loss is uniform.

Alternatively, referring to fig. 2, fig. 4 and fig. 5, along the length direction of the signal line 14: the length of the first impedance segment 41, the length of the second impedance segment 42, and the length of the third impedance segment 43 are all equal. Thus, the first impedance section 41, the second impedance section 42, and the third impedance section 43 can form multi-stage impedance matching, which is beneficial to improving impedance matching performance, and can form a plurality of sections with high return loss in the Ka band. Along the width direction of the signal line 14: the width of the first impedance segment 41 is less than the width of the third impedance segment 43 and the width of the third impedance segment 43 is less than the width of the second impedance segment 42. This allows the impedances of the second impedance section 42, the third impedance section 43 and the first impedance section 41 to be gradually increased, and the magnitudes of the impedances in the second impedance section 42, the third impedance section 43 and the first impedance section 41 can be changed in a gradient manner. Therefore, the calculation of the impedance in the design process is facilitated, the design efficiency can be improved by adjusting the width of each section when the characteristic impedance is adjusted, and the design is simplified. Moreover, the width of the third impedance section 43 is between the first impedance section 41 and the second impedance section 42, so that the widths of the first impedance section 41 and the third impedance section 43 are gradually changed, which is beneficial to controlling the pattern shape in the printing process, improving the processing precision of the impedance transformation branch 4 and improving the consistency of products.

Referring to fig. 6, the circuit shown in fig. 6 is an equivalent circuit of the gold wire 3 when the gold wire 3 is used to directly connect the chip 2 and the signal line 14. The equivalent circuit comprises two inductors L1, two resistors R1, two capacitors C1 and a capacitor C2, wherein the inductor L1, the resistor R1, the resistor R1 and the inductor L1 are sequentially connected in series, one end, away from the two resistors R1, of one inductor L1 is a chip end used for being connected with the chip 2, one end, away from the two resistors R1, of the other inductor L1 is a signal line end used for being connected with the signal line 14, namely from the chip end to the signal line end, and the inductor L1, the resistor R1, the resistor R1 and the inductor L1 are sequentially connected in series; the chip end is grounded through a capacitor C1, the signal line end is grounded through another capacitor C1, and the two resistors R1 are grounded through a capacitor C2.

Referring to fig. 7, fig. 7 is an equivalent circuit of the impedance transformation stub 4 and the gold wire 3, wherein the impedance transformation stub 4 and the gold wire 3 are connected by using the impedance transformation stub 4 in the above embodiment, the equivalent circuit includes two inductors L1, two resistors R1, an inductor Lp, a capacitor Cp1, a capacitor Cp1, two capacitors C1 and a capacitor C2, wherein the inductor L1, the resistor R1, the resistor R1, the inductor L1 and the inductor Lp are sequentially connected in series, one end of the inductor L1 away from the inductor Lp is a chip end for connecting the chip 2, one end of the inductor Lp away from the two resistors R1 is a signal line end for connecting the signal wire 14, that is, from the chip end to the signal line end, and the inductor L1, the resistor R1, the resistor R1, the inductor L1 and the inductor Lp are sequentially connected in series; the chip end is grounded through a capacitor C1, the two resistors R1 are grounded through a capacitor C2, the other capacitor C1 is connected with the capacitors Cp1 and Cp2 in parallel, and the end, far away from the signal line end, of the inductor Lp is grounded through a capacitor Cp1 and a capacitor Cp 2. The inductor Lp and the capacitors Cp1 and Cp2 connected in parallel can form an L-type impedance matching network, that is, the equivalent circuit using the impedance transformation branch 4 is equivalent to adding the L-type impedance matching network to the signal line end of the equivalent circuit directly using the gold wire 3 to connect the signal line 14, so that the input impedance Zin observed from the signal line end to the chip end is as close as possible to the signal line impedance, thereby reducing the impedance mismatch degree; moreover, because the capacitor Cp1 and the capacitor Cp2 exist at the same time, a plurality of sections with high return loss can be formed, and the operating frequency band of the impedance transformation stub 4 is increased. The capacitors Cp1, Cp2 and Lp correspond to the parasitic effects of the second impedance segment 42, the third impedance segment 43 and the first impedance segment 41, respectively. Of course, the sizes of the inductor Lp, the capacitor Cp and the capacitor Cp2 can be adjusted by changing the sizes of the first impedance segment 41, the second impedance segment 42 and the third impedance segment 43, so that the impedance transformation branch 4 has portability to be suitable for grounded coplanar waveguides of gold wires of other sizes/shapes or substrates of different materials.

In one embodiment, referring to fig. 1, 4 and 5, the characteristic impedance of the grounded coplanar waveguide 1 is 50 Ω, and the impedance transformation branch 4 is a gold layer; the length of the first impedance section 41 along the length direction of the signal line 14 is 0.2mm, and the width of the first impedance section 41 along the width direction of the signal line 14 is 0.12 mm; the length of the third impedance section 43 along the length direction of the signal line 14 is 0.2mm, and the width of the third impedance section 43 along the width direction of the signal line 14 is 0.4 mm; the length of the second impedance section 42 along the length direction of the signal line 14 is 0.2mm, the width of the second impedance section 42 along the width direction of the signal line 14 is 0.7mm, and the impedance transformation branch 4 of the structure can well realize the impedance matching between the gold wire 3 and the grounding coplanar waveguide 1 with the characteristic impedance of 50 omega in the Ka wave band, thereby ensuring the good link transmission performance. In the actual processing process, the length and width processing errors of the impedance transformation branch 4 can be +/-0.03 mm, and the sizes are favorable for reducing the influence caused by the processing precision errors.

In an embodiment of the present application, referring to fig. 1 and fig. 3, a transition section 141 is disposed at an end of the signal line 14 away from the chip 2, the transition section 141 is disposed along a length direction of the signal line 14, and a width of the transition section 141 gradually decreases from an end of the transition section 141 connected to the signal line 14 to an end of the transition section 141 away from the signal line 14. The transition section 141 is welded to the inner conductor of the coaxial connector in practical application, and when the signal line is connected to the coaxial connector, the conductor in the coaxial connector is welded to the transition section, so that the input/output inductance can be increased, and the parasitic capacitance effect caused by the connection between the signal line and the inner conductor of the coaxial connector can be counteracted.

In one embodiment, referring to fig. 1 to 3, the signal line 14 and the grounding surface layer 13 are all made of gold, the width of the signal line 14 is 0.38mm, and the gap between the signal line 14 and each grounding surface layer 13 is 0.4mm, so that the grounding coplanar waveguide 1 has good transmission performance, and the grounding coplanar waveguide 1 has 50 Ω characteristic impedance, thereby improving the application range of the grounding coplanar waveguide 1.

In an embodiment, referring to fig. 3 and 4, the thickness of the gold layer is in a range of 10-20 μm, that is, the impedance transformation branch 4 is made of gold material, the thickness of the impedance transformation branch 4 is in a range of 10-20 μm, the signal line 14 and the grounding surface layer 13 are made of gold material, and the thickness of the signal line 14 and the grounding surface layer 13 is in a range of 10-20 μm, so as to ensure that the grounding coplanar waveguide 1 has good transmission performance and the impedance transformation branch 4 realizes impedance matching between the gold wire 3 and the signal line 14 well. Alternatively, the thickness of each gold layer may be 12 μm, 15 μm, 17 μm, or the like, and may be selected according to the transmission performance and the impedance matching characteristics of the ground coplanar waveguide 1 and the impedance transformation stub 4.

In one embodiment, referring to fig. 1 and fig. 3, the length of the transition section 141 along the length direction of the signal line 14 ranges from 0.8mm to 1.6mm, the width of the transition section 141 near the chip 2 is equal to the width of the signal line 14, and the width of the transition section 141 far from the chip 2 ranges from 0.1mm to 0.5 mm. Therefore, the processing of the transition section 141 and the signal wire 14 is facilitated, the welding of the inner conductor of the coaxial connector is facilitated, the stability of a welding position can be guaranteed, and the influence of a parasitic capacitance effect can be better counteracted. Alternatively, the length of the transition section 141 may be 0.6mm, 0.8mm, 1mm, etc., and the width of the transition section 141 away from the chip 2 may be 0.2mm, 0.3mm, 0.4mm, etc. Of course, the length of the transition section 141 and the width of the other end of the transition section 141 may be adjusted according to the matching effect with the coaxial connector.

Alternatively, referring to fig. 1 and fig. 3, the transition section 141 is an isosceles trapezoid. Therefore, the alignment of the conductor in the process of welding the coaxial connector can be facilitated, the shape is simple, and the processing is convenient.

In one embodiment, referring to fig. 5, the impedance transformation branch 4, the signal line 14 and the grounding surface layer 13 have the same thickness, so as to facilitate the manufacturing process, such as printing on the substrate 11.

In one embodiment, referring to fig. 2, 4 and 5, the impedance transformation branch 4 is connected to the chip 2 through two gold wires 3, the two gold wires 3 are arranged in a splay shape along the length direction of the signal line 14, and the distance between the two gold wires 3 and the end close to the chip 2 is smaller than the distance between the two gold wires 3 and the end close to the impedance transformation branch 4. The two gold wires 3 are used for connecting the impedance conversion branches 4 and the chip 2, so that the two gold wires 3 form a symmetrical structure better, the impedance is reduced, and the transmission performance is improved.

In an embodiment, referring to fig. 2, 4 and 5, the span of each gold wire 3 is less than or equal to 300 μm, the arch height of each gold wire 3 is in a range of 100 μm to 200 μm, the distance between two gold wires 3 near one end of the chip 2 is less than or equal to 50 μm, and the distance between two gold wires 3 near one end of the impedance transformation stub 4 is in a range of 100 μm to 250 μm, so that the gold wires 3 have smaller resistance and inductance characteristics, that is, the impedance of the gold wires 3 is reduced, the transmission performance of the gold wires 3 is improved, and the gold wires are well matched with the impedance transformation stub 4, and the processing and the manufacturing are also convenient.

In some embodiments, the span of each gold wire 3 is 260 μm, the arch height of each gold wire 3 is 150 μm, the distance between one end of each gold wire 3 close to the chip 2 is 25 μm, and the distance between one end of each gold wire 3 close to the impedance transformation branch 4 is 175 μm, so that the gold wires 3 have smaller resistance and inductance characteristics, that is, the impedance of the gold wires 3 is reduced, the transmission performance of the gold wires 3 is improved, the gold wires 3 are better ensured to be well connected with the impedance transformation branch 4 and the chip 2, and the impedance transformation branches 4 of the gold wires 3 are better matched.

In one embodiment, referring to fig. 1, 4 and 5, the impedance transformation branch 4 is symmetrically disposed about a central line of the signal line 14 in the length direction, the grounding coplanar waveguide 1 is symmetrically disposed about a central line of the signal line 14 in the length direction, and the two gold wires 3 are symmetrically disposed about a central line of the signal line 14 in the length direction, so that the grounding coplanar waveguide 1, the gold wires 3 and the impedance transformation branch 4 form a symmetrical structure, which facilitates the processing and manufacturing, and ensures the good transmission performance and the low return loss of the gold wire transition structure of the Ka-band grounding coplanar waveguide. Certainly, in some embodiments, if the substrate 11 or the chip 2 itself has an asymmetric structure, only the positions of the signal line 14, the impedance transformation branch 4 and the gold wire 3 need to be adjusted correspondingly, so that good impedance matching between the gold wire 3 and the signal line 14 can be realized, and good transmission performance is ensured.

In an embodiment, referring to fig. 1, fig. 2 and fig. 5, the signal line 14 is two segments, the two segments of the signal line 14 are respectively located at two ends of the accommodating groove 111, one end of each signal line 14 adjacent to the chip 2 is respectively connected to the impedance transforming branches 4, and the two impedance transforming branches 4 are respectively connected to two ends of the chip 2 through the gold wires 3, so that the chip 2 is convenient to mount, and the two ends of the chip 2 can be connected to the two segments of the signal line 14 in a matching manner. In other embodiments, when only one end of the chip 2 is required to be connected to the signal line 14, the receiving groove 111 may be disposed at one end of the substrate 11, so as to mount the chip 2 on the edge of the substrate 11.

In an embodiment, referring to fig. 1 and fig. 2, when the signal line 14 is two segments, the lengths of the two segments of the signal line 14 are equal, and the receiving groove 111 is located at the middle position of the substrate 11, so that the grounded coplanar waveguide 1 is symmetrically arranged with respect to the center line of the substrate 11 in the length direction, thereby facilitating the design and manufacture and ensuring good transmission performance of the grounded coplanar waveguide 1.

In one embodiment, referring to fig. 1 and fig. 2, at least two rows of ground vias 112 are respectively disposed on two sides of the signal line 14 on the substrate 11, and each ground via 112 connects the corresponding ground surface layer 13 and the ground bottom layer 12, so as to improve the transmission performance of the grounded coplanar waveguide 1, improve the transmission efficiency, and reduce the loss.

In one embodiment, referring to fig. 1 and 2, each side of the signal line 14 is adjacent to two rows of ground vias 112 of the signal line 14: the distance between two adjacent ground vias 112 in each row of ground vias 112 ranges from 0.5mm to 1.1 mm; the distance between the two rows of the grounding through holes 112 is 0.5mm-1.5mm, the two adjacent rows of the grounding through holes 112 are arranged along the length direction of the signal line 14 in a staggered mode, and the staggered distance along the length direction of the signal line 14 is 0.3-0.7mm, so that the transmission efficiency of the grounding coplanar waveguide 1 is improved better, and the loss is reduced. Along the length direction of the signal line 14: the distance from each ground via 112 to the edge of the substrate 11 is greater than or equal to 0.3 mm.

In one embodiment, each ground via 112 has an aperture in the range of 0.1mm to 0.3mm for ease of manufacturing. In one embodiment, the aperture of each ground via 112 is 0.2mm, which facilitates the fabrication and improves the transmission efficiency of the grounded coplanar waveguide 1, thereby balancing the improvement of the transmission efficiency of the grounded coplanar waveguide 1 with the simplicity of the fabrication process.

In one embodiment, each side of a signal line 14 is adjacent to the signal line 14 in two rows of ground vias 112: the connecting line between the axes of any adjacent three grounding through holes 112 is in an isosceles triangle shape, so as to better prevent electromagnetic leakage and improve the transmission efficiency of the grounding coplanar waveguide 1. Optionally, each side of the signal line 14 is adjacent to two rows of ground vias 112 of the signal line 14: the connecting line between the axes of any adjacent three ground vias 112 is in the shape of an equilateral triangle, which not only facilitates the design and manufacture, but also improves the transmission efficiency of the grounded coplanar waveguide 1.

In one embodiment, each side of a signal line 14 is adjacent to the signal line 14 in two rows of ground vias 112: the distance between two adjacent ground vias 112 in each row of ground vias 112 is in the range of 0.7mm to 1.2mm, so as to facilitate the processing and manufacturing.

In one embodiment, referring to fig. 4, the gap between the impedance transformation branch 4 and each grounding surface layer 13 is greater than or equal to 0.225mm, so as to meet the requirements of most planar circuit processing technologies, facilitate the processing and manufacturing, and reduce the cost. The gap between the impedance transformation stub 4 and each grounding surface layer 13 may be 0.25mm, 0.28mm, 0.35mm, or the like.

In one embodiment, referring to fig. 1 and 5, the dielectric constant of the substrate 11 ranges from 5.0 to 10.0, and the dielectric loss factor tan α of the substrate 11 is less than or equal to 0.004, so as to ensure good transmission performance of the grounded coplanar waveguide 1. The substrate 11 may use a ceramic material so that the grounded coplanar waveguide 1 can be fabricated by a low temperature co-fired ceramic process. Of course, the substrate 11 may be made of other materials.

In one embodiment, the substrate 11 is rectangular, the signal lines 14 are disposed along the length direction of the substrate 11, and the length direction of the substrate 11 is the length direction of the signal lines 14, i.e., the X-axis direction; the width direction of the substrate 11 is the width direction of the signal line 14, i.e., the Y-axis direction; the thickness direction of the substrate 11 is the thickness direction of the signal line 14, i.e., the Z-axis direction. The structure can better make the grounding coplanar waveguide 1 into a symmetrical structure, thereby improving the transmission performance and reducing the transmission loss.

In one embodiment, the length of the substrate 11 is 25.4mm, the width of the substrate 11 is 12.7mm, and the thickness of the substrate 11 is 0.31mm, so that the size of the gold transition structure of the Ka-band grounded coplanar waveguide is small and convenient to use.

In one embodiment, referring to fig. 5, the distance between the inner wall of the receiving cavity 111 and the side surface of the chip 2 is in a range of 60-100 μm, so as to facilitate the chip 2 to be mounted in the receiving cavity 111. In one embodiment, the distance between the inner wall of the receiving cavity 111 and the side surface of the chip 2 is 80 μm, which facilitates the chip 2 to be mounted in the receiving cavity 111 and also facilitates the chip 2 to be fixed.

In one embodiment, the front surface of the chip 2 is flush with the front surface of the grounded coplanar waveguide 1, so that the requirements of a planar circuit processing technology can be better met, and the manufacturing accuracy is improved.

In some embodiments, the bottom surface of the chip 2 may be grounded to the ground plane 12 through metal pads to reduce transmission loss.

Referring to fig. 8, an effect diagram of transmission performance simulation of the gold wire transition structure of the Ka-band grounded coplanar waveguide provided in the embodiment of the present application is shown, in which a back-metallization coplanar waveguide with 50 Ω characteristic impedance is used to replace the chip 2 for electromagnetic simulation. In the figure, the horizontal coordinate axis Freq is frequency and the unit is GHz; the longitudinal axis of the left hand insert/Return Loss is the Insertion/Return Loss in dB. The Curve Info Curve information, wherein a line S (1, 1) is a Curve of return loss corresponding to each frequency, the frequency at a high point m1 on the line S (1, 1) is 37.33GHz, and the return loss is-21.7177 dB; line S (2, 1) is a curve of insertion loss for each frequency, with the frequency at the low point m2 on line S (2, 1) being 40GHz and the insertion loss being-1.3599 dB. As can be seen from the figure, the Ka-band ground coplanar waveguide gold wire transition structure of the embodiment of the present application has excellent transmission performance in the Ka band, an insertion loss is less than 1.4dB, a return loss is greater than 21.0dB, a plurality of sections with large return loss values (four sections with a return loss greater than 40dB exist, and frequency bands of the four sections approximately correspond to 30.3GHz, 33.7GHz, 35.7GHz, and 39.1GHz, respectively) exist in the Ka band, the distribution of the plurality of sections in the Ka band is relatively uniform, the operating frequency band of the impedance transformation stub 4 is obviously increased, and good matching performance is achieved in a wide frequency band.

The Ka-band grounded coplanar waveguide gold wire transition structure in the embodiment of the application can be manufactured by adopting an LTCC (Low Temperature Co-fired Ceramic) process or other planar printing processes, for example, a cavity can be drawn out at a corresponding position of a green Ceramic chip, and stacked from bottom to top to print metal patterns and fill holes of each layer; and sintering and forming, wherein the substrate 11 can be electroplated and cleaned, and the chip 2 and the gold wire 3 are mounted and bonded in sequence by adopting a chip mounting process.

The gold wire transition structure of the Ka-band grounding coplanar waveguide can be applied to a Ka-band receiving and transmitting assembly and can also be applied to equipment such as microwave communication, radar systems and electronic countermeasure.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

A transition structure of a gold wire of a Ka-band grounding coplanar waveguide comprises a grounding coplanar waveguide, a chip and a gold wire connecting the chip and the grounding coplanar waveguide, wherein the grounding coplanar waveguide comprises a substrate, a grounding bottom layer arranged on the back surface of the substrate, a signal wire arranged on the front surface of the substrate and grounding surface layers respectively positioned on two sides of the signal wire, each grounding surface layer is arranged on the front surface of the substrate, the signal wire and each grounding surface layer are arranged at intervals, a containing groove is arranged on the front surface of the substrate, the chip is arranged in the containing groove, the signal wire extends to one end of the containing groove, the gold wire is connected with the chip, an impedance transformation branch which is used for carrying out impedance matching with the gold wire is cascaded between one end of the signal wire adjacent to the chip and the gold wire, and the impedance transformation branch is arranged on the front surface of the substrate, the impedance transformation branch is positioned between the two grounding surface layers, and is characterized in that: the impedance transformation branch comprises a first impedance section connected with the signal wire, a second impedance section connected with the gold wire and a third impedance section connected with the first impedance section and the second impedance section, wherein the impedance of the first impedance section is greater than that of the third impedance section, and the impedance of the third impedance section is greater than that of the second impedance section.
2. The Ka band ground coplanar waveguide gold wire transition structure of claim 1, wherein: one end of the first impedance section is connected with the middle part of the signal wire along the width direction of the signal wire, the other end of the first impedance section is connected with the middle part of one end of the third impedance section along the width direction of the signal wire, and the other end of the third impedance section is connected with the middle part of the second impedance section along the width direction of the signal wire; along the signal line length direction: the length of the first impedance segment, the length of the second impedance segment and the length of the third impedance segment are all equal; along the signal line width direction: the width of the first impedance segment is less than the width of the third impedance segment, which is less than the width of the second impedance segment.
3. The Ka band ground coplanar waveguide gold wire transition structure of claim 1, wherein: the characteristic impedance of the grounding coplanar waveguide is 50 omega, and the impedance transformation branch is a gold layer; the length of the first impedance section along the length direction of the signal wire is 0.2mm, and the width of the first impedance section along the width direction of the signal wire is 0.12 mm; the length of the third impedance section along the length direction of the signal wire is 0.2mm, and the width of the third impedance section along the width direction of the signal wire is 0.4 mm; the length of the second impedance section along the length direction of the signal wire is 0.2mm, and the width of the second impedance section along the width direction of the signal wire is 0.7 mm.
4. The Ka band ground coplanar waveguide gold wire transition structure of claim 1, wherein: the signal line is far away from the one end of chip is equipped with the transition, the transition sets up along signal line length direction, the width of transition by the one end that the transition links to each other with the signal line to the other end of transition reduces gradually.
5. The Ka-band grounded coplanar waveguide gold wire transition structure of claim 4, wherein: the signal lines and the grounding surface layers are all made of gold layers, the width of each signal line is 0.38mm, and gaps between the signal lines and the grounding surface layers are 0.4 mm.
6. The Ka-band grounded coplanar waveguide gold wire transition structure of claim 5, wherein: the length range of the transition section is 0.8mm-1.6mm, the width of one end of the transition section is equal to the width of the signal line, and the width range of the other end of the transition section is 0.15mm-0.5 mm.
7. The Ka-band grounded coplanar waveguide gold wire transition structure of claim 4, wherein: the gradual change section is isosceles trapezoid structure.
8. The Ka-band grounded coplanar waveguide gold wire transition structure of any one of claims 1 to 7, wherein: the impedance conversion branch is connected with the chip through the two gold wires, the two gold wires are arranged in a splayed shape along the length direction of the signal wire, and the distance between the two gold wires and the end, close to the chip, of the two gold wires is smaller than the distance between the two gold wires and the end, close to the impedance conversion branch, of the two gold wires.
9. The Ka band ground coplanar waveguide gold wire transition structure of claim 8, wherein: the span range of each gold wire is less than or equal to 300 mu m, the arch height range of each gold wire is 100 mu m-200 mu m, the distance range of one end, close to the chip, of each gold wire is less than or equal to 50 mu m, and the distance range of one end, close to the impedance transformation minor matters, of each gold wire is 100 mu m-250 mu m.
10. The Ka-band grounded coplanar waveguide gold wire transition structure of any one of claims 1 to 7, wherein: the signal lines are two sections, the two sections of signal lines are respectively located at two ends of the accommodating groove, one end, adjacent to the chip, of each signal line is respectively connected with the impedance transformation branches, and the two impedance transformation branches are respectively connected with two ends of the chip through the gold wires.