阅读说明：本技术 半空气填充基片集成凹槽间隙波导及其微带过渡转换装置 (Semi-air filling substrate integrated groove gap waveguide and microstrip transition conversion device thereof ) 是由 施永荣 冯文杰 吴启晖 于 2020-06-15 设计创作，主要内容包括：本发明公开了一种半空气填充基片集成凹槽间隙波导及其微带过渡转换装置,所述基片集成凹槽间隙波导利用倒装芯片技术将上下两块基板通过BGA焊料球倒装而成,上下两块基板垂直叠加在一起,基板之间的空气间隙层由焊料球支撑,空气间隙层和下层基板内的部分介质构成了该基板集成凹槽间隙基片集成凹槽间隙波导电磁波传输的路径。所述基片集成凹槽间隙波导的微带过渡转换装置。所述过渡转换装置由T形枝节、阻抗匹配段、一对反射焊料球构成。该发明的过渡转换装置能够实现所发明的新型半空气填充基片集成凹槽间隙波导至微带线的径向过渡转换。本发明具有剖面低、重量轻、体积小、易于集成等优点。(The invention discloses a semi-air filling substrate integrated groove gap waveguide and a microstrip transition conversion device thereof, wherein the substrate integrated groove gap waveguide is formed by reversely mounting an upper substrate and a lower substrate through BGA solder balls by utilizing a flip chip technology, the upper substrate and the lower substrate are vertically overlapped together, an air gap layer between the substrates is supported by the solder balls, and the air gap layer and partial media in the lower substrate form an electromagnetic wave transmission path of the substrate integrated groove gap waveguide. The substrate is integrated with a microstrip transition conversion device of the groove gap waveguide. The transition conversion device is composed of a T-shaped branch, an impedance matching section and a pair of reflection solder balls. The transition conversion device can realize the radial transition conversion from the novel semi-air filling substrate integrated groove gap waveguide to the microstrip line. The invention has the advantages of low profile, light weight, small volume, easy integration and the like.)

1. The semi-air-filled substrate integrated groove gap waveguide is characterized by comprising a T substrate (4) and a B substrate (5), wherein the T substrate (4) is arranged right above the B substrate (5) in parallel;

the lower surface of the T substrate (4) is provided with a first metallization layer (6), and the first metallization layer (6) is covered with a solder mask layer and used for ball planting of the BGA solder balls (2);

the lower surface of the substrate B (5) is provided with a second metallization layer (7), and the two longitudinal sides of the upper surface of the substrate B (5) are provided with the same metal pad arrays for welding BGA solder balls (2);

the BGA solder balls (2) are welded on the lower surface of the T substrate (4) according to the positions corresponding to the metal pad arrays, and then the T substrate (4) is assembled right above the B substrate (5) through the flip-chip technology, so that the T substrate (4) and the B substrate (5) are supported through two rows of BGA solder ball arrays to form an air gap layer (3);

each BGA solder ball (2), the part of the T substrate (4) right above the BGA solder ball, the part of the B substrate (5) right below the BGA solder ball and the part of the air gap layer (3) form a BGA periodic unit;

the groove (1) of the substrate integrated groove gap waveguide is positioned between BGA solder balls (2) and consists of an air gap layer (3) and a B substrate (5), and the groove (1) of the substrate integrated groove gap waveguide.

2. The semi-air filled substrate integrated slot gap waveguide of claim 1, wherein the T-substrate (4) and B-substrate (5) are Al₂O₃。

3. The semi-air-filled substrate integrated groove-gap waveguide of claim 1, wherein for a W-band substrate integrated groove-gap waveguide design, the BGA periodic unit has a period p set to 0.8mm, the BGA solder balls (2) have a diameter of 300um, and the height of the air gap layer (3), i.e., the final collapse height of the BGA solder balls (2), is set to h₂0.16mm, and a dielectric constant_r9.9, loss tangent tan 0.0001, height h of the T substrate (4)₁0.254mm, height h of the B substrate (5)₃The distance g between the BGA solder ball arrays on the two sides of the groove (1) is 2.2 mm.

4. The half-air filled substrate integrated slot gap waveguide of claim 1, wherein the BGA periodic unit has a period p less than half a wavelength.

5. The semi-air filled substrate integrated groove-gap waveguide of claim 1, wherein the BGA solder balls (2) are less than 0.5p in diameter.

6. The microstrip transition device of a semi-air filled substrate integrated slot gap waveguide according to any one of claims 1 to 5,

the transition conversion device comprises a T-shaped branch (9), an impedance matching section (10) and a pair of reflecting solder balls (11);

the T-shaped branch (9) is inserted into the joint of the microstrip line (8) and the substrate integrated groove gap waveguide and extends towards the inside of the substrate integrated groove gap waveguide;

the impedance matching section (10) consists of microstrip line sections with the width gradually changed according to a certain rule and is positioned between the T-shaped branch (9) and the microstrip line (8);

the shape and specification of the pair of reflecting solder balls (11) are consistent with those of the BGA solder balls (2) in the substrate integrated groove gap waveguide, and the reflecting solder balls are positioned on two sides of the center of the impedance matching section (10);

the T-shaped branch (9) realizes the distribution and the coupling of the electromagnetic field of the microstrip line to the groove (1) of the substrate integrated groove gap waveguide, and a magnetic field matching area is contained in the T-shaped branch;

the impedance matching section (10) realizes the impedance matching function from the microstrip line to the T-shaped branch (9);

the pair of reflective solder balls (11) effects reflection of the electromagnetic field, causing the electromagnetic field to be transmitted towards the groove (1) of the substrate-integrated groove-gap waveguide.

7. The microstrip transition conversion device according to claim 6, wherein the transition conversion device has specific structural parameters: the series width of the impedance matching section (10) with the gradual change of the micro-strip is respectively as follows: w is a₁＝0.067mm，w₂＝0.15mm，w₃＝0.24mm，w₄＝0.28mm，w₅＝0.42mm，w₆0.6 mm; the series lengths of the microstrip gradual change from the microstrip line (8) to the impedance matching section (10) and the T-shaped branch (9) are respectively as follows: l₁＝0.83mm，l₂＝0.95mm，l₃＝1.57mm，l₄＝1.66mm，l₅＝1.8mm，l₆＝1.9mm，l₇2.0 mm; the distance between the centers of a pair of reflective solder balls (11) and the symmetry axis of the groove (1) is w₇0.6 mm; the radius of a circle of a circular magnetic field matching area in the T-shaped branch (9) is r_v0.25 mm; the distance between the center of the circular magnetic field matching area inside the T-shaped branch (9) and the edge of the microstrip line is d₁1.8 mm; the distance between the centers of a pair of reflection solder balls (11) and the edge of the microstrip line is d₂1.4 mm; the longitudinal distance between the microstrip line (8) and the impedance matching section (10) outside the T substrate is d₃＝1.0mm。

8. The microstrip transition conversion device according to claim 6, wherein the substrate integrated groove gap waveguide operating frequency is designed in the millimeter wave band and the terahertz band.

9. The microstrip transition device of claim 8, wherein the transition device is designed to operate in a frequency band matching a substrate integrated slot gap waveguide.

Technical Field

The invention belongs to the technical field of electromagnetic field and microwave, and particularly relates to a semi-air filling substrate integrated groove gap waveguide (BGA-GWG) and a microstrip transition conversion device thereof.

Background

With the rapid development and application of wireless communication technology, the information transmission efficiency and quality of various novel wireless communication systems are higher and higher, and the structures are more and more complex. Especially in millimeter wave and terahertz working frequency bands, in various microwave systems, signal transmission and the realization of passive and active circuits do not leave low-loss transmission media. To meet the requirements of low-loss, highly integrated systems, professor p. -s.kildal, sweden, 2009, proposes Gap-substrate integrated groove Gap Waveguide (GWG) transmission line technology. Compared with the traditional substrate integrated groove gap waveguide, the GWG has the advantage of low transmission loss in millimeter wave and terahertz working frequency band application. In addition, the GWG has a non-contact electromagnetic shield perpendicular to the propagation direction, so its transmission quality is not sensitive to processing errors, which is also important for millimeter wave and terahertz engineering applications.

Gap substrate integrated slot gap waveguides are divided into three types: the ridge gap substrate integrates a Groove gap waveguide (RidgeGWG), the Groove gap substrate integrates a Groove gap waveguide (Groove GWG) and the microstrip gap substrate integrates a Groove gap waveguide. These three GWG structures may be formed of all metals or metal mixed with a Printed Circuit Board (PCB). Electromagnetic waves propagate in the ridge/microstrip GWG and the groove GWG in the form of a quasi-Transverse Electromagnetic (TEM) mode and a quasi-Transverse Electric (TE) mode, respectively.

The typical ridge GWG design uses a pin-type periodic cell. The ridges are surrounded by periodic pins in the non-propagating direction, typically machined. The ridge GWG may also be integrated by a PCB or a low temperature co-fired ceramic (LTCC) substrate. In these substrate-integrated ridge GWG, mushroom-type periodic units are employed. In some studies published in the past, LTCC or PCB substrates were supported by a substrate frame based on a metal base to maintain an air gap layer, achieving low transmission loss characteristics. However, it is difficult to maintain a constant air gap height over large dimensions, even at any small pressure or impact, resulting in degraded or unstable performance. There are also studies that propose complete substrate integration ridges GWG that show the advantage of self-sealing even with more substrate loss.

Typical groove GWG designs also use primarily pin-type periodic elements, with the grooves between the pin arrays being the propagation paths for electromagnetic waves. Due to the lightness of design, the slot GWG is typically fabricated using 3-D printing techniques rather than machining. Researchers have studied micro-electro-mechanical systems (MEMS) technology to design W-band slot GWG bandpass filters for substrate-integrated slot-gap waveguides and packages. At present, compared with a 3-D printing technology, the MEMS technology has the advantages of high processing precision and small volume. However, the design size of the trench GWG is limited to the wafer size, and the cost of its research is relatively high. Furthermore, the MEMS trench GWG requires two silicon wafers as boundaries during the manufacturing process, which makes it difficult to integrate with other elements or substrates. In order to solve the above problems, it is necessary to develop a novel substrate integration trench GWG solution.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a semi-air filling substrate integrated groove gap waveguide and a microstrip transition conversion device thereof, aiming at the defects of the prior art, the invention is a substrate integration solution of the traditional groove gap substrate integrated groove gap waveguide, has the advantages of low profile, light weight, small volume, easy integration and the like, can be applied to active chips such as a front-end transceiver of embedded wafer level packaging and the like to construct a full-medium integrated front-end system, and is applied to platforms such as a small unmanned aerial vehicle and the like with higher requirements on size and weight.

In order to achieve the technical purpose, the technical scheme adopted by the invention is as follows:

the semi-air-filled substrate integrated groove gap waveguide comprises a T substrate and a B substrate, wherein the T substrate is arranged right above the B substrate in parallel;

the lower surface of the T substrate is provided with a first metallization layer, and the first metallization layer is covered with a solder mask layer and used for Ball planting of Ball Grid Array (BGA) solder balls;

the lower surface of the substrate B is a second metallization layer, and the two longitudinal sides of the upper surface of the substrate B are provided with the same metal pad arrays for welding BGA solder balls;

the BGA solder balls are welded on the lower surface of the T substrate according to the positions corresponding to the metal pad arrays, and then the T substrate is assembled right above the B substrate through the flip-chip technology, so that the T substrate and the B substrate are supported through two rows of BGA solder ball arrays to form an air gap layer;

each BGA solder ball, the part of the T substrate right above the BGA solder ball, the part of the B substrate right below the BGA solder ball and the part of the air gap layer form a BGA periodic unit;

the groove of the substrate integrated groove gap waveguide is positioned between the BGA solder balls and consists of an air gap layer and a B substrate, and the groove of the substrate integrated groove gap waveguide.

In order to optimize the technical scheme, the specific measures adopted further comprise:

the T substrate and the B substrate are Al₂O₃。

For the W-band substrate integrated groove gap waveguide design, the period p of the BGA periodic unit is set to 0.8mm, the diameter of the BGA solder ball is 300um, and the height of the air gap layer, namely the final collapse height of the BGA solder ball, is set to h₂0.16mm, and a dielectric constant_r9.9, loss tangent tan 0.0001, T height of substrate h₁0.254mm, height h of the B substrate₃The distance g between the BGA solder ball arrays on the two sides of the groove is 2.2mm which is 0.127 mm.

The period p of the BGA periodic unit is less than half of the wavelength.

The diameter of the BGA solder balls is less than 0.5 p.

The transition conversion device comprises a T-shaped branch, an impedance matching section and a pair of reflecting solder balls;

the T-shaped branch is inserted into the joint of the microstrip line and the substrate integrated groove gap waveguide and extends towards the inside of the substrate integrated groove gap waveguide;

the impedance matching section consists of a microstrip line section with the width gradually changed according to a certain rule and is positioned between the T-shaped branch and the microstrip line;

the shape specification of the pair of reflection solder balls is consistent with that of the BGA solder balls in the substrate integrated groove gap waveguide, and the pair of reflection solder balls are positioned on two sides near the center of the impedance matching section;

the T-shaped branch realizes the distribution and the coupling of the electromagnetic field of the microstrip line to the groove of the substrate integrated groove gap waveguide, and the inside of the T-shaped branch contains a magnetic field matching area;

the impedance matching section realizes the impedance matching function from the microstrip line to the T-shaped branch;

the pair of reflective solder balls reflects an electromagnetic field to transmit the electromagnetic field to the groove of the substrate integrated groove gap waveguide.

The specific structural parameters of the transition conversion device are as follows: the series width of the impedance matching section microstrip gradual change is w respectively₁＝0.067mm，w₂＝0.15mm，w₃＝0.24mm，w₄＝0.28mm，w₅＝0.42mm，w₆0.6 mm; the series length of the microstrip gradual change from the microstrip line to the impedance matching section and the T-shaped branch is l₁＝0.83mm，l₂＝0.95mm，l₃＝1.57mm，l₄＝1.66mm，l₅＝1.8mm，l₆＝1.9mm，l₇2.0 mm; the distance between the centers of a pair of reflective solder balls and the symmetry axis of the groove is w₇0.6 mm; the radius of a circle of a circular magnetic field matching region in the T-shaped branch is r_v0.25 mm; the distance from the center of the circular magnetic field matching region inside the T-shaped branch to the edge of the microstrip line is d₁1.8 mm; the distance between the center of the pair of reflection solder balls and the edge of the microstrip line is d₂1.4 mm; the longitudinal distance between the microstrip line and the impedance matching section outside the T substrate is d₃＝1.0mm。

The working frequency of the substrate integrated groove gap waveguide is designed in a millimeter wave frequency band and a terahertz frequency band.

The transition conversion device is designed to work in a frequency band matched with the substrate integrated groove gap waveguide.

The invention has the following beneficial effects:

the novel semi-air-filled substrate integrated groove gap waveguide is formed by reversely mounting an upper substrate and a lower substrate through Ball Grid Array (BGA) solder balls by utilizing a Flip-Chip technology, so that the novel semi-air-filled substrate integrated groove gap waveguide is also called BGA-GWG for short in the invention. In the novel semi-air-filled substrate integrated groove gap waveguide, an upper substrate and a lower substrate are vertically overlapped together, an air gap layer between the substrates is supported by a solder ball, and the air gap layer and partial media in the lower substrate form an electromagnetic wave transmission path of the substrate integrated groove gap waveguide.

In order to facilitate system integration with other passive/active devices, the invention also discloses a novel microstrip transition conversion device of the substrate integrated groove gap waveguide filled with semi-air. The transition conversion device is composed of a T-shaped branch, an impedance matching section and a pair of reflecting solder balls. The microstrip transition conversion device can realize the radial transition conversion from the novel semi-air filled substrate integrated groove gap waveguide to the microstrip line.

Compared with the existing groove gap waveguide integrated by machining or three-dimensionally printing a groove gap substrate, the all-dielectric integrated waveguide integrated by the method has the advantages of low profile, light weight, all-dielectric integration and the like, can be widely applied to the field of millimeter wave and terahertz circuit design and antennas, is matched with a wafer-level embedded packaged front-end receiving and transmitting chip, can provide an all-dielectric integration scheme for a millimeter wave and terahertz frequency band front-end system, and is particularly suitable for the field of miniaturized unmanned aerial vehicle-mounted application with high requirements on size and weight.

Drawings

FIG. 1 is a schematic diagram of the structure of a substrate integrated slot gap waveguide of the present invention;

FIG. 2 is a schematic diagram of the transition conversion apparatus of the present invention;

FIG. 3 is a substrate integrated slot gap waveguide transmission performance result simulated in accordance with the present invention;

fig. 4 is a simulation result of back-to-back transmission performance of the substrate integrated slot gap waveguide-to-microstrip line transition conversion device simulated according to the present invention.

Wherein the reference numerals are: the structure comprises a groove 1, BGA solder balls 2, an air gap layer 3, a T substrate 4, a B substrate 5, a first metallization layer 6, a second metallization layer 7, a microstrip line 8, a T-shaped branch 9, an impedance matching section 10 and a pair of reflection solder balls 11.

Detailed Description

Embodiments of the present invention are described in further detail below with reference to the accompanying drawings.

Referring to fig. 1, a semi-air filled substrate integrated slot gap waveguide is formed by vertically mounting an upper substrate and a lower substrate with metalized bottom layers through BGA solder balls, and the upper substrate and the lower substrate are respectively called a T substrate 4 and a B substrate 5 according to their relative positions; the lower surfaces of the T substrate 4 and the B substrate 5 are covered by metal to form a metal parallel plate; the width and the length of the substrate integrated groove gap waveguide are w and l respectively, and the substrate integrated groove gap waveguide can conveniently form a full-medium integrated front-end receiving and transmitting system with an embedded wafer-level packaged millimeter wave and terahertz active chip.

Specifically, the substrate integrated groove gap waveguide comprises a T substrate 4 and a B substrate 5, wherein the T substrate 4 is arranged right above the B substrate 5 in parallel, and the shape of the substrates is not limited to a rectangle;

a first metallization layer 6 is arranged on the lower surface of the T substrate 4, and a solder mask layer is covered on the first metallization layer 6 and used for ball planting of the BGA solder balls 2;

the lower surface of the substrate B5 is provided with a second metallization layer 7, and the two longitudinal sides of the upper surface of the substrate B5 are provided with the same metal pad arrays for welding BGA solder balls 2;

the BGA solder balls 2 are welded on the lower surface of the T substrate 4 according to the positions corresponding to the metal pad arrays, and then the T substrate 4 is assembled right above the B substrate 5 through the flip-chip technology, so that the T substrate 4 and the B substrate 5 are supported through two rows of BGA solder ball arrays to form an air gap layer 3;

each BGA solder ball 2, the portion of the T substrate 4 directly above it, the portion of the B substrate 5 directly below it, and the portion of the air gap layer 3 constitute a BGA periodic unit;

the groove 1 of the substrate integrated groove gap waveguide is positioned between BGA solder balls 2 and consists of an air gap layer 3 and a B substrate 5, and the groove 1 of the substrate integrated groove gap waveguide.