Compact broadband 3dB directional coupler based on lamination technology

Abstract

In order to solve the problems that an existing traditional directional coupler is large in size and narrow in bandwidth, the invention provides a compact type broadband 3dB directional coupler based on the lamination technology, and belongs to the field of radio frequency elements, and the compact type broadband 3dB directional coupler comprises a ceramic body, an outer electrode outside the ceramic body and a circuit layer inside the ceramic body. The external electrode comprises a port 1, a port 2, a port 3, a port 4, a first grounding port GND1 and a second grounding port GND2. And the port 1, the port 2, the port 3 and the port 4 can be used as input ends. The directional coupler is compact in size, the relative bandwidth reaches 23.3%, and the installation of the directional coupler in an integrated system is high in flexibility due to the high symmetry of an internal circuit.

Description

Technical Field

[0001] The invention relates to a compact broadband 3dB directional coupler and belongs to the field of radio frequency components. Background Art

[0002] 3dB directional couplers are key passive components used in wireless communications, radar, satellite systems, and microwave test equipment, enabling equal power distribution, signal combination, or phase control. Traditional 3dB directional couplers typically utilize branch-line couplers, Lange couplers, or ring bridge structures. However, these designs often suffer from large size and limited operating bandwidth, making them difficult to meet the demands of modern communication systems for miniaturization, broadband connectivity, and integration. Summary of the Invention

[0003] The invention aims to solve the problems of large size and narrow bandwidth of existing traditional directional couplers.

[0004] The present invention proposes a compact broadband 3dB directional coupler based on stacking technology, comprising a ceramic body, a circuit layer inside the ceramic body, and an external electrode outside the ceramic body. The external electrode includes four mutually equivalent functional ports: Port 1, Port 2, Port 3, and Port 4.

[0005] The circuit layer inside the directional coupler ceramic is used to implement the following circuit structure:

[0006] The circuit structure includes capacitor C1, capacitor C2, capacitor C3, capacitor C4, capacitor C5, capacitor C6, inductor L1, inductor L2, inductor L3, inductor L4, inductor L5, inductor L6 and inductor L7, and C1=C2=C4=C5, L1=L2=L3=L4, L6=L7, C3=C6;

[0007] The left port of inductor L1 is connected to the lower port of capacitor C1, the upper port of inductor L6, and the port Port1; the right port of inductor L1 is connected to the lower port of capacitor C3, the upper port of inductor L5, and the left port of inductor L2; the right port of inductor L2 is connected to the lower port of capacitor C2, the upper port of inductor L7, and the port Port2; the right port of inductor L4 is connected to the lower port of capacitor C2, the lower port of inductor L7, and the port Port3; the left port of inductor L4 is connected to The lower port of inductor L5, the right port of inductor L3, and the upper port of capacitor C6 are connected; the left port of inductor L3 is connected to the lower port of inductor L6, the upper port of capacitor C4, and port Port4; the upper port of capacitor C1, the upper port of capacitor C2, and the upper port of capacitor C3 are connected together and grounded, and the lower port of capacitor C4, the lower port of capacitor C5, and the lower port of capacitor C6 are connected together and grounded; the circuit as a whole constitutes a second-order coupler, which increases the bandwidth of the coupler, and the symmetrical structure improves flexibility during installation.

[0008] Preferably, the outer electrode further includes two symmetrically arranged ground ports: port GND1 and port GND2;

[0009] The upper port of the capacitor C1, the upper port of the capacitor C2 and the upper port of the capacitor C3 are connected together and grounded through the port GND1;

[0010] The lower ports of the capacitor C4, the capacitor C5 and the capacitor C6 are connected together and grounded via the port GND2;

[0011] Preferably, the ground ports GND1 and GND2 are always grounded. When port Port1 is the input end, port Port2 is the through end, port Port3 is the coupling end, and port Port4 is the isolation end; when port Port2 is the input end, port Port1 is the through end, port Port4 is the coupling end, and port Port3 is the isolation end; when port Port3 is the input end, port Port4 is the through end, port Port1 is the coupling end, and port Port2 is the isolation end; when port Port4 is the input end, port Port3 is the through end, port Port2 is the coupling end, and port Port1 is the isolation end.

[0012] Preferably, the circuit layer inside the ceramic is specifically several layers of metal circuits printed on the green porcelain tape: capacitor C1, capacitor C2, capacitor C3, capacitor C4, capacitor C5, capacitor C6, inductor L1, inductor L2, inductor L3, inductor L4, inductor L5, inductor L6 and inductor L7 are connected by the metal circuits printed on each layer of green porcelain tape.

[0013] Preferably, the directional coupler package is rectangular, the long side refers to the long side of the rectangle, and the wide side refers to the short side of the rectangle; the metal sheet refers to a printed block-shaped metal pattern, and the transmission line refers to a printed strip-shaped metal pattern;

[0014] The directional coupler consists of 14 layers of metal circuit packaging printed on green porcelain tape:

[0015] The first layer circuit includes a first metal sheet P1, a second metal sheet P2, a third metal sheet P3, a fourth metal sheet P4, a fifth metal sheet P5, a sixth metal sheet P6, a first via H1, a second via H2, a third via H3, a fourth via H4, a fifth via H5, and a sixth via H6;

[0016] The first metal sheet P1 and the third metal sheet P3, the fourth metal sheet P4 and the sixth metal sheet P6, the first via hole H1 and the third via hole H3, and the fourth via hole H4 and the sixth via hole H6 are symmetrical about the perpendicular midline of the long side;

[0017] The first metal sheet P1 and the fourth metal sheet P4, the second metal sheet P2 and the fifth metal sheet P5, the third metal sheet P3 and the sixth metal sheet P6, the first via hole H1 and the fourth via hole H4, the second via hole H2 and the fifth via hole H5, and the third via hole H3 and the sixth via hole H6 are symmetrical about the perpendicular midline of the broadside;

[0018] The second layer circuit includes the seventh metal sheet P7, the eighth metal sheet P8, the ninth metal sheet P9, the tenth metal sheet P10, the eleventh metal sheet P11, the twelfth metal sheet P12, the first via H1, the second via H2, the third via H3, the fourth via H4, the fifth via H5, the sixth via H6, the seventh via H7, the eighth via H8, the ninth via H9, the tenth via H10, the eleventh via H11 and the twelfth via H12.

[0019] The seventh metal sheet P7 and the ninth metal sheet P9, the tenth metal sheet P10 and the twelfth metal sheet P12, the seventh via hole H7 and the ninth via hole H9, and the tenth via hole H10 and the twelfth via hole H12 are symmetrical about the perpendicular midline of the long side.

[0020] The seventh metal sheet P7 and the tenth metal sheet P10, the eighth metal sheet P8 and the eleventh metal sheet P11, the ninth metal sheet P9 and the twelfth metal sheet P12, the seventh via H7 and the tenth via H10, the eighth via H8 and the eleventh via H11, the ninth via H9 and the twelfth via H12 are symmetrical about the perpendicular midline of the broadside.

[0021] The third layer circuit includes the thirteenth metal sheet P13, the fourteenth metal sheet P14, the fifteenth metal sheet P15, the sixteenth metal sheet P16, the seventeenth metal sheet P17, the eighteenth metal sheet P18, the first via H1, the second via H2, the third via H3, the fourth via H4, the fifth via H5, the sixth via H6, the seventh via H7, the eighth via H8, the ninth via H9, the tenth via H10, the eleventh via H11 and the twelfth via H12.

[0022] The thirteenth metal sheet P13 and the fifteenth metal sheet P15, the sixteenth metal sheet P16 and the eighteenth metal sheet P18 are symmetrical about the perpendicular midline of the long side;

[0023] The thirteenth metal sheet P13 and the sixteenth metal sheet P16 , the fourteenth metal sheet P14 and the seventeenth metal sheet P17 , and the fifteenth metal sheet P15 and the eighteenth metal sheet P18 are symmetrical about the perpendicular midline of the broadside.

[0024] The fourth layer circuit includes the nineteenth metal sheet P19, the twentieth metal sheet P20, the twenty-first metal sheet P21, the twenty-second metal sheet P22, the twenty-third metal sheet P23, the twenty-fourth metal sheet P24, the first via H1, the second via H2, the third via H3, the fourth via H4, the fifth via H5, the sixth via H6, the seventh via H7, the eighth via H8, the ninth via H9, the tenth via H10, the eleventh via H11 and the twelfth via H12.

[0025] The nineteenth metal sheet P19 and the twenty-first metal sheet P21, the twenty-second metal sheet P122 and the twenty-fourth metal sheet P24 are symmetrical about the perpendicular midline of the long side;

[0026] The nineteenth metal sheet P19 and the twenty-second metal sheet P22 , the fourteenth metal sheet P14 and the seventeenth metal sheet P17 , and the fifteenth metal sheet P15 and the eighteenth metal sheet P18 are symmetrical about the perpendicular midline of the broadside.

[0027] The fifth layer circuit includes the twenty-fifth metal sheet P25, the twenty-sixth metal sheet P26, the twenty-seventh metal sheet P27, the twenty-eighth metal sheet P28, the twenty-ninth metal sheet P29, the thirtieth metal sheet P30, the first via H1, the second via H2, the third via H3, the fourth via H4, the fifth via H5, the sixth via H6, the eighth via H8 and the eleventh via H11.

[0028] In particular:

[0029] The twenty-fifth metal sheet P25 and the twenty-seventh metal sheet P27, as well as the twenty-eighth metal sheet P28 and the thirtieth metal sheet P30 are symmetrical about the perpendicular midline of the long side;

[0030] The twenty-fifth metal sheet P25 and the twenty-eighth metal sheet P28 , and the twenty-seventh metal sheet P27 and the thirtieth metal sheet P30 are symmetrical about the perpendicular midline of the broadside.

[0031] The sixth layer circuit includes a thirty-first metal sheet P31 , a thirty-second metal sheet P32 , an eighth via H8 , an eleventh via H11 , a thirteenth via H13 , and a fourteenth via H14 .

[0032] The thirty-first metal piece P31 and the thirty-second metal piece P32 , and the thirteenth via hole H13 and the fourteenth via hole H14 are symmetrical about the perpendicular midline of the broadside.

[0033] The seventh layer circuit includes a thirty-third transmission line P33, a thirty-fourth transmission line P34, an eighth via H8, an eleventh via H11, a thirteenth via H13, a fourteenth via H14, a fifteenth via H15, and a sixteenth via H16.

[0034] The thirty-third transmission line P33 and the thirty-fourth transmission line P34 , and the fifteenth via hole H15 and the sixteenth via hole H16 are centrosymmetric with respect to the geometric center of the circuit layer.

[0035] The eighth layer circuit includes a thirty-fifth transmission line P35, a thirty-sixth transmission line P36, a thirty-seventh transmission line P37, a thirty-eighth transmission line P38, a thirty-ninth transmission line P39, a fortieth transmission line P40, a forty-first transmission line P41, a forty-second transmission line P42, an eighth via H8, an eleventh via H11, a fifteenth via H15, a sixteenth via H16, a seventeenth via H17, an eighteenth via H18, a nineteenth via H19, a twentieth via H20, a twenty-first via H21, a twenty-second via H22, a twenty-third via H23, a twenty-fourth via H24, a twenty-fifth via H25 and a twenty-sixth via H26.

[0036] The thirty-fifth transmission line P35 and the thirty-sixth transmission line P36, the thirty-seventh transmission line P37 and the thirty-eighth transmission line P38, the thirty-ninth transmission line P39 and the fortieth transmission line P40, the seventeenth via hole H17 and the eighteenth via hole H18, the twentieth via hole H20 and the twenty-third via hole H23, the twenty-first via hole H21 and the twenty-fourth via hole H24, and the twenty-fifth via hole H25 and the twenty-sixth via hole H26 are symmetrical about the perpendicular midline of the long side;

[0037] The thirty-fifth transmission line P35 and the thirty-seventh transmission line P37, the thirty-sixth transmission line P36 and the thirty-eighth transmission line P38, the seventeenth via hole H17 and the twenty-sixth via hole H26, and the eighteenth via hole H18 and the twenty-fifth via hole H25 are symmetrical about the perpendicular midline of the broadside;

[0038] The forty-first transmission line P41 and the forty-second transmission line P42 , and the nineteenth via hole H19 and the twenty-second via hole H22 are centrosymmetric with respect to the geometric center of the circuit layer.

[0039] The ninth layer circuit includes the forty-third transmission line P43, the forty-fourth transmission line P44, the forty-fifth transmission line P45, the forty-sixth transmission line P46, the forty-seventh transmission line P47, the forty-eighth transmission line P48, the forty-ninth transmission line P49, the fiftieth transmission line P50, the eighth via H8, the eleventh via H11, the fifteenth via H15, the sixteenth via H16, the seventeenth via H17, the eighteenth via H18, the nineteenth via H19, the twentieth via H20, the twenty-first via H21, the twenty-second via H22, the twenty-third via H23, the twenty-fourth via H24, the twenty-fifth via H25, the twenty-sixth via H26, the twenty-seventh via H27, the twenty-eighth via H28, the twenty-ninth via H29, the thirtieth via H30, the thirty-first via H31, the thirty-second via H32, the thirty-third via H33 and the thirty-fourth via H34.

[0040] The forty-third transmission line P43 and the forty-fourth transmission line P44, the forty-fifth transmission line P45 and the forty-sixth transmission line P46, the forty-eighth transmission line P48 and the forty-ninth transmission line P49, the twenty-seventh via hole H27 and the twenty-eighth via hole H28, the twenty-ninth via hole H29 and the thirtieth via hole H30, and the thirty-first via hole H31 and the thirty-second via hole H32 are symmetrical about the perpendicular midline of the long side.

[0041] The forty-third transmission line P43 and the forty-fifth transmission line P45, the forty-fourth transmission line P44 and the forty-sixth transmission line P46, the twenty-seventh via hole H27 and the twenty-ninth via hole H29, and the twenty-eighth via hole H28 and the thirtieth via hole H30 are symmetrical about the perpendicular midline of the broadside.

[0042] The forty-seventh transmission line P47 and the fiftieth transmission line P50 , the thirty-third via hole H33 , and the thirty-fourth via hole H34 are centrosymmetric with respect to the geometric center of the circuit layer.

[0043] The tenth layer circuit includes the fifty-first transmission line P51, the fifty-second transmission line P52, the fifty-third transmission line P53, the fifty-fourth transmission line P54, the fifty-fifth transmission line P55, the fifty-sixth transmission line P56, the fifty-seventh transmission line P57, the eighth via H8, the eleventh via H11, the twenty-first via H21, the twenty-fourth via H24, the thirty-third via H33, the thirty-fourth via H34, the thirty-fifth via H35, the thirty-sixth via H36, the thirty-seventh via H37, the thirty-eighth via H38, the thirty-ninth via H39 and the fortieth via H40.

[0044] The fifty-first transmission line P51 and the fifty-second transmission line P52, the fifty-third transmission line P53 and the fifty-fourth transmission line P54, the fifty-fifth transmission line P55 and the fifty-sixth transmission line P56, the thirty-fifth via hole H35 and the thirty-sixth via hole H36, the thirty-seventh via hole H37 and the thirty-eighth via hole H38, and the thirty-ninth via hole H39 and the fortieth via hole H40 are symmetrical about the perpendicular midline of the long side.

[0045] The fifty-first transmission line P51 and the fifty-third transmission line P53, the fifty-second transmission line P52 and the fifty-fourth transmission line P54, the thirty-fifth via hole H35 and the thirty-seventh via hole H37, and the thirty-sixth via hole H36 and the thirty-eighth via hole H38 are symmetrical about the perpendicular midline of the broadside.

[0046] The shape of the fifty-seventh transmission line P57 is centrosymmetric about the geometric center of the circuit layer.

[0047] The eleventh layer circuit includes the fifty-eighth transmission line P58, the fifty-ninth transmission line P59, the sixtieth transmission line P60, the sixty-first transmission line P61, the sixty-first transmission line P61, the sixty-second transmission line P62, the sixty-third transmission line P63, the sixty-fourth transmission line P64, the sixty-fifth transmission line P65, the sixty-sixth transmission line P66, the sixty-seventh transmission line P67, the eighth via H8, the eleventh via H11, the twenty-first via H21, the twenty-fourth via H24, the thirty-fifth via H35, the thirty-sixth via H36, the thirty-seventh via H37, the thirty-eighth via H38, the thirty-ninth via H39, the fortieth via H40, the forty-first via H41, the forty-second via H42, the forty-third via H43, the forty-fourth via H44, the forty-fifth via H45, the forty-sixth via H46, the forty-seventh via H47 and the forty-eighth via H48.

[0048] The fifty-eighth transmission line P58 and the fifty-ninth transmission line P59, the sixtieth transmission line P60 and the sixty-first transmission line P61, the sixty-second transmission line P62 and the sixty-third transmission line P63, the sixty-fourth transmission line P64 and the sixty-fifth transmission line P65, the sixty-sixth transmission line P66 and the sixty-seventh transmission line P67, the forty-first via hole H41 and the forty-second via hole H42, the forty-third via hole H43 and the forty-fourth via hole H44, the forty-fifth via hole H45 and the forty-sixth via hole H46, and the forty-seventh via hole H47 and the forty-eighth via hole H48 are respectively symmetrical about the perpendicular midline of the long side;

[0049] The fifty-eighth transmission line P58 and the sixty-fourth transmission line P64, the sixtieth transmission line P60 and the sixty-sixth transmission line P66, the sixty-first transmission line P61 and the sixty-seventh transmission line P67, the fifty-ninth transmission line P59 and the sixty-fifth transmission line P65, the forty-first via hole H41 and the forty-third via hole H43, and the forty-second via hole H42 and the forty-fourth via hole H44 are respectively symmetrical about the perpendicular midline of the wide side.

[0050] The twelfth layer circuit includes the sixty-eighth transmission line P68, the sixty-ninth transmission line P69, the seventieth transmission line P70, the seventy-first transmission line P71, the eighth via H8, the eleventh via H11, the forty-first via H41, the forty-second via H42, the forty-third via H43, the forty-fourth via H44, the forty-fifth via H45, the forty-sixth via H46, the forty-seventh via H47, the forty-eighth via H48, the forty-ninth via H49 and the fiftieth via H50.

[0051] The 70th transmission line P70 and the 71st transmission line P71, the 49th via hole H49 and the 50th via hole H50 are symmetrical about the perpendicular midline of the long side; the shapes of the 68th transmission line P68 and the 69th transmission line P69 are symmetrical about the perpendicular midline of the long side;

[0052] The sixty-eighth transmission line P68 and the sixty-ninth transmission line P69 are symmetrical about the perpendicular midline of the broadside.

[0053] The thirteenth layer circuit includes a seventy-second transmission line P72, a seventy-third transmission line P73, a forty-fifth via H45, a forty-sixth via H46, a forty-ninth via H49, a fiftieth via H50, a fifty-first via H51, and a fifty-second via H52.

[0054] The seventy-second transmission line P72 and the seventy-third transmission line P73 , and the fifty-first via hole H51 and the fifty-second via hole H52 are symmetrical about the perpendicular midline of the long side.

[0055] The thirteenth layer circuit includes a seventy-fourth transmission line P74, a seventy-fifth transmission line P75, a forty-fifth via H45, a forty-sixth via H46, a fifty-first via H51, and a fifty-second via H52.

[0056] The seventy-fourth transmission line P74 and the seventy-fifth transmission line P75 are symmetrical about the perpendicular midline of the long side.

[0057] The thirty-eighth transmission line P38, the forty-sixth transmission line P46, the fifty-fourth transmission line P54, and the sixty-seventh transmission line P67 are connected end to end in sequence via the twenty-fifth via H25, the thirtieth via H30, and the thirty-eighth via H38, and together form the inductor L1;

[0058] The thirty-seventh transmission line P37, the forty-fifth transmission line P45, the fifty-third transmission line P53, and the sixty-sixth transmission line P66 are connected end to end in sequence via the twenty-sixth via H26, the twenty-ninth via H29, and the thirty-seventh via H37, and together form the inductor L2;

[0059] The 36th transmission line P36, the 44th transmission line P44, the 52nd transmission line P52 and the 61st transmission line P61 are connected end to end in sequence via the 18th via H18, the 28th via H28 and the 36th via H36, and together form the inductor L3;

[0060] The 35th transmission line P3, the 43rd transmission line P43, the 51st transmission line P51 and the 60th transmission line P60 are connected end to end in sequence via the 17th via H17, the 27th via H27 and the 35th via H35, and together form the inductor L4;

[0061] The thirty-third transmission line P33, the forty-first transmission line P41, the forty-seventh transmission line P47, the fifty-seventh transmission line P57, the fiftieth transmission line P50, the forty-second transmission line P42, and the thirty-fourth transmission line are connected end to end in sequence via the fifteenth via H15, the nineteenth via H19, the thirty-third via H33, the thirty-fourth via H34, the twenty-first via H21, and the sixteenth via H16, to form an inductor L5.

[0062] The 40th transmission line P40, the 49th transmission line P49, the 56th transmission line P56, the 63rd transmission line P63, the 71st transmission line P71, the 73rd transmission line P73 and the 75th transmission line P75 are connected end to end in sequence via the 23rd via H23, the 32nd via H32, the 40th via H40, the 48th via H48, the 50th via H50 and the 52nd via H52, together forming the inductor L6;

[0063] The thirty-ninth transmission line P39, the forty-eighth transmission line P48, the fifty-fifth transmission line P55, the sixty-second transmission line P62, the seventieth transmission line P70, the seventy-second transmission line P72, and the seventy-fourth transmission line P74 are connected end to end in sequence via the twentieth via H20, the thirty-first via H31, the thirty-ninth via H39, the forty-seventh via H47, the forty-ninth via H59, and the fifty-first via H51, to form an inductor L7.

[0064] The sixth metal sheet P6, the eighteenth metal sheet P18, and the thirtieth metal sheet P30 are vertically connected to form a whole through the sixth via H6, and the twelfth metal sheet P12 and the twenty-fourth metal sheet P24 are vertically connected to form a whole through the twelfth via H12, and the two wholes form a capacitor C1 through vertical coupling;

[0065] The fourth metal sheet P4, the sixteenth metal sheet P16, and the twenty-eighth metal sheet P28 are vertically connected to form a whole through the fourth via H4, and the tenth metal sheet P10 and the twenty-second metal sheet P22 are vertically connected to form a whole through the tenth via H10. The two wholes are vertically coupled to form a capacitor C2.

[0066] The fifth metal sheet P5, the seventeenth metal sheet P17, and the twenty-ninth metal sheet P29 are vertically connected to form a whole through the fifth via H5. The eleventh metal sheet P11, the twenty-third metal sheet P23, and the thirty-second metal sheet P32 are vertically connected to form a whole through the eleventh via H11. The two wholes form a capacitor C3 through vertical coupling.

[0067] The third metal sheet P3, the fifteenth metal sheet P15, and the twenty-seventh metal sheet P27 are vertically connected to form a whole through the third via H3, and the ninth metal sheet P9 and the twenty-first metal sheet P21 are vertically connected to form a whole through the ninth via H9. The two wholes form a capacitor C4 through vertical coupling.

[0068] The first metal sheet P1, the thirteenth metal sheet P13, and the twenty-fifth metal sheet P25 are vertically connected to form a whole through the first via H1, and the seventh metal sheet P7 and the nineteenth metal sheet P19 are vertically connected to form a whole through the seventh via H7. The two wholes form a capacitor C5 through vertical coupling;

[0069] The second metal sheet P2, the fourteenth metal sheet P14, and the twenty-sixth metal sheet P26 are vertically connected into a whole through the second via H2, and the eighth metal sheet P8, the twentieth metal sheet P20, and the thirty-first metal sheet P31 are vertically connected into a whole through the eighth via H8. The two wholes are vertically coupled to form a capacitor C6.

[0070] Preferably, in the inductor L1, the thirty-eighth transmission line P38 is connected to the port Port1, and the sixty-seventh transmission line P67 is connected to the sixty-ninth transmission line P69 through the forty-fourth via H44;

[0071] In the inductor L2, the thirty-seventh transmission line P37 is connected to the port Port2, and the sixty-sixth transmission line P66 is connected to the sixty-ninth transmission line H69 through the forty-third via H43;

[0072] In the inductor L3, the thirty-sixth transmission line P36 is connected to the port Port4, and the sixty-first transmission line P61 is connected to the sixty-eighth transmission line H68 through the forty-second via H42;

[0073] In the inductor L4, the thirty-fifth transmission line P35 is connected to the port Port3, and the sixtieth transmission line P60 is connected to the sixty-eighth transmission line H68 through the forty-first via H41;

[0074] In the inductor L5, the thirty-third transmission line P33 is connected to the thirty-first metal piece P31 in the capacitor C6 through the thirteenth via H13, and the thirty-fourth transmission line P34 is connected to the thirty-second metal piece P32 in the capacitor C3 through the fourteenth via H14;

[0075] In the inductor L6, the 40th transmission line P40 is connected to one end of the 65th transmission line P65 through the 24th via H24, and the other end of the 65th transmission line P65 is connected to the port Port1; the 75th transmission line P75 is connected to one end of the 59th transmission line P59 through the 46th via H46, and the other end of the 59th transmission line P59 is connected to the port Port4;

[0076] In the inductor L7, the thirty-ninth transmission line P39 is connected to one end of the sixty-fourth transmission line P64 through the twenty-first via H21, and the other end of the sixty-fourth transmission line P64 is connected to the port Port3; the seventy-fourth transmission line P74 is connected to one end of the fifty-eighth transmission line P58 through the forty-fifth via H45, and the other end of the fifty-eighth transmission line P58 is connected to the port Port3;

[0077] In the capacitor C1, the twelfth metal piece P12 and the twenty-fourth metal piece P24 are connected to the port Port1 through a microstrip line; the sixth metal piece P6 is connected to the fifth metal piece P5 in the capacitor C3;

[0078] In the capacitor C2, the tenth metal sheet P10 and the twenty-second metal sheet P22 are connected to the port Port2 via a microstrip line; the fourth metal sheet P4 is connected to the fifth metal sheet P5 in the capacitor C3;

[0079] In the capacitor C3, the fifth metal piece P5 is connected to the first ground terminal GND1 through a microstrip line; the thirty-second metal piece P32 is connected to the sixty-ninth transmission line P69 through the eleventh via H11;

[0080] In the capacitor C4, the ninth metal sheet P9 and the twenty-first metal sheet P21 are connected to the port Port4 via a microstrip line; the third metal sheet P3 is connected to the second metal sheet P2 in the capacitor C6;

[0081] In the capacitor C5, the seventh metal piece P7 and the nineteenth metal piece P19 are connected to the port Port3 via a microstrip line; the first metal piece P1 is connected to the second metal piece P2 in the capacitor C6;

[0082] In the capacitor C6, the second metal piece P2 is connected to the second ground terminal GND2 through a microstrip line; the thirty-first metal piece P31 is connected to the sixty-eighth transmission line P68 through the eighth via H8.

[0083] The directional coupler has a compact size, a relative bandwidth of 23.3%, and a high degree of symmetry of the internal circuit, which makes it highly flexible in installation in integrated systems.

[0084] Low Temperature Co-fired Ceramics (LTCC) technology embeds equivalent circuits inside ceramic blocks and uses metallized vias to vertically connect various components, greatly improving the flexibility of component layout and significantly reducing the size of the device. At the same time, LTCC technology can achieve multi-layer wiring, high integration, light weight, and high reliability.

[0085] The compact broadband 3dB directional coupler based on stacking technology provided by the present invention converts the traditional double-branch coupler into a second-order LC coupler, and integrates the equivalent circuit constituting the coupler inside the ceramic. It has the characteristics of compact size, wide bandwidth, and high reliability. It is suitable for miniaturized communication systems and solves the problems of large size and narrow bandwidth of traditional directional couplers. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the specific embodiments or the description of the prior art. Hereinafter, some specific embodiments of the present invention will be described in detail in an illustrative and non-limiting manner with reference to the drawings. The same reference numerals in the drawings indicate the same or similar components or parts. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0087] Figure 1 Schematic diagram of the external packaging of the present invention.

[0088] Figure 2 It is a schematic diagram of the internal structure of the present invention.

[0089] Figure 3 This is a description of the port configuration of the present invention.

[0090] Figure 4 Schematic diagram of the equivalent circuit of the present invention.

[0091] Figure 5 This is a schematic diagram of the first layer circuit structure of the present invention.

[0092] Figure 6 This is a schematic diagram of the second-layer circuit structure of the present invention.

[0093] Figure 7 This is a schematic diagram of the third layer circuit structure of the present invention.

[0094] Figure 8 This is a schematic diagram of the fourth layer circuit structure of the present invention.

[0095] Figure 9 This is a schematic diagram of the fifth layer circuit structure of the present invention.

[0096] Figure 10 This is a schematic diagram of the sixth layer circuit structure of the present invention.

[0097] Figure 11 This is a schematic diagram of the seventh layer circuit structure of the present invention.

[0098] Figure 12 This is a schematic diagram of the eighth layer circuit structure of the present invention.

[0099] Figure 13 This is a schematic diagram of the ninth layer circuit structure of the present invention.

[0100] Figure 14 This is a schematic diagram of the tenth layer circuit structure of the present invention.

[0101] Figure 15 This is a schematic diagram of the eleventh layer circuit structure of the present invention.

[0102] Figure 16 This is a schematic diagram of the twelfth-layer circuit structure of the present invention.

[0103] Figure 17 This is a schematic diagram of the thirteenth layer circuit structure of the present invention.

[0104] Figure 18 This is a schematic diagram of the fourteenth layer circuit structure of the present invention.

[0105] Figure 19 FIG. 4 is an S-parameter curve diagram of the directional coupler of the present invention.

[0106] Figure 20 is the amplitude balance of the directional coupler of the present invention.

[0107] Figure 21 is the insertion loss of the directional coupler of the present invention.

[0108] Figure 22 is the phase difference of the directional coupler of the present invention. DETAILED DESCRIPTION

[0109] In order to make the purpose, technical solutions and advantages of this application more clear, the following further describes this application in detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0110] In this embodiment, the compact broadband 3dB directional coupler based on stacking technology includes a ceramic body, a circuit layer inside the ceramic, and external electrodes outside the ceramic body. The electrodes include functional terminals Port1, Port2, Port3, Port4 and ground terminals GND1 and GND2. The connection between layers is achieved through metallized vias.

[0111] The 3dB directional coupler package is rectangular, measuring 2.5mm × 2.0mm × 0.7mm. To facilitate description of circuit layer characteristics, the 2.5mm side is referred to as the long side, and the 2.0mm side is referred to as the wide side. Some vias penetrate multiple circuit layers, so only their initial placement is described.

[0112] The block-shaped metal pattern is defined as a "metal sheet" and the strip-shaped metal pattern is defined as a "transmission line." In the present invention, the width of the transmission line is 0.08 mm and the radius of the via hole is 0.04 mm.

[0113] Figure 1 Schematic diagram of the external packaging of the present invention.

[0114] Among them: 1. Ceramic body; external electrodes GND1 and GND2 are ground terminals; ports Port1, Port2, Port3, and Port4 are functional ports; 2. Identification.

[0115] Figure 2 It is a schematic diagram of the internal structure of the present invention.

[0116] There are fourteen circuit layers in total, from bottom to top: the first circuit layer, the second circuit layer, the third circuit layer, the fourth circuit layer, the fifth circuit layer, the sixth circuit layer, the seventh circuit layer, the eighth circuit layer, the ninth circuit layer, the tenth circuit layer, the eleventh circuit layer, the twelfth circuit layer, the thirteenth circuit layer and the fourteenth circuit layer. Each layer of green porcelain tape is printed with a specific metal circuit.

[0117] Figure 3 This is a description of the port configuration of the present invention.

[0118] Ground ports GND1 and GND2 are always grounded. When port Port1 is the input port, port Port2 is the pass-through port, port Port3 is the coupling port, and port Port4 is the isolation port. When port Port2 is the input port, port Port1 is the pass-through port, port Port4 is the coupling port, and port Port3 is the isolation port. When port Port3 is the input port, port Port4 is the pass-through port, port Port1 is the coupling port, and port Port2 is the isolation port. When port Port4 is the input port, port Port3 is the pass-through port, port Port2 is the coupling port, and port Port1 is the isolation port.

[0119] Figure 4 Schematic diagram of the equivalent circuit of the present invention.

[0120] The circuit is symmetrical in both vertical and horizontal directions, with the following relationships: C1 = C2 = C4 = C5, L1 = L2 = L3 = L4, L6 = L7, and C3 = C6. The connection relationships of the various components in the circuit are as follows: the left port of inductor L1 is connected to the lower port of capacitor C1, the upper port of inductor L6, and also to port Port1; the right port of inductor L1 is connected to the lower port of capacitor C3, the upper port of inductor L5, and the left port of inductor L2; the right port of inductor L2 is connected to the lower port of capacitor C2, the upper port of inductor L7, and also to port Port2; the right port of inductor L4 is connected to the lower port of capacitor C2 and the lower port of inductor L7. The left port of inductor L4 is connected to the lower port of inductor L5, the right port of inductor L3, and the upper port of capacitor C6. The left port of inductor L3 is connected to the lower port of inductor L6, the upper port of capacitor C4, and Port4. The upper ports of capacitors C1, C2, and C3 are connected together and grounded, while the lower ports of capacitors C4, C5, and C6 are connected together and grounded. This circuit forms a second-order coupler, increasing the coupler's bandwidth. Its symmetrical structure also improves installation flexibility.

[0121] Figure 5 This is a schematic diagram of the first layer circuit structure of the present invention.

[0122] The first layer circuit includes a first metal sheet P1, a second metal sheet P2, a third metal sheet P3, a fourth metal sheet P4, a fifth metal sheet P5, a sixth metal sheet P6, a first via H1, a second via H2, a third via H3, a fourth via H4, a fifth via H5 and a sixth via H6.

[0123] In particular:

[0124] The first metal sheet P1 and the third metal sheet P3, the fourth metal sheet P4 and the sixth metal sheet P6, the first via hole H1 and the third via hole H3, and the fourth via hole H4 and the sixth via hole H6 are symmetrical about the perpendicular midline of the long side;

[0125] The first metal sheet P1 and the fourth metal sheet P4, the second metal sheet P2 and the fifth metal sheet P5, the third metal sheet P3 and the sixth metal sheet P6, the first via H1 and the fourth via H4, the second via H2 and the fifth via H5, and the third via H3 and the sixth via H6 are symmetrical about the perpendicular midline of the wide side.

[0126] Figure 6 This is a schematic diagram of the second-layer circuit structure of the present invention.

[0127] The second layer circuit includes a seventh metal sheet P7, an eighth metal sheet P8, a ninth metal sheet P9, a tenth metal sheet P10, an eleventh metal sheet P11, a twelfth metal sheet P12, a first via H1, a second via H2, a third via H3, a fourth via H4, a fifth via H5, a sixth via H6, a seventh via H7, an eighth via H8, a ninth via H9, a tenth via H10, an eleventh via H11 and a twelfth via H12.

[0128] In particular:

[0129] The seventh metal sheet P7 and the ninth metal sheet P9, the tenth metal sheet P10 and the twelfth metal sheet P12, the seventh via hole H7 and the ninth via hole H9, and the tenth via hole H10 and the twelfth via hole H12 are symmetrical about the perpendicular midline of the long side.

[0130] The seventh metal sheet P7 and the tenth metal sheet P10, the eighth metal sheet P8 and the eleventh metal sheet P11, the ninth metal sheet P9 and the twelfth metal sheet P12, the seventh via H7 and the tenth via H10, the eighth via H8 and the eleventh via H11, the ninth via H9 and the twelfth via H12 are symmetrical about the perpendicular midline of the broadside.

[0131] Figure 7 This is a schematic diagram of the third layer circuit structure of the present invention.

[0132] The third layer circuit includes a thirteenth metal sheet P13, a fourteenth metal sheet P14, a fifteenth metal sheet P15, a sixteenth metal sheet P16, a seventeenth metal sheet P17, an eighteenth metal sheet P18, a first via H1, a second via H2, a third via H3, a fourth via H4, a fifth via H5, a sixth via H6, a seventh via H7, an eighth via H8, a ninth via H9, a tenth via H10, an eleventh via H11 and a twelfth via H12.

[0133] In particular:

[0134] The thirteenth metal sheet P13 and the fifteenth metal sheet P15, the sixteenth metal sheet P16 and the eighteenth metal sheet P18 are symmetrical about the perpendicular midline of the long side;

[0135] The thirteenth metal sheet P13 and the sixteenth metal sheet P16 , the fourteenth metal sheet P14 and the seventeenth metal sheet P17 , and the fifteenth metal sheet P15 and the eighteenth metal sheet P18 are symmetrical about the perpendicular midline of the broadside.

[0136] Figure 8 This is a schematic diagram of the fourth layer circuit structure of the present invention.

[0137] The fourth layer circuit includes a nineteenth metal sheet P19, a twentieth metal sheet P20, a twenty-first metal sheet P21, a twenty-second metal sheet P22, a twenty-third metal sheet P23, a twenty-fourth metal sheet P24, a first via H1, a second via H2, a third via H3, a fourth via H4, a fifth via H5, a sixth via H6, a seventh via H7, an eighth via H8, a ninth via H9, a tenth via H10, an eleventh via H11 and a twelfth via H12.

[0138] In particular:

[0139] The nineteenth metal sheet P19 and the twenty-first metal sheet P21, the twenty-second metal sheet P122 and the twenty-fourth metal sheet P24 are symmetrical about the perpendicular midline of the long side;

[0140] The nineteenth metal sheet P19 and the twenty-second metal sheet P22 , the fourteenth metal sheet P14 and the seventeenth metal sheet P17 , and the fifteenth metal sheet P15 and the eighteenth metal sheet P18 are symmetrical about the perpendicular midline of the broadside.

[0141] Figure 9 This is a schematic diagram of the fifth layer circuit structure of the present invention.

[0142] The fifth layer circuit includes a twenty-fifth metal sheet P25, a twenty-sixth metal sheet P26, a twenty-seventh metal sheet P27, a twenty-eighth metal sheet P28, a twenty-ninth metal sheet P29, a thirtieth metal sheet P30, a first via H1, a second via H2, a third via H3, a fourth via H4, a fifth via H5, a sixth via H6, an eighth via H8 and an eleventh via H11.

[0143] In particular:

[0144] The twenty-fifth metal sheet P25 and the twenty-seventh metal sheet P27, as well as the twenty-eighth metal sheet P28 and the thirtieth metal sheet P30 are symmetrical about the perpendicular midline of the long side;

[0145] The twenty-fifth metal sheet P25 and the twenty-eighth metal sheet P28 , and the twenty-seventh metal sheet P27 and the thirtieth metal sheet P30 are symmetrical about the perpendicular midline of the broadside.

[0146] Figure 10 This is a schematic diagram of the sixth layer circuit structure of the present invention.

[0147] The sixth layer circuit includes a thirty-first metal sheet P31, a thirty-second metal sheet P32, an eighth via H8, an eleventh via H11, a thirteenth via H13, and a fourteenth via H14.

[0148] In particular:

[0149] The thirty-first metal piece P31 and the thirty-second metal piece P32 , and the thirteenth via hole H13 and the fourteenth via hole H14 are symmetrical about the perpendicular midline of the broadside.

[0150] Figure 11 This is a schematic diagram of the seventh layer circuit structure of the present invention.

[0151] The seventh layer circuit includes a thirty-third transmission line P33, a thirty-fourth transmission line P34, an eighth via H8, an eleventh via H11, a thirteenth via H13, a fourteenth via H14, a fifteenth via H15, and a sixteenth via H16.

[0152] In particular:

[0153] The thirty-third transmission line P33 and the thirty-fourth transmission line P34 , and the fifteenth via hole H15 and the sixteenth via hole H16 are centrosymmetric with respect to the geometric center of the circuit layer.

[0154] Figure 12 This is a schematic diagram of the eighth layer circuit structure of the present invention.

[0155] The eighth layer circuit includes a thirty-fifth transmission line P35, a thirty-sixth transmission line P36, a thirty-seventh transmission line P37, a thirty-eighth transmission line P38, a thirty-ninth transmission line P39, a fortieth transmission line P40, a forty-first transmission line P41, a forty-second transmission line P42, an eighth via H8, an eleventh via H11, a fifteenth via H15, a sixteenth via H16, a seventeenth via H17, an eighteenth via H18, a nineteenth via H19, a twentieth via H20, a twenty-first via H21, a twenty-second via H22, a twenty-third via H23, a twenty-fourth via H24, a twenty-fifth via H25 and a twenty-sixth via H26.

[0156] In particular:

[0157] The thirty-fifth transmission line P35 and the thirty-sixth transmission line P36, the thirty-seventh transmission line P37 and the thirty-eighth transmission line P38, the thirty-ninth transmission line P39 and the fortieth transmission line P40, the seventeenth via hole H17 and the eighteenth via hole H18, the twentieth via hole H20 and the twenty-third via hole H23, the twenty-first via hole H21 and the twenty-fourth via hole H24, and the twenty-fifth via hole H25 and the twenty-sixth via hole H26 are symmetrical about the perpendicular midline of the long side;

[0158] The thirty-fifth transmission line P35 and the thirty-seventh transmission line P37, the thirty-sixth transmission line P36 and the thirty-eighth transmission line P38, the seventeenth via hole H17 and the twenty-sixth via hole H26, and the eighteenth via hole H18 and the twenty-fifth via hole H25 are symmetrical about the perpendicular midline of the broadside;

[0159] The forty-first transmission line P41 and the forty-second transmission line P42 , and the nineteenth via hole H19 and the twenty-second via hole H22 are centrosymmetric with respect to the geometric center of the circuit layer.

[0160] Figure 13 This is a schematic diagram of the ninth layer circuit structure of the present invention.

[0161] The ninth layer circuit includes the forty-third transmission line P43, the forty-fourth transmission line P44, the forty-fifth transmission line P45, the forty-sixth transmission line P46, the forty-seventh transmission line P47, the forty-eighth transmission line P48, the forty-ninth transmission line P49, the fiftieth transmission line P50, the eighth via H8, the eleventh via H11, the fifteenth via H15, the sixteenth via H16, the seventeenth via H17, the eighteenth via H18, the nineteenth via H19, the twentieth via H20, the twenty-first via H21, the twenty-second via H22, the twenty-third via H23, the twenty-fourth via H24, the twenty-fifth via H25, the twenty-sixth via H26, the twenty-seventh via H27, the twenty-eighth via H28, the twenty-ninth via H29, the thirtieth via H30, the thirty-first via H31, the thirty-second via H32, the thirty-third via H33 and the thirty-fourth via H34.

[0162] In particular:

[0163] The forty-third transmission line P43 and the forty-fourth transmission line P44, the forty-fifth transmission line P45 and the forty-sixth transmission line P46, the forty-eighth transmission line P48 and the forty-ninth transmission line P49, the twenty-seventh via hole H27 and the twenty-eighth via hole H28, the twenty-ninth via hole H29 and the thirtieth via hole H30, and the thirty-first via hole H31 and the thirty-second via hole H32 are symmetrical about the perpendicular midline of the long side.

[0164] The forty-third transmission line P43 and the forty-fifth transmission line P45, the forty-fourth transmission line P44 and the forty-sixth transmission line P46, the twenty-seventh via hole H27 and the twenty-ninth via hole H29, and the twenty-eighth via hole H28 and the thirtieth via hole H30 are symmetrical about the perpendicular midline of the broadside.

[0165] The forty-seventh transmission line P47 and the fiftieth transmission line P50 , the thirty-third via hole H33 , and the thirty-fourth via hole H34 are centrosymmetric with respect to the geometric center of the circuit layer.

[0166] Figure 14 This is a schematic diagram of the tenth layer circuit structure of the present invention.

[0167] The tenth layer circuit includes a fifty-first transmission line P51, a fifty-second transmission line P52, a fifty-third transmission line P53, a fifty-fourth transmission line P54, a fifty-fifth transmission line P55, a fifty-sixth transmission line P56, a fifty-seventh transmission line P57, an eighth via H8, an eleventh via H11, a twenty-first via H21, a twenty-fourth via H24, a thirty-third via H33, a thirty-fourth via H34, a thirty-fifth via H35, a thirty-sixth via H36, a thirty-seventh via H37, a thirty-eighth via H38, a thirty-ninth via H39 and a fortieth via H40.

[0168] In particular:

[0169] The fifty-first transmission line P51 and the fifty-second transmission line P52, the fifty-third transmission line P53 and the fifty-fourth transmission line P54, the fifty-fifth transmission line P55 and the fifty-sixth transmission line P56, the thirty-fifth via hole H35 and the thirty-sixth via hole H36, the thirty-seventh via hole H37 and the thirty-eighth via hole H38, and the thirty-ninth via hole H39 and the fortieth via hole H40 are symmetrical about the perpendicular midline of the long side.

[0170] The fifty-first transmission line P51 and the fifty-third transmission line P53, the fifty-second transmission line P52 and the fifty-fourth transmission line P54, the thirty-fifth via hole H35 and the thirty-seventh via hole H37, and the thirty-sixth via hole H36 and the thirty-eighth via hole H38 are symmetrical about the perpendicular midline of the broadside.

[0171] The shape of the fifty-seventh transmission line P57 is centrosymmetric about the geometric center of the circuit layer.

[0172] Figure 15 This is a schematic diagram of the eleventh layer circuit structure of the present invention.

[0173] The eleventh layer circuit includes the fifty-eighth transmission line P58, the fifty-ninth transmission line P59, the sixtieth transmission line P60, the sixty-first transmission line P61, the sixty-first transmission line P61, the sixty-second transmission line P62, the sixty-third transmission line P63, the sixty-fourth transmission line P64, the sixty-fifth transmission line P65, the sixty-sixth transmission line P66, the sixty-seventh transmission line P67, the eighth via H8, the eleventh via H11, the twenty-first via H21, the twenty-fourth via H24, the thirty-fifth via H35, the thirty-sixth via H36, the thirty-seventh via H37, the thirty-eighth via H38, the thirty-ninth via H39, the fortieth via H40, the forty-first via H41, the forty-second via H42, the forty-third via H43, the forty-fourth via H44, the forty-fifth via H45, the forty-sixth via H46, the forty-seventh via H47 and the forty-eighth via H48.

[0174] In particular:

[0175] The fifty-eighth transmission line P58 and the fifty-ninth transmission line P59, the sixtieth transmission line P60 and the sixty-first transmission line P61, the sixty-second transmission line P62 and the sixty-third transmission line P63, the sixty-fourth transmission line P64 and the sixty-fifth transmission line P65, the sixty-sixth transmission line P66 and the sixty-seventh transmission line P67, the forty-first via hole H41 and the forty-second via hole H42, the forty-third via hole H43 and the forty-fourth via hole H44, the forty-fifth via hole H45 and the forty-sixth via hole H46, and the forty-seventh via hole H47 and the forty-eighth via hole H48 are respectively symmetrical about the perpendicular midline of the long side;

[0176] The fifty-eighth transmission line P58 and the sixty-fourth transmission line P64, the sixtieth transmission line P60 and the sixty-sixth transmission line P66, the sixty-first transmission line P61 and the sixty-seventh transmission line P67, the fifty-ninth transmission line P59 and the sixty-fifth transmission line P65, the forty-first via hole H41 and the forty-third via hole H43, and the forty-second via hole H42 and the forty-fourth via hole H44 are respectively symmetrical about the perpendicular midline of the wide side.

[0177] Figure 16 This is a schematic diagram of the twelfth-layer circuit structure of the present invention.

[0178] The twelfth layer circuit includes the sixty-eighth transmission line P68, the sixty-ninth transmission line P69, the seventieth transmission line P70, the seventy-first transmission line P71, the eighth via H8, the eleventh via H11, the forty-first via H41, the forty-second via H42, the forty-third via H43, the forty-fourth via H44, the forty-fifth via H45, the forty-sixth via H46, the forty-seventh via H47, the forty-eighth via H48, the forty-ninth via H49 and the fiftieth via H50.

[0179] In particular:

[0180] The 70th transmission line P70 and the 71st transmission line P71, the 49th via hole H49 and the 50th via hole H50 are symmetrical about the perpendicular midline of the long side; the shapes of the 68th transmission line P68 and the 69th transmission line P69 are symmetrical about the perpendicular midline of the long side;

[0181] The sixty-eighth transmission line P68 and the sixty-ninth transmission line P69 are symmetrical about the perpendicular midline of the broadside.

[0182] Figure 17 This is a schematic diagram of the thirteenth layer circuit structure of the present invention.

[0183] The thirteenth layer circuit includes a seventy-second transmission line P72, a seventy-third transmission line P73, a forty-fifth via H45, a forty-sixth via H46, a forty-ninth via H49, a fiftieth via H50, a fifty-first via H51, and a fifty-second via H52.

[0184] In particular:

[0185] The seventy-second transmission line P72 and the seventy-third transmission line P73 , and the fifty-first via hole H51 and the fifty-second via hole H52 are symmetrical about the perpendicular midline of the long side.

[0186] Figure 18 This is a schematic diagram of the fourteenth layer circuit structure of the present invention.

[0187] The thirteenth layer circuit includes a seventy-fourth transmission line P74, a seventy-fifth transmission line P75, a forty-fifth via H45, a forty-sixth via H46, a fifty-first via H51, and a fifty-second via H52.

[0188] In particular:

[0189] The seventy-fourth transmission line P74 and the seventy-fifth transmission line P75 are symmetrical about the perpendicular midline of the long side.

[0190] The implementation methods of each component are:

[0191] The thirty-eighth transmission line P38, the forty-sixth transmission line P46, the fifty-fourth transmission line P54, and the sixty-seventh transmission line P67 are connected end to end in sequence via the twenty-fifth via H25, the thirtieth via H30, and the thirty-eighth via H38, and together form an equivalent inductor L1;

[0192] The thirty-seventh transmission line P37, the forty-fifth transmission line P45, the fifty-third transmission line P53 and the sixty-sixth transmission line P66 are connected end to end in sequence via the twenty-sixth via H26, the twenty-ninth via H29 and the thirty-seventh via H37, and together form an equivalent inductor L2;

[0193] The thirty-sixth transmission line P36, the forty-fourth transmission line P44, the fifty-second transmission line P52, and the sixty-first transmission line P61 are connected end to end in sequence via the eighteenth via H18, the twenty-eighth via H28, and the thirty-sixth via H36, and together form an equivalent inductor L3;

[0194] The 35th transmission line P3, the 43rd transmission line P43, the 51st transmission line P51 and the 60th transmission line P60 are connected end to end in sequence via the 17th via H17, the 27th via H27 and the 35th via H35, and together form an equivalent inductor L4;

[0195] The thirty-third transmission line P33, the forty-first transmission line P41, the forty-seventh transmission line P47, the fifty-seventh transmission line P57, the fiftieth transmission line P50, the forty-second transmission line P42, and the thirty-fourth transmission line are connected end to end in sequence via the fifteenth via H15, the nineteenth via H19, the thirty-third via H33, the thirty-fourth via H34, the twenty-first via H21, and the sixteenth via H16, and together form an equivalent inductor L5;

[0196] The 40th transmission line P40, the 49th transmission line P49, the 56th transmission line P56, the 63rd transmission line P63, the 71st transmission line P71, the 73rd transmission line P73 and the 75th transmission line P75 are connected end to end in sequence by the 23rd via H23, the 32nd via H32, the 40th via H40, the 48th via H48, the 50th via H50 and the 52nd via H52, and together form an equivalent inductor L6;

[0197] The thirty-ninth transmission line P39, the forty-eighth transmission line P48, the fifty-fifth transmission line P55, the sixty-second transmission line P62, the seventieth transmission line P70, the seventy-second transmission line P72, and the seventy-fourth transmission line P74 are connected end to end in sequence via the twentieth via H20, the thirty-first via H31, the thirty-ninth via H39, the forty-seventh via H47, the forty-ninth via H59, and the fifty-first via H51, and together form an equivalent inductor L7;

[0198] The sixth metal sheet P6, the eighteenth metal sheet P18, and the thirtieth metal sheet P30 are vertically connected to form a whole through the sixth via H6, and the twelfth metal sheet P12 and the twenty-fourth metal sheet P24 are vertically connected to form a whole through the twelfth via H12, and the two wholes form an equivalent capacitor C1 through vertical coupling;

[0199] The fourth metal sheet P4, the sixteenth metal sheet P16, and the twenty-eighth metal sheet P28 are vertically connected to form a whole through the fourth via H4, and the tenth metal sheet P10 and the twenty-second metal sheet P22 are vertically connected to form a whole through the tenth via H10. The two wholes form an equivalent capacitor C2 through vertical coupling;

[0200] The fifth metal sheet P5, the seventeenth metal sheet P17, and the twenty-ninth metal sheet P29 are vertically connected to form a whole through the fifth via H5. The eleventh metal sheet P11, the twenty-third metal sheet P23, and the thirty-second metal sheet P32 are vertically connected to form a whole through the eleventh via H11. The two wholes form an equivalent capacitor C3 through vertical coupling.

[0201] The third metal sheet P3, the fifteenth metal sheet P15, and the twenty-seventh metal sheet P27 are vertically connected to form a whole through the third via H3, and the ninth metal sheet P9 and the twenty-first metal sheet P21 are vertically connected to form a whole through the ninth via H9. The two wholes form an equivalent capacitor C4 through vertical coupling;

[0202] The first metal sheet P1, the thirteenth metal sheet P13, and the twenty-fifth metal sheet P25 are vertically connected to form a whole through the first via H1, and the seventh metal sheet P7 and the nineteenth metal sheet P19 are vertically connected to form a whole through the seventh via H7. The two wholes form an equivalent capacitor C5 through vertical coupling;

[0203] The second metal sheet P2, the fourteenth metal sheet P14, and the twenty-sixth metal sheet P26 are vertically connected into a whole through the second via H2, and the eighth metal sheet P8, the twentieth metal sheet P20, and the thirty-first metal sheet P31 are vertically connected into a whole through the eighth via H8. The two wholes are vertically coupled to form an equivalent capacitor C6.

[0204] The connection of each component is realized as follows:

[0205] In the equivalent inductor L1, the thirty-eighth transmission line P38 is connected to the port Port1, and the sixty-seventh transmission line P67 is connected to the sixty-ninth transmission line P69 through the forty-fourth via H44;

[0206] In the equivalent inductor L2, the thirty-seventh transmission line P37 is connected to the port Port2, and the sixty-sixth transmission line P66 is connected to the sixty-ninth transmission line H69 through the forty-third via H43;

[0207] In the equivalent inductor L3, the thirty-sixth transmission line P36 is connected to the port Port4, and the sixty-first transmission line P61 is connected to the sixty-eighth transmission line H68 through the forty-second via H42;

[0208] In the equivalent inductor L4, the thirty-fifth transmission line P35 is connected to the port Port3, and the sixtieth transmission line P60 is connected to the sixty-eighth transmission line H68 through the forty-first via H41;

[0209] In the equivalent inductor L5, the thirty-third transmission line P33 is connected to the thirty-first metal piece P31 in the equivalent capacitor C6 through the thirteenth via H13, and the thirty-fourth transmission line P34 is connected to the thirty-second metal piece P32 in the equivalent capacitor C3 through the fourteenth via H14;

[0210] In the equivalent inductor L6, the 40th transmission line P40 is connected to one end of the 65th transmission line P65 through the 24th via H24, and the other end of the 65th transmission line P65 is connected to the port Port1; the 75th transmission line P75 is connected to one end of the 59th transmission line P59 through the 46th via H46, and the other end of the 59th transmission line P59 is connected to the port Port4;

[0211] In the equivalent inductor L7, the thirty-ninth transmission line P39 is connected to one end of the sixty-fourth transmission line P64 through the twenty-first via H21, and the other end of the sixty-fourth transmission line P64 is connected to the port Port3; the seventy-fourth transmission line P74 is connected to one end of the fifty-eighth transmission line P58 through the forty-fifth via H45, and the other end of the fifty-eighth transmission line P58 is connected to the port Port3;

[0212] In the equivalent capacitor C1, the twelfth metal sheet P12 and the twenty-fourth metal sheet P24 are connected to the port Port1 through a microstrip line; the sixth metal sheet P6 is connected to the fifth metal sheet P5 in the equivalent capacitor C3;

[0213] In the equivalent capacitor C2, the tenth metal sheet P10 and the twenty-second metal sheet P22 are both connected to the port Port2 via a microstrip line; the fourth metal sheet P4 is connected to the fifth metal sheet P5 in the equivalent capacitor C3;

[0214] In the equivalent capacitor C3, the fifth metal piece P5 is connected to the first ground terminal GND1 through a microstrip line; the thirty-second metal piece P32 is connected to the sixty-ninth transmission line P69 through the eleventh via H11;

[0215] In the equivalent capacitor C4, the ninth metal sheet P9 and the twenty-first metal sheet P21 are connected to the port Port4 via a microstrip line; the third metal sheet P3 is connected to the second metal sheet P2 in the equivalent capacitor C6;

[0216] In the equivalent capacitor C5, the seventh metal piece P7 and the nineteenth metal piece P19 are connected to the port Port3 through a microstrip line; the first metal piece P1 is connected to the second metal piece P2 in the equivalent capacitor C6;

[0217] In the equivalent capacitor C6, the second metal piece P2 is connected to the second ground terminal GND2 through a microstrip line; the thirty-first metal piece P31 is connected to the sixty-eighth transmission line P68 through the eighth via H8.

[0218] The equivalent circuit used in the present invention has the advantages of solving the problems of narrow bandwidth of traditional single-branch directional couplers and large size of double-branch directional couplers. The second-order LC directional coupler achieves broadband and has a more compact size.

[0219] The advantages of the three-dimensional model established by the present invention are: full utilization of vertical space to achieve compact size; the model has high symmetry, so that the functional ports Port1, Port2, Port3, and Port4 can all be used as output ports, and have high flexibility when installed in an integrated system.

[0220] Figure 19 FIG. 4 is an S-parameter curve diagram of the directional coupler of the present invention. Figure 20 is the amplitude balance of the directional coupler of the present invention. Figure 21 is the insertion loss of the directional coupler of the present invention. Figure 22 is the phase difference of the directional coupler of the present invention. Figures 19 to 22 It can be seen that the 3dB directional coupler of the present invention has a frequency range of 1.9GHz to 2.4GHz, a bandwidth of 500MHz, a relative bandwidth of 23.3%, an in-band return loss greater than 18dB, insertion losses of both the through-end and the coupled end are approximately 3dB, and the isolation of the isolated end is greater than 20dB; the overall return loss of the directional coupler is less than 0.7dB, the amplitude balance is ±0.7dB, and the phase balance of a 90° phase difference is ±0.3°.

[0221] The above description is only part of the specific implementation methods of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any person familiar with the art within the technical scope disclosed in the present invention should be covered by the protection scope of the present invention.

Claims

1. A compact broadband 3dB directional coupler based on stacking technology, characterized in that: The device comprises a ceramic body, a circuit layer inside the ceramic body, and an external electrode outside the ceramic body, wherein the external electrode comprises four mutually equivalent functional ports: port 1, port 2, port 3, and port 4; The circuit layer inside the directional coupler ceramic is used to implement the following circuit structure: The circuit structure includes capacitor C1, capacitor C2, capacitor C3, capacitor C4, capacitor C5, capacitor C6, inductor L1, inductor L2, inductor L3, inductor L4, inductor L5, inductor L6 and inductor L7, and C1=C2=C4=C5, L1=L2=L3=L4, L6=L7, C3=C6; The left port of inductor L1 is connected to the lower port of capacitor C1, the upper port of inductor L6, and the port Port1; the right port of inductor L1 is connected to the lower port of capacitor C3, the upper port of inductor L5, and the left port of inductor L2; the right port of inductor L2 is connected to the lower port of capacitor C2, the upper port of inductor L7, and the port Port2; the right port of inductor L4 is connected to the lower port of capacitor C2, the lower port of inductor L7, and the port Port3; the left port of inductor L4 is connected to the lower port of inductor L5, the right port of inductor L3, and the upper port of capacitor C6; the left port of inductor L3 is connected to the lower port of inductor L6, the upper port of capacitor C4, and the port Port4; the upper port of capacitor C1, the upper port of capacitor C2, and the upper port of capacitor C3 are connected together and grounded, and the lower port of capacitor C4, the lower port of capacitor C5, and the lower port of capacitor C6 are connected together and grounded.

2. A compact broadband 3dB directional coupler based on stacking technology as claimed in claim 1, characterized in that: The outer electrode further includes two symmetrically arranged ground ports: port GND1 and port GND2; The upper port of the capacitor C1, the upper port of the capacitor C2 and the upper port of the capacitor C3 are connected together and grounded through the port GND1; The lower ports of the capacitor C4 , the capacitor C5 , and the capacitor C6 are connected together and grounded through the port GND2 .

3. A compact broadband 3dB directional coupler based on stacking technology as claimed in claim 2, characterized in that: Ground ports GND1 and GND2 are always grounded. When Port1 is the input port, Port2 is the pass-through port, Port3 is the coupling port, and Port4 is the isolation port. When Port2 is the input port, Port1 is the pass-through port, Port4 is the coupling port, and Port3 is the isolation port. When Port3 is the input port, Port4 is the pass-through port, Port1 is the coupling port, and Port2 is the isolation port. When Port4 is the input port, Port3 is the pass-through port, Port2 is the coupling port, and Port1 is the isolation port.

4. The compact broadband 3dB directional coupler based on stacking technology according to claim 2, characterized in that: The circuit layer inside the ceramic is specifically several layers of metal circuits printed on the green porcelain tape: capacitor C1, capacitor C2, capacitor C3, capacitor C4, capacitor C5, capacitor C6, inductor L1, inductor L2, inductor L3, inductor L4, inductor L5, inductor L6 and inductor L7 are connected by the metal circuits printed on each layer of green porcelain tape.

5. The compact broadband 3dB directional coupler based on stacking technology as claimed in claim 4, characterized in that: The directional coupler package is rectangular, the long side refers to the long side of the rectangle, and the wide side refers to the short side of the rectangle; the metal sheet refers to a printed block-shaped metal pattern, and the transmission line refers to a printed strip-shaped metal pattern; The directional coupler consists of 14 layers of metal circuit packaging printed on green porcelain tape: The first layer circuit includes a first metal sheet P1, a second metal sheet P2, a third metal sheet P3, a fourth metal sheet P4, a fifth metal sheet P5, a sixth metal sheet P6, a first via H1, a second via H2, a third via H3, a fourth via H4, a fifth via H5, and a sixth via H6; The first metal sheet P1 and the third metal sheet P3, the fourth metal sheet P4 and the sixth metal sheet P6, the first via hole H1 and the third via hole H3, and the fourth via hole H4 and the sixth via hole H6 are symmetrical about the perpendicular midline of the long side; The first metal sheet P1 and the fourth metal sheet P4, the second metal sheet P2 and the fifth metal sheet P5, the third metal sheet P3 and the sixth metal sheet P6, the first via hole H1 and the fourth via hole H4, the second via hole H2 and the fifth via hole H5, and the third via hole H3 and the sixth via hole H6 are symmetrical about the perpendicular midline of the broadside; The second layer circuit includes a seventh metal sheet P7, an eighth metal sheet P8, a ninth metal sheet P9, a tenth metal sheet P10, an eleventh metal sheet P11, a twelfth metal sheet P12, a first via H1, a second via H2, a third via H3, a fourth via H4, a fifth via H5, a sixth via H6, a seventh via H7, an eighth via H8, a ninth via H9, a tenth via H10, an eleventh via H11, and a twelfth via H12; The seventh metal sheet P7 and the ninth metal sheet P9, the tenth metal sheet P10 and the twelfth metal sheet P12, the seventh via hole H7 and the ninth via hole H9, and the tenth via hole H10 and the twelfth via hole H12 are symmetrical about the perpendicular midline of the long side. The seventh metal sheet P7 and the tenth metal sheet P10, the eighth metal sheet P8 and the eleventh metal sheet P11, the ninth metal sheet P9 and the twelfth metal sheet P12, the seventh via hole H7 and the tenth via hole H10, the eighth via hole H8 and the eleventh via hole H11, and the ninth via hole H9 and the twelfth via hole H12 are symmetrical about the perpendicular midline of the broadside; The third layer circuit includes a thirteenth metal sheet P13, a fourteenth metal sheet P14, a fifteenth metal sheet P15, a sixteenth metal sheet P16, a seventeenth metal sheet P17, an eighteenth metal sheet P18, a first via H1, a second via H2, a third via H3, a fourth via H4, a fifth via H5, a sixth via H6, a seventh via H7, an eighth via H8, a ninth via H9, a tenth via H10, an eleventh via H11, and a twelfth via H12; The thirteenth metal sheet P13 and the fifteenth metal sheet P15, the sixteenth metal sheet P16 and the eighteenth metal sheet P18 are symmetrical about the perpendicular midline of the long side; The thirteenth metal sheet P13 and the sixteenth metal sheet P16, the fourteenth metal sheet P14 and the seventeenth metal sheet P17, and the fifteenth metal sheet P15 and the eighteenth metal sheet P18 are symmetrical about the perpendicular midline of the broadside. The fourth layer circuit includes a nineteenth metal sheet P19, a twentieth metal sheet P20, a twenty-first metal sheet P21, a twenty-second metal sheet P22, a twenty-third metal sheet P23, a twenty-fourth metal sheet P24, a first via H1, a second via H2, a third via H3, a fourth via H4, a fifth via H5, a sixth via H6, a seventh via H7, an eighth via H8, a ninth via H9, a tenth via H10, an eleventh via H11, and a twelfth via H12; The nineteenth metal sheet P19 and the twenty-first metal sheet P21, the twenty-second metal sheet P122 and the twenty-fourth metal sheet P24 are symmetrical about the perpendicular midline of the long side; The nineteenth metal sheet P19 and the twenty-second metal sheet P22, the fourteenth metal sheet P14 and the seventeenth metal sheet P17, and the fifteenth metal sheet P15 and the eighteenth metal sheet P18 are symmetrical about the perpendicular midline of the broadside. The fifth layer circuit includes a twenty-fifth metal sheet P25, a twenty-sixth metal sheet P26, a twenty-seventh metal sheet P27, a twenty-eighth metal sheet P28, a twenty-ninth metal sheet P29, a thirtieth metal sheet P30, a first via H1, a second via H2, a third via H3, a fourth via H4, a fifth via H5, a sixth via H6, an eighth via H8, and an eleventh via H11; in particular: The twenty-fifth metal sheet P25 and the twenty-seventh metal sheet P27, as well as the twenty-eighth metal sheet P28 and the thirtieth metal sheet P30 are symmetrical about the perpendicular midline of the long side; The twenty-fifth metal sheet P25 and the twenty-eighth metal sheet P28, as well as the twenty-seventh metal sheet P27 and the thirtieth metal sheet P30 are symmetrical about the perpendicular midline of the broadside; The sixth layer circuit includes a thirty-first metal sheet P31, a thirty-second metal sheet P32, an eighth via H8, an eleventh via H11, a thirteenth via H13, and a fourteenth via H14; The thirty-first metal piece P31 and the thirty-second metal piece P32, the thirteenth via hole H13 and the fourteenth via hole H14 are symmetrical about the perpendicular midline of the broadside; The seventh layer circuit includes a thirty-third transmission line P33, a thirty-fourth transmission line P34, an eighth via H8, an eleventh via H11, a thirteenth via H13, a fourteenth via H14, a fifteenth via H15, and a sixteenth via H16; The thirty-third transmission line P33 and the thirty-fourth transmission line P34, the fifteenth via hole H15 and the sixteenth via hole H16 are centrosymmetric about the geometric center of the circuit layer; The eighth layer circuit includes a thirty-fifth transmission line P35, a thirty-sixth transmission line P36, a thirty-seventh transmission line P37, a thirty-eighth transmission line P38, a thirty-ninth transmission line P39, a fortieth transmission line P40, a forty-first transmission line P41, a forty-second transmission line P42, an eighth via H8, an eleventh via H11, a fifteenth via H15, a sixteenth via H16, a seventeenth via H17, an eighteenth via H18, a nineteenth via H19, a twentieth via H20, a twenty-first via H21, a twenty-second via H22, a twenty-third via H23, a twenty-fourth via H24, a twenty-fifth via H25, and a twenty-sixth via H26; The thirty-fifth transmission line P35 and the thirty-sixth transmission line P36, the thirty-seventh transmission line P37 and the thirty-eighth transmission line P38, the thirty-ninth transmission line P39 and the fortieth transmission line P40, the seventeenth via hole H17 and the eighteenth via hole H18, the twentieth via hole H20 and the twenty-third via hole H23, the twenty-first via hole H21 and the twenty-fourth via hole H24, and the twenty-fifth via hole H25 and the twenty-sixth via hole H26 are symmetrical about the perpendicular midline of the long side; The thirty-fifth transmission line P35 and the thirty-seventh transmission line P37, the thirty-sixth transmission line P36 and the thirty-eighth transmission line P38, the seventeenth via hole H17 and the twenty-sixth via hole H26, and the eighteenth via hole H18 and the twenty-fifth via hole H25 are symmetrical about the perpendicular midline of the broadside; The forty-first transmission line P41 and the forty-second transmission line P42 , the nineteenth via hole H19 and the twenty-second via hole H22 are centrosymmetric with respect to the geometric center of the circuit layer; The ninth layer circuit includes a forty-third transmission line P43, a forty-fourth transmission line P44, a forty-fifth transmission line P45, a forty-sixth transmission line P46, a forty-seventh transmission line P47, a forty-eighth transmission line P48, a forty-ninth transmission line P49, a fiftieth transmission line P50, an eighth via H8, an eleventh via H11, a fifteenth via H15, a sixteenth via H16, a seventeenth via H17, an eighteenth via H18, a nineteenth via H19, a twentieth via H20, a twenty-first via H21, a twenty-second via H22, a twenty-third via H23, a twenty-fourth via H24, a twenty-fifth via H25, a twenty-sixth via H26, a twenty-seventh via H27, a twenty-eighth via H28, a twenty-ninth via H29, a thirtieth via H30, a thirty-first via H31, a thirty-second via H32, a thirty-third via H33, and a thirty-fourth via H34; The forty-third transmission line P43 and the forty-fourth transmission line P44, the forty-fifth transmission line P45 and the forty-sixth transmission line P46, the forty-eighth transmission line P48 and the forty-ninth transmission line P49, the twenty-seventh via hole H27 and the twenty-eighth via hole H28, the twenty-ninth via hole H29 and the thirtieth via hole H30, and the thirty-first via hole H31 and the thirty-second via hole H32 are symmetrical about the perpendicular midline of the long side. The forty-third transmission line P43 and the forty-fifth transmission line P45, the forty-fourth transmission line P44 and the forty-sixth transmission line P46, the twenty-seventh via hole H27 and the twenty-ninth via hole H29, and the twenty-eighth via hole H28 and the thirtieth via hole H30 are symmetrical about the perpendicular midline of the broadside. The forty-seventh transmission line P47 and the fiftieth transmission line P50, the thirty-third via hole H33, and the thirty-fourth via hole H34 are centrosymmetric with respect to the geometric center of the circuit layer; The tenth layer circuit includes a fifty-first transmission line P51, a fifty-second transmission line P52, a fifty-third transmission line P53, a fifty-fourth transmission line P54, a fifty-fifth transmission line P55, a fifty-sixth transmission line P56, a fifty-seventh transmission line P57, an eighth via H8, an eleventh via H11, a twenty-first via H21, a twenty-fourth via H24, a thirty-third via H33, a thirty-fourth via H34, a thirty-fifth via H35, a thirty-sixth via H36, a thirty-seventh via H37, a thirty-eighth via H38, a thirty-ninth via H39, and a fortieth via H40; The fifty-first transmission line P51 and the fifty-second transmission line P52, the fifty-third transmission line P53 and the fifty-fourth transmission line P54, the fifty-fifth transmission line P55 and the fifty-sixth transmission line P56, the thirty-fifth via hole H35 and the thirty-sixth via hole H36, the thirty-seventh via hole H37 and the thirty-eighth via hole H38, and the thirty-ninth via hole H39 and the fortieth via hole H40 are symmetrical about the perpendicular midline of the long side. The fifty-first transmission line P51 and the fifty-third transmission line P53, the fifty-second transmission line P52 and the fifty-fourth transmission line P54, the thirty-fifth via hole H35 and the thirty-seventh via hole H37, and the thirty-sixth via hole H36 and the thirty-eighth via hole H38 are symmetrical about the perpendicular midline of the broadside. The shape of the fifty-seventh transmission line P57 is centrosymmetric about the geometric center of the circuit layer; The eleventh layer circuit includes a fifty-eighth transmission line P58, a fifty-ninth transmission line P59, a sixtieth transmission line P60, a sixty-first transmission line P61, a sixty-first transmission line P61, a sixty-second transmission line P62, a sixty-third transmission line P63, a sixty-fourth transmission line P64, a sixty-fifth transmission line P65, a sixty-sixth transmission line P66, a sixty-seventh transmission line P67, an eighth via H8, an eleventh via H11, a twenty-first via H21, a twenty-fourth via H24, a thirty-fifth via H35, a thirty-sixth via H36, a thirty-seventh via H37, a thirty-eighth via H38, a thirty-ninth via H39, a fortieth via H40, a forty-first via H41, a forty-second via H42, a forty-third via H43, a forty-fourth via H44, a forty-fifth via H45, a forty-sixth via H46, a forty-seventh via H47, and a forty-eighth via H48; The fifty-eighth transmission line P58 and the fifty-ninth transmission line P59, the sixtieth transmission line P60 and the sixty-first transmission line P61, the sixty-second transmission line P62 and the sixty-third transmission line P63, the sixty-fourth transmission line P64 and the sixty-fifth transmission line P65, the sixty-sixth transmission line P66 and the sixty-seventh transmission line P67, the forty-first via hole H41 and the forty-second via hole H42, the forty-third via hole H43 and the forty-fourth via hole H44, the forty-fifth via hole H45 and the forty-sixth via hole H46, and the forty-seventh via hole H47 and the forty-eighth via hole H48 are respectively symmetrical about the perpendicular midline of the long side; The fifty-eighth transmission line P58 and the sixty-fourth transmission line P64, the sixtieth transmission line P60 and the sixty-sixth transmission line P66, the sixty-first transmission line P61 and the sixty-seventh transmission line P67, the fifty-ninth transmission line P59 and the sixty-fifth transmission line P65, the forty-first via hole H41 and the forty-third via hole H43, and the forty-second via hole H42 and the forty-fourth via hole H44 are symmetrical about the perpendicular midline of the broadside respectively; The twelfth layer circuit includes a sixty-eighth transmission line P68, a sixty-ninth transmission line P69, a seventieth transmission line P70, a seventy-first transmission line P71, an eighth via H8, an eleventh via H11, a forty-first via H41, a forty-second via H42, a forty-third via H43, a forty-fourth via H44, a forty-fifth via H45, a forty-sixth via H46, a forty-seventh via H47, a forty-eighth via H48, a forty-ninth via H49, and a fiftieth via H50; The 70th transmission line P70 and the 71st transmission line P71, the 49th via hole H49 and the 50th via hole H50 are symmetrical about the perpendicular midline of the long side; the shapes of the 68th transmission line P68 and the 69th transmission line P69 are symmetrical about the perpendicular midline of the long side; The sixty-eighth transmission line P68 and the sixty-ninth transmission line P69 are symmetrical about the perpendicular midline of the broadside; The thirteenth layer circuit includes a seventy-second transmission line P72, a seventy-third transmission line P73, a forty-fifth via H45, a forty-sixth via H46, a forty-ninth via H49, a fiftieth via H50, a fifty-first via H51, and a fifty-second via H52; The 72nd transmission line P72 and the 73rd transmission line P73, and the 51st via hole H51 and the 52nd via hole H52 are symmetrical about the perpendicular midline of the long side. The thirteenth layer circuit includes a seventy-fourth transmission line P74, a seventy-fifth transmission line P75, a forty-fifth via H45, a forty-sixth via H46, a fifty-first via H51, and a fifty-second via H52; The seventy-fourth transmission line P74 and the seventy-fifth transmission line P75 are symmetrical about the perpendicular midline of the long side; The thirty-eighth transmission line P38, the forty-sixth transmission line P46, the fifty-fourth transmission line P54, and the sixty-seventh transmission line P67 are connected end to end in sequence via the twenty-fifth via H25, the thirtieth via H30, and the thirty-eighth via H38, and together form the inductor L1; The thirty-seventh transmission line P37, the forty-fifth transmission line P45, the fifty-third transmission line P53, and the sixty-sixth transmission line P66 are connected end to end in sequence via the twenty-sixth via H26, the twenty-ninth via H29, and the thirty-seventh via H37, and together form the inductor L2; The 36th transmission line P36, the 44th transmission line P44, the 52nd transmission line P52 and the 61st transmission line P61 are connected end to end in sequence via the 18th via H18, the 28th via H28 and the 36th via H36, and together form the inductor L3; The 35th transmission line P3, the 43rd transmission line P43, the 51st transmission line P51 and the 60th transmission line P60 are connected end to end in sequence via the 17th via H17, the 27th via H27 and the 35th via H35, and together form the inductor L4; The thirty-third transmission line P33, the forty-first transmission line P41, the forty-seventh transmission line P47, the fifty-seventh transmission line P57, the fiftieth transmission line P50, the forty-second transmission line P42, and the thirty-fourth transmission line are connected end to end in sequence via the fifteenth via H15, the nineteenth via H19, the thirty-third via H33, the thirty-fourth via H34, the twenty-first via H21, and the sixteenth via H16, to form an inductor L5. The 40th transmission line P40, the 49th transmission line P49, the 56th transmission line P56, the 63rd transmission line P63, the 71st transmission line P71, the 73rd transmission line P73 and the 75th transmission line P75 are connected end to end in sequence via the 23rd via H23, the 32nd via H32, the 40th via H40, the 48th via H48, the 50th via H50 and the 52nd via H52, together forming the inductor L6; The thirty-ninth transmission line P39, the forty-eighth transmission line P48, the fifty-fifth transmission line P55, the sixty-second transmission line P62, the seventieth transmission line P70, the seventy-second transmission line P72, and the seventy-fourth transmission line P74 are connected end to end in sequence via the twentieth via H20, the thirty-first via H31, the thirty-ninth via H39, the forty-seventh via H47, the forty-ninth via H59, and the fifty-first via H51, to form an inductor L7. The sixth metal sheet P6, the eighteenth metal sheet P18, and the thirtieth metal sheet P30 are vertically connected to form a whole through the sixth via H6, and the twelfth metal sheet P12 and the twenty-fourth metal sheet P24 are vertically connected to form a whole through the twelfth via H12, and the two wholes form a capacitor C1 through vertical coupling; The fourth metal sheet P4, the sixteenth metal sheet P16, and the twenty-eighth metal sheet P28 are vertically connected to form a whole through the fourth via H4, and the tenth metal sheet P10 and the twenty-second metal sheet P22 are vertically connected to form a whole through the tenth via H10. The two wholes are vertically coupled to form a capacitor C2. The fifth metal sheet P5, the seventeenth metal sheet P17, and the twenty-ninth metal sheet P29 are vertically connected to form a whole through the fifth via H5. The eleventh metal sheet P11, the twenty-third metal sheet P23, and the thirty-second metal sheet P32 are vertically connected to form a whole through the eleventh via H11. The two wholes form a capacitor C3 through vertical coupling. The third metal sheet P3, the fifteenth metal sheet P15, and the twenty-seventh metal sheet P27 are vertically connected to form a whole through the third via H3, and the ninth metal sheet P9 and the twenty-first metal sheet P21 are vertically connected to form a whole through the ninth via H9. The two wholes form a capacitor C4 through vertical coupling. The first metal sheet P1, the thirteenth metal sheet P13, and the twenty-fifth metal sheet P25 are vertically connected to form a whole through the first via H1, and the seventh metal sheet P7 and the nineteenth metal sheet P19 are vertically connected to form a whole through the seventh via H7. The two wholes form a capacitor C5 through vertical coupling; The second metal sheet P2, the fourteenth metal sheet P14, and the twenty-sixth metal sheet P26 are vertically connected into a whole through the second via H2, and the eighth metal sheet P8, the twentieth metal sheet P20, and the thirty-first metal sheet P31 are vertically connected into a whole through the eighth via H8. The two wholes are vertically coupled to form a capacitor C6.

6. The compact broadband 3dB directional coupler based on stacking technology according to claim 5, characterized in that: In the inductor L1, the thirty-eighth transmission line P38 is connected to the port Port1, and the sixty-seventh transmission line P67 is connected to the sixty-ninth transmission line P69 through the forty-fourth via H44; In the inductor L2, the thirty-seventh transmission line P37 is connected to the port Port2, and the sixty-sixth transmission line P66 is connected to the sixty-ninth transmission line H69 through the forty-third via H43; In the inductor L3, the thirty-sixth transmission line P36 is connected to the port Port4, and the sixty-first transmission line P61 is connected to the sixty-eighth transmission line H68 through the forty-second via H42; In the inductor L4, the thirty-fifth transmission line P35 is connected to the port Port3, and the sixtieth transmission line P60 is connected to the sixty-eighth transmission line H68 through the forty-first via H41; In the inductor L5, the thirty-third transmission line P33 is connected to the thirty-first metal piece P31 in the capacitor C6 through the thirteenth via H13, and the thirty-fourth transmission line P34 is connected to the thirty-second metal piece P32 in the capacitor C3 through the fourteenth via H14; In the inductor L6, the 40th transmission line P40 is connected to one end of the 65th transmission line P65 through the 24th via H24, and the other end of the 65th transmission line P65 is connected to the port Port1; the 75th transmission line P75 is connected to one end of the 59th transmission line P59 through the 46th via H46, and the other end of the 59th transmission line P59 is connected to the port Port4; In the inductor L7, the thirty-ninth transmission line P39 is connected to one end of the sixty-fourth transmission line P64 through the twenty-first via H21, and the other end of the sixty-fourth transmission line P64 is connected to the port Port3; the seventy-fourth transmission line P74 is connected to one end of the fifty-eighth transmission line P58 through the forty-fifth via H45, and the other end of the fifty-eighth transmission line P58 is connected to the port Port3; In the capacitor C1, the twelfth metal piece P12 and the twenty-fourth metal piece P24 are connected to the port Port1 through a microstrip line; the sixth metal piece P6 is connected to the fifth metal piece P5 in the capacitor C3; In the capacitor C2, the tenth metal sheet P10 and the twenty-second metal sheet P22 are connected to the port Port2 via a microstrip line; the fourth metal sheet P4 is connected to the fifth metal sheet P5 in the capacitor C3; In the capacitor C3, the fifth metal piece P5 is connected to the first ground terminal GND1 through a microstrip line; The thirty-second metal piece P32 is connected to the sixty-ninth transmission line P69 through the eleventh via hole H11; In the capacitor C4, the ninth metal sheet P9 and the twenty-first metal sheet P21 are connected to the port Port4 via a microstrip line; the third metal sheet P3 is connected to the second metal sheet P2 in the capacitor C6; In the capacitor C5, the seventh metal piece P7 and the nineteenth metal piece P19 are connected to the port Port3 via a microstrip line; the first metal piece P1 is connected to the second metal piece P2 in the capacitor C6; In the capacitor C6, the second metal piece P2 is connected to the second ground terminal GND2 through a microstrip line; the thirty-first metal piece P31 is connected to the sixty-eighth transmission line P68 through the eighth via H8.

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