CN112736446A - LTCC-based millimeter wave packaging antenna and array antenna - Google Patents

Abstract

The invention relates to a millimeter wave packaging antenna and an array antenna based on LTCC (low temperature co-fired ceramic). A first stratum is used as a reference stratum of a radiation unit layer and provides a reference ground plane for the radiation unit layer so as to realize the radiation characteristic of an antenna unit. The second ground layer can realize the mutual isolation of the control signal layer and the first radio frequency circuit layer. The third ground layer can realize the mutual isolation of the first radio frequency circuit layer and the second radio frequency circuit layer and is also a reference ground plane of the first radio frequency circuit layer and the second radio frequency circuit layer. The millimeter wave packaging antenna based on the LTCC can realize the input and output of radio frequency signals of the radiation unit layers of the multilayer circuit board designed by the LTCC, can be suitable for the production and the manufacture of the mature LTCC process, and has low cost, small volume and light weight.

Description

LTCC-based millimeter wave packaging antenna and array antenna

Technical Field

The invention relates to the technical field of communication antennas, in particular to a millimeter wave packaging antenna and an array antenna based on LTCC.

Background

With the development of 5G communication technology, in order to overcome the problem of shortage of sub-6G spectrum resources, millimeter waves have significant advantages in large bandwidth and high-rate communication. However, in the 5G millimeter wave frequency band, the space loss of electromagnetic wave signals is large, and the propagation path is short.

The traditional 5G millimeter wave single-polarized array antenna meets the requirement of hybrid-Beamforming (hybrid Beamforming) application scene MIMO communication through two array antennas with different polarizations, and is generally realized by adopting an LTCC (Low Temperature Co-fired Ceramic) process. However, the traditional 5G millimeter wave single-polarized array antenna has a complex laminated structure, high cost and large volume.

Disclosure of Invention

Therefore, the defects of the prior art need to be overcome, and the millimeter wave packaging antenna and the array antenna based on the LTCC are provided, so that the millimeter wave packaging antenna and the array antenna based on the LTCC can be suitable for the LTCC process production and manufacture with mature process, can simplify the laminated structure, and can realize low cost and small volume.

The technical scheme is as follows: an LTCC based millimeter wave packaged antenna comprising a multilayer circuit board, the multilayer circuit board comprising: the radiation unit layer, the first stratum, the control signal layer, the second stratum, the first radio frequency circuit layer, the third stratum and the second radio frequency circuit layer are sequentially arranged in an overlapped mode; high-frequency dielectric materials are arranged among adjacent layers of the radiation unit layer, the first stratum, the control signal layer, the second stratum, the first radio frequency circuit layer, the third stratum and the second radio frequency circuit layer; the beam forming chip is provided with a first radio frequency signal input and output pin, a second radio frequency signal input and output pin, a grounding pin and a control pin; the first radio frequency signal input/output pin is electrically connected to the first radio frequency circuit layer, and the first radio frequency circuit layer is electrically connected with the radiation unit layer; the second radio frequency signal input/output pin is electrically connected to the second radio frequency circuit layer; the ground pin is electrically connected to the third ground layer; the control signal layer is provided with a control circuit, and the control pin is electrically connected with the control circuit.

In the LTCC-based millimeter wave packaged antenna, an external device may send a trigger signal to the beamforming chip through the control signal layer via the control line and the control pin, so as to trigger the beamforming chip, and the beamforming chip performs a related action after being triggered; when the wave beam forming chip works, an external device sends an antenna signal to the wave beam forming chip through the second radio frequency circuit layer and the second radio frequency signal input/output pin of the wave beam forming chip, the radio frequency signal is input to the first radio frequency circuit layer through the first radio frequency signal input/output pin of the wave beam forming chip and is conveyed to the radiation unit layer through the first radio frequency circuit layer, the antenna signal received by the radiation unit layer can also enter the wave beam forming chip through the first radio frequency signal input/output pin, and the second radio frequency signal input/output pin of the wave beam forming chip is output to the second radio frequency circuit layer and is fed back to the external device through the second radio frequency circuit layer. In addition, the first stratum is used as a reference stratum of the radiation unit layer and provides a reference ground plane for the radiation unit layer so as to realize the radiation characteristic of the antenna unit. The second ground layer can realize the mutual isolation of the control signal layer and the first radio frequency circuit layer. The third ground layer can realize the mutual isolation of the first radio frequency circuit layer and the second radio frequency circuit layer and is also a reference ground plane of the first radio frequency circuit layer and the second radio frequency circuit layer. Therefore, the millimeter wave packaging antenna based on the LTCC can realize the input and output of radio frequency signals of the radiation unit layers of the multilayer circuit board designed by the LTCC, can be suitable for the production and the manufacture of the mature LTCC process, and has low cost, small volume and light weight.

In one embodiment, the multilayer circuit board further comprises a power plane layer disposed between the first ground layer and the control signal layer; the beam forming chip is also provided with a power supply pin, and the power supply pin is electrically connected with the power supply surface of the power supply plane layer.

In one embodiment, the beam forming chip is disposed on the second rf circuit layer.

In one embodiment, the radiation unit layer is provided with a plurality of radiation oscillator pieces and two feed trays arranged corresponding to the radiation oscillator pieces; the first radio frequency circuit layer is electrically connected with the feed tray.

In one embodiment, the first rf circuit layer includes a one-to-N power dividing feed line, the first rf signal input/output pin is electrically connected to the combining end of the one-to-N power dividing feed line, and a plurality of branch ends of the one-to-N power dividing feed line are respectively and correspondingly electrically connected to the plurality of feed trays.

In one embodiment, the multilayer circuit board is provided with a plurality of first vertical interconnection metalized vias, the plurality of first vertical interconnection metalized vias are arranged in one-to-one correspondence with the plurality of feed trays, the first vertical interconnection metalized vias penetrate from the radiation unit layer to the first radio frequency circuit layer, one end of each first vertical interconnection metalized via is electrically connected with the feed tray, and the other end of each first vertical interconnection metalized via is electrically connected with a branch end of the one-to-N power distribution feed line;

the multilayer circuit board is also provided with a plurality of second vertical interconnection metalized via holes, the second vertical interconnection metalized via holes penetrate from the first radio frequency line layer to the second radio frequency line layer, one end of each second vertical interconnection metalized via hole is connected with the closing end of the one-to-N power distribution feeder, and the other end of each second vertical interconnection metalized via hole is electrically connected with the first radio frequency signal input/output pin;

the multilayer circuit board is also provided with a third vertical interconnection metalized through hole; the third vertical interconnection metalized via penetrates from the first ground layer to the second radio frequency circuit layer, one end of the third vertical interconnection metalized via is electrically connected with the control circuit, and the other end of the third vertical interconnection metalized via is electrically connected with the control pin;

the multilayer circuit board is further provided with a plurality of fourth vertical interconnection metalized via holes, the fourth vertical interconnection metalized via holes penetrate through the first ground layer to the second radio frequency circuit layer, and the power surface of the power plane layer is electrically connected with the grounding pins through the fourth vertical interconnection metalized via holes.

In one embodiment, the multilayer circuit board is further provided with a plurality of fifth vertical interconnection metallization vias and a plurality of sixth vertical interconnection metallization vias, the fifth vertical interconnection metallization vias penetrate from the first ground layer to the first radio frequency circuit layer, the sixth vertical interconnection metallization vias penetrate from the first radio frequency circuit layer to the second radio frequency circuit layer, the fifth vertical interconnection metallization vias are electrically connected with the sixth vertical interconnection metallization vias, and the first ground layer, the second ground layer and the third ground layer are electrically connected with each other through the fifth vertical interconnection metallization vias.

In one embodiment, the first vertical interconnect metallization via is surrounded by a plurality of spaced fifth vertical interconnect metallization vias, and the second vertical interconnect metallization via is surrounded by a plurality of spaced sixth vertical interconnect metallization vias.

In one embodiment, the multilayer circuit board is further provided with a first-order metalized via, the first-order metalized via penetrates from the third ground layer to the second radio frequency circuit layer, and the third ground layer is electrically connected with the ground pin through the first-order metalized via.

An array antenna comprises more than two LTCC-based millimeter wave package antennas.

In the array antenna, an external device can send a trigger signal to the beam forming chip through the control signal layer and the control pin through the control circuit to trigger the beam forming chip, and the beam forming chip performs related actions after being triggered; when the wave beam forming chip works, an external device sends an antenna signal to the wave beam forming chip through the second radio frequency circuit layer and the second radio frequency signal input/output pin of the wave beam forming chip, the radio frequency signal is input to the first radio frequency circuit layer through the first radio frequency signal input/output pin of the wave beam forming chip and is conveyed to the radiation unit layer through the first radio frequency circuit layer, the antenna signal received by the radiation unit layer can also enter the wave beam forming chip through the first radio frequency signal input/output pin, and the second radio frequency signal input/output pin of the wave beam forming chip is output to the second radio frequency circuit layer and is fed back to the external device through the second radio frequency circuit layer. In addition, the first stratum is used as a reference stratum of the radiation unit layer and provides a reference ground plane for the radiation unit layer so as to realize the radiation characteristic of the antenna unit. The second ground layer can realize the mutual isolation of the control signal layer and the first radio frequency circuit layer. The third ground layer can realize the mutual isolation of the first radio frequency circuit layer and the second radio frequency circuit layer and is also a reference ground plane of the first radio frequency circuit layer and the second radio frequency circuit layer. Therefore, the millimeter wave packaging antenna based on the LTCC can realize the input and output of radio frequency signals of the radiation unit layers of the multilayer circuit board designed by the LTCC, can be suitable for the production and the manufacture of the mature LTCC process, and has low cost, small volume and light weight.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention.

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

Fig. 1 is a schematic structural diagram of a beamforming chip of an LTCC-based millimeter wave packaged antenna according to an embodiment of the present invention;

fig. 2 is a schematic cross-sectional view of an LTCC-based millimeter wave package antenna according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a radiation unit layer of an LTCC-based millimeter wave package antenna according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a metal-free wiring layer of an LTCC-based millimeter wave package antenna according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a first ground layer of an LTCC-based millimeter wave packaged antenna according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of a power plane layer of an LTCC-based millimeter wave package antenna according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a control signal layer of an LTCC-based millimeter wave package antenna according to an embodiment of the present invention;

fig. 8 is a schematic structural diagram of a first rf circuit layer of an LTCC-based millimeter wave package antenna according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a third ground layer of the LTCC-based millimeter wave packaged antenna according to an embodiment of the present invention;

fig. 10 is a schematic structural diagram of a second rf circuit layer of the LTCC-based millimeter wave package antenna according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of a radiation unit layer of an array antenna according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of the array antenna according to an embodiment of the present invention, in which a second rf signal input/output pin is connected to a power division feeding network;

fig. 13 is a schematic diagram of an arrangement structure of a plurality of beam forming chips in the array antenna according to an embodiment of the present invention.

10. A radiation unit layer; 11. a radiation oscillator piece; 12. a feed tray; 20. a beam forming chip; 21. a first radio frequency signal input/output pin; 22. a second radio frequency signal input/output pin; 23. a ground pin; 24. a control pin; 25. a power supply pin; 30. a first radio frequency circuit layer; 31. dividing N power supply lines; 311. a path combining end; 312. a branch end; 50. a second radio frequency circuit layer; 60. a control signal layer; 61. a control circuit; 70. a power plane layer; 71. a power plane; 81. a first earth formation; 82. a second earth formation; 83. a second earth formation; 91. a first vertical interconnect metallization via; 92. a first anti-pad; 93. a second vertical interconnect metallization via; 94. a second anti-pad; 95. a third vertical interconnect metallization via; 96. a third anti-pad; 97. a fourth vertical interconnect metallization via; 98. a fourth anti-pad; 981. a first power supply plane; 991. a fifth vertical interconnect metallization via; 992. a sixth vertical interconnect metallization via; 993. a first-order metallized via; 995. a fifth anti-pad; 996. a second power supply plane; 101. a first dielectric layer; 102. a second dielectric layer; 103. a third dielectric layer; 104. a fourth dielectric layer; 105. a fifth dielectric layer; 106. a sixth dielectric layer; 107. a seventh dielectric layer; 121. a one-to-sixteen power division feed network; 123. a radio frequency feed port; 124. a digital multi-pin socket; 125. a connection pad; 126. a daisy chain main line; 127. a microstrip line.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Referring to fig. 1 and fig. 2, fig. 1 illustrates a schematic structural diagram of a beamforming chip 20 of an LTCC-based millimeter wave packaged antenna according to an embodiment of the present invention; fig. 2 is a schematic cross-sectional view of an LTCC-based millimeter wave package antenna according to an embodiment of the present invention. An embodiment of the invention provides an LTCC-based millimeter wave packaged antenna, which comprises a multilayer circuit board. The multi-layer circuit board includes a radiation unit layer 10, a first ground layer 81, a control signal layer 60, a second ground layer 8382, a first rf circuit layer 30, a third ground layer, a second rf circuit layer 50, and a beam forming chip 20, which are sequentially stacked. High-frequency dielectric materials are arranged among adjacent layers of the radiating unit layer 10, the first ground layer 81, the control signal layer 60, the second ground layer 8382, the first radio frequency circuit layer 30, the third ground layer and the second radio frequency circuit layer 50. The beam forming chip 20 has a first rf signal input/output pin 21, a second rf signal input/output pin 22, a ground pin 23, and a control pin 24. The first rf signal input/output pin 21 is electrically connected to the first rf circuit layer 30, and the first rf circuit layer 30 is electrically connected to the radiating unit layer 10. The second rf signal input/output pin 22 is electrically connected to the second rf circuit layer 50. The ground pin 23 is electrically connected to the third ground layer.

Referring to fig. 7 in combination, fig. 7 is a schematic structural diagram illustrating a control signal layer 60 of an LTCC-based millimeter wave package antenna according to an embodiment of the present invention. The control signal layer 60 is provided with a control circuit 61, and the control pin 24 is electrically connected with the control circuit 61. The external device may respectively send the trigger signals to the beamforming chip 20 through the control signal layer 60, so as to trigger the beamforming chip 20, and the beamforming chip 20 performs related actions after being triggered.

In the above LTCC-based millimeter wave packaged antenna, an external device may send a trigger signal to the beamforming chip 20 through the control signal layer 60 via the control line 61 and the control pin 24, so as to trigger the beamforming chip 20, and the beamforming chip 20 performs a related action after being triggered; when the beam forming chip 20 works, an external device sends an antenna signal to the beam forming chip 20 through the second radio frequency circuit layer 50 and the second radio frequency signal input/output pin 22 of the beam forming chip 20, the radio frequency signal is input to the first radio frequency circuit layer 30 through the first radio frequency signal input/output pin 21 of the beam forming chip 20 and is transmitted to the radiation unit layer 10 through the first radio frequency circuit layer 30, the antenna signal received by the radiation unit layer 10 can also enter the beam forming chip 20 through the first radio frequency signal input/output pin 21, the second radio frequency signal input/output pin 22 of the beam forming chip 20 is output to the second radio frequency circuit layer 50, and the antenna signal is fed back to the external device through the second radio frequency circuit layer 50. In addition, the first ground layer 81 serves as a reference ground layer of the radiating element layer 10, and provides a reference ground plane for the radiating element layer 10, so as to realize the radiation characteristics of the antenna element. The second ground layer 8382 enables the control signal layer 60 and the first radio frequency circuitry layer 30 to be isolated from each other. The third ground layer can realize the mutual isolation of the first radio frequency circuit layer 30 and the second radio frequency circuit layer 50, and is also a reference ground plane of the first radio frequency circuit layer 30 and the second radio frequency circuit layer 50. Therefore, the millimeter wave packaging antenna based on the LTCC can realize the input and output of the radio frequency signals of the radiation unit layer 10 of the multilayer circuit board designed by the LTCC, can be suitable for the production and the manufacture of the mature LTCC process, and has low cost, small volume and light weight.

In one embodiment, the LTCC-based millimeter wave package antenna is manufactured by sintering and stacking green ceramic tapes with a relative dielectric constant of 6.0 in a production process of the LTCC-based millimeter wave package antenna. Wherein, two kinds of specification products that the minimum thickness of green porcelain area adopted is 44um and 92um can, do not restrict here.

In one embodiment, during the manufacturing process of the LTCC-based millimeter wave packaged antenna, the radiating element layer 10, the first ground layer 81, the control signal layer 60, the second ground layer 8382, the first radio frequency circuit layer 30, the third ground layer, and the second radio frequency circuit layer 50 are printed on the surface of the corresponding high frequency dielectric material plate by using silver paste, and are formed after casting, punching, printing, laminating, isostatic pressing, cutting, and sintering.

In one embodiment, the radiation unit layer 10 is located on a surface layer of the LTCC-based millimeter wave packaged antenna, and can perform radiation and reception functions of the antenna, receive radio frequency signals of the beamforming chip 20, and transmit antenna signals to the beamforming chip 20.

Referring to fig. 1, fig. 2 and fig. 6, fig. 6 is a schematic structural diagram of a power plane layer 70 of an LTCC-based millimeter wave package antenna according to an embodiment of the present invention. Further, the multilayer circuit board also includes a power plane layer 70. The beamforming chip 20 is also provided with a power pin 25. The power pins 25 are electrically connected to the power plane 71 of the power plane layer 70. It should be noted that the number of the power supply pins 25 of the beam forming chip 20 is one, two, three, four or other numbers, and the number is not limited. In this embodiment, the number of the power supply pins 25 of the beam forming chip 20 illustrated in fig. 1 is four, and the power supply voltages connected to the four power supply pins 25 are the same.

Referring to fig. 2, more specifically, the high-frequency dielectric materials between adjacent layers of the radiation unit layer 10 and the second radio frequency circuit layer 50 have 7 layers, which are respectively referred to as a first dielectric layer 101, a second dielectric layer 102, a third dielectric layer 103, a fourth dielectric layer 104, a fifth dielectric layer 105, a sixth dielectric layer 106, and a seventh dielectric layer 107.

Optionally, the thickness of the first dielectric layer 101 is 1.1mm to 1.3mm, specifically, for example, 1.196mm, so that the distance between the radiation unit layer 10 and the first ground layer 81 can be ensured to be sufficient, and thus the radiation efficiency, the directional pattern, and other characteristics of the radiation unit layer 10 can be optimized.

Optionally, the thickness of the second dielectric layer 102, the thickness of the third dielectric layer 103, and the thickness of the fourth dielectric layer 104 are the same or substantially the same, and the thicknesses are 0.08mm to 0.1mm, for example, 0.092 mm. Therefore, the product performance of the millimeter wave packaging antenna based on the LTCC is ensured, and meanwhile, the thickness of the second dielectric layer 102, the thickness of the third dielectric layer 103 and the thickness of the fourth dielectric layer 104 are small enough, so that the miniaturization of the product size can be realized, and the product weight is reduced.

Optionally, the thickness of the fifth dielectric layer 105 is the same as or approximately the same as that of the sixth dielectric layer 106, and is 0.2mm to 0.3mm, for example, 0.264 mm. Thus, the thickness of the fifth dielectric layer 105 and the sixth dielectric layer 106 is relatively moderate, so that the stripline in the first rf circuit layer 30 cannot be too thin, and needs to meet the manufacturer processing requirements (e.g., not less than 0.1 mm).

Optionally, the thickness of the seventh dielectric layer 107 is 0.12mm to 0.22mm, specifically, for example, 0.176 mm. Thus, the thickness of the seventh dielectric layer 107 is relatively moderate, which can ensure that the microstrip line 127 located on the second rf circuit layer 50 cannot be too thin, and needs to meet the manufacturer processing requirement (for example, not less than 0.1 mm).

In one embodiment, the radiation unit layer 10 is provided with a plurality of radiation oscillator pieces 11, and two feeding pads 12 arranged corresponding to the radiation oscillator pieces 11. The first rf circuit layer 30 is electrically connected to the feeding pad 12.

Specifically, referring to fig. 2 and fig. 3, the radiation unit layer 10 is provided with a plurality of radiation oscillator pieces 11, and two feeding pads 12 corresponding to the radiation oscillator pieces 11. The radiation oscillator piece 11 is, for example, a square, a circle, an ellipse, or the like, and is not limited herein.

In addition, referring to fig. 8, fig. 8 is a schematic structural diagram of a first rf circuit layer 30 of a LTCC-based millimeter wave package antenna according to an embodiment of the present invention. The first radio frequency line layer 30 includes a one-to-N power dividing feeder 31. The first rf signal input/output pin 21 is electrically connected to the combining terminal 311 of the one-to-N power dividing feeder 31. The branch ends 312 of the one-to-N power distribution feeder 31 are electrically connected to the plurality of feeding panels 12, respectively.

Referring to fig. 1 again, it should be noted that the number of the second rf signal input/output pins 22 of the beam forming chip 20 is not limited, and is illustrated as one in the drawing in this embodiment; in addition, the number of the first rf signal input/output pins 21 of the beam forming chip 20 is not limited, and may be, for example, one, two, three, four or another number, for example, four of the first rf signal input/output pins 21 illustrated in fig. 1 in this embodiment, and the arrangement manner of the four first rf signal input/output pins 21 is a 2 × 2 array arrangement. Of course, the arrangement of the first rf signal input/output pins 21 may also be, for example, 8, and adopt a 2 × 4 array arrangement. The number of the ground pins 23 of the beam forming chip 20 is not limited, and may be, for example, one, two, three, four or another number.

Referring to fig. 3, it should be noted that the corresponding arrangement of the two feeding pads 12 and the radiating oscillator piece 11 means that the two feeding pads 12 are oppositely arranged on the periphery of the radiating oscillator piece 11, and a connection line of the centers of the two feeding pads 12 passes through the center of the radiating oscillator piece 11. In addition, the feeding pad 12 and the edge of the radiating oscillator piece 11 are provided with a gap for coupling feeding, and may be directly connected with the edge of the radiating oscillator piece 11 for feeding. Two feed disks 12 feed a first polarization direction signal (for example, a +45 ° polarization direction signal or a-45 ° polarization direction signal) to the radiation oscillator piece 11, so as to realize a millimeter wave single-polarization 5G array antenna. When the edge of the feed pad 12 and the edge of the radiating oscillator piece 11 are provided with intervals for coupling feed, broadband characteristics can be realized, and the 5GNRn258 frequency band of 24.25 GHz-27.5 GHz can be covered.

Further, two feed pads 12 and one radiating oscillator piece 11 form one array sub-unit, two array sub-units shown in a dashed line frame P in fig. 3 form one sub-array unit driving two, and 4 same sub-array units are shared in fig. 3, so as to form a 2 × 2 sub-array driving two. In addition, the horizontal spacing between adjacent subarray elements is S1 as shown in fig. 3, and S1 is generally less than half a wavelength, and is optimized according to beam scanning range, side lobe and grating lobe requirements, and the like. The vertical spacing between adjacent subarray elements is S2 as shown in fig. 3, and S2 may be slightly longer than half a wavelength, and is optimized according to beam sweep range, side lobe and grating lobe requirements, and the like. It should be noted that one wavelength is equal to the speed of light/antenna frequency, i.e. related to the antenna frequency, which is for example 26GHz, and one wavelength is about 11.5 mm.

Referring to fig. 2 and 8 again, it should be noted that N in the one-to-N power dividing feeder 31 is a natural number not less than 2, and may be, for example, 2, 3, 4, 6, 8, and so on. In this embodiment, N in the one-to-N power splitting feeder 31 illustrated in fig. 8 is specifically 4.

Referring to fig. 1, fig. 2 and fig. 7, in particular, the number of the control pins 24 provided in the beam forming chip 20 may be one, two or other, and is not limited. In this embodiment, two control pins 24 of the beamforming chip 20 are provided, and one of the control pins 24 is, for example, a TDD (Test-drive Development) switching control pin, so as to implement time division switching control on a TDD signal. The other control pin 24 is, for example, an SPI (Serial Peripheral Interface) control pin, and implements configuration of the chip, including phase control, amplitude control, power detection, temperature compensation, and the like.

The control signal layer 60 is provided in one layer, two layers, three layers or other number according to the actual wiring condition, and the number of the layers is not limited to a specific number. In the present embodiment, the control signal layer 60 illustrated in fig. 2 is two layers.

It should be noted that the structures of the first formation 81 and the second formation 8382 may be the same or different, and in this embodiment, the structures of the first formation 81 and the second formation 8382 are the same, and fig. 5 illustrates the structure of the first formation 81.

Referring to fig. 2, further, the multi-layer circuit board is provided with a plurality of first vertical interconnection metallization vias 91. The plurality of first vertical interconnection metalized vias 91 are arranged in one-to-one correspondence with the plurality of feed trays 12, the first vertical interconnection metalized vias 91 penetrate from the radiation unit layer 10 to the first radio frequency circuit layer 30, one end of each first vertical interconnection metalized via 91 is electrically connected with the feed tray 12, and the other end of each first vertical interconnection metalized via 91 is electrically connected with the branch end 312 of the one-to-N power distribution feed line 31.

It is understood that in order to avoid electrically connecting the first vertical interconnect metallization via 91 to the lines of the first ground layer 81, the power plane layer 70, the control signal layer 60 and the second ground layer 8382, the first ground layer 81, the power plane layer 70, the control signal layer 60 and the second ground layer 8382 are provided with a first anti-pad 92 circumferentially disposed around the first vertical interconnect metallization via 91.

Further, the multilayer circuit board is further provided with a plurality of second vertical interconnect metallization vias 93. The second vertical interconnection metalized via 93 penetrates from the first rf circuit layer 30 to the second rf circuit layer 50, one end of the second vertical interconnection metalized via 93 is electrically connected to the combining end 311 of the one-to-N power splitting feeder 31, and the other end of the second vertical interconnection metalized via 93 is electrically connected to the first rf signal input/output pin 21.

It will be appreciated that in order to avoid electrical connection of the second vertical interconnect metallization via 93 to the ground plane of the third ground layer, a second anti-pad 94 is provided on the third ground layer, circumferentially disposed around the second vertical interconnect metallization via 93.

Further, the multilayer circuit board is also provided with a third vertical interconnect metallization via 95. The third vertical interconnection metallization via 95 penetrates from the first ground layer 81 to the second rf circuit layer 50, one end of the third vertical interconnection metallization via 95 is electrically connected to the control circuit 61, and the other end of the third vertical interconnection metallization via 95 is electrically connected to the control pin 24.

It is understood that, in order to avoid the third vertical interconnection metallization via 95 being electrically connected to the lines of the first ground layer 81, the power plane layer 70, the second ground layer 8382, the first rf line layer 30 and the third ground layer, the first ground layer 81, the power plane layer 70, the second ground layer 8382, the first rf line layer 30 and the third ground layer are provided with a third anti-pad 96 circumferentially disposed around the third vertical interconnection metallization via 95.

Furthermore, the multilayer circuit board is further provided with a plurality of fourth vertical interconnection metallized via holes 97, the fourth vertical interconnection metallized via holes 97 penetrate from the first ground layer 81 to the second radio frequency circuit layer 50, and the power plane 71 of the power plane layer 70 is electrically connected with the ground pin 23 through the fourth vertical interconnection metallized via holes 97.

Referring to fig. 5 to 9, it is understood that, in order to avoid the electrical connection between the fourth vertical interconnection metallization via 97 and the circuits of the first ground layer 81, the control signal layer 60, the second ground layer 8382 and the third ground layer, the first ground layer 81, the second ground layer 8382 and the third ground layer are respectively provided with a fourth anti-pad 98 circumferentially disposed around the fourth vertical interconnection metallization via 97.

Referring to fig. 5 to 9, the number of the fourth vertical interconnection metallization via 97 is not limited, and may be, for example, one, two, three, four or other numbers, and the number is illustrated as four in the present embodiment. Further, the first ground layer 81, the control signal layer 60, the second ground layer 8382, the first rf circuit layer 30 and the third ground layer are all provided with a first power plane 981, and the fourth vertical interconnection metalized via 97 is electrically connected to the first power plane 981. The first ground layer 81, the second ground layer 8382 and the fourth anti-pad 98 on the third ground layer are circumferentially disposed around the first power plane 981. In this way, the first power plane 981 can achieve mutual electrical conduction between the four fourth vertical interconnect metallization vias 97, thereby achieving good conduction between the power plane 71 and the power pins 25 of the beam forming chip 20.

Further, the multilayer circuit board is further provided with a plurality of fifth vertical interconnection metallization vias 991 and a plurality of sixth vertical interconnection metallization vias 992. The fifth vertical interconnection metallization via 991 penetrates the first radio frequency circuit layer 30 from the first ground layer 81, the sixth vertical interconnection metallization via 992 penetrates the second radio frequency circuit layer 50 from the first radio frequency circuit layer 30, and the fifth vertical interconnection metallization via 991 is electrically connected with the sixth vertical interconnection metallization via 992. The first ground layer 81, the second ground layer 8382 and the third ground layer are all electrically connected to each other through a fifth vertical interconnect metallization via 991, and a sixth vertical interconnect metallization via 992 is electrically connected to the ground pin 23.

It is understood that, in order to avoid the electrical connection between the fifth vertical interconnect metallization via 991 and the circuits of the power plane layer 70 and the control signal layer 60, a fifth anti-pad 995 circumferentially disposed around the fifth vertical interconnect metallization via 991 is optionally disposed on the power plane layer 70 and the control signal layer 60. Of course, the fifth anti-pad 995 may not be provided, as long as the fifth vertical interconnection metallization via 991 avoids the circuits of the power plane layer 70 and the control signal layer 60 when passing through the circuits of the power plane layer 70 and the control signal layer 60.

Referring to fig. 2, 5-8, in one embodiment, a plurality of spaced fifth vertical interconnect metallization vias 991 are disposed around the periphery of the first vertical interconnect metallization via 91.

Further, a second power plane 996 is disposed on each power plane layer 70, and the fifth vertical interconnection metallized via 991 is electrically connected to the second power plane 996. Wherein the fifth anti-pad 995 is circumferentially disposed about the second supply surface 996 such that the second supply surface 996 is spaced from the power supply surface 71. Thus, the second power plane 996 can achieve mutual electrical conduction between the five fifth vertical interconnect metalized vias 991, and thus can achieve good conduction between the fifth vertical interconnect metalized vias 991 and the ground pins 23 of the beam forming chip 20. The power supply plane can be similarly disposed on the control signal layer 60, which is not described in detail.

Referring to fig. 2, 9 and 10, fig. 10 is a schematic structural diagram of a second rf circuit layer 50 of an LTCC-based millimeter wave package antenna according to an embodiment of the present invention. A plurality of spaced sixth vertical interconnect metallization vias 992 are provided around the periphery of the second vertical interconnect metallization via 93.

Thus, the first vertical interconnection metalized via 91 and the plurality of spaced fifth vertical interconnection metalized vias 991 arranged around the periphery thereof, the second vertical interconnection metalized via 93 and the plurality of spaced sixth vertical interconnection metalized vias 992 arranged around the periphery thereof are all equivalent to coaxial cables, and the transmission of signals is more stable.

The number of the fifth vertical interconnect metallization vias 991 arranged around the periphery of the first vertical interconnect metallization via 91 illustrated in the figure is 5, but may be other numbers, which is not limited herein. The number of the sixth vertical interconnect metallization vias 992 around the periphery of the second vertical interconnect metallization via 93 is 4, but may be other numbers, and is not limited herein.

Referring to fig. 2, 9 and 10, the second rf circuit layer 50 is provided with a microstrip line 127 or a GCPW transmission line, which is described by taking the microstrip line 127 as an example. The microstrip line 127 is used for connecting the first rf signal input/output pin 21 and the second vertical interconnection metallized via 93. Specifically, the four microstrip lines 127 electrically connect the four first rf signal input/output pins 21 and the four second vertical interconnection metalized vias 93. In order to achieve phase consistency of each feed, the lengths of the four microstrip lines 127 are required to be equal.

Referring to fig. 2, in one embodiment, the multilayer circuit board further has a first-order metalized via 993, the first-order metalized via 993 penetrates from the third ground layer to the second rf circuit layer 50, and the third ground layer is electrically connected to the ground pin 23 through the first-order metalized via 993.

In one embodiment, the vertical via size of the first vertical interconnect metallization via 91, the size of the first anti-pad 92, requires the use of electromagnetic simulation tools to complete the optimized design.

It will be appreciated that in LTCC processes, the formation of the first vertical interconnect metallization via 91 by tape casting and sintering processes enables the interconnection of the radiating element layer 10 through to any of the layers of the first radio frequency circuitry layer 30. The second vertical interconnect metallization via 93, the third vertical interconnect metallization via 95, the fourth vertical interconnect metallization via 97, the fifth vertical interconnect metallization via 991 and the sixth vertical interconnect metallization via 992 are similar and not limited herein.

In one embodiment, the apertures of the first vertical interconnect metallization vias 91 are each specifically, for example, 0.2 mm. The outer diameter of the first anti-pad 92 is specifically, for example, 0.8 mm. In addition, the pitch between the first vertical interconnect metallization via 91 and the five vertical interconnect metallization vias surrounding the first vertical interconnect metallization via is, for example, 0.65 mm. It should be noted that the aperture of the first vertical interconnection metalized via 91 is only a specific value, and the aperture of the first vertical interconnection metalized via 91 is not specifically limited in this embodiment, and the size of the first vertical interconnection metalized via 91 may also be adjusted according to actual situations. The diameter of the outer circle of the first anti-pad 92, the pitch of the first vertical interconnection metallization via 91 and the five vertical interconnection metallization vias around the periphery thereof are similar, and are not described again.

In one embodiment, the apertures of the second vertical interconnect metallization vias 93 are each specifically, for example, 0.1 mm. The outer diameters of the second anti-pads 94 are each, specifically, 0.24mm, for example. In addition, the pitch between the second vertical interconnect metallization via 93 and the six vertical interconnect metallization vias surrounding the second vertical interconnect metallization via is, for example, 0.42 mm. It should be noted that the aperture of the second vertical interconnection metalized via 93 is only a specific value, and the aperture of the first vertical interconnection metalized via 91 is not specifically limited in this embodiment, and the size of the second vertical interconnection metalized via 93 may also be adjusted according to actual situations. The diameter of the outer circle of the second anti-pad 94, the second vertical interconnection metalized via 93 and the distance between the six vertical interconnection metalized vias wound around the periphery thereof are similar, and are not described again.

Referring to fig. 11 to 12, fig. 11 is a schematic structural diagram illustrating a radiation unit layer 10 of an array antenna according to an embodiment of the present invention; fig. 12 is a schematic structural diagram illustrating that the second rf signal input/output pin 22 of the array antenna is connected to the power division feeding network according to an embodiment of the present invention.

In one embodiment, an array antenna comprises two or more LTCC-based millimeter wave package antennas of any of the above embodiments.

In the array antenna, an external device can send a trigger signal to the beamforming chip 20 through the control signal layer 60 via the control line 61 and the control pin 24, so as to trigger the beamforming chip 20, and the beamforming chip 20 performs a related action after being triggered; when the beam forming chip 20 works, an external device sends an antenna signal to the beam forming chip 20 through the second radio frequency circuit layer 50 and the second radio frequency signal input/output pin 22 of the beam forming chip 20, the radio frequency signal is input to the first radio frequency circuit layer 30 through the first radio frequency signal input/output pin 21 of the beam forming chip 20 and is transmitted to the radiation unit layer 10 through the first radio frequency circuit layer 30, the antenna signal received by the radiation unit layer 10 can also enter the beam forming chip 20 through the first radio frequency signal input/output pin 21, the second radio frequency signal input/output pin 22 of the beam forming chip 20 is output to the second radio frequency circuit layer 50, and the antenna signal is fed back to the external device through the second radio frequency circuit layer 50. In addition, the first ground layer 81 serves as a reference ground layer of the radiating element layer 10, and provides a reference ground plane for the radiating element layer 10, so as to realize the radiation characteristics of the antenna element. The second ground layer 8382 enables the control signal layer 60 and the first radio frequency circuitry layer 30 to be isolated from each other. The third ground layer can realize the mutual isolation of the first radio frequency circuit layer 30 and the second radio frequency circuit layer 50, and is also a reference ground plane of the first radio frequency circuit layer 30 and the second radio frequency circuit layer 50. Therefore, the millimeter wave packaging antenna based on the LTCC can realize the input and output of the radio frequency signals of the radiation unit layer 10 of the multilayer circuit board designed by the LTCC, can be suitable for the production and the manufacture of the mature LTCC process, and has low cost, small volume and light weight.

Referring to fig. 3 and fig. 11, in addition, in the present embodiment, an array antenna of 8 × 16 is formed by using one driving two sub-array units (as shown by the dashed line frame P in fig. 11). The whole array antenna is rectangular, the long side of the array antenna is L1 shown in FIG. 11, the length of L1 is 80mm, for example, and the short side of the array antenna is L2 shown in FIG. 11, and the length of L2 is 40mm, for example. According to 3D electromagnetic simulation, in the range of 5G NRn25824.25GHz-27.5 GHz, the beam direction of the pitching plane of the array antenna can reach +/-15 degrees, and the beam direction of the azimuth plane can reach +/-60 degrees. The invention has the characteristics of wide bandwidth, low cost, small volume, light weight and mature process, and can meet the application requirements of 5G millimeter wave communication equipment on large-scale market.

Referring to fig. 11 and 12, further, when the present embodiment adopts an array antenna of 8 × 16 formed by two sub-array units, the second rf circuit layer 50 of the array antenna is correspondingly provided with a one-to-sixteen power dividing and feeding network 121. The one-to-sixteen power division feeding network 121 can be implemented by using, for example, a classical one-to-two wilkinson power division unit in a cascade manner. An output port of the one-sixteen power dividing power feeding network 121 is connected to the second rf signal input/output pin 22 of the beam forming chip 20. 16 beamforming chips 20 are used for each polarization direction.

The rf feed port 123 of the one-to-sixteen power splitting feed network 121 may be implemented by using an SMP socket (not shown in the figure), so as to interconnect with other PCBs of external devices, thereby implementing feeding and signal receiving to the radiating element layer 10.

Referring to fig. 12 and 13, fig. 13 is a schematic diagram illustrating an arrangement structure of a plurality of beam forming chips 20 in an array antenna according to an embodiment of the invention. A digital multi-pin socket 124 is further disposed in the second rf circuit layer 50, and a plurality of connection pads 125 are disposed on the digital multi-pin socket 124. The internal control traces (see fig. 7) are electrically connected to the connection pads 125 by, for example, daisy-chain routing (see fig. 13 for schematic illustration), through vertical interconnect metallization vias. Through the digital multi-pin socket 124, interconnection with other PCBs of external devices can be realized, so that functions of power supply, logic control and the like of the antenna module are realized.

FIG. 13 illustrates a classic daisy chain wiring interconnect schematic. S3 is the distance between adjacent beam shaping chips 20 in the wiring; s4 is the distance from the daisy chain bus 126 to the control pin 24 of the beamforming chip 20, which is as short as possible to improve signal integrity. In the design of the multilayer circuit board, since the clock rate of the control signal is high (90MHz), in order to avoid the problem of signal integrity, the daisy chain wiring adopts a serial four structure as shown in fig. 13, for example. It should be noted that the daisy chain main line 126 is a projection of the control line 61 on the second rf line layer 50.

The simulation performance of the single-polarized millimeter wave phased active array antenna of the present embodiment is shown in the following table:

8 x 16 single polarized active phased array antenna performance

The millimeter wave packaging antenna based on the LTCC has the advantages of being wide in bandwidth, low in cost, small in size, light in weight and mature in process, and can meet the requirement of 5G millimeter wave communication equipment on large-scale market. In the present embodiment, fig. 3 to 12 illustrate a single-polarized array formed by driving two array elements, but the present invention is not limited thereto, and may be a single-polarized array formed by driving one array element, driving three array elements, driving four array elements, or driving other array elements.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

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

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Claims (10)

1. An LTCC-based millimeter wave packaged antenna, comprising a multilayer circuit board, the multilayer circuit board comprising:

the radiation unit layer, the first stratum, the control signal layer, the second stratum, the first radio frequency circuit layer, the third stratum and the second radio frequency circuit layer are sequentially arranged in an overlapped mode; high-frequency dielectric materials are arranged among adjacent layers of the radiation unit layer, the first stratum, the control signal layer, the second stratum, the first radio frequency circuit layer, the third stratum and the second radio frequency circuit layer;

the beam forming chip is provided with a first radio frequency signal input and output pin, a second radio frequency signal input and output pin, a grounding pin and a control pin; the first radio frequency signal input/output pin is electrically connected to the first radio frequency circuit layer, and the first radio frequency circuit layer is electrically connected with the radiation unit layer; the second radio frequency signal input/output pin is electrically connected to the second radio frequency circuit layer; the ground pin is electrically connected to the third ground layer; the control signal layer is provided with a control circuit, and the control pin is electrically connected with the control circuit.

2. The LTCC-based millimeter-wave packaged antenna of claim 1, wherein the multilayer circuit board further comprises a power plane layer disposed between the first ground layer and the control signal layer; the beam forming chip is also provided with a power supply pin, and the power supply pin is electrically connected with the power supply surface of the power supply plane layer.

3. The LTCC-based millimeter-wave package antenna of claim 2, wherein the beamforming chip is disposed on the second radio frequency circuitry layer.

4. The LTCC-based millimeter wave packaged antenna according to claim 3, wherein the radiation unit layer is provided with a plurality of radiation oscillator pieces, and two feeding pads are disposed corresponding to the radiation oscillator pieces; the first radio frequency circuit layer is electrically connected with the feed tray.

5. The LTCC-based millimeter wave package antenna according to claim 4, wherein the first rf circuit layer comprises a one-to-N power dividing feeder, the first rf signal input/output pin is electrically connected to the combining end of the one-to-N power dividing feeder, and a plurality of branch ends of the one-to-N power dividing feeder are electrically connected to the plurality of feed pads respectively.

6. The LTCC-based millimeter wave package antenna according to claim 5, wherein the multilayer circuit board is provided with a plurality of first vertical interconnection metalized vias, the plurality of first vertical interconnection metalized vias are arranged in a one-to-one correspondence with a plurality of feed trays, the first vertical interconnection metalized vias penetrate from the radiation unit layer to the first radio frequency line layer, one end of each first vertical interconnection metalized via is electrically connected with the feed tray, and the other end of each first vertical interconnection metalized via is electrically connected with a branch end of the one-N power distribution feed line;

the multilayer circuit board is also provided with a plurality of second vertical interconnection metalized via holes, the second vertical interconnection metalized via holes penetrate from the first radio frequency line layer to the second radio frequency line layer, one end of each second vertical interconnection metalized via hole is connected with the closing end of the one-to-N power distribution feeder, and the other end of each second vertical interconnection metalized via hole is electrically connected with the first radio frequency signal input/output pin;

the multilayer circuit board is also provided with a third vertical interconnection metalized through hole; the third vertical interconnection metalized via penetrates from the first ground layer to the second radio frequency circuit layer, one end of the third vertical interconnection metalized via is electrically connected with the control circuit, and the other end of the third vertical interconnection metalized via is electrically connected with the control pin;

the multilayer circuit board is further provided with a plurality of fourth vertical interconnection metalized via holes, the fourth vertical interconnection metalized via holes penetrate through the first ground layer to the second radio frequency circuit layer, and the power surface of the power plane layer is electrically connected with the grounding pins through the fourth vertical interconnection metalized via holes.

7. The LTCC-based millimeter wave package antenna according to claim 6, wherein the multilayer circuit board further comprises a plurality of fifth vertical interconnection metallization vias and a plurality of sixth vertical interconnection metallization vias, the fifth vertical interconnection metallization vias penetrate from the first ground layer to the first rf line layer, the sixth vertical interconnection metallization vias penetrate from the first rf line layer to the second rf line layer, the fifth vertical interconnection metallization vias are electrically connected to the sixth vertical interconnection metallization vias, and the first ground layer, the second ground layer and the third ground layer are electrically connected to each other through the fifth vertical interconnection metallization vias.

8. The LTCC-based millimeter-wave package antenna of claim 7, wherein the first vertical interconnect metalized via is peripherally surrounded by a plurality of spaced fifth vertical interconnect metalized vias, and wherein the second vertical interconnect metalized via is peripherally surrounded by a plurality of spaced sixth vertical interconnect metalized vias.

9. The LTCC-based millimeter-wave package antenna according to claim 6, wherein the multilayer circuit board further comprises a first-order metalized via, the first-order metalized via penetrates from the third ground layer to the second rf line layer, and the third ground layer is electrically connected to the ground pin through the first-order metalized via.

10. An array antenna comprising two or more LTCC based millimeter wave packaged antennas according to any of claims 1 to 9.

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