A heterogeneous integrated packaged antenna with back radiation

Abstract

The present invention discloses a heterogeneous integrated package antenna with back radiation, wherein the dielectric substrates are stacked in multiple layers, the first dielectric substrate is located on the top layer as a cover plate, the center of the second dielectric substrate is completely hollowed out to accommodate the DC bonding wire, the center of the third dielectric substrate is etched to place the MMIC chip, and the fourth dielectric substrate is thinned around to suppress surface waves and improve radiation efficiency; the metal shielding layer is attached to the surface of the dielectric substrate, and a rectangular coupling window is left to regulate the transmission mode; an on-chip antenna is designed on the MMIC chip, and the antenna energy is transferred to the third dielectric substrate through the MMIC chip substrate, and is guided to the fourth dielectric substrate by the metallized through-hole fence, and finally radiated into the air. The heterogeneous integrated package antenna with back radiation combines the MMIC chip process and the multi-layer dielectric substrate process, and realizes the high-performance design of the antenna and the miniaturized packaging of the system at the same time, and can be applied to large-scale phased array and reverse array systems in the millimeter wave and terahertz frequency bands.

Description

Technical Field

[0001] The present invention belongs to the field of packaged antennas, and in particular relates to heterogeneous integrated packaged antennas in millimeter wave and terahertz frequency bands. Background Art

[0002] In the RF systems of millimeter wave and terahertz frequency bands, there are two mainstream antenna design schemes, namely antenna on chip AoC (Antenna on Chip) and packaged antenna AiP (Antenna in Package). The AoC scheme directly connects the antenna to the back end of the RF chip, and can transmit and receive signals without additional processes. This scheme has a simple design, few processes, and high integration, but poor performance. The AiP scheme designs the antenna outside the chip, and then packages the antenna and RF chip together through a series of processes. This scheme compromises antenna performance and system volume.

[0003] At present, although the AoC and AiP solutions have been recognized by people, both solutions have exposed some problems in application and need to be solved urgently. In the AoC solution, the thickness of the on-chip dielectric layer is small, and the mirror effect of the on-chip antenna relative to the metal ground is significant, which greatly reduces the radiation efficiency of the on-chip antenna and causes the gain of the on-chip antenna to be extremely low. In addition, the relative dielectric constant of the on-chip dielectric layer is small, and the physical size of the antenna as a resonant radiation structure is closely related to the relative dielectric constant. The on-chip antenna often occupies a large on-chip area. In the AiP solution, on-chip circuits and off-chip antennas are often connected by bonding or flip-chip bonding. The discontinuity at the connection will introduce transition losses. At the same time, due to assembly errors, there are deviations between the finished product and the simulation model, and the test results are uncertain. Secondly, the dielectric loss of the dielectric board will increase with the increase of frequency. The off-chip RF routing will introduce considerable path loss. In the terahertz frequency band, this problem becomes more serious. In addition, the off-chip antenna will occupy additional area, making it difficult to control a single transmit and receive link at one wavelength, which increases the design difficulty of large-scale phased array and reverse array systems. Summary of the invention

[0004] Technical problem: In view of the shortcomings of the existing technology, the present invention discloses a back-radiating heterogeneous integrated packaged antenna, which realizes the high-performance design of the antenna in the millimeter wave and terahertz frequency bands and the miniaturized packaging of the system.

[0005] Technical solution: A back-radiating heterogeneous integrated packaged antenna used in the present invention includes a dielectric substrate, a metal shielding layer, a metalized through-hole fence, an MMIC chip and an on-chip antenna;

[0006] The dielectric substrate has four layers in total, which are stacked in sequence. The first dielectric substrate is a complete piece; the center of the second dielectric substrate is completely hollowed out to form a rectangular cavity that is transparent from top to bottom; the center of the third dielectric substrate is partially etched to retain the dielectric base; the fourth dielectric substrate is thinned on all sides to form a rectangular dielectric block with the center protruding downward;

[0007] The metal shielding layer is attached to the surface of the dielectric substrate, the first metal shielding layer is attached to the top surface of the first dielectric substrate, the second metal shielding layer is between the first dielectric substrate and the second dielectric substrate, the third metal shielding layer is between the second dielectric substrate and the third dielectric substrate, the fourth metal shielding layer is between the third dielectric substrate and the fourth dielectric substrate, the fifth metal shielding layer is attached to the bottom surface of the fourth dielectric substrate, the sixth metal shielding layer is attached to the side surface of the rectangular cavity of the second dielectric substrate, the seventh metal shielding layer is attached to the side surface of the rectangular cavity of the third dielectric substrate, and the eighth metal shielding layer is attached to the bottom surface of the rectangular cavity of the third dielectric substrate;

[0008] The metallized through-hole fence is connected end to end and is rectangular in shape as a whole, and passes through the eighth metal shielding layer, the third dielectric substrate, the fourth metal shielding layer, the fourth dielectric substrate and the fifth metal shielding layer from top to bottom in sequence;

[0009] The MMIC chip is placed in the rectangular cavity of the third dielectric substrate;

[0010] The on-chip antenna is arranged on the MMIC chip at a central position.

[0011] The rectangular dielectric block protruding downward from the center of the fourth dielectric substrate has no attached metal shielding layer.

[0012] A rectangular coupling window is left in the center of the fourth metal shielding layer.

[0013] A rectangular coupling window is reserved in the center of the fifth metal shielding layer.

[0014] A rectangular coupling window is left in the center of the eighth metal shielding layer.

[0015] The on-chip antenna is selected from a patch antenna, a monopole antenna, a dipole antenna or a slot antenna.

[0016] The feeding mode of the on-chip antenna is selected from single-ended feeding or differential feeding.

[0017] The invention discloses a millimeter wave and terahertz frequency band antenna composed of a back-radiating heterogeneous integrated packaged antenna. The millimeter wave and terahertz frequency band antenna comprises two or more forward-radiating heterogeneous integrated packaged antennas.

[0018] Beneficial effects: Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) Higher performance: Compared with traditional on-chip antennas, the present invention has higher radiation efficiency and gain;

[0020] (2) Smaller area: The area of ​​the on-chip antenna of the present invention is only half of that of the traditional on-chip antenna;

[0021] (3) Lower processing difficulty: The present invention does not require post-processing steps such as bonding and flip-chip to guide the RF signal, and has higher processing consistency;

[0022] (4) Smaller path loss: The present invention does not require off-chip RF routing, which greatly reduces path loss;

[0023] (5) Higher system integration: The present invention heterogeneously integrates MMIC chips and multi-layer dielectric substrates, which can control a single transceiver link within one wavelength, providing an option for large-scale phased array and reverse array systems in the millimeter wave and terahertz frequency bands. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a cross-sectional view of a heterogeneous integrated packaged antenna with back radiation in an embodiment of the present invention;

[0025] Figure 2 is a stacking diagram of a dielectric substrate in an embodiment of the present invention;

[0026] Figure 3 A stacking diagram of a metal shielding layer in an embodiment of the present invention;

[0027] Figure 4 is a top view of an on-chip antenna in an embodiment of the present invention;

[0028] Figure 5 is the gain of the heterogeneous integrated packaged antenna with back radiation in an embodiment of the present invention;

[0029] Figure 6 is the radiation efficiency of the heterogeneous integrated packaged antenna with back radiation in an embodiment of the present invention;

[0030] In the figure, there are: 11-first dielectric substrate, 12-second dielectric substrate, 13-third dielectric substrate, 14-fourth dielectric substrate, 21-first metal shielding layer, 22-second metal shielding layer, 23-third metal shielding layer, 24-fourth metal shielding layer, 25-fifth metal shielding layer, 26-sixth metal shielding layer, 27-seventh metal shielding layer, 28-eighth metal shielding layer, 3-metallized through-hole fence, 4-MMIC chip, 5-on-chip antenna. DETAILED DESCRIPTION

[0031] The present invention will be further described below in conjunction with the embodiments and drawings.

[0032] Example

[0033] like Figures 1 to 4 As shown, this embodiment designs a back-radiating heterogeneous integrated packaged antenna, which combines the MMIC chip process and the multi-layer dielectric substrate process, operates in the D band, and is composed of a dielectric substrate, a metal shielding layer, a metallized through-hole fence (3), an MMIC chip 4 and an on-chip antenna 5.

[0034] The dielectric material of the dielectric substrate is silicon, which is finely processed using a micro-electro-mechanical system (MEMS). There are four dielectric substrates in total, each 250um thick, stacked in sequence. The first dielectric substrate 11 is on the top layer as a cover; the center of the second dielectric substrate 12 is completely etched to form a rectangular cavity that is transparent from top to bottom, which is used to accommodate the bonding wire to supply DC bias; the center of the third dielectric substrate 13 is etched to retain the silicon base, which is used to place the MMIC chip 4. The depth of the etched cavity is basically consistent with the height of the MMIC chip 4 to reduce the difficulty of loading the DC bonding wire; the fourth dielectric substrate 14 is thinned on all sides to protrude the central rectangular dielectric block to suppress surface waves and improve the radiation efficiency and gain of the antenna.

[0035] The metal shielding layer is attached to the surface of the dielectric substrate and is used to bind electromagnetic energy so that the signal can be transmitted along the planned path. The first metal shielding layer 21 is attached to the top surface of the first dielectric substrate 11, the second metal shielding layer 22 is between the first dielectric substrate 11 and the second dielectric substrate 12, the third metal shielding layer 23 is between the second dielectric substrate 12 and the third dielectric substrate 13, the fourth metal shielding layer 24 is between the third dielectric substrate 13 and the fourth dielectric substrate 14, the fifth metal shielding layer 25 is attached to the bottom surface of the fourth dielectric substrate 14, the sixth metal shielding layer 26 is attached to the side surface of the rectangular cavity of the second dielectric substrate 12, the seventh metal shielding layer 27 is attached to the side surface of the rectangular cavity of the third dielectric substrate 13, and the eighth metal shielding layer 28 is attached to the bottom surface of the rectangular cavity of the third dielectric substrate 13.

[0036] The metallized through hole fence 3 is connected end to end to form a rectangular electromagnetic shielding fence for guiding signal transmission. The metallized through hole fence passes through the eighth metal shielding layer 28, the third dielectric substrate 13, the fourth metal shielding layer 24, the fourth dielectric substrate 14 and the fifth metal shielding layer 25 from top to bottom.

[0037] The MMIC chip 4 is based on a CMOS 40 nm process node, and its substrate is thinned from 300 um to 100 um to facilitate placement in the rectangular cavity of the third dielectric substrate 13 .

[0038] The on-chip antenna 5 is designed based on the top metal layer of the MMIC chip, and the metal layers of the MMIC chip below it are all hollowed out. When the on-chip antenna 5 is working, the antenna energy is first transferred to the substrate of the MMIC chip 4 through the on-chip dielectric layer, and then this part of the energy passes through the rectangular coupling window of the eighth metal shielding layer 28, the third dielectric substrate 13, the rectangular coupling window of the fourth metal shielding layer 24, and the rectangular coupling window of the fifth metal shielding layer 25 in sequence, and finally reaches the downward convex rectangular dielectric block of the fourth dielectric substrate 14 and radiates into the air.

[0039] In this embodiment, the on-chip antenna 5 uses a dual-polarized antenna. There are two types of antennas, one is a single-ended fed monopole antenna, and the other is a differentially fed dipole antenna. The monopole antenna is used to excite vertical linear polarized waves, and the dipole antenna is used to excite horizontal linear polarized waves. The two polarizations are orthogonal and can work in a co-frequency duplex system. The dipole antenna is differentially fed from both sides, and a stepped line width is used to achieve 50Ω port matching.

[0040] Figure 5 and Figure 6 The gain and radiation efficiency of this embodiment are shown respectively. When the monopole antenna is excited by single-ended feeding, the maximum radiation efficiency of this embodiment reaches 29.9% and the maximum gain is 2.56dBi. When the dipole antenna is excited by differential feeding, the maximum radiation efficiency of this embodiment reaches 39.4% and the maximum gain is 4.40dBi.

[0041] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A heterogeneous integrated packaged antenna with back radiation, characterized in that: It includes a dielectric substrate, a metal shielding layer, a metalized through-hole fence (3), an MMIC chip (4) and an on-chip antenna (5); The dielectric substrates have four layers in total, which are stacked in sequence. The first dielectric substrate (11) is a complete piece. The center of the second dielectric substrate (12) is completely hollowed out to form a rectangular cavity that is transparent from top to bottom. The central part of the third dielectric substrate (13) is etched to retain the dielectric base; The fourth dielectric substrate (14) is a rectangular dielectric block with thinned edges and a downwardly protruding center; The metal shielding layer is attached to the surface of the dielectric substrate, the first metal shielding layer (21) is attached to the top surface of the first dielectric substrate (11), the second metal shielding layer (22) is between the first dielectric substrate (11) and the second dielectric substrate (12), the third metal shielding layer (23) is between the second dielectric substrate (12) and the third dielectric substrate (13), the fourth metal shielding layer (24) is between the third dielectric substrate (13) and the fourth dielectric substrate (14), the fifth metal shielding layer (25) is attached to the bottom surface of the fourth dielectric substrate (14), the sixth metal shielding layer (26) is attached to the side surface of the rectangular cavity of the second dielectric substrate (12), the seventh metal shielding layer (27) is attached to the side surface of the rectangular cavity of the third dielectric substrate (13), and the eighth metal shielding layer (28) is attached to the bottom surface of the rectangular cavity of the third dielectric substrate (13); The metallized through-hole fence (3) is connected end to end and is rectangular in shape as a whole, and passes through the eighth metal shielding layer (28), the third dielectric substrate (13), the fourth metal shielding layer (24), the fourth dielectric substrate (14) and the fifth metal shielding layer (25) in sequence from top to bottom; The MMIC chip (4) is placed in the rectangular cavity of the third dielectric substrate (13); The on-chip antenna (5) is arranged on the MMIC chip (4) and is located at a central position.

2. The back-radiating heterogeneous integrated packaged antenna according to claim 1, characterized in that: The rectangular dielectric block protruding downward in the center of the fourth dielectric substrate (14) has no attached metal shielding layer.

3. The back-radiating heterogeneous integrated packaged antenna according to claim 1, characterized in that: A rectangular coupling window is left in the center of the fourth metal shielding layer (24).

4. The back-radiating heterogeneous integrated packaged antenna according to claim 1, characterized in that: A rectangular coupling window is left in the center of the fifth metal shielding layer (25).

5. The back-radiating heterogeneous integrated packaged antenna according to claim 1, characterized in that: A rectangular coupling window is left in the center of the eighth metal shielding layer (28).

6. The back-radiating heterogeneous integrated packaged antenna according to claim 1, characterized in that: The on-chip antenna (5) is selected from a patch antenna, a monopole antenna, a dipole antenna or a slot antenna.

7. The back-radiating heterogeneous integrated packaged antenna according to claim 6, characterized in that: The feeding mode of the on-chip antenna (5) is selected from single-ended feeding or differential feeding.

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