CN-121983782-A - Antenna array with high isolation based on MEMS technology and preparation method thereof

CN121983782ACN 121983782 ACN121983782 ACN 121983782ACN-121983782-A

Abstract

According to the antenna array with high isolation and the preparation method based on the MEMS technology, the size of the antenna array is precisely controlled by utilizing the characteristic of high processing precision of the silicon-based MEMS technology, the performance consistency of an antenna array in a W wave band is ensured, the loss caused by processing errors is effectively reduced, the radiation efficiency and gain stability of the antenna are improved, the formed antenna array has miniaturization and high integration level, mass production and production cost reduction are facilitated, a shielding cavity formed by a third TSV column and an isolation structure formed by a first TSV column and a second TSV column are designed, the spatial coupling of signals in the transmission process from a radio frequency signal wire to a feed probe is effectively restrained, the isolation of the antenna array is improved, the performance of the antenna is remarkably improved, the performance deterioration caused by array directional diagram and cross coupling change in the process of large-angle beam scanning is effectively reduced by optimizing the layout and the low cross coupling design of the antenna array, the wider scanning angle range is supported, and the space coverage capability of the antenna array is improved.

Inventors

XU ANNAN
KANG HONGYI
Guo Zhoushan
GUO ZICHEN
GUO XI
WANG ZHIYU
MO JIONGJIONG
YU FAXIN

Assignees

浙江大学

Dates

Publication Date: 20260505
Application Date: 20260205

Claims (17)

1. The antenna array with high isolation based on the MEMS technology is characterized by comprising a plurality of antenna units, wherein the antenna units sequentially comprise: A ninth metal layer is arranged on the front surface of the fifth silicon substrate, a tenth metal layer is arranged on the back surface of the fifth silicon substrate, a first coaxial structure is formed in the fifth silicon substrate, a first coaxial feed-out point is formed in the ninth metal layer, a first coaxial feed-in point is formed in the tenth metal layer, the first coaxial feed-in point and the first coaxial feed-out point are respectively and electrically connected with the first coaxial structure, and a multi-functional chip with an amplitude phase is bonded on the tenth metal layer; A seventh metal layer is arranged on the front surface of the fourth silicon substrate, an eighth metal layer is arranged on the back surface of the fourth silicon substrate, a second coaxial feed-in point is formed in the eighth metal layer and is electrically connected with the first coaxial feed-out point, a radio frequency signal wire is arranged in the seventh metal layer, a first cavity is arranged between the radio frequency signal wire and the seventh metal layer, a second TSV center column is arranged between the radio frequency signal wire and the second coaxial feed-in point, and a plurality of first TSV columns are also arranged in the fourth silicon substrate; A fifth metal layer is arranged on the front surface of the third silicon substrate, a sixth metal layer is arranged on the back surface of the third silicon substrate, a second bonding pad and a second cavity are formed in the sixth metal layer, the second bonding pad is electrically connected with the radio frequency signal wire, a first bonding pad is formed in the fifth metal layer, a third central TSV column and a plurality of second TSV columns are arranged in the third silicon substrate, the third central TSV column is electrically connected with the first bonding pad and the second bonding pad, and the second TSV column is electrically connected with the first TSV column; The first metal layer is arranged on the front side of the first silicon substrate, a first bonding pad is formed in the first bonding pad, a U-shaped groove radiation patch is arranged in the first metal layer, a first cavity is formed by the U-shaped groove radiation patch and the first metal layer, a feed probe and a plurality of first TSV columns are arranged in the first silicon substrate, the feed probe is electrically connected with the first bonding pad, and the first TSV columns are circumferentially distributed along the first cavity to form a shielding cavity; The first silicon substrate, be formed with the radiation mouth in the first silicon substrate, still be equipped with first metal layer on the radiation mouth, the back of first silicon substrate is equipped with the second metal layer, the second metal layer with form electric connection between the third metal layer.
2. The high isolation antenna array of claim 1, wherein the antenna array comprises 64 antenna elements arranged in an 8x 8 configuration.
3. The high isolation antenna array based on MEMS process of claim 1, wherein the first coaxial structure comprises a first central TSV column and a first peripheral TSV column penetrating through the fifth silicon substrate, wherein a top end of the first central TSV column is coupled with the first coaxial feed-out point, and a bottom end of the first central TSV column is coupled with the first coaxial feed-in point.
4. The high isolation antenna array based on MEMS process of claim 1, wherein the radio frequency signal line comprises a third coaxial feed-in point, a matching block, a strip line and a second coaxial feed-out point, wherein the third coaxial feed-in point is coupled with the second bonding pad point, and the second coaxial feed-out point is coupled with the second coaxial feed-in point through the second TSV center pillar.
5. The high isolation antenna array based on MEMS process of claim 3, wherein the width of the matching block is larger than the width of the strip line.
6. The MEMS process-based high isolation antenna array of claim 3, wherein the feed probe has a diameter of 30 μm, is coaxially disposed between the third center TSV column and the third coaxial feed point, and is electrically connected through the first bonding pad.
7. The MEMS process-based high isolation antenna array of claim 1, wherein the material of the first metal layer comprises gold or copper, and the thickness of the first metal layer is 3-6 μm.
8. The MEMS process-based high isolation antenna array of claim 1, wherein the first TSV pillars are distributed identically in the fourth silicon substrate and the second TSV pillars are distributed identically in the third silicon substrate and form an electrical connection.
9. The MEMS process-based high isolation antenna array of claim 1, wherein the first, second and third TSV pillars are the same size, the spacing between adjacent first TSV pillars is 60-90 μm, the spacing between adjacent second TSV pillars is 60-90 μm, and the spacing between adjacent third TSV pillars is 60-90 μm.
10. The antenna array with high isolation based on the MEMS process of claim 1, wherein the radiation port comprises a fourth cavity, a fifth cavity and a sixth cavity which are coaxially arranged from bottom to top, the widths of the fourth cavity, the fifth cavity and the sixth cavity are gradually increased, the fifth cavity and the sixth cavity are respectively provided with a raised ridge which is oppositely arranged, the raised ridge faces the U-shaped groove radiation patch, and the width of the fourth cavity is equal to the width of a shielding cavity surrounded by the third TSV column.
11. The high isolation antenna array of claim 10, wherein said U-shaped slot radiating patch is disposed coaxially with said third cavity and said feed probe is centered on said U-shaped slot radiating patch.
12. A method for preparing an antenna array with high isolation based on a MEMS process, which is used for preparing the antenna array with high isolation according to any one of claims 1 to 11, and is characterized by comprising the following steps: Providing a fifth silicon substrate, wherein a ninth metal layer and a tenth metal layer are oppositely arranged on two sides of the fifth silicon substrate, a first coaxial feed-out point is formed in the ninth metal layer, a first coaxial feed-in point is formed in the tenth metal layer, a first coaxial structure is formed in the fifth silicon substrate, the first coaxial structure comprises a first central TSV column and a first peripheral TSV column which penetrate through the fifth silicon substrate, the top end of the first central TSV column is coupled with the first coaxial feed-out point, and the bottom end of the first central TSV column is coupled with the first coaxial feed-in point; Providing a fourth silicon substrate, wherein a seventh metal layer and an eighth metal layer which are oppositely arranged are arranged on two sides of the fourth silicon substrate, a patterning process is carried out on the seventh metal layer to form a radio frequency signal line and a first cavity, a patterning process is carried out on the eighth metal layer to form a second coaxial feed-in point, the second coaxial feed-in point is connected with the radio frequency signal line through a second central TSV (through silicon) column, a plurality of first TSV columns are further arranged in the fourth silicon substrate, and the fifth front metal layer and the fourth back metal layer are bonded to enable the second coaxial feed-in point and the first coaxial feed-out point to be coupled; Providing a third silicon substrate, wherein a fifth metal layer and a sixth metal layer which are oppositely arranged are arranged on two sides of the third silicon substrate, patterning the sixth metal layer to form a second cavity and a second bonding pad, patterning the fifth metal layer to form a first bonding pad, patterning the third silicon substrate to form a third central TSV column and a plurality of second TSV columns, wherein the top end of the third central TSV column is coupled with the first bonding pad, and the bottom end of the third central TSV column is coupled with the second bonding pad; Providing a second silicon substrate, wherein a third metal layer and a fourth metal layer are oppositely arranged on two sides of the second silicon substrate, patterning the third metal layer to form a third cavity and a U-shaped groove radiation patch, forming a feed probe and a plurality of third TSV columns in the second silicon substrate, wherein the feed probe is coupled with the U-shaped groove radiation patch, the third TSV columns are circumferentially distributed along the third cavity to form a shielding cavity, patterning the fourth metal layer to form a third bonding pad, the third bonding pad is electrically connected with the feed probe, and bonding the fourth metal layer with the fifth metal layer; bonding the sixth metal layer and the seventh metal layer to electrically connect the radio frequency signal line and the second bonding pad; Providing a first silicon substrate, wherein the first silicon substrate is provided with a front surface and a back surface which are oppositely arranged, performing a deep silicon etching process on the front surface of the first silicon substrate to form a radiation opening, performing an electroplating process on the side wall of the radiation opening and the front surface of the first silicon substrate to form a first metal layer, performing an electroplating process on the back surface of the first silicon substrate to form a second metal layer, and bonding the second metal layer and the third metal layer; And bonding a multi-functional chip in an amplitude phase on the tenth metal layer, wherein radiation from the multi-functional chip in an amplitude phase to a free space through the radiation port is realized through the first coaxial structure, the second central TSV column, the radio frequency signal line, the third central TSV column and the feed probe.
13. The method of claim 12, wherein the RF signal line includes a third coaxial feed-in point, a matching block, a strip line, and a second coaxial feed-out point, wherein the third coaxial feed-in point is electrically connected to the second bonding pad, and the second coaxial feed-out point is electrically connected to the second coaxial feed-in point through a second TSV column.
14. The method of manufacturing a high isolation antenna array according to claim 13, wherein the width of the matching block is larger than the width of the strip line.
15. The method of claim 12, wherein the first TSV pillars are distributed in the same location on the fourth silicon substrate and the second TSV pillars are distributed in the same location on the third silicon substrate and form electrical connection.
16. The method of manufacturing an antenna array with high isolation based on MEMS technology as claimed in claim 15, wherein the first TSV pillars, the second TSV pillars and the third TSV pillars are the same in size, the spacing between the adjacent first TSV pillars is 60-90 μm, the spacing between the adjacent second TSV pillars is 60-90 μm, and the spacing between the adjacent third TSV pillars is 60-90 μm.
17. The method of manufacturing an antenna array with high isolation according to claim 12, wherein the second silicon substrate, the third silicon substrate, the fourth silicon substrate and the fifth silicon substrate have equal resistivity and higher resistivity than the first silicon substrate.

Description

Antenna array with high isolation based on MEMS technology and preparation method thereof Technical Field The invention belongs to the technical field of MEMS (micro electro mechanical systems), and particularly relates to an antenna array with high isolation based on an MEMS process and a preparation method thereof. Background The millimeter wave frequency band, particularly the W-band (the frequency range usually covers 75-110 GHz), has the outstanding characteristics of wide frequency band, short wavelength, high resolution and the like, and has great application potential in the fields of high-speed wireless communication, high-precision automobile radar, human body security inspection imaging, radio astronomy and the like. With the development of modern wireless technology, broadband, high transmission rate, miniaturization and multifunctional integrated communication equipment are the development trend, and the antenna is used as a key front-end component of a wireless communication and detection system, and the performance of the antenna directly influences the transmission rate, detection precision, imaging quality and acting distance of the wireless communication and detection system, so that the design and implementation of the high-performance antenna are very important. Currently, the conventional antenna types suitable for the W-band mainly include a slot antenna based on a dielectric integrated waveguide (SIW) and a conventional patch antenna or a magneto-electric dipole antenna based on a Printed Circuit Board (PCB), wherein the slot antenna based on the dielectric integrated waveguide (SIW) has a certain application in the millimeter-wave band, but the physical size of the slot antenna is usually large, and when the antenna is arrayed, the array element spacing is limited by the working wavelength and the structure, so that it is difficult to realize the wide-angle beam scanning. In addition, the SIW structure cannot realize an omni-directional (coaxial) feed port, so that when a large array is constructed, the wiring of a feed network is extremely complex, the design and processing difficulty is remarkably increased, the urgent requirements of a modern wireless system on equipment miniaturization, light weight and high integration level are difficult to meet, and when the working frequency of a traditional patch antenna or a magneto-electric dipole antenna based on a Printed Circuit Board (PCB) is increased to an ultra-high frequency band of 94GHz, the surface wave effect is rapidly enhanced, and strong inter-array element mutual coupling is caused, so that the radiation efficiency and scanning performance of the antenna are seriously deteriorated, and in addition, the space coupling is further aggravated by the extremely small antenna array element spacing, so that the antenna array with high isolation and low mutual coupling becomes extremely challenging. Therefore, it is necessary to provide an antenna array which can be miniaturized in the W-band, has high isolation and low mutual coupling, and can be mass-produced at low cost. Disclosure of Invention In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide an antenna array with high isolation based on MEMS technology and a manufacturing method thereof, which are used for solving the problems that in the prior art, a SIW slot antenna suitable for W-band has a large physical size, is difficult to realize a large-angle beam scan, is difficult to be miniaturized and has high integration, and a conventional patch antenna or a magneto dipole antenna suitable for W-band has increased isolation due to surface wave effect enhancement at 94GHz, thereby seriously affecting antenna performance. To achieve the above and other related objects, the present invention provides a high isolation antenna array based on MEMS technology, comprising a plurality of antenna units, the antenna units sequentially comprising, from bottom to top: A ninth metal layer is arranged on the front surface of the fifth silicon substrate, a tenth metal layer is arranged on the back surface of the fifth silicon substrate, a first coaxial structure is formed in the fifth silicon substrate, a first coaxial feed-out point is formed in the ninth metal layer, a first coaxial feed-in point is formed in the tenth metal layer, the first coaxial feed-in point and the first coaxial feed-out point are respectively and electrically connected with the first coaxial structure, and a multi-functional chip with an amplitude phase is bonded on the tenth metal layer; A seventh metal layer is arranged on the front surface of the fourth silicon substrate, an eighth metal layer is arranged on the back surface of the fourth silicon substrate, a second coaxial feed-in point is formed in the eighth metal layer and is electrically connected with the first coaxial feed-out point, a radio frequency signal wire is arranged in the seventh metal layer,