CN111063989B

CN111063989B - On-chip multi-band terahertz three-dimensional antenna

Info

Publication number: CN111063989B
Application number: CN201911248056.8A
Authority: CN
Inventors: 徐雷钧; 殷鹏程; 白雪
Original assignee: Jiangsu University
Current assignee: Taijing Technology (Nanjing) Co., Ltd
Priority date: 2019-12-09
Filing date: 2019-12-09
Publication date: 2021-10-12
Anticipated expiration: 2039-12-09
Also published as: CN111063989A

Abstract

The invention discloses an on-chip multi-band terahertz three-dimensional antenna which mainly comprises ten radiation patches and ten NMOS tube switches. The planar antenna structure is changed into a three-dimensional structure by utilizing the characteristics of multilayer metals in a TSMC40nm CMOS process, each layer of metal of M1-M10 is designed into a rectangular radiation patch with a simple structure, an I-shaped groove is formed in the middle of the rectangular radiation patch, a section of microstrip transmission line is led out to be connected with the source electrode of an NMOS tube, a microstrip feeder line is connected with the drain electrode of the NMOS tube, and the grid electrode of the NMOS tube is connected with bias voltage. By adjusting the grid bias voltage of the NMOS tube, the NMOS tube is conducted, namely a switch is closed, a layer of radiation patch is added to the antenna, the shape of the antenna is changed, and a new working frequency is obtained. When all switches are closed, the antenna is a three-dimensional structure connected by ten layers of radiation patches, and various different working frequencies can be realized. In addition, the antenna and the terahertz circuit are integrated on the same chip and designed into the terahertz detector, so that the multi-band detection function can be realized.

Description

On-chip multi-band terahertz three-dimensional antenna

Technical Field

The invention belongs to the field of antenna structure design. In particular to an on-chip multi-band terahertz solid antenna.

Background

Terahertz (THz) generally refers to an electromagnetic wave having a frequency range of 100GHz to 10THz and a wavelength range of 30 μm to 3mm, and is between millimeter waves and infrared light in the electromagnetic spectrum. The terahertz frequency band, which is the last frequency window to be fully studied in the electromagnetic spectrum, has not been fully recognized and applied, and is therefore called "terahertz Gap (THz Gap)". Compared with electromagnetic waves of other frequencies in the electromagnetic spectrum, the terahertz wave has many unique response characteristics, such as transient property, nondestructive property, high penetrability, low energy property and the like, so that the advantages of the terahertz wave as a detection technology are gradually highlighted, and nondestructive detection can be realized in a true sense. Compared with the detector in the traditional optical method form, the detector combining the terahertz circuit and the antenna is more convenient, faster and more stable, and the miniaturization and portability of the detector can be realized.

The antenna is used as a key part for receiving and transmitting signals of the terahertz detector, and the performance of the antenna directly influences the quality of signal receiving and transmitting. Currently, common terahertz antennas include a horn antenna, a reflector antenna, a new material antenna and an on-chip antenna. However, the terahertz horn antenna and the reflecting surface antenna have large volumes, complex structures and difficult processing, and are difficult to be switched with a circuit; the new material antenna is still in the research and development stage of the laboratory depending on the development of the new material and the innovation of the processing technology, and is also a great potential direction for the development of the future terahertz antenna. With the rapid development of the CMOS technology, the on-chip antenna based on the CMOS process becomes the first choice of the terahertz antenna design and is widely applied. The on-chip antenna can well solve the defect of difficulty in a mechanical antenna switching circuit, and meanwhile, the on-chip antenna is small in size, simple to manufacture, low in cost and easy to integrate and array. The rectangular patch antenna has a simple structure, easily meets the design rule of a CMOS (complementary metal oxide semiconductor) process, can be used as an independent antenna, and can be designed into an array antenna as an array element. But also has the disadvantages of single frequency band, narrow bandwidth and low gain.

Disclosure of Invention

Based on the defects of the prior art, the invention uses the characteristics of multilayer metal of the TSMC40nm CMOS process to change the planar antenna structure into a three-dimensional structure, each layer is designed into a rectangular radiation patch with a simple structure, a section of microstrip transmission line is led out to be connected with the source electrode of an NMOS tube, a microstrip feeder line is connected with the drain electrode of the NMOS tube, and whether the NMOS tube is conducted or not is controlled by adjusting the grid bias voltage of the NMOS tube. When the NMOS tube is conducted, the switch is closed, namely, a layer of radiation patch is added, the shape of the antenna is changed, and various different working frequencies can be obtained. The antenna is mainly applied to the design of a terahertz detector chip, is integrated with a terahertz circuit in the same chip, and is designed into a terahertz detector, so that the multi-band detection function is realized.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a chip multi-band terahertz three-dimensional antenna comprises a plurality of rectangular metal radiation patches which are sequentially arranged from top to bottom, wherein all the metal radiation patches are wrapped by a medium, and the medium is filled between the metal radiation patches; all the metal radiation patches are provided with I-shaped grooves in the middle; each metal radiation patch is connected with the source electrode of an NMOS tube through a microstrip transmission line, the drain electrode of the NMOS tube is connected with a microstrip feeder line, the grid electrode of the NMOS tube is connected with a bias voltage, and the switching-on and switching-off of a switch are realized by changing the grid electrode bias voltage of the NMOS tube, so that whether the metal radiation patch is connected with the microstrip feeder line or not is controlled, various antennas with different working frequencies can be obtained, and multi-band detection is realized.

Further, the metal radiation patch is designed by using a metal layer of a TSMC40nm CMOS process.

Furthermore, 10 rectangular metal radiation patches which are sequentially arranged from top to bottom are M10 and M9... M1, the TSMC40nm CMOS process at least comprises twelve dielectric layers which are an IMD10 combined layer, an IMD9 dielectric layer, an IMD8 dielectric layer, an IMD7 dielectric layer, an IMD6 dielectric layer, an IMD5 dielectric layer, an IMD4 dielectric layer, an IMD3 dielectric layer, an IMD2 dielectric layer, an IMD1 dielectric layer, a passivation layer and a silicon substrate layer from top to bottom; the IMD10 merging layer is positioned on the upper layer of the metal radiation patch M10, the passivation layer is positioned on the lower layer of the metal radiation patch M1, and the silicon substrate layer is positioned on the bottommost layer.

Further, IMD10 combined layer, thickness was 5.275 μm, relative dielectric constant was 4.65; an IMD9 dielectric layer with a thickness of 1.59 μm and a relative dielectric constant of 4.48; an IMD8 dielectric layer with a thickness of 0.74 μm and a relative dielectric constant of 3.96; IMD 7-IMD 2 dielectric layers with the thickness of 0.235 mu m and the relative dielectric constant of 3.17; an IMD1 dielectric layer with a thickness of 0.215 μm and a relative dielectric constant of 3.43; a passivation layer having a thickness of 0.5225 μm and a relative dielectric constant of 4.03; a silicon substrate layer with a resistivity of 10 omega cm, a thickness of 300 mu m and a relative dielectric constant of 11.9; m10 metal layer radiation patch, the metal thickness is 3.5 μ M; m9 metal layer radiation patch, the metal thickness is 0.85 μ M; m8 metal layer radiation patch, the metal thickness is 0.74 μ M; M7-M2 metal layer radiation patches, wherein the thickness of the metal is 0.145 mu M; m1 Metal layer radiation patch, the metal thickness is 0.125 μ M.

Furthermore, the I-shaped groove enables the current on the surface of the metal radiating patch to change along the designed slot, the current path is lengthened, and the size of the antenna can be reduced, and the bandwidth and the gain of the antenna can be improved.

Furthermore, the ratio of the width a of the transverse edge a at the two ends of the I-shaped groove, the width b of the short edge b in the middle of the I-shaped groove and the width c of the microstrip transmission line is 50:5:8, and the ratio of the height d of the vertical edge of the I-shaped groove, the height e of the transverse edge of the I-shaped groove and the height f of the microstrip transmission line is 10:1: 14.

The invention has the beneficial effects that:

the invention belongs to the field of antenna structure design of terahertz frequency bands. Particularly, the planar antenna structure is changed into a three-dimensional structure by utilizing the characteristics of multilayer metal in a CMOS (complementary metal oxide semiconductor) process, the connection and disconnection between the radiation patch and the microstrip feeder line are controlled by a switch, the metal radiation patches are increased or decreased, and the shape of the antenna is changed, so that the working frequency of the antenna is changed to realize the function of multi-band detection.

1. The antenna can realize various different working frequencies by using ten NMOS tubes as switches to control whether the microstrip transmission line is connected with a microstrip feeder line or not;

2. the antenna and the circuit are integrated on the same chip to be designed into a terahertz detector, so that the multi-band detection function is realized.

The I-shaped groove is used for destroying the current distribution of the original resonance mode, so that the current on the surface of the metal radiation patch is changed along the designed slot, the current path is lengthened, the distribution along the slot is prolonged, the resonance wavelength of the antenna is increased, namely the area of the antenna is increased by phase change, and the size of the antenna can be effectively reduced; in addition, capacitive reactance can be introduced while slotting, partial inductive reactance introduced by a microstrip transmission line can be counteracted, the bandwidth and gain of the antenna can be greatly improved, the optimization of the size of the I-shaped groove is influenced by nonlinearity and is comprehensively restricted by the return loss and gain results of the antenna, a great deal of creative experimental optimization is performed in the embodiment, and the optimal embodiment is given that the ratio of the transverse edge a at two ends of the I-shaped groove, the middle short edge b and the width c of the microstrip transmission line is 50:5:8, and the ratio of the height d of the vertical edge of the I-shaped groove, the height e of the transverse edge of the I-shaped groove and the height f of the microstrip transmission line is 10:1: 14.

Drawings

FIG. 1 is a schematic cross-sectional view of the process of the present invention;

fig. 2 is a top view of a radiation patch of the present invention;

FIG. 3 is a structural diagram of a multi-band terahertz stereo antenna of the invention.

Detailed Description

The invention relates to an on-chip multi-band terahertz three-dimensional antenna design, which is clearly and completely described by combining the technical scheme in the embodiment of the invention.

As shown in fig. 1, which is a simplified process cross-sectional diagram of the present invention, there are 12 dielectric layers from top to bottom, and an IMD10 combined layer, an IMD9 dielectric layer, an IMD8 dielectric layer, an IMD7 dielectric layer, an IMD6 dielectric layer, an IMD5 dielectric layer, an IMD4 dielectric layer, an IMD3 dielectric layer, an IMD2 dielectric layer, an IMD1 dielectric layer, a passivation layer and a silicon substrate layer from top to bottom. 11-22 in sequence, 11 is an IMD10 combined layer, the thickness is 5.275 mu m, and the relative dielectric constant is 4.65; 12 is IMD9 dielectric layer with thickness of 1.59 μm and relative dielectric constant of 4.48; 13 is an IMD8 dielectric layer with the thickness of 0.74 μm and the relative dielectric constant of 3.96; 14-19 are IMD 7-IMD 2 dielectric layers respectively, the thickness is 0.235 mu m, and the relative dielectric constant is 3.17; 20 is an IMD1 dielectric layer with the thickness of 0.215 μm and the relative dielectric constant of 3.43; 21 is a passivation layer, the thickness is 0.5225 μm, and the relative dielectric constant is 4.03; 22 is a silicon substrate layer, the resistivity is 10 Ω · cm, the thickness is 300 μm, and the relative dielectric constant is 11.9. Wherein, 11-20 dielectric layers all contain metal layers, namely 1-10, which are also used by ten radiation patches in the invention. 1 is M10 metal layer radiation patch, the metal thickness is 3.5 μ M; 2 is M9 metal layer radiation patch, the metal thickness is 0.85 μ M; 3 is M8 metal layer radiation patch, the metal thickness is 0.74 μ M; 4-9M 7-M2 metal layer radiation patches, wherein the thickness of the metal is 0.145 mu M; 10 is an M1 metal layer radiating patch, the metal thickness is 0.125 μ M.

As shown in fig. 2, which is a top view of a top-layer radiating patch, ten layers of different metals are all designed into rectangular patches, the feeding mode of the radiating patch is microstrip line feeding, and a patch antenna radiates through an electromagnetic field near the edge between an upper metal sheet and a lower metal sheet; 23, an I-shaped groove is introduced into the radiation patch to destroy the original current distribution condition on the surface of the antenna, so that the current is changed according to a specific slotting structure, the size of the antenna is reduced, and the bandwidth and the gain of the antenna are improved; 24 is a microstrip transmission line, which plays a role of signal transmission and connects the radiation patch with the microstrip feeder line.

As a preferred embodiment of the invention, as shown in FIG. 3, it is a structure diagram of a multiband terahertz solid antenna, 35 is a microstrip feed line, and M1-M10 are connected with ten metal layer radiation patchesAnd the sheet is fed in a side feeding mode. Wherein N1-N10 are ten NMOS transistors as switches, i.e. 25-34, by adjusting the gate bias voltage vg of the NMOS transistors₁～vg₁₀And respectively controlling whether the ten NMOS tubes are conducted or not so as to control the connection and disconnection of each layer of metal radiation patch and the microstrip feed line. Specifically, the gate bias voltage vg is adjusted₁The NMOS tube N1 is turned on, and the M10 metal layer radiating patch is connected to the microstrip feed line through the drain electrode of the NMOS tube N1; further, the gate bias voltage vg is adjusted₂The NMOS tube N2 is turned on, and the M9 metal layer radiating patch is connected to the microstrip feed line through the drain electrode of the NMOS tube N2;

further, the gate bias voltage vg is adjusted₃The NMOS tube N3 is turned on, and the M8 metal layer radiating patch is connected to the microstrip feed line through the drain electrode of the NMOS tube N3; further, the gate bias voltage vg is adjusted₄The NMOS tube N4 is turned on, and the M7 metal layer radiating patch is connected to the microstrip feed line through the drain electrode of the NMOS tube N4; further, the gate bias voltage vg is adjusted₅The NMOS tube N5 is turned on, and the M6 metal layer radiating patch is connected to the microstrip feed line through the drain electrode of the NMOS tube N5; further, the gate bias voltage vg is adjusted₆The NMOS tube N6 is turned on, and the M5 metal layer radiating patch is connected to the microstrip feed line through the drain electrode of the NMOS tube N6; further, the gate bias voltage vg is adjusted₇The NMOS tube N7 is turned on, and the M4 metal layer radiating patch is connected to the microstrip feed line through the drain electrode of the NMOS tube N7; further, the gate bias voltage vg is adjusted₈The NMOS tube N8 is turned on, and the M3 metal layer radiating patch is connected to the microstrip feed line through the drain electrode of the NMOS tube N8; further, the gate bias voltage vg is adjusted₉The NMOS tube N9 is turned on, and the M2 metal layer radiating patch is connected to the microstrip feed line through the drain electrode of the NMOS tube N9; further, the gate bias voltage vg is adjusted₁₀And the NMOS transistor N10 is turned on, and the M1 metal radiating patch is connected to the microstrip feed line through the drain electrode of the NMOS transistor N10. The switch is switched on and off by changing the grid bias voltage of the NMOS tube, so that whether the metal radiation patch is connected with the microstrip feeder line or not is controlled, multiple antennas with different working frequencies can be obtained, and the multi-band detection function is realized.

In summary, the on-chip multi-band terahertz solid antenna mainly comprises ten radiation patches and ten NMOS tube switches. The planar antenna structure is changed into a three-dimensional structure by utilizing the characteristics of multilayer metals in a TSMC40nm CMOS process, each layer of metal of M1-M10 is designed into a rectangular radiation patch with a simple structure, an I-shaped groove is formed in the middle of the rectangular radiation patch, a section of microstrip transmission line is led out to be connected with the source electrode of an NMOS tube, a microstrip feeder line is connected with the drain electrode of the NMOS tube, and the grid electrode of the NMOS tube is connected with bias voltage. By adjusting the grid bias voltage of the NMOS tube, the NMOS tube is conducted, namely a switch is closed, a layer of radiation patch is added to the antenna, the shape of the antenna is changed, and a new working frequency is obtained. When all switches are closed, the antenna is a three-dimensional structure connected by ten layers of radiation patches, and various different working frequencies can be realized. In addition, the antenna and the terahertz circuit are integrated on the same chip and designed into the terahertz detector, so that the multi-band detection function can be realized.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples" or the like mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. The on-chip multi-band terahertz three-dimensional antenna is characterized by comprising a plurality of rectangular metal radiation patches which are sequentially arranged from top to bottom, wherein all the metal radiation patches are wrapped by a medium, and the medium is filled between the metal radiation patches; all the metal radiation patches are provided with I-shaped grooves in the middle; each metal radiation patch is connected with the source electrode of an NMOS tube through a microstrip transmission line, the drain electrode of the NMOS tube is connected with a microstrip feeder line, the grid electrode of the NMOS tube is connected with a bias voltage, and the switching-on and switching-off of a switch are realized by changing the grid electrode bias voltage of the NMOS tube, so that whether the metal radiation patch is connected with the microstrip feeder line or not is controlled, various antennas with different working frequencies can be obtained, and multi-band detection is realized.

2. The on-chip multi-band terahertz stereo antenna is characterized in that the metal radiation patch is designed by using a metal layer of a TSMC40nm CMOS (complementary metal-oxide-semiconductor transistor) process.

3. The on-chip multiband terahertz solid antenna of claim 2, wherein 10 rectangular metal radiation patches are M10, M9... M1 arranged in sequence from top to bottom, the TSMC40nm CMOS process comprises at least twelve dielectric layers, which are an IMD10 combined layer, an IMD9 dielectric layer, an IMD8 dielectric layer, an IMD7 dielectric layer, an IMD6 dielectric layer, an IMD5 dielectric layer, an IMD4 dielectric layer, an IMD3 dielectric layer, an IMD2 dielectric layer, an IMD1 dielectric layer, a passivation layer and a silicon substrate layer in sequence from top to bottom; the IMD10 merging layer is positioned on the upper layer of the metal radiation patch M10, the passivation layer is positioned on the lower layer of the metal radiation patch M1, and the silicon substrate layer is positioned on the bottommost layer.

4. The on-chip multi-band terahertz stereo antenna is characterized in that the IMD10 is a combined layer, the thickness is 5.275 μm, and the relative dielectric constant is 4.65; an IMD9 dielectric layer with a thickness of 1.59 μm and a relative dielectric constant of 4.48; an IMD8 dielectric layer with a thickness of 0.74 μm and a relative dielectric constant of 3.96; IMD 7-IMD 2 dielectric layers with the thickness of 0.235 mu m and the relative dielectric constant of 3.17; an IMD1 dielectric layer with a thickness of 0.215 μm and a relative dielectric constant of 3.43; a passivation layer having a thickness of 0.5225 μm and a relative dielectric constant of 4.03; a silicon substrate layer with a resistivity of 10 omega cm, a thickness of 300 mu m and a relative dielectric constant of 11.9; m10 metal layer radiation patch, the metal thickness is 3.5 μ M; m9 metal layer radiation patch, the metal thickness is 0.85 μ M; m8 metal layer radiation patch, the metal thickness is 0.74 μ M; M7-M2 metal layer radiation patches, wherein the thickness of the metal is 0.145 mu M; m1 Metal layer radiation patch, the metal thickness is 0.125 μ M.

5. The on-chip multi-band terahertz stereo antenna is characterized in that the I-shaped groove enables the current on the surface of the metal radiation patch to be changed along the designed slot, the current path is lengthened, the size of the antenna can be reduced, and the bandwidth and the gain of the antenna can be improved.

6. The on-chip multi-band terahertz solid antenna as claimed in claim 5, wherein the ratio of the width a of the transverse edge at the two ends of the I-shaped groove, the width b of the vertical edge in the middle of the I-shaped groove and the width c of the microstrip transmission line is 50:5:8, and the ratio of the height d of the vertical edge of the I-shaped groove, the height e of the transverse edge of the I-shaped groove and the height f of the microstrip transmission line is 10:1: 14.