阅读说明：本技术 一种片上双馈电太赫兹正交极化天线设计方法 (Design method of on-chip double-feed terahertz orthogonal polarization antenna ) 是由 白雪 葛星梅 徐雷钧 于 2020-07-24 设计创作，主要内容包括：本发明公开了一种片上双馈电太赫兹正交极化天线设计方法,该天线在圆形的辐射贴片的基础上,采用曲流技术对天线进行开槽,通过改变贴片天线表面的电流路径来有效提高天线的带宽,片上贴片天线采用圆形结构连接两条相互垂直的微带线,微带线分别连接两个馈电端口,当天线从端口1和端口2同时馈电时,可以激发相位相差90°的正交信号,当天线仅从端口1馈电时,产生水平极化偏振；当天线仅从端口2馈电时,产生垂直极化偏振。所提出的天线的辐射特性显示出双极化行为和波束的切换状态。另外,将所述天线与太赫兹电路集成在同一块芯片,设计成外差混频太赫兹探测器,可以实现多频段探测并且有效提高探测器的灵敏度。(The invention discloses a design method of an on-chip dual-feed terahertz orthogonal polarization antenna, which is characterized in that on the basis of a circular radiation patch, the antenna is grooved by adopting a meander technology, the bandwidth of the antenna is effectively improved by changing a current path on the surface of the patch antenna, the on-chip patch antenna adopts a circular structure to connect two mutually perpendicular microstrip lines, the microstrip lines are respectively connected with two feed ports, when the antenna feeds power from the port 1 and the port 2 simultaneously, orthogonal signals with the phase difference of 90 degrees can be excited, and when the antenna only feeds power from the port 1, horizontal polarization is generated; when the antenna is fed only from port 2, vertical polarization is produced. The radiation characteristic of the proposed antenna shows a dual polarization behavior and a switching state of the beam. In addition, the antenna and the terahertz circuit are integrated on the same chip and designed into a heterodyne mixing terahertz detector, multi-band detection can be realized, and the sensitivity of the detector can be effectively improved.)

1. A design method of an on-chip dual-feed terahertz orthogonal polarization antenna is characterized by comprising the following steps: the antenna decomposes received terahertz waves into two signals in the horizontal and vertical polarization directions in space, a terahertz radiation source is formed by double feed switching, the orthogonality is realized by adopting a horizontal component and a vertical component of 0 degrees and 90 degrees, an octagon is embedded in a metal circular radiation patch, an octagon groove is opened by adopting a meander technology, the bandwidth and the gain of the antenna are increased by changing the current direction, the metal circular radiation patch is connected with the source electrode of an NMOS (N-channel metal oxide semiconductor) 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, the closing and the opening of a switch are realized by changing the grid bias voltage of the NMOS tube, so that whether the metal circular radiation patch is connected with the microstrip feeder line or not is controlled, the antennas with different working.

2. The design method of the on-chip dual-feed terahertz orthogonal polarization antenna as claimed in claim 1, wherein the metal circular radiation patch is designed by using a metal layer of a CMOS process.

3. The design method of the on-chip dual-feed terahertz cross-polarized antenna is characterized in that the metal circular radiation patch is an M10 layer, the 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 M10 layer of the metal circular radiation patch, the passivation layer is positioned on the lower layer of the M1, and the silicon substrate layer is positioned on the bottommost layer.

4. The design method of the on-chip dual-feed terahertz orthogonal polarization antenna as claimed in claim 3, wherein the IMD10 merging layer has a thickness of 5.275 μm and a relative dielectric constant of 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 circular radiating patch of metal, the metal thickness is 3.5 μ M.

5. The design method of the on-chip dual-feed terahertz orthogonal polarization antenna as claimed in claim 1, wherein the antenna is formed by combining two linear polarization antennas which are perpendicular to each other in space, and respectively receives electromagnetic waves in horizontal polarization and vertical polarization directions, and the total polarization direction of the incident signal can be obtained by measuring the intensities of the electromagnetic waves in the horizontal direction and the vertical direction.

Technical Field

The invention belongs to the field of antenna structure design. In particular to a design method of an on-chip dual-feed terahertz orthogonal polarization antenna.

Background

Terahertz (THz) generally refers to an electromagnetic wave having a frequency range of 0.1 to 10THz, and a corresponding wavelength range of 0.03 to 3mm, which is located between millimeter waves and infrared light in an electromagnetic spectrum. The terahertz is neither completely processed by a theory of photonics nor is suitable for being studied by an electronic method, so the terahertz is once called as a "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 size of the terahertz antenna is inversely proportional to the frequency, and when the frequency of a detection signal is in a terahertz wave band, the small-sized antenna is integrated on a CMOS chip and is combined with an integrated circuit. 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.

Disclosure of Invention

In view of the above-described deficiencies of the prior art, the present invention in this context implements orthogonality in a CMOS process using a 0 ° to 90 ° horizontal component and a vertical component. The antenna on the circular radiation patch is connected with two mutually vertical microstrip lines by adopting a circular structure, the introduced microstrip transmission line is connected with the source electrode of the NMOS tube, the microstrip feeder line is connected with the drain electrode of the NMOS tube, and the grid electrode of the NMOS tube is connected with a bias voltage. By adjusting the grid bias voltage of the NMOS tube, the NMOS tube is conducted, namely a switch is closed. The microstrip lines are respectively connected with the feed ports 1 and 2, and the switching state of the beam is changed by switching the feed ports. The antenna is mainly applied to the design of a terahertz detector chip, is integrated with a terahertz circuit on the same chip and is designed into a heterodyne mixing terahertz detector, and the sensitivity of the detector is effectively improved while multi-band detection is realized.

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

a design method of an on-chip double-feed terahertz orthogonal polarization antenna comprises the following steps: the antenna decomposes received terahertz waves into two signals in the horizontal and vertical polarization directions in space, a terahertz radiation source is formed by double feed switching, the orthogonality is realized by adopting a horizontal component and a vertical component of 0 degrees and 90 degrees, an octagon is embedded in a metal circular radiation patch, an octagon groove is opened by adopting a meander technology, the bandwidth and the gain of the antenna are increased by changing the current direction, the metal circular radiation patch is connected with the source electrode of an NMOS (N-channel metal oxide semiconductor) 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, the closing and the opening of a switch are realized by changing the grid bias voltage of the NMOS tube, so that whether the metal circular radiation patch is connected with the microstrip feeder line or not is controlled, the antennas with different working.

Further, the metal circular radiating patch is designed using a metal layer of a CMOS process.

Further, the metal circular radiation patch is M10, the CMOS process at least comprises twelve dielectric layers, namely 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 circular radiation patch M10, the passivation layer is positioned on the lower layer of the 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 circular radiating patch of metal, the metal thickness is 3.5 μ M.

Furthermore, the antenna is formed by combining two linear polarization antennas which are mutually vertical in space, electromagnetic waves in the horizontal polarization direction and the vertical polarization direction are respectively received, and the overall polarization direction of an incident signal can be obtained by measuring the intensity of the electromagnetic waves in the horizontal direction and the vertical direction.

Furthermore, on the basis of a circular radiation patch, an octagonal groove is formed through a meander technology, and the current direction is changed to increase the bandwidth and the gain of the antenna.

The invention has the beneficial effects that:

the invention belongs to the field of antenna structure design of terahertz frequency bands. In particular, orthogonality is achieved on CMOS processes with 0 ° and 90 ° horizontal and vertical components. The switching state of the wave beam is changed by switching the connection state of the microstrip line on the circular radiation patch and the two feed ports, so that the sensitivity of the detector is effectively improved while multi-band detection is realized.

1. The two NMOS tubes are used as switches to control whether the microstrip transmission line is connected with a microstrip feeder line or not, and the antenna can realize various different working frequencies;

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.

3. The octagonal slot enables the current on the surface of the metal circular radiation patch to change 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 is introduced while slotting, partial inductive reactance introduced by a microstrip transmission line can be offset, and the bandwidth and the gain of the antenna can be greatly improved. The two linear polarization antennas which are mutually vertical in space are combined to form an antenna, electromagnetic waves in the horizontal polarization direction and the vertical polarization direction are respectively received, the total polarization direction of an incident signal can be obtained by measuring the intensity of the electromagnetic waves in the horizontal direction and the vertical direction, and the sensitivity of the detector can be improved.

Drawings

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

FIG. 2 is a structural diagram of an on-chip dual-feed terahertz orthogonal polarization antenna of the invention;

fig. 3 is a schematic cross-sectional view of an on-chip dual-feed terahertz orthogonal polarization antenna of the present invention.

Detailed Description

The invention relates to an on-chip dual-feed terahertz orthogonal polarization 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. As a specific embodiment of the invention, the merging layer, the dielectric layer, the passivation layer and the silicon substrate layer are all non-metal layer silicon dioxide, and the metal layer is copper.

As shown in fig. 2, which is a top view of the top radiating patch. Designing a layer of metal into a circular patch, opening an octagonal groove by a meander technology on the basis of the circular radiation patch, leading out two mutually perpendicular microstrip lines on the circular patch, respectively connecting the microstrip lines with two feed ports, and generating horizontal polarization when the antenna only feeds from the port 1; when the antenna is fed from port 2 only, vertical polarization is produced, and when the antenna is fed from port 1 and port 2 simultaneously, quadrature signals that are 90 ° out of phase can be excited. The microstrip lines are switched to connect different ports, so that the radiation characteristic of the antenna shows dual polarization behavior and the switching state of the wave beams. Therefore, the antenna can respectively receive the electromagnetic waves in the horizontal polarization direction and the vertical polarization direction, the total polarization direction of an incident signal can be obtained by measuring the intensity of the electromagnetic waves in the horizontal direction and the vertical direction, and the sensitivity of the heterodyne mixing terahertz detector is improved.

In summary, the on-chip dual-feed terahertz cross-polarization antenna of the invention mainly comprises a radiation patch and two NMOS Q1 and Q2 switches. On the basis of a circular radiation patch, an octagon groove is formed on an antenna by adopting a meander technology, the patch antenna on the chip adopts a circular structure to be connected with two mutually vertical microstrip lines, an led microstrip transmission line is connected with a source electrode of an NMOS (N-channel metal oxide semiconductor) tube, a microstrip feeder line is connected with a drain electrode of the NMOS tube, and a grid electrode of the NMOS tube is connected with a bias voltage. By adjusting the gate bias Q1 of the NMOS transistor, the NMOS transistor N1 is turned on, and by adjusting the gate bias Q2 of the NMOS transistor, the NMOS transistor N2 is turned on. The microstrip lines are respectively connected with the feed ports 1 and 2, and the switching state of the beam is changed by switching the feed ports. In addition, the antenna is mainly applied to the design of a terahertz detector chip, is integrated with a terahertz circuit on the same chip and is designed into a heterodyne mixing terahertz detector, and the sensitivity of the detector is effectively improved while multi-band detection is 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.