220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna based on high-resistance silicon substrate

Abstract

The invention provides a 220GHz on-chip high-gain series-fed circularly-polarized micro-convex antenna based on a high-resistance silicon substrate, which comprises an upper metal layer, a PI layer, a lower metal layer, a dielectric plate provided with a high-resistance silicon substrate, a plurality of antenna units arranged on the upper surface of the upper metal layer and a microstrip line, each antenna unit comprises four circular patches, a micro-convex structure is arranged above each circular patch, each circular patch is connected with a rectangular strip, the plurality of antenna units are superposed in a series feed mode to form an antenna array, each circular patch is in contact with a microstrip line through the correspondingly connected rectangular strip, and the micro-convex structure is arranged above each circular patch. And one side of the upper metal layer is provided with a feed port. The 220GHz on-chip high-gain series-fed circularly-polarized micro-convex antenna has the beneficial effects that 1, the loss of the 220GHz on-chip high-gain series-fed circularly-polarized micro-convex antenna is small, and the antenna gain and the antenna radiation efficiency are high; and 2, the 220GHz on-chip high-gain series-fed circularly-polarized micro-convex antenna is simple in structure and easy to manufacture.

Description

Technical Field

[0001] The present invention relates to the field of antenna technology, and in particular to a 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna based on a high-resistance silicon substrate. Background Art

[0002] At present, among various millimeter wave antenna structures, microstrip array antennas have been widely used due to their attractive advantages such as low manufacturing cost, light weight, and thin profile. In order to compensate for the high loss characteristics of microstrip antennas, millimeter wave microstrip antennas use as many radiating elements as possible to form an antenna array. The antenna array is usually composed of series feeding, parallel feeding, or series-parallel feeding arrays. Compared with parallel feeding arrays, series feeding arrays are more conducive to shortening the feed line length, and have a simpler feeding network structure and lower cross polarization.

[0003] Circularly polarized antenna is a special polarized antenna. Polarization is a property that describes the vibration direction of electromagnetic waves. It can be horizontal, vertical linear polarization, or left-hand or right-hand circular polarization. In wireless communication, the polarization direction of the signal is crucial for the transmission and reception of the signal. Circularly polarized antennas have been widely used in wireless communication systems such as mobile and satellite communications due to their strong ability to resist multipath interference, insensitivity to depolarization, and unaffected by the "Faraday rotation" effect. Circularly polarized waves can also make the direction of the transmitter and receiver more flexible and provide more stable radiation performance.

[0004] The micro-convex antenna is a new type of antenna based on the standard on-chip process that improves the radiation efficiency and gain of the on-chip antenna. The micro-convex solder ball structure is placed on the original planar antenna. On the basis of the original radiation pattern, the current on the micro-convex solder ball will stimulate a new current pattern. The superposition of the two patterns increases the equivalent antenna height and reduces the mirror current, so that the radiation efficiency and gain of the standard on-chip process antenna are optimized at the same time.

[0005] According to the phase variation characteristics of the traveling wave of the microstrip line series feed, by designing a reasonable excitation position for the planar microstrip antenna, each patch unit is sequentially excited at a distance of 1 / 4 wavelength from the feed line. This sequential feeding method can stimulate circularly polarized radiation. The radiation performance and radiation efficiency of the antenna can be further improved by forming a series-fed array with a micro-convex structure and multiple units. At present, no micro-convex circularly polarized antenna based on standard on-chip technology has been reported.

[0006] Defects of existing technologies:

[0007] 1. The antenna processed by standard on-chip process has high loss, resulting in low antenna gain and antenna radiation efficiency;

[0008] 2. The traditional on-chip circularly polarized antenna has a complex structure and is difficult to manufacture;

[0009] 3. No circularly polarized micro-convex antenna structure has been reported. Summary of the invention

[0010] In order to solve the problems in the prior art, the present invention provides a 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna based on a high-resistance silicon substrate, comprising an upper metal layer, a PI layer, a lower metal layer, and a dielectric plate provided with a high-resistance silicon substrate, which are vertically arranged from top to bottom, a plurality of antenna units and a microstrip line are provided on the upper surface of the upper metal layer, each of the antenna units comprises four circular patches, a micro-convex structure is provided above each of the circular patches, each of the circular patches is respectively connected to a rectangular strip, a plurality of the antenna units are superimposed by series feeding to form an antenna array, each of the circular patches is in contact with the microstrip line through the correspondingly connected rectangular strips, a feeding port is provided on one side of the upper metal layer, the feeding port is connected to the microstrip line, electromagnetic energy is transmitted along the microstrip line according to the characteristics of traveling waves, and each of the rectangular strips slightly contacts the microstrip line, thereby coupling excitation energy for the circular patches.

[0011] As a further improvement of the present invention, the distance between every two adjacent antenna units is two λe.

[0012] As a further improvement of the present invention, the radius length of each circular patch is 1 / 4λe.

[0013] As a further improvement of the present invention, the distance between every two adjacent rectangular strips is 1 / 4λe.

[0014] As a further improvement of the present invention, the microstrip line width is 30 um.

[0015] As a further improvement of the present invention, two of the circular patches and the rectangular strips connected to the circular patches of each antenna unit are arranged above the microstrip line, and the other two of the circular patches and the rectangular strips connected to the circular patches of each antenna unit are arranged below the microstrip line.

[0016] As a further improvement of the present invention, each of the rectangular strips has the same size.

[0017] As a further improvement of the present invention, the number of the antenna units is eight.

[0018] The beneficial effects of the present invention are: 1. The 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna of the present invention has low loss, high antenna gain and high antenna radiation efficiency; 2. The 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna of the present invention has a simple structure and is easy to manufacture. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a top view of the 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna of the present invention;

[0020] Figure 2 is the forward current pattern of the antenna unit of the present invention;

[0021] Figure 3 is a side view of the antenna unit of the present invention;

[0022] Figure 4 This is a decomposition structure diagram of the 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna of the present invention;

[0023] Figure 5 It is a schematic diagram of the impedance bandwidth of the 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna covering 210-223.17GHz and 227.62-240GHz of the present invention;

[0024] Figure 6 It is a schematic diagram of the 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna of the present invention with a left-hand circularly polarized 3dB gain bandwidth covering 224.07-232.42GHz;

[0025] Figure 7-8 It is a schematic diagram of the 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna of the present invention, the peak gain of the YOZ plane and the XOZ plane directional pattern at 228GHz is 12.65dBi, and the cross-polarization level is lower than -20dBi;

[0026] Fig. 9 It is a schematic diagram of the 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna of the present invention with a 3dB axial ratio bandwidth of 209.01 to 236.19GHz;

[0027] Fig.10 It is a schematic diagram showing that the radiation efficiency of the 220 GHz on-chip high-gain series-fed circularly polarized micro-convex antenna of the present invention can reach a maximum value of 30.1% at 236 GHz. DETAILED DESCRIPTION

[0028] At present, the 220GHz frequency band has been developed but has no specific application. However, the "6G Communication White Paper" points out that the frequency band near 220GHz has been allocated for terrestrial and mobile communications, and the antenna of the present invention can be used as the RF front-end part of the 6G communication system.

[0029] like Figure 4As shown, the present invention discloses a 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna based on a high-resistance silicon substrate, comprising an upper metal layer 1, a PI layer 2, a lower metal layer 9, and a dielectric plate 3 provided with a high-resistance silicon substrate, which are vertically arranged from top to bottom, the upper metal layer 1 is installed on the upper surface of the PI layer 2, the lower metal layer 9 is installed on the lower surface of the PI layer, and the dielectric plate 3 with a high-resistance silicon substrate is installed below the lower metal layer 9, and a plurality of antenna units and a microstrip line 4 are arranged on the upper surface of the upper metal layer 1, each antenna unit includes four circular Patch 5, a micro-convex structure 8 is provided above each circular patch 5, each circular patch 5 is respectively connected to a rectangular strip 6, and multiple antenna units are superimposed to form an antenna array by series feeding. Each circular patch 5 is in contact with the microstrip line 4 through the corresponding connected rectangular strip 6. A feeding port 7 is provided on one side of the upper metal layer 1, and the feeding port 7 is connected to the microstrip line 4. Electromagnetic energy is transmitted along the microstrip line 4 according to the characteristics of traveling waves. Each rectangular strip 6 slightly contacts the microstrip line 4, thereby coupling and exciting the circular patch 5 with strong energy.

[0030] like Figure 1 , 3 As shown, the antenna unit of the 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna of the present invention is composed of four circular patches 5 and rectangular strips 6, and a micro-convex structure 8 is added above each circular patch 5. The micro-convex structure 8 is realized by using the micro-convex balls in the on-chip processing technology. Its original function is to realize the interconnection between different functional layers. Its specific shape needs to be determined according to the processing technology that can be provided by the processing manufacturer. In most cases, it is a sphere, and the processing party's design criteria use a sphere. Therefore, the micro-convex structure 8 used in the design of the 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna of the present invention is a sphere. Eight antenna units are superimposed by serial feeding to form an antenna array, and the feeding part is composed of a ground-signal-ground (Ground-Signal-Ground, GSG) structure at one end. Due to the high integration of the antenna on chip and the chip, its test needs to be tested by a probe. There are many high-frequency probe structures, among which the ground-signal-ground structure is more commonly used. Therefore, the 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna of the present invention is designed with a ground-signal-ground structure matching the probe, wherein the left end portion of the antenna top view is the ground-signal-ground structure.

[0031] The distance between each two adjacent antenna units is about two λe (λe is the wavelength in the medium), the radius of each circular patch 5 is about 1 / 4λe long, and the distance between each two adjacent excitation branches (rectangular strips 6) is about 1 / 4λe. By reasonably setting the above parameters, the antenna can achieve high gain and circular polarization in the 220GHz frequency band.

[0032] The present invention discloses a 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna, the feeding of which is composed of a long microstrip line 4 extending from a GSG structure, the microstrip line 4 is designed to be thin enough, the width of the microstrip line 4 is preferably 30um, and the sufficiently thin microstrip line can prevent its current from radiating energy in the transmission direction. Electromagnetic energy is transmitted along the microstrip line according to the characteristics of traveling waves, each rectangular strip 6 slightly contacts the microstrip line 4, thereby coupling and exciting a circular patch 5 with strong energy, and the spacing between each two adjacent rectangular strips 6 is 1 / 4λe, ensuring that each circular patch 5 has a phase difference of 90deg, thereby forming a left-handed circularly polarized radiated electromagnetic wave.

[0033] Two circular patches 5 of each antenna unit and rectangular strips 6 connected to the circular patches 5 are arranged above the microstrip line 4, and the other two circular patches 5 of each antenna unit and rectangular strips 6 connected to the circular patches 5 are arranged below the microstrip line 4. Each rectangular strip 6 has the same size.

[0034] PI stands for polyimide.

[0035] The dielectric plate 3 is formed by a plurality of dielectric stacks, the main dielectric layer being a high-resistance silicon substrate which is arranged in the dielectric plate 3 .

[0036] The performance of the 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna of the present invention is as follows:

[0037] like Figure 5 As shown, the impedance bandwidth covers 210-223.17 GHz and 227.62-240 GHz;

[0038] like Figure 6 As shown, the left-hand circular polarization 3dB gain bandwidth covers 224.07-232.42GHz;

[0039] like Figure 7-8 As shown, at 228 GHz, the peak gain of the YOZ and XOZ plane patterns is 12.65 dBi, and the cross-polarization level is less than -20 dBi;

[0040] like Fig. 9 As shown, the 3dB axial ratio bandwidth is 209.01 to 236.19GHz;

[0041] like Fig.10 As shown, the antenna radiation efficiency can reach a maximum value of 30.1% at 236 GHz (an increase of 16% compared to the antenna without the micro-convex structure).

[0042] The performance of the antenna is as follows:

[0043]

[0044]

[0045] The beneficial effects of the present invention are: 1. The 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna of the present invention has low loss, high antenna gain and high antenna radiation efficiency; 2. The 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna of the present invention has a simple structure and is easy to manufacture.

[0046] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A 220GHz on-chip high-gain series-fed circularly polarized micro-convex antenna based on a high-resistance silicon substrate, characterized in that: The invention comprises an upper metal layer (1), a PI layer (2), a lower metal layer (9), and a dielectric plate (3) provided with a high-resistance silicon substrate, which are arranged vertically in sequence from top to bottom. The upper surface of the upper metal layer (1) is provided with a plurality of antenna units and a microstrip line (4). Each of the antenna units comprises four circular patches (5). A micro-convex structure (8) is provided above each of the circular patches (5). Each of the circular patches (5) is connected to a rectangular strip (6). The plurality of antenna units are stacked to form an antenna array by means of series feeding. Each of the circular patches (5) contacts the microstrip line (4) through the correspondingly connected rectangular strip (6). A feeding port (7) is provided on one side of the upper metal layer (1). The feeding port (7) is connected to the microstrip line (4). Electromagnetic energy is transmitted along the microstrip line (4) according to the characteristics of a traveling wave. Each of the rectangular strips (6) contacts the microstrip line (4), thereby coupling excitation energy to the circular patches (5).

2. The 220 GHz on-chip high-gain series-fed circularly polarized micro-convex antenna according to claim 1, characterized in that: The distance between every two adjacent antenna units is two λe.

3. The 220 GHz on-chip high-gain series-fed circularly polarized micro-convex antenna according to claim 1, characterized in that: The radius length of each circular patch (5) is 1 / 4λe.

4. The 220 GHz on-chip high-gain series-fed circularly polarized micro-convex antenna according to claim 1, characterized in that: The distance between every two adjacent rectangular strips (6) is 1 / 4λe.

5. The 220 GHz on-chip high-gain series-fed circularly polarized micro-convex antenna according to claim 1, characterized in that: The width of the microstrip line (4) is 30 um.

6. The 220 GHz on-chip high-gain series-fed circularly polarized micro-convex antenna according to claim 1, characterized in that: The feeding port (7) is configured as a GSG structure suitable for on-chip antenna testing.

7. The 220 GHz on-chip high-gain series-fed circularly polarized micro-convex antenna according to claim 1, characterized in that: Two of the circular patches (5) of each antenna unit and the rectangular strips (6) connected to the circular patches (5) are arranged above the microstrip line (4), and the other two of the circular patches (5) of each antenna unit and the rectangular strips (6) connected to the circular patches (5) are arranged below the microstrip line (4).

8. The 220 GHz on-chip high-gain series-fed circularly polarized micro-convex antenna according to claim 1, characterized in that: Each of the rectangular strips (6) has the same size.

9. The 220 GHz on-chip high-gain series-fed circularly polarized micro-convex antenna according to claim 1, characterized in that: There are eight antenna units.

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