Waveguide array antenna and terahertz slot waveguide filtering antenna loaded with quartz

Abstract

The invention discloses a waveguide array antenna which comprises a waveguide, a quartz dielectric layer and a plurality of radiation patches. The quartz dielectric layer is located on the upper surface of the waveguide, and the plurality of radiation patches are arranged on the upper surface of the quartz dielectric layer; a plurality of coupling gaps are etched on the upper surface of the waveguide, and the radiation patches on the upper surface of the quartz dielectric layer cover the coupling gaps in a one-to-one correspondence manner; feed-in energy penetrates through the quartz dielectric layer through the coupling gap and is coupled to the corresponding radiation patch. The resonant frequency of the waveguide array antenna is adjusted by controlling the size of the radiation patch; the invention further discloses a terahertz slot waveguide filtering antenna loaded with quartz, the terahertz slot waveguide filtering antenna is formed by cascading the band-pass filter and the waveguide array antenna, the functions of filtering and radiation can be achieved at the same time, and meanwhile due to the fact that quartz has good transparency and low loss characteristics in terahertz, the preparation process is good, and the machining precision can reach + / -2 microns at present, the terahertz slot waveguide filtering antenna loaded with quartz can be applied to the terahertz antenna. The method is very suitable for application of an actual terahertz system.

Description

Technical Field

[0001] The present invention belongs to the technical field of terahertz passive devices, and is specifically a waveguide array antenna and a terahertz gap waveguide filter antenna loading quartz. Background Art

[0002] With the rapid development of communication systems and wireless transmission, the microwave frequency band is obviously unable to meet future needs. Therefore, many scientists and researchers have begun to turn their attention to the terahertz frequency band. Terahertz technology has attracted widespread attention. Since the terahertz frequency band is located between the microwave and optical frequency bands, with a frequency range of 100GHz to 10THz, it has a shorter wavelength and a wider spectrum than microwaves, and has broad application prospects in communication, imaging, detection, etc.

[0003] With the research and development of application technology, the demand for terahertz devices is growing. As one of the core technologies of terahertz technology, filters need to use their frequency selection characteristics to filter out noise and obtain useful signals in different application scenarios. The research on terahertz filters is mainly divided into two categories. One is the quasi-optical filter developed based on optical methods, such as metamaterials, metasurfaces, etc. The other is the electronic filter developed based on the theory of electronic filters combined with high-precision processing technology. Since the latter has the characteristics of low insertion loss, high reliability, and easy integration with the system, the present invention mainly focuses on this type of filter.

[0004] Due to the high loss and high dispersion of terahertz waves, most current research focuses on how to design low-loss, high-efficiency passive devices. At the same time, due to the reduction in the size of terahertz devices, the requirements for processing accuracy are extremely strict, so the design and development of high-precision, low-cost processing methods is also a difficulty in the design of terahertz devices. Although the existing design methods can realize the function of terahertz filtering antennas, they all have the following defects:

[0005] (1) The antenna gain is low, and the number of stacked layers is large, and the structure is complex;

[0006] (2) The sidelobe level of the filter antenna is high;

[0007] (3) Due to the limitations of traditional material processing technology, it is difficult to ensure that the size, shape and surface quality of the waveguide meet the requirements, resulting in low accuracy and large errors in testing and simulation. Summary of the invention

[0008] Purpose of the invention: To solve the defects of the existing design methods, the present invention proposes a waveguide array antenna and a terahertz slot waveguide filter antenna loaded with quartz, which utilize a dual-mode resonant cavity and an eight-element array antenna to simultaneously realize the functions of filtering and radiation. At the same time, since quartz has good transparency and low loss characteristics in terahertz, and the preparation process is relatively good, the processing accuracy can currently reach ±2μm, which is very suitable for the application of actual terahertz systems.

[0009] Technical solution: a waveguide array antenna, including a waveguide, a quartz dielectric layer and several radiation patches;

[0010] The quartz dielectric layer is located on the upper surface of the waveguide, and several radiation patches are arranged on the upper surface of the quartz dielectric layer;

[0011] A plurality of coupling slots are etched on the upper surface of the waveguide, the number of the coupling slots is consistent with the number of the radiation patches, and the radiation patches located on the upper surface of the quartz dielectric layer cover the coupling slots one by one; the fed energy is coupled to the corresponding radiation patches through the coupling slots through the quartz dielectric layer;

[0012] Adjust the resonant frequency of the waveguide array antenna by controlling the size of the radiation patch.

[0013] Further, the offset of each of the coupling gaps is calculated using the Taylor comprehensive algorithm.

[0014] Further, a traveling wave array is used to design the coupling gap.

[0015] The invention discloses a quartz-loaded terahertz slot waveguide filter antenna, which is composed of a bandpass filter and a waveguide array antenna cascaded; the waveguide array antenna is a waveguide array antenna disclosed above.

[0016] Furthermore, the bandpass filter adopts two dual-mode resonant cavity cascade; two dual-mode resonant cavity TM with different structural parameters 110 The upper and lower cutoff frequencies of the mode construction passband.

[0017] Further, the structural parameters include: the height and length of the dual-mode resonant cavity.

[0018] Further, the two dual-mode resonant cavity TM with different structural parameters are described. 110 The mode constructs the upper and lower cutoff frequency points of the passband, including:

[0019] Regulate the height of the first resonant cavity and control the upper cutoff frequency point of the passband;

[0020] Adjust the height of the second resonant cavity and control the lower cutoff frequency point of the passband.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0022] (1) The antenna plays an important role in the RF front-end system. Its design and performance are directly related to the overall quality of the communication transceiver system. The present invention adopts a waveguide slot-coupled feed patch antenna. The resonance point can be flexibly adjusted by adjusting the size of the radiation patch. At the same time, a quartz dielectric layer is used as the upper substrate. A coupling slot is etched in the metal layer at the connection between the quartz dielectric layer and the waveguide. The fed energy is coupled to the radiation patch on the surface of the quartz dielectric layer through the slot. The high-precision antenna structure is manufactured by using electroplating and etching technology.

[0023] (2) The present invention utilizes a dual-mode resonant cavity and an eight-element array antenna to simultaneously achieve the functions of filtering and radiation. At the same time, since quartz has good transparency and low loss characteristics in terahertz and has a good preparation process, the processing accuracy can currently reach ±2μm, ensuring that the size meets the performance requirements, and is very suitable for the application of actual terahertz systems;

[0024] (3) The quartz-loaded terahertz slot waveguide filter antenna designed by the present invention has a passband of 220.92 GHz to 223.46 GHz, a center frequency of 222.19 GHz, a -10 dB bandwidth of 1.143%, and a high gain of not less than 14 dBi within the passband range;

[0025] (4) The quartz used in the present invention is a transparent material that can meet the needs of high-precision processing, so that the size and performance of the device meet the requirements. At the same time, the dual-mode resonator and the antenna are cascaded to form a complete cavity structure, which can achieve flexible regulation of the passband bandwidth to form a complete waveguide cavity structure with a simple structure and easy processing, thus solving the problem that traditional mechanical processing methods cannot meet the requirements in terms of processing accuracy and surface roughness. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is the structure diagram of the dual-mode resonant cavity;

[0027] Figure 2 The effect of the height of the dual-mode resonant cavity on the upper and lower stopband transmission zero point, Figure 2 (a) is the influence of the height b1 of the dual-mode resonant cavity on the upper stopband transmission zero point, Figure 2 (b) in this is the influence of the height b2 of the dual-mode resonant cavity on the lower stopband transmission zero point;

[0028] Figure 3 A structural diagram of a bandpass filter using a dual-mode resonant cavity cascade;

[0029] Figure 4 This is the S parameter simulation diagram of the bandpass filter;

[0030] Figure 5 Schematic diagram of the traveling wave array;

[0031] Figure 6 A structural diagram of a quartz-loaded terahertz gap waveguide filter antenna proposed for the present invention;

[0032] Figure 7 A schematic diagram of the overall structure of a quartz-loaded terahertz gap waveguide filter antenna proposed for the present invention;

[0033] Figure 8 S parameter simulation diagram of a quartz-loaded terahertz gap waveguide filter antenna proposed for the present invention;

[0034] Fig. 9 A gain curve of a quartz-loaded terahertz slot waveguide filter antenna proposed for the present invention;

[0035] Fig.10 The directional diagram of a quartz-loaded terahertz gap waveguide filter antenna proposed for the present invention; wherein, Fig.10 (a) is the E-plane directional diagram. Fig.10 (b) in the figure is the H-plane direction diagram. DETAILED DESCRIPTION

[0036] In order to make the object, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be further explained in the following in conjunction with the accompanying drawings and embodiments.

[0037] Embodiment 1:

[0038] like Figure 3 As shown, this embodiment proposes a bandpass filter based on a dual-mode resonant cavity, using a solution of cascading two dual-mode resonant cavities, and the low-high frequency transmission zero point of the bandpass filter uses a dual-mode resonant cavity TM with different structural parameters. 110 The mode is constructed, and the position of the transmission zero point is mainly determined by the resonance frequency of TM110. The TE101 mode has almost no effect on the position of the transmission zero point. The dual-mode resonant cavity TM 110 Mode H x The component is an odd function about the center of the cross-section of the waveguide. When the input and output waveguides are offset downward, the relative symbols at both ends of the input and output change, thereby generating a transmission zero.

[0039] Figure 1 The structure diagram of the dual-mode resonant cavity is shown. In this embodiment, the fixed width a of the dual-mode resonant cavity remains unchanged, to 1.0922mm, which is consistent with the standard waveguide WR-4, and first determine the appropriate d z Dimensions, offset d z1 and d z2 Both are set to a fixed value of 0.25mm.

[0040] According to the design indicators, the height b and length l of the dual-mode resonant cavity are changed to adjust the resonant frequency of TM1110, and the influence of key parameters on the transmission zeros of the upper and lower stopbands is explored. The transmission zero position can be independently controlled by changing the height and width of the dual-mode resonant cavity. Specifically: adjusting the height and width of the first dual-mode resonant cavity produces a low-frequency transmission zero, and adjusting the height and width of the second dual-mode resonant cavity produces a low-frequency transmission zero.

[0041] like Figure 2 As shown in the figure, through simulation research, it is found that the height b of the dual-mode resonant cavity has a significant impact on the transmission zero point of the resonant cavity. Adjusting the height b1 of the first resonant cavity can independently control the upper cutoff frequency of the passband, and adjusting the height b2 of the second resonant cavity can independently control the lower cutoff frequency of the passband. Therefore, adjusting the height of the two dual-mode resonant cavities can achieve flexible control of the passband.

[0042] Embodiment 2:

[0043] like Figure 6 As shown, this embodiment proposes a waveguide eight-element array antenna, including a waveguide 1, a quartz dielectric layer 2 and a radiation patch 3; the upper surface of the waveguide is connected to the quartz dielectric layer. For the convenience of description, the upper surface of the waveguide is recorded as a metal layer, and eight coupling slots 4 are etched on the metal layer. The energy fed is coupled to the corresponding radiation patch through the coupling slot through the quartz dielectric layer, and the resonant frequency is adjusted by controlling the size of the radiation patch. In this embodiment, a quartz dielectric layer is provided between the radiation patch and the metal layer. The use of quartz processing technology can greatly improve the processing accuracy, reduce the dimensional error, and ensure that the size meets the performance requirements.

[0044] In this embodiment, by using the Taylor synthesis algorithm, the center frequency is set to 222GHz, the side lobe level is -20dB, and the number of radiating patches is 8, and the offset of each coupling slot is calculated. The Taylor synthesis method can control the preset number of equal-amplitude side lobes close to both sides of the main lobe, while gradually reducing the amplitude of the side lobes away from the main lobe, which can effectively improve the directivity of the antenna to increase the gain of the antenna, and can make the power distribution of each radiating patch no longer jump, simplifying the feeding design.

[0045] like Figure 5 As shown, this embodiment adopts the traveling wave array to design the coupling slots, which will not cause a significant impact on the internal field of the waveguide. When in the resonant state, the waveguide is still a traveling wave transmission. The spacing between the two coupling slots d≠λ g / 2,λ g Indicates the waveguide wavelength. The radiation patch is above the quartz dielectric layer and covers the corresponding coupling gap, and the four corners of the coupling gap are chamfered.

[0046] The material of the metal layer used in this embodiment is copper, and the material selection of the quartz dielectric layer is Quartz (Fused) (lossy), the dielectric constant is 3.75, and the loss tangent tanδ = 0.0009.

[0047] Embodiment 3:

[0048] This embodiment proposes a terahertz gap waveguide filtering antenna that loads quartz, such as Figure 7 As shown, the dual-mode resonant cavity cascade bandpass filter proposed in Example 1 and the waveguide eight-element array antenna proposed in Example 2 are cascaded into one to form a complete cavity structure, which has the functions of filtering and antenna radiation, can realize flexible regulation of the passband bandwidth, and form a complete waveguide cavity structure with a simple structure and easy processing.

[0049] The commercial electromagnetic simulation software CST Studio Suite is used to simulate the S parameters of the dual-mode resonant cavity of the bandpass filter, so that the simulation results of the upper and lower stopbands and the influence of key parameters on the transmission zero position can be accurately obtained. The two are cascaded to determine the frequency range of the passband. The various parameter settings of the bandpass filter thus constructed are shown in Table 1. The overall structure of the bandpass filter is shown in Figure 3 The simulation results are shown in Figure 4 As shown, the passband range is 218.93~224.52GHz, the center frequency is 221.725GHz, and the relative bandwidth is 2.52%.

[0050] Table 1 Parameter settings for bandpass filters using dual-mode resonant cavity cascade

[0051]

[0052]

[0053] The length and width of the coupling slot in the waveguide eight-element array antenna proposed in Example 2 are optimized to meet the performance indicators, and the resonant frequency is adjusted by optimizing the length and width of the radiation patch in the waveguide eight-element array antenna proposed in Example 2. The specific structural parameters of the waveguide eight-element array antenna are shown in Table 2.

[0054] Table 2 Structural parameters of waveguide eight-element array antenna

[0055] <![CDATA[Slit length L1 / mm]]> 0.66 <![CDATA[Gap width L W / mm]]> 0.10 Gap spacing d / mm 0.86 <![CDATA[Patch length w3 / mm]]> 0.71 <![CDATA[Chip width w4 / mm]]> 0.60 <![CDATA[Distance L from the waveguide terminal s / mm]]> 0.43 <![CDATA[Gap offset d1 / mm]]> 0.15 <![CDATA[Gap offset d8 / mm]]> 0.15 Gap chamfer radius / mm 0.05 <![CDATA[Gap offset d2 / mm]]> 0.15 <![CDATA[Gap offset d7 / mm]]> 0.15 Quartz layer thickness h / mm 0.05 <![CDATA[Gap offset d3 / mm]]> 0.18 <![CDATA[Gap offset d6 / mm]]> 0.18 Metal layer thickness s / mm 0.003 <![CDATA[Gap offset d4 / mm]]> 0.19 <![CDATA[Gap offset d5 / mm]]> 0.19

[0056] At the same time Figure 7 As shown, the filtered antenna is simulated using the time domain solver of CST software, and the S parameter curve obtained is as follows: Figure 8As shown, its passband range is: 220.92GHz to 223.46GHz, the center frequency is 222.19GHz, and the -10dB bandwidth is 1.143%. The gain curve of the filtered antenna is as follows Fig. 9 As shown, from the figure, the maximum gain of the filtered antenna at a frequency of 222GHz is 15.4dBi, and the directional diagram is as follows Fig.10 shown.

[0057] The simulation results show that the -10dB bandwidth of the filtering antenna proposed in this embodiment is 1.143% GHz, and its gain is not less than 14dBi in the passband of 220.92GHz to 223.46GHz, with a maximum of 15.4dB. It has both filtering and antenna functions, and the results are in line with expectations.

Claims

1. A waveguide array antenna, characterized in that: It includes a waveguide, a quartz dielectric layer and a number of radiation patches; The quartz dielectric layer is located on the upper surface of the waveguide, and a plurality of radiation patches are arranged on the upper surface of the quartz dielectric layer; A plurality of coupling slots are etched on the upper surface of the waveguide, the number of the coupling slots is consistent with the number of the radiation patches, and the radiation patches located on the upper surface of the quartz dielectric layer cover the coupling slots one by one; the fed energy is coupled to the corresponding radiation patches through the coupling slots through the quartz dielectric layer; The resonant frequency of the waveguide array antenna is adjusted by controlling the size of the radiating patch.

2. A waveguide array antenna according to claim 1, characterized in that: The offset of each coupling gap is calculated using a Taylor synthesis algorithm.

3. A waveguide array antenna according to claim 1, characterized in that: The coupling gap is designed using a traveling wave array.

4. A quartz loaded terahertz slot waveguide filter antenna, characterized in that: It is composed of a bandpass filter and a waveguide array antenna cascaded; the waveguide array antenna is a waveguide array antenna as described in any one of claims 1 to 3.

5. The quartz-loaded terahertz slot waveguide filter antenna according to claim 4, characterized in that: The bandpass filter is composed of two dual-mode resonant cavities cascaded; two dual-mode resonant cavities TM with different structural parameters are used. 110 The upper and lower cutoff frequencies of the mode construction passband.

6. The quartz-loaded terahertz slot waveguide filter antenna according to claim 5, characterized in that: The structural parameters include: the height and length of the dual-mode resonant cavity.

7. The quartz-loaded terahertz slot waveguide filter antenna according to claim 5, characterized in that: The two dual-mode resonant cavities TM with different structural parameters 110 The upper and lower cutoff frequencies of the mode construction passband include: Adjust the height of the first resonant cavity to control the upper cutoff frequency of the passband; By adjusting the height of the second resonant cavity, the lower cutoff frequency of the passband is controlled.

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