An E-band millimeter-wave dielectric rod antenna

Abstract

An E-band millimeter-wave dielectric rod antenna belongs to the field of satellite communication technology, and solves the problems of complex structure, inability to cover the frequency band, and large size of the existing E-band antennas. The antenna includes: a micro-coaxial structure, a transition structure, and a dielectric rod radiation structure; the micro-coaxial structure includes a feeding part and an SIW matching part; the inner conductor of the feeding part is connected to the stepped and tapered transition structure through the resonant cavity of the SIW matching part, and the transition structure connects the ridge waveguide of the SIW matching part to the ridge waveguide of the dielectric rod radiation structure. The present invention is applicable to integrated and miniaturized communication scenarios.

Description

Technical Field

[0001] The present invention belongs to the technical field of satellite communication, and particularly relates to the technical field of millimeter-wave antennas. Background Art

[0002] The E-band, namely 71 - 76 GHz and 81 - 86 GHz, can provide up to 10 GHz of huge spectrum resources, and its free-space atmospheric absorption is less than 1 dB / km. Therefore, it has been allocated to the GB wireless system by the Federal Communications Commission. There are currently many application scenarios within the E-band, such as fixed cellular backhaul links, broadband local area networks, and potential next-generation mobile communications, outdoor point-to-point backhaul, millimeter-wave radar, etc. High-gain antennas in the E-band are also important technical challenges for these applications.

[0003] Therefore, high-gain broadband miniaturized antennas operating in the E-band are a hot research topic today. However, currently, high-gain ultra-wideband antennas in the E-band face problems such as the inability to simultaneously balance size, gain, bandwidth, and processing difficulty and cost, which has led to problems in the use of E-band spectrum resources. Compared with other broadband antennas, dielectric rod antennas have significant performance advantages, such as high gain, compact size, small feed cross-section that can be closely arranged, circularly symmetric radiation patterns, and suppression of cross polarization. This makes it possible to simultaneously solve technical problems such as small electrical size, high gain, and ultra-wideband.

[0004] As an important application frequency band, existing E-band antennas have problems such as complex structures, inability to cover the frequency band, and large sizes. Dielectric rod antennas can solve the above problems in the low-frequency band and have good radiation performance and matching characteristics. However, due to electrical size limitations, the size of E-band dielectric rod antennas will be very small, making it difficult to process. This requires improvement in the traditional dielectric rod design concept for the E-band. The development of micro-coaxial technology and micro-electro-mechanical system technology has made it possible to implement dielectric rod antennas in the E-band. Summary of the Invention

[0005] The present invention proposes a dielectric rod antenna operating in the E-band, which solves the problems of complex structure, inability to cover the frequency band, and large size of existing E-band antennas.

[0006] An E-band millimeter-wave dielectric rod antenna, characterized in that the antenna comprises: a micro-coaxial structure, a transition structure, and a dielectric rod radiation structure;

[0007] The micro-coaxial structure comprises a feeding part and an SIW matching part;

[0008] The feeding part comprises a central conductor and an outer conductor;

[0009] The SIW matching part is provided with a ridged waveguide and a resonant cavity;

[0010] The dielectric rod radiation structure is provided with a ridged waveguide;

[0011] The micro coaxial structure is connected to the transition structure through the central conductor of the feeding part and the resonant cavity, and the ridged waveguide of the SIW matching part is connected to the ridged waveguide of the dielectric rod radiation structure through the transition structure;

[0012] Further, the central conductor of the feeding part is a suspended central conductor;

[0013] Further, the outer conductor of the feeding part is grounded and surrounds the feeding part;

[0014] Further, the transition structure is a linear tapered structure;

[0015] Further, the dielectric rod radiation structure includes a plurality of dielectric plates, and the plurality of dielectric plates are connected in a dovetail shape;

[0016] Further, the dielectric rod radiation structure further includes a plurality of holes with a gradually changing number arranged in a dovetail shape;

[0017] Further, the cross-sectional area of the dielectric rod radiation structure gradually decreases from the head to the tip;

[0018] Further, the feeding part further includes two rectangular process holes;

[0019] Further, the micro coaxial structure is composed of 5-layer metal structures.

[0020] Advantages of the present invention:

[0021] The present invention first applies the dielectric rod antenna design technology to the design of E-band high-gain antennas. Compared with other E-band high-gain antennas, the high-gain antenna obtained by the present invention does not require the design of a complex feeding network, has a lower transverse profile, and realizes excellent radiation characteristics of the dielectric rod antenna in the E-band. For example, advantages such as high gain, compact size, small feed cross-section that can be closely arranged, circular symmetry of the radiation pattern, and suppression of cross polarization can be achieved through the present invention in the E-band. Moreover, the present invention combines the micro coaxial technology and the PCB chip processing technology to carry out engineering treatment on the antenna structure, making the antenna of the present invention more suitable for batch processing.

[0022] The reflection coefficient of this antenna is less than -10 dB in the bandwidth of the operating frequency from 60 to 90 GHz, having a good feed matching effect. At the center operating frequency of 77 GHz, the gain reaches 12.74 dBi, having a good directional radiation ability. The sidelobe level is less than -10 dB in both the E-plane and H-plane, having a low sidelobe level. At the operating frequency, the radiation pattern has a good rotational symmetry. In terms of the antenna size, the maximum transverse size of the antenna is about 1.2 cm, and the longitudinal size is 0.75 mm, having the characteristic of small size, which is convenient for array formation. As a feed antenna for millimeter-wave imaging, it can make the imaging system achieve higher accuracy, and due to its small size, it is convenient for integrated and miniaturized applications.

[0023] The present invention is applicable to integrated and miniaturized communication scenarios. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of an E-band millimeter-wave dielectric rod antenna according to Embodiment 1. The figure includes: a micro coaxial structure 1, a transition structure 2, and a dielectric rod radiation structure 3;

[0025] Figure 2 It is a schematic structural diagram of the feeding part according to Embodiment 1, Embodiment 2, Embodiment 3, and Embodiment 9. Among them, 4 is the center conductor, 5 is the outer conductor, and 6 is a rectangular process hole;

[0026] Figure 3 It is a schematic internal structure diagram of the SIW matching part according to Embodiment 1. Among them, 7 is a ridged waveguide, 8 is a resonant cavity, 9 is a micro coaxial, 10 is a straight tapered ridge, and 11 is the transition part of the straight tapered ridge;

[0027] Figure 4 For Figure 3 A partial enlarged view, where k_l1 is the length of the straight tapered ridge, k_h1 is the front height of the straight tapered ridge, k_h2 is the rear height of the straight tapered ridge section, k_h3 is the height of the straight transition section, k_l4 is the thickness of the ground layer, and k_a3 is the thickness of the resonant cavity;

[0028] Figure 5 For Figure 3 A side view sectional view in the feeding direction, where k_a2 is the ridge width, k_a1 is the ridged waveguide width, k_b2 is the height of the resonant cavity, and k_b1 is the height of the ridged waveguide;

[0029] Figure 6 It is a schematic diagram of the transition structure according to Embodiment 4;

[0030] Figure 7 For Figure 8Schematic diagram of the structure of the assembled SIW ridge waveguide, where f_a1 is the ridge waveguide width, f_a2 is the ridge width, f_b2 is the ridge thickness, and f_b1 is the ridge waveguide height;

[0031] Figure 8 Side view cross-sectional view of the dielectric rod radiation structure described in Embodiment 6, where f_l1 is the length of the dielectric transition layer, f_l2 is the length of the dovetail transition section, f_l3 is the length of the mode conversion section, f_l4 is the dielectric radiation length, f_a3 is the width of the mode conversion section, FR-4 is the dielectric material of the dielectric dovetail transition section, Rogers TMM 13i is the dielectric material of the dielectric radiation part, and Rogers RT6006 is the material of the dielectric transition section;

[0032] Figure 9 Schematic diagram of the dielectric rod radiation structure described in Embodiment 6;

[0033] Figure 10 Antenna reflection coefficient diagram described in Embodiment 1, where the abscissa in the figure is frequency, with the unit of GHz; the ordinate is the reflection coefficient, with the unit of dB;

[0034] Figure 11 Antenna gain curve diagram described in Embodiment 1, where the abscissa in the figure is frequency, with the unit of GHz; the ordinate is the gain, with the unit of dBi;

[0035] Figure 12 Schematic diagram of the filled dielectric described in Embodiment 11;

[0036] Figure 13 Schematic diagram of replacing metal filling with metal posts described in Embodiment 11;

[0037] Figure 14 Schematic diagram of replacing linear gradient with stepped gradient described in Embodiment 11, where k_l1 / 2 is the stepped transformation length and k_h3 / 2 is the stepped transformation height;

[0038] Figure 15 Schematic diagram of the equivalent of a dovetail-shaped dielectric plate using a varying number of holes described in Embodiment 7. Specific implementation mode

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] Embodiment 1: Refer to Figures 1 to 11 to illustrate this embodiment.

[0041] An E-band millimeter-wave dielectric rod antenna according to the present embodiment, the antenna comprising: a micro-coaxial structure, a transition structure, and a dielectric rod radiation structure;

[0042] The micro-coaxial structure includes a feeding portion and an SIW matching portion;

[0043] The feeding portion includes a central conductor and an outer conductor;

[0044] The SIW matching portion is provided with a ridge waveguide and a resonant cavity;

[0045] The dielectric rod radiation structure is provided with a ridge waveguide;

[0046] The micro-coaxial structure is connected to the transition structure through the central conductor of the feeding portion and the resonant cavity of the SIW matching portion, and the ridge waveguide of the SIW matching portion is connected to the ridge waveguide of the dielectric rod radiation structure through the transition structure.

[0047] Specifically:

[0048] In the antenna according to the present embodiment, each component can be connected by bonding or welding.

[0049] Such as Figure 3 , Figure 4 As shown, the SIW matching portion further includes a linear tapered ridge.

[0050] The feeding portion of the micro-coaxial structure has key high-frequency circuit characteristics such as ultra-wide bandwidth and ultra-low loss, greatly improving the millimeter-wave / terahertz circuit performance and system integration ability.

[0051] The working principle of an E-band millimeter-wave dielectric rod antenna according to the present embodiment is as follows: when the antenna works, it is fed by the micro-coaxial structure, and the SIW matching portion of the micro-coaxial structure completes matching and mode conversion. Subsequently, as the electromagnetic wave propagates in the dielectric waveguide, as the cross-sectional area of the dielectric rod decreases, the phase velocity of the electromagnetic wave increases. When it reaches the tip of the dielectric rod, the phase velocity approaches the speed of light and then can be radiated into free space to form a directional radiation.

[0052] The reflection loss of the antenna according to the present embodiment is as Figure 10 shown, and the gain curve is as Figure 11 shown. The reflection coefficient of the antenna is less than -10 dB in the bandwidth of the operating frequency of 60 - 90 GHz, having a good feeding matching effect. At the central operating frequency of 77 GHz, the gain reaches 12.74 dBi, having a good directional radiation ability. The sidelobe level is less than -10 dB in both the E-plane and the H-plane, having a low sidelobe level. At the operating frequency, the radiation pattern has a good rotational symmetry.

[0053] In terms of the antenna size, the maximum lateral size of the antenna is approximately 1.2 cm, and the longitudinal size is 0.75 mm. It has the characteristic of small size, which is convenient for array formation. As a feed antenna for millimeter-wave imaging, it can make the imaging system achieve higher accuracy. Moreover, due to its small size, it is convenient for integrated and miniaturized applications. The antenna described in this embodiment is a sheet structure, which combines PCB chip processing and micro-coaxial structure processing technologies.

[0054] Embodiment 2: Refer to Figure 2 to illustrate this embodiment.

[0055] This embodiment is a further example of the central conductor of the feeding part in an E-band millimeter-wave dielectric rod antenna described in Embodiment 1.

[0056] The central conductor of the feeding part described in this embodiment is a suspended central conductor.

[0057] Embodiment 3: Refer to Figure 2 to illustrate this embodiment.

[0058] This embodiment is a further example of the outer conductor of the feeding part in an E-band millimeter-wave dielectric rod antenna described in Embodiment 1.

[0059] The outer conductor of the feeding part described in this embodiment is grounded and surrounds the feeding part.

[0060] Specifically:

[0061] The feeding part of the micro-coaxial structure described in this embodiment is composed of a suspended central conductor and a grounded outer conductor that surrounds the feeding part. Such a feeding part has key high-frequency circuit characteristics such as ultra-wide bandwidth and ultra-low loss, greatly improving the performance of millimeter-wave / terahertz circuits and system integration capabilities.

[0062] Embodiment 4: Refer to Figure 6 to illustrate this embodiment.

[0063] This embodiment is a further example of the transition structure in an E-band millimeter-wave dielectric rod antenna described in Embodiment 1.

[0064] The transition structure described in this embodiment is a linear tapered structure.

[0065] The transition structure also includes a linear tapered ridge.

[0066] Embodiment 5: Refer to Figure 4 、 Figure 5 to illustrate this embodiment.

[0067] This embodiment further illustrates the ridged waveguide of the SIW matching part described in Embodiment 1 of an E-band millimeter-wave dielectric rod antenna.

[0068] The ridged waveguide of the SIW matching part described in this embodiment is a two-stage stepped tapered metal ridged waveguide. The ridged waveguide is arranged at the end of the SIW matching part.

[0069] Specifically:

[0070] The two-stage stepped tapered metal ridged waveguide described in this embodiment is matched with the linear tapered transition structure described in Embodiment 4. The ridged waveguide at the end of the SIW matching part is connected to the linear tapered transition part, and the linear tapered transition part connects the ridged waveguide of the SIW matching part and the ridged waveguide of the dielectric rod radiation part.

[0071] Embodiment 6: Refer to Figure 7 , Figure 8 , Figure 9 to illustrate this embodiment.

[0072] This embodiment further illustrates the dielectric rod radiation structure described in Embodiment 1 of an E-band millimeter-wave dielectric rod antenna.

[0073] The dielectric rod radiation structure described in this embodiment includes a plurality of dielectric plates, and the plurality of dielectric plates are connected in a dovetail shape.

[0074] Specifically:

[0075] As Figure 8 , Figure 9 shown, the dielectric rod radiation structure is composed of four connected dielectric plates, and the dielectric plates are connected in the structure shown in the figure and are symmetric about the central axis of the dielectric rod structure. Electromagnetic waves are equiva lently matched by dovetail-shaped holes with a gradually changing number. This part of the dielectric is FR-4; then it is matched through a dielectric transition part composed of Rogers RT6006 material, and finally radiated to a tapered dielectric rod body composed of Rogers TMM13i material.

[0076] Embodiment 7: Refer to Figure 15 to illustrate this embodiment.

[0077] This embodiment further illustrates the dielectric rod radiation structure described in Embodiment 1 of an E-band millimeter-wave dielectric rod antenna.

[0078] The dielectric rod radiation structure described in this embodiment further includes a plurality of holes with a gradually changing number arranged in a dovetail shape.

[0079] Specifically: for the convenience of processing, the following treatment can be done to the radiation part. The original dovetail part is equivalent by using a gradually varying number of holes, and in the original air part, a hollow and hole-array-loaded method is used to make the dielectric constant of the medium closer to that of air.

[0080] After the above substitution, the operating bandwidth of the antenna can reach 60 - 80 GHz, the gain at the center operating frequency reaches more than 8.5 dBi, and the radiation characteristics still have a low sidelobe level, good directional radiation ability, and excellent rotational symmetry.

[0081] Embodiment VIII: Refer to Figure 1 Describe this embodiment.

[0082] This embodiment is a further example illustration of the dielectric rod radiation structure described in Embodiment I for an E-band millimeter-wave dielectric rod antenna.

[0083] The cross-sectional area of the dielectric rod radiation structure described in this embodiment gradually decreases from the head to the tip.

[0084] Embodiment IX: Refer to Figure 2 Describe this embodiment.

[0085] This embodiment is a further example illustration of the feeding part described in Embodiment I for an E-band millimeter-wave dielectric rod antenna.

[0086] The feeding part described in this embodiment further includes two rectangular process holes.

[0087] Specifically:

[0088] The rectangular process holes described in this embodiment are the process holes reserved for injecting etching solution during the processing of the micro-coaxial structure.

[0089] Embodiment X:

[0090] This embodiment is a further example illustration of the micro-coaxial structure described in Embodiment I for an E-band millimeter-wave dielectric rod antenna.

[0091] The micro-coaxial structure described in this embodiment is composed of 5 layers of metal structures.

[0092] Specifically:

[0093] The micro-coaxial adopts a copper-based 3D micro-coaxial process based on lithography technology. On this basis, a planarization process and a supporting dielectric material are introduced, enabling a multi-layer and suspended complex coaxial structure.

[0094] The micro coaxial structure consists of a 5-layer metal structure. Using a layered additive manufacturing method to replace the machining method of welding and assembling the metal waveguide structure one by one, the machining accuracy and consistency are improved.

[0095] For the feeding part and the SIW matching part of the micro coaxial structure, PCB chip processing technology and layered processing technology are adopted.

[0096] For the dielectric rod radiation structure, 3D printing technology is used to print out the radiation rod bodies for connection.

[0097] Embodiment XI: Refer to Figure 12 , Figure 13 , Figure 14 to illustrate this embodiment.

[0098] This embodiment is a further example of the E-band millimeter-wave dielectric rod antenna described in Embodiment I.

[0099] For the antenna described in this embodiment, for the convenience of machining, the straight tapered ridge and the resonant cavity of the SIW matching part can be processed as follows: Use a square metal column with a side length of d1 = 0.35 mm, and the center spacing of the metal columns is s1 = 0.4 mm to equivalent the resonant cavity part. At the grounding part, use a square metal column with a side length of d2 = 0.3 mm, and the center spacing of the metal columns is s2 = 0.35 for equivalent grounding. Fill with Rogers RT5880 material, perform a hollow operation on the dielectric material, and drill holes. At the grounding part, the dielectric material at the grounding part is removed to optimize the grounding effect.

[0100] Table 1 Radiation Size Table (Unit / μm)

[0101]

[0102]

[0103] Where t is the metal layer thickness.

[0104] Table 2 Feeding Matching Part Size (Unit / μm)

[0105]

Claims

1. An E-band millimeter-wave dielectric rod antenna, characterized in that, The antenna includes: a micro coaxial structure (1), a transition structure (2), and a dielectric rod radiation structure (3); The micro coaxial structure (1) includes a feeding part and a SIW matching part; The feeding part includes a center conductor (4) and an outer conductor (5); The SIW matching part is provided with a ridge waveguide (7) and a resonant cavity (8); The dielectric rod radiation structure (3) is provided with a ridge waveguide; The micro coaxial structure (1) is connected to the transition structure (2) through the center conductor of the feeding part and the resonant cavity (8), and the ridge waveguide (7) of the SIW matching part is connected to the ridge waveguide of the dielectric rod radiation structure through the transition structure; The center conductor (4) of the feeding part is a suspended center conductor.

2. The E-band millimeter-wave dielectric rod antenna according to claim 1, wherein The outer conductor (5) of the feeding part is grounded and surrounds the feeding part.

3. The E-band millimeter-wave dielectric rod antenna according to claim 1, wherein The transition structure (2) is a linear gradient structure.

4. The E-band millimeter-wave dielectric rod antenna according to claim 1, characterized in that The ridge waveguide (7) of the SIW matching part is a two-segment stepped gradient metal ridge waveguide.

5. The E-band millimeter-wave dielectric rod antenna according to claim 1, characterized in that The dielectric rod radiation structure (3) includes a plurality of dielectric plates, and the plurality of dielectric plates are connected in a dovetail shape.

6. The E-band millimeter-wave dielectric rod antenna according to claim 1, characterized in that, The dielectric rod radiation structure (3) further includes a plurality of holes with a gradually changing number arranged in a dovetail shape.

7. The E-band millimeter-wave dielectric rod antenna according to claim 1, characterized in that, The cross-sectional area of the dielectric rod radiation structure (3) gradually decreases from the head to the tip.

8. The E-band millimeter-wave dielectric rod antenna according to claim 1, characterized in that The feeding part further includes two rectangular process holes (6).

9. The E-band millimeter-wave dielectric rod antenna according to claim 1, characterized in that, The micro coaxial structure (1) is composed of 5 layers of metal structures.

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