A broadband, low insertion loss millimeter-wave reconfigurable reflector based on HTCC technology

Abstract

This invention belongs to the field of broadband antenna technology, and specifically relates to a broadband, low insertion loss millimeter-wave reconfigurable reflector based on HTCC technology. The invention includes an HTCC multilayer wiring ceramic housing, within which a unit metal circuit chip is installed. The unit metal circuit chip is connected to several pin switching diodes. A DC control stub is disposed within the housing, with its other end extending from the cavity of the HTCC multilayer wiring ceramic housing. A circular pad for soldering BGA balls is formed at the bottom of the HTCC multilayer wiring ceramic housing. The housing also contains several quartz planar spiral inductors, which are connected to the unit metal circuit chip and the DC control stub via gold wires. A metal cover plate is connected to the opening of the housing, and a metal shorting post connects the center of the unit metal circuit chip to the metal cover plate. This invention provides a broadband, low insertion loss millimeter-wave reconfigurable reflector based on HTCC technology.

Description

Technical Field

[0001] This invention belongs to the field of broadband antenna technology, and specifically relates to a broadband, low insertion loss millimeter-wave reconfigurable reflector based on HTCC technology. Background Technology

[0002] Traditional phased array systems are complex in architecture, highly flexible, and have high aperture efficiency, offering rapid two-dimensional beam scanning, but are typically expensive. Traditional parabolic reflector antenna systems are simple, high-gain, and have wide bandwidth, but their beams are fixed, and they are generally less expensive. Reconfigurable reflector arrays combine the rapid beam scanning capability of traditional phased arrays with the simple open-feed method of parabolic reflectors, making them one of the low-cost solutions for high-gain, rapid-beam scanning antennas today.

[0003] In engineering practice, reconfigurable reflector arrays are far less prevalent than phased arrays and parabolic reflector antennas, primarily due to their low aperture efficiency and narrow operating bandwidth. The aperture efficiency of a reconfigurable reflector array is mainly determined by the feed efficiency, illumination efficiency, feed obstruction, and element insertion loss. Among these, the feed efficiency, illumination efficiency, and feed obstruction are determined during the selection of the open-feed architecture, following the same selection principles as traditional parabolic reflector antennas, with a maximum efficiency of approximately 70%. Element insertion loss is mainly determined by the insertion loss of the reflection amplitude and the accuracy of the reflection phase of the reconfigurable reflector elements. The operating bandwidth of a reconfigurable reflector array depends primarily on the operating bandwidth of the feed and the bandwidth of the reflector elements. To achieve high efficiency, horn antennas are typically chosen as feeds, with an operating bandwidth ratio of at least 3:1. Therefore, the main factor limiting the bandwidth of a reconfigurable reflector array is the bandwidth of the reflector elements. Given a fixed open-feed architecture, improving the reflection amplitude and phase performance of the elements over a wide bandwidth can effectively enhance the aperture efficiency and operating bandwidth of the reconfigurable reflector array.

[0004] Xi'an University of Electronic Science and Technology disclosed a broadband beam scanning reflective array antenna based on a multi-resonant frequency reconfigurable reflective element in its patent application "A Broadband Beam Scanning Reflective Array Antenna" (application number 202011411499.7, publication number CN 113113774A). This element comprises two layers of patches with similar shapes but different resonant frequencies, connected in series with pin diodes and then grounded. A 180° reflection phase difference is formed by controlling the on and off states of the pin diodes. The 180°±20° phase bandwidth is approximately 24.5%. The reflection amplitude insertion loss of this element is less than 0.65dB, which can effectively improve the aperture efficiency after arraying. However, due to the only 1-bit phase resolution, it introduces an additional 3dB of quantization insertion loss.

[0005] In their paper "A 2-bit Circularly Polarized Reconfigurable Reflectarray Using pin Diode Tuned Crossed-Bowtie Patch Elements" published in IEEE TRANSACTIONS ON ANTENNA AND PROPAGATION, Vol. 71, No. 9, SEPTEMBER, 2023, Fan Wu et al. proposed a 2-bit reconfigurable reflectarray based on rotating phase. This array consists of eight diodes loaded with four sets of bowtie dipoles. Only one pair of pin diodes is selected at a time, while the others are cut off, achieving a 90° phase difference step. The array bandwidth is greater than 20%, and the phase difference is stable at 90° ± 5°. While the phase of this array is extremely stable, the bandwidth is slightly insufficient, and using only eight pin diodes to achieve a 2-bit phase results in wasted cost.

[0006] To further improve the bandwidth of the reconfigurable reflective unit while reducing the insertion loss, this invention proposes a millimeter-wave reconfigurable unit based on HTCC multilayer wiring technology. By leveraging the HTCC three-dimensional wiring capability and high ceramic body strength, an air medium is introduced into the unit, effectively improving the unit's bandwidth while reducing the insertion loss introduced by the medium. Summary of the Invention

[0007] To address the aforementioned problems in the existing technology, the present invention aims to provide a broadband, low insertion loss millimeter-wave reconfigurable reflective unit based on HTCC technology. By leveraging the three-dimensional wiring capability of HTCC and the high ceramic body strength, an air medium is introduced into the unit, effectively increasing the unit's bandwidth while reducing the insertion loss introduced by the medium.

[0008] The technical solution adopted in this invention is as follows:

[0009] A broadband, low insertion loss millimeter-wave reconfigurable reflector based on HTCC technology includes an HTCC multilayer wiring ceramic housing. A unit metal circuit chip is installed inside the HTCC multilayer wiring ceramic housing, and the unit metal circuit chip is connected to several pin switching diodes. A DC control stub is disposed inside the HTCC multilayer wiring ceramic housing, with the other end of the DC control stub extending vertically from the cavity of the HTCC multilayer wiring ceramic housing to the bottom of the HTCC multilayer wiring ceramic housing along its outer side. A circular pad is formed at the bottom of the HTCC multilayer wiring ceramic housing, and BGA balls are soldered onto the circular pad. Several quartz planar spiral inductors are also disposed in the HTCC multilayer wiring ceramic housing, and the quartz planar spiral inductors are connected to the unit metal circuit chip and the DC control stub via gold wires. A metal cover plate is connected to the opening of the HTCC multilayer wiring ceramic housing, and a metal shorting post is connected to the center of the unit metal circuit chip, with the other end of the metal shorting post connected to the metal cover plate.

[0010] The HTCC multilayer wiring ceramic housing has a hollow structure (with an internal cavity). The metal circuitry of the reconfigurable reflector unit is printed on the inner surface of the cavity and plated with gold. During operation, the metal circuitry resonates in various operating modes through the air cavity, forming a wide operating bandwidth. A pin-switch diode is mounted on the circuitry inside the cavity to control the on / off state of the RF signal in the corresponding branch. A quartz planar spiral inductor is connected in series with the pin-switch diode to suppress the RF signal and conduct the DC control signal. BGA solder balls are connected to the quartz planar inductor through metal stubs on the outside of the housing, interconnecting with the PCB adapter board and transferring the DC control signal. External millimeter-wave signals are induced by the metal circuitry, flow through the conducting pin-switch diode to the corresponding branch, are suppressed by the quartz planar spiral inductor, and reflected to form a reflected wave. The DC control signal, through the BGA solder balls and the quartz planar spiral inductor, controls the on / off state switching of the pin-switch diode.

[0011] This invention addresses the low market acceptance of reconfigurable reflector arrays due to their low aperture efficiency and narrow operating bandwidth. It proposes a broadband, low insertion loss millimeter-wave reconfigurable reflector unit based on HTCC multilayer wiring technology. This invention primarily utilizes HTCC multilayer wiring technology to form metal unit circuits and air cavities, with the air cavity acting as the medium for unit resonance. This expands the operating bandwidth of the reconfigurable reflector unit to 34.7%, improves phase stability to ±0.5°, and reduces unit insertion loss to 1dB. Simultaneously, the unit becomes a standard ceramic packaged device.

[0012] As a preferred embodiment of the present invention, a sealing ring is provided between the metal cover plate and the opening of the HTCC multilayer wiring ceramic tube shell. The sealing ring and the metal cover plate form an airtight and watertight enclosure for the cavity of the tube shell, so that the reconfigurable reflective unit is formed into a standard ceramic packaged device in terms of manufacturing process.

[0013] As a preferred embodiment of the present invention, the quartz planar spiral inductor is connected to the unit metal circuit chip and the DC control branch respectively through a φ20um gold wire; the inductance value of the quartz planar spiral inductor is 5nH at 20GHz.

[0014] As a preferred embodiment of the present invention, the composition and weight ratio of the BGA solder ball are: 90% lead and 10% tin; the diameter of the BGA solder ball is 550 μm.

[0015] As a preferred embodiment of the present invention, the thickness of the metal cover plate is 20 μm; the thickness of the sealing ring is 30 μm.

[0016] As a preferred embodiment of the present invention, the material of the HTCC multilayer wiring ceramic housing comprises 92% alumina by weight.

[0017] As a preferred embodiment of the present invention, the HTCC multilayer wiring ceramic tube shell is in the shape of a regular hexagonal prism; the interior of the HTCC multilayer wiring ceramic tube shell is a cavity, which is also a regular hexagonal prism, and three non-adjacent corners of the cavity are chamfered.

[0018] As a preferred embodiment of the present invention, the HTCC multilayer wiring ceramic tube shell has a side length of 7.2 mm and a height of 1.9 mm; the cavity height is 1.3 mm, the chamfer side length is 1.76 mm, and the thickness of the HTCC multilayer wiring ceramic tube shell is 0.85 mm.

[0019] As a preferred embodiment of the present invention, the unit metal circuit chip includes a circular patch and three fan-shaped branches that are rotationally symmetrically distributed on the circular patch. Each fan-shaped branch is equipped with a flip-chip pin switching diode. The three pin switching diodes are connected in parallel and share a common ground. A DC control stub is provided between adjacent fan-shaped branches.

[0020] As a preferred embodiment of the present invention, the radius of the circular patch is 0.98 mm, the inner radius of the fan-shaped branch is 1.58 mm, the outer radius of the fan-shaped branch is 2.26 mm, and the angle of the fan-shaped branch is 75°; the angle between the fan-shaped branch and its adjacent DC control branch is 75°, the radius of the DC control branch is 0.59 mm, and the width is 0.7 mm.

[0021] The beneficial effects of this invention are as follows:

[0022] This invention addresses the low market acceptance of reconfigurable reflector arrays due to their low aperture efficiency and narrow operating bandwidth. It proposes a broadband, low insertion loss millimeter-wave reconfigurable reflector unit based on HTCC multilayer wiring technology. This invention primarily utilizes HTCC multilayer wiring technology to form metal unit circuits and air cavities, with the air cavity acting as the medium for unit resonance. This expands the operating bandwidth of the reconfigurable reflector unit to 34.7%, improves phase stability to ±0.5°, and reduces unit insertion loss to 1dB. Simultaneously, the unit becomes a standard ceramic packaged device. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of an HTCC multilayer wiring ceramic housing;

[0025] Figure 3 It is a structural schematic diagram of a unit metal circuit chip, a pin switch diode, and a DC control stub;

[0026] Figure 4 The figure shows the simulation results of the normal principal polarization reflection amplitude under three states according to the present invention.

[0027] Figure 5 The figure shows the simulation results of the normal cross-polarization reflection amplitude under three states according to the present invention;

[0028] Figure 6 The simulation results of the normal principal polarization reflection phase under three states are shown in the figure.

[0029] Figure 7 The figure shows the simulation results of the normal main polarization phase shift deviation under three states according to the present invention.

[0030] In the diagram: 101 - Overall perspective structure of the unit; 102 - Exploded structure of the unit; 103 - HTCC multilayer wiring ceramic tube shell; 104 - Unit metal circuit piece; 105 - Pin switching diode; 106 - DC control stub; 107 - Quartz planar spiral inductor; 108 - Metal shorting post; 109 - BGA solder ball; 110 - Metal cover plate; 111 - Sealing ring. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the invention can be combined with each other.

[0033] like Figures 1-3 As shown, the broadband, low insertion loss millimeter-wave reconfigurable reflector unit based on HTCC technology in this embodiment includes an HTCC multilayer wiring ceramic housing 103. A unit metal circuit chip 104 is installed inside the HTCC multilayer wiring ceramic housing 103. The unit metal circuit chip 104 is connected to several pin switching diodes 105. A DC control stub 106 is disposed inside the HTCC multilayer wiring ceramic housing 103. A metal cover plate 110 is connected to the opening of the HTCC multilayer wiring ceramic housing 103. A metal short-circuit post 108 is connected to the center of the unit metal circuit chip 104. The other end of the metal short-circuit post is connected to the metal cover plate 110. A sealing ring 111 is disposed between the metal cover plate 110 and the opening of the HTCC multilayer wiring ceramic housing 103.

[0034] The unit metal circuit chip 104, pin switching diode 105, and quartz planar spiral inductor 107 are all located inside the cavity of the HTCC multilayer wiring ceramic casing 103. The DC control stub 106 extends vertically from inside the cavity of the HTCC multilayer wiring ceramic casing 103 through the ceramic wall, along the outer side of the ceramic wall to the bottom of the casing, forming a circular pad at the bottom for soldering BGA balls. The quartz planar spiral inductor 107 is connected to the unit metal circuit chip 104 and the DC control stub 106 via φ20um gold wires. The quartz planar spiral inductor 107 has an inductance of 5nH at 20GHz and is a mature microwave device. The metal shorting post 108 connects the geometric center of the unit metal circuit chip 104 to the metal cover plate 110, serving as the DC ground for the pin switching diode 105. The BGA solder ball 109 consists of 90% lead and 10% tin by weight, with a ball diameter of 550um. The metal cover plate 110 has a thickness of 20um. The thickness of the sealing ring 111 is 30um.

[0035] Figure 2 This is an enlarged view of the HTCC multilayer wiring ceramic housing 103 in this embodiment. The HTCC multilayer wiring ceramic housing 103 is made of 92% alumina (black ceramic) by weight. Its shape is a regular hexagonal prism with a side length of c and a thickness of h1. The inside of the housing is a cavity, which is a chamfered regular hexagonal prism with a height of h2 and a chamfered side length of a. The housing thickness is b. Specific parameters are shown in Table 1.

[0036] Table 1 shows the dimensional parameters of HTCC multilayer wiring ceramic tube shell 103:

[0037] a b c h1 h2 1.76mm 0.85mm 7.2mm 1.9mm 1.3mm

[0038] Figure 3 This is an enlarged view of the unit metal circuit piece 104, pin switching diode 105, and DC control stub 106 in this embodiment. These three parts are symmetrically distributed with point O as the origin, rotating 120°. The unit metal circuit piece 104 includes a circular patch with radius R1 and three fan-shaped branches with inner radius R3, outer radius R2, and angle φ1. Each fan-shaped branch is equipped with a flip-chip pin switching diode 105. The three pin switching diodes 105 are connected in parallel and share a common ground, numbered 1#, 2#, and 3# in a counterclockwise direction. The angle between the fan-shaped branch and its adjacent DC control stub 106 is φ0. The radius of the DC control stub 106 is R5, and its width is W1. The specific values ​​of each parameter are shown in Table 2.

[0039] Table 2 shows the dimensional parameters of unit metal circuit piece 104, pin switching diode 105, and DC control stub 106:

[0040] R1 R2 R3 R4 R5 φ0 φ1 W1 0.98mm 2.26mm 1.58mm 2.2mm 0.59mm 75° 15° 0.7mm

[0041] Figures 4-7 This figure shows the simulation results of a broadband, low insertion loss millimeter-wave reconfigurable reflector unit based on HTCC technology in this embodiment. The switch codes in the figure represent the on / off states of the three pin switching diodes 105 in the unit. "0" represents the off state, and "1" represents the on state. The coding order is 1#2#3#. For example, "010" means that pin switching diode 105 is on, and pin switching diodes 1# and 3# are off. The simulation was performed using periodic boundary conditions in ANSYS 2021 with a triangular array and a spacing of 7.15mm. The pin switching diodes 105 use the equivalent data provided by the manufacturer; when on, they are equivalent to a 4.5Ω resistor; when off, they are equivalent to a 0.026pF capacitor.

[0042] Figure 4 The normal main polarization reflection amplitudes of the broadband, low insertion loss millimeter-wave reconfigurable reflector based on HTCC technology in this embodiment are shown in three states. It can be seen that within the range of 15.5 to 22 GHz, the insertion loss of the main polarization reflection amplitude is uniform and stable in all three states, which is about 1 dB. The insertion loss is low in the existing millimeter-wave reconfigurable reflector design, and the relative bandwidth is 34.6%.

[0043] Figure 5The normal cross-polarization reflection amplitudes of the broadband, low insertion loss millimeter-wave reconfigurable reflector based on the HTCC process in this embodiment are shown in three states. It can be seen that within the range of 15.5 to 22 GHz, the cross-polarization reflection amplitudes in all three states are less than -13 dB, indicating good cross-polarization.

[0044] Figure 6 The normal main polarization reflection phases of the broadband, low insertion loss millimeter-wave reconfigurable reflection unit based on HTCC technology in this embodiment are shown in three states. It can be seen that within the range of 14 to 23 GHz, the main polarization reflection phase difference in the three states is stable at 120°, achieving good three-phase shift phase.

[0045] Figure 7 The normal main polarization phase shift deviation of the broadband, low insertion loss millimeter-wave reconfigurable reflector based on HTCC technology in this embodiment is shown. It can be seen that within the range of 14 to 23 GHz, the phase shift deviation of the unit in the three states is no greater than ±0.5°, and the phase shift accuracy is good.

[0046] This embodiment demonstrates a broadband, low insertion loss millimeter-wave reconfigurable reflector based on HTCC technology. By combining the reflection amplitude and phase of the three states, it can be seen that after introducing an air dielectric resonator through HTCC multilayer wiring technology, the unit's operating bandwidth is 34.7% while maintaining a 1dB insertion loss. This is approximately 10% wider than the bandwidth of current broadband millimeter-wave reconfigurable reflectors, and the phase shift stability is improved to within ±0.5°, proving the effectiveness of the proposed method.

[0047] This invention is not limited to the above-described optional embodiments. Anyone can derive other various forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that falls within the scope of the claims of this invention shall be protected by this invention.

Claims

1. A broadband, low insertion loss millimeter-wave reconfigurable reflective unit based on HTCC technology, characterized in that: The device includes an HTCC multilayer wiring ceramic housing (103), within which a unit metal circuit piece (104) is installed. The unit metal circuit piece (104) is connected to several pin switching diodes (105). A DC control stub (106) is disposed within the HTCC multilayer wiring ceramic housing (103). The other end of the DC control stub (106) extends from the cavity of the HTCC multilayer wiring ceramic housing (103) and vertically along the outer side of the HTCC multilayer wiring ceramic housing (103) to the bottom of the HTCC multilayer wiring ceramic housing (103). The bottom of the HTCC multilayer wiring ceramic housing (103) forms a circular pad, and the circular pad is soldered with BGA solder balls. The HTCC multilayer wiring ceramic housing (103) is also provided with several quartz planar spiral inductors (107). The quartz planar spiral inductors (107) are connected to the unit metal circuit piece (104) and the DC control branch (106) respectively through gold wires. The opening of the HTCC multilayer wiring ceramic housing (103) is connected to a metal cover plate (110). The center of the unit metal circuit piece (104) is connected to a metal shorting post (108), and the other end of the metal shorting post is connected to the metal cover plate (110).

2. The broadband, low insertion loss millimeter-wave reconfigurable reflector unit based on HTCC technology according to claim 1, characterized in that: A sealing ring (111) is provided between the metal cover plate (110) and the opening of the HTCC multilayer wiring ceramic tube shell (103).

3. The broadband, low insertion loss millimeter-wave reconfigurable reflector unit based on HTCC technology according to claim 1, characterized in that: The quartz planar spiral inductor (107) is connected to the unit metal circuit piece (104) and the DC control stub (106) respectively through a φ20um gold wire; the inductance value of the quartz planar spiral inductor (107) is 5nH at 20GHz.

4. The broadband, low insertion loss millimeter-wave reconfigurable reflector unit based on HTCC technology according to claim 1, characterized in that: The composition and weight ratio of the BGA solder ball (109) are: 90% lead and 10% tin; the diameter of the BGA solder ball (109) is 550 μm.

5. A broadband, low insertion loss millimeter-wave reconfigurable reflector unit based on HTCC technology according to claim 2, characterized in that: The thickness of the metal cover plate (110) is 20 μm; the thickness of the sealing ring (111) is 30 μm.

6. The broadband, low insertion loss millimeter-wave reconfigurable reflector unit based on HTCC technology according to claim 1, characterized in that: The material of the HTCC multilayer wiring ceramic housing (103) includes 92% alumina by weight.

7. A broadband, low insertion loss millimeter-wave reconfigurable reflector unit based on HTCC technology according to claim 1, characterized in that: The HTCC multilayer wiring ceramic housing (103) is in the shape of a regular hexagonal prism; the interior of the HTCC multilayer wiring ceramic housing (103) is a cavity, which is also a regular hexagonal prism, and three non-adjacent corners of the cavity are chamfered.

8. A broadband, low insertion loss millimeter-wave reconfigurable reflector unit based on HTCC technology according to claim 7, characterized in that: The HTCC multilayer wiring ceramic housing (103) has a side length of 7.2 mm and a height of 1.9 mm; the cavity has a height of 1.3 mm, a chamfer side length of 1.76 mm, and a thickness of 0.85 mm.

9. A broadband, low insertion loss millimeter-wave reconfigurable reflector unit based on HTCC technology according to claim 1, characterized in that: The unit metal circuit chip (104) includes a circular patch and three fan-shaped branches that are rotationally symmetrically distributed on the circular patch. Each fan-shaped branch is equipped with a flip-chip pin switching diode (105). The three pin switching diodes (105) are connected in parallel and grounded together. A DC control stub (106) is provided between adjacent fan-shaped branches.

10. A broadband, low insertion loss millimeter-wave reconfigurable reflector unit based on HTCC technology according to claim 9, characterized in that: The circular patch has a radius of 0.98 mm, the inner radius of the fan-shaped branch is 1.58 mm, the outer radius of the fan-shaped branch is 2.26 mm, and the angle of the fan-shaped branch is 75°; the angle between the fan-shaped branch and its adjacent DC control stub (106) is 75°, the radius of the DC control stub (106) is 0.59 mm, and the width is 0.7 mm.

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