Reflectarray unit and millimeter-wave frequency multiplexing reflectarray antenna based on germanium telluride

Abstract

The present invention discloses a reflective array unit based on germanium telluride and a millimeter wave frequency multiplexing reflective array antenna, wherein the reflective array antenna comprises a plurality of reflective array units, a dielectric substrate, a metal floor, and a feed source. The reflective array unit is located on the upper surface of the dielectric substrate, and is composed of a ring body and two phase delay lines. Two first germanium telluride films are embedded in the ring body, and the ring body is divided into two parts of equal length. Each part of the ring body is respectively connected to the middle of a phase delay line. Two second germanium telluride films are embedded in the phase delay line, and the two second germanium telluride films are symmetrical up and down with the middle of the phase delay line as the center. Both the first germanium telluride film and the second germanium telluride film can be turned on or off, so as to adjust the frequency or phase of the reflective array unit, and the frequency and phase are adjusted independently. The present invention not only has the characteristics of high aperture efficiency, wide gain bandwidth, and low cross polarization, but also has flexible unit phase adjustment and high design freedom.

Description

Technical Field

[0001] The present invention belongs to the technical field of reflective array antennas, and in particular relates to a reflective array unit based on germanium telluride and a millimeter wave frequency multiplexing reflective array antenna. Background Art

[0002] Millimeter wave communication has attracted widespread attention due to its extremely wide bandwidth and high transmission data rate. For long-distance wireless communication systems, antennas need to have both high gain and wide bandwidth. As a new type of high-gain antenna, the planar reflectarray combines the advantages of parabolic antennas and array antennas. By reasonably designing the reflection phase of each reflector on the array, specific high-gain beam pointing can be achieved.

[0003] In addition, in order to accommodate more RF transceiver channels, multi-frequency multiplexing antennas have become a good solution for realizing multifunctional communication systems. By switching the state of the control switch according to different application scenarios, reconfigurable characteristics can be achieved within a single aperture. Traditional RF switches, such as PIN diodes and varactor diodes, have the advantages of fast switching speed and small size. However, most of them operate at low frequencies and have problems of high loss and low isolation in the millimeter wave band. Compared with these switches, germanium telluride, as a common phase change material, can not only ensure lower loss and higher isolation in the millimeter wave band, but also can be well integrated with RF devices at low driving voltage. However, the multifunctional antenna based on germanium telluride is still combined with simple patch antennas and slot antennas, and the control method is limited and the advantages of germanium telluride are not fully utilized. Therefore, the millimeter wave multi-frequency multiplexing reflect array antenna based on germanium telluride needs to be studied and overcome. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a reflectarray unit based on germanium telluride and a millimeter-wave frequency multiplexing reflectarray antenna in view of the above-mentioned existing deficiencies. The reflectarray unit based on germanium telluride of the present invention can realize dual-frequency switching and high phase compensation accuracy and low unit loss in two frequency bands. The millimeter-wave frequency multiplexing reflectarray antenna designed using the reflectarray unit can obtain high-gain focused beams in two frequency bands. The present invention not only has the characteristics of high aperture efficiency, wide gain bandwidth, and low cross-polarization, but also has flexible unit phase control and high design freedom. It is very suitable for multi-frequency reflectantenna array design, and can be effectively applied to the design of high-gain multi-frequency reflectarray devices in millimeter-wave and terahertz frequency bands, and is convenient for large-scale production.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is:

[0006] The reflective array unit based on germanium telluride is composed of a ring body and two phase delay lines. Two first germanium telluride films are embedded in the ring body to divide the ring body into two parts of equal length. Each part of the ring body is connected to the middle of a phase delay line. Two second germanium telluride films are embedded in the phase delay line, and the two second germanium telluride films are symmetrical up and down with the middle of the phase delay line as the center. The first germanium telluride film and the second germanium telluride film can both be conductive or insulated, thereby changing the length of the ring body to adjust the frequency of the reflective array unit, or changing the length of the phase delay line to adjust the phase of the reflective array unit, and the regulation of frequency and phase is independent.

[0007] To optimize the above technical solutions, the specific measures taken also include:

[0008] The above-mentioned germanium telluride-based reflective array unit also includes a dielectric substrate and a metal floor. The ring body and the phase delay line are both connected to the upper surface of the dielectric substrate, and the lower surface of the dielectric substrate is connected to the metal floor.

[0009] The first germanium telluride film and the second germanium telluride film are interdigitated germanium telluride films.

[0010] The above-mentioned ring body is a polygonal ring body or a circular ring, and the phase delay line is a straight line or a bent line or a curve.

[0011] The above-mentioned ring body, phase delay line and metal floor are made of gold, silver or copper, and the dielectric substrate is a low-temperature co-fired ceramic substrate, a PCB board or a quartz glass board.

[0012] The millimeter-wave frequency multiplexing reflectarray antenna based on germanium telluride includes a plurality of reflectarray units and a feed source. The reflectarray units form a reflectarray according to phase distribution. The feed source is placed near the reflectarray to feed the reflectarray. The reflectarray converges electromagnetic waves to achieve broadband high gain for the electromagnetic waves.

[0013] The required phases of the reflective array unit at different frequencies are different, and the phase delay line lengths of the reflective array units with different phases are different. The required phases of the reflective array unit at different frequencies are calculated by the following formula: , is the reflect array unit frequency, is the direction in which the reflection forms the main beam, is the position coordinate of the reflector array unit, is the free-space wave number at that frequency, is at frequency When the phase center of the feed source is The distance between the reflective array units is different at different frequencies. Set the phase delay line length of the reflectarray element.

[0014] When the first germanium telluride film of the reflective array unit is turned on or insulated, the ring body has two different frequencies. The two frequencies correspond to two required phases, that is, to two phase delay line lengths. Assuming the longer length is a and the shorter length is b, the total length of the phase delay line of the reflective array unit is a, and the length of the phase delay line between the two second germanium telluride films is b.

[0015] It is a horn feed, a dipole antenna or a patch antenna, and the feed incident mode is vertical incidence or oblique incidence.

[0016] When the length of the phase delay line is greater than the length of the dielectric substrate, the phase delay line is bent.

[0017] The beneficial effects of the present invention are:

[0018] (1) The germanium telluride-based reflective array unit proposed in the present invention realizes a smooth coverage of the 0-360° reflection phase variation range in two frequency bands by loading a phase delay line whose length is adapted to the frequency on the ring body. Then, a first germanium telluride film is arranged on the ring body, and a second germanium telluride film is embedded on the phase delay line. By changing the germanium telluride state (conduction or insulation) at two positions, independent and precise control of the frequency and compensation phase and low unit reflection loss (unit reflection loss in the millimeter wave band is less than 0.5dB) can be achieved.

[0019] (2) Compared with the conventional dual-frequency reconfigurable reflectarray antenna unit, the germanium telluride-based reflectarray unit proposed in the present invention has a simple structure, is easy to control, has a large frequency tuning ratio, and can realize arbitrary compensation phase switching.

[0020] (3) The germanium telluride-based reflective array unit proposed in the present invention greatly improves the design freedom and can be realized with only one layer of structure, making the germanium telluride-based frequency multiplexing reflective array flexible and diverse in form.

[0021] (4) The millimeter-wave frequency multiplexing reflectarray antenna based on germanium telluride proposed in the present invention has a high aperture efficiency due to the low reflection loss and broadband characteristics of the reflectarray unit based on germanium telluride.

[0022] (5) The germanium telluride-based reflectarray unit and the germanium telluride-based millimeter-wave frequency multiplexing reflectarray antenna proposed in the present invention have a simple structure and a low array profile, are easy to mass produce, and can be widely used in the design of reflectarray antennas in the millimeter-wave and terahertz frequency bands. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a three-dimensional schematic diagram of the millimeter wave frequency multiplexing reflect array antenna based on germanium telluride of the present invention;

[0024] Figure 2It is a three-dimensional schematic diagram of the structure of a reflective array unit (a delay line reflective array unit) based on germanium telluride in Example 1 of the present invention;

[0025] Figure 3 : is a schematic top view of the structure of a reflective array unit (three-segment delay line reflective array unit) based on germanium telluride in Example 1 of the present invention, wherein g l1 is the width of the second germanium telluride film, W d is the width of each delay line;

[0026] Figure 4 is a schematic side view of the structure of a reflective array unit based on germanium telluride in Example 1 of the present invention;

[0027] Figure 5 It is an amplitude and phase characteristic curve of the reflective array unit based on germanium telluride of the present invention when the first germanium telluride film is in the on state;

[0028] Figure 6 It is an amplitude and phase characteristic curve of the reflective array unit based on germanium telluride of the present invention when the first germanium telluride film is in an insulating state;

[0029] Figure 7 The gain and aperture efficiency of the millimeter wave frequency multiplexing reflect array antenna based on germanium telluride in two frequency bands of the present invention;

[0030] Figure 8 The E-plane and H-plane radiation patterns of the millimeter-wave frequency multiplexing reflect array antenna based on germanium telluride in the present invention in two frequency bands;

[0031] Fig. 9 yes Figure 1 A magnified view of the structure of part A;

[0032] Fig.10 yes Figure 1 A magnified view of the structure of part B;

[0033] Fig.11 yes Figure 1 A magnified view of the C-section structure;

[0034] The symbols in the accompanying drawings mean: reflectarray antenna 1, reflectarray unit 2, dielectric substrate 3, metal floor 4, ring body 5, phase delay line 6, first germanium telluride film 7, second germanium telluride film 8, one-stage delay line reflectarray unit 9, two-stage delay line reflectarray unit 10, three-stage delay line reflectarray unit 11, and horn feed source 12. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Based on the embodiments provided in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0036] Obviously, the drawings described below are only some examples or embodiments of the present application. For ordinary technicians in this field, the present application can also be applied to other similar scenarios based on these drawings without creative work. In addition, it can also be understood that although the efforts made in this development process may be complicated and lengthy, for ordinary technicians in this field related to the content disclosed in this application, some changes in design, manufacturing or production based on the technical content disclosed in this application are just conventional technical means, and should not be understood as insufficient content disclosed in this application.

[0037] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those of ordinary skill in the art that the embodiments described in this application may be combined with other embodiments without conflict.

[0038] Unless otherwise defined, the technical terms or scientific terms involved in this application should be understood by people with ordinary skills in the technical field to which this application belongs. The words "one", "a", "a", "the" and the like involved in this application do not indicate a quantitative limitation, and may represent the singular or plural. The terms "include", "comprise", "have" and any of their variations involved in this application are intended to cover non-exclusive inclusions; for example, a process, method, system, product or device that includes a series of steps or units (units) is not limited to the listed steps or units, but may also include steps or units that are not listed, or may also include other steps or units inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" / "several" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, "A and / or B" can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the objects before and after are in an "or" relationship. The terms "first", "second", "third", etc. involved in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0039] like Figure 1 as well as Figure 9-11 As shown, the millimeter-wave frequency multiplexing reflectarray antenna 1 based on germanium telluride includes a plurality of reflectarray units 2 based on germanium telluride, a dielectric substrate 3, a metal floor 4 and a bent horn feed 12.

[0040] like Figure 2 As shown, the reflector array unit 2 is located on the upper surface of the dielectric substrate 3, and is composed of a square ring body 5 and a pair of phase delay lines 6, and the phase delay lines 6 are symmetrically loaded on both sides of the square ring body 5. A pair of interdigital first germanium telluride films 7 responsible for frequency regulation are symmetrically embedded on both sides of the square ring body 5 where the delay line is not loaded, and two pairs of interdigital second germanium telluride films 8 responsible for phase regulation are symmetrically embedded on the phase delay line 6. The lower surface of the dielectric substrate 3 is a metal floor 4. The reflector array unit 2 based on germanium telluride constitutes a millimeter-wave frequency multiplexing reflector array antenna 1 based on germanium telluride according to the phase distribution. The bent horn feed source 12 is placed directly above the reflector array for feeding, and the radiated electromagnetic waves are converged by the reflector array antenna to achieve a broadband high gain effect.

[0041] Since the phase distribution of reflection arrays of different frequencies is different, and different phases determine different phase delay line lengths, and since the size of the dielectric substrate 3 is limited, delay lines of different lengths are bent according to actual needs to form a one-segment delay line reflective array unit 9, a two-segment delay line reflective array unit 10, and a three-segment delay line reflective array unit 11.

[0042] When the first germanium telluride film 7 of the reflective array unit 2 is turned on or insulated, the ring body 5 has two different frequencies, which correspond to two required phases, that is, to two lengths of the phase delay line 6. Let the longer length be a and the shorter length be b, then the total length of the phase delay line 6 of the reflective array unit 2 is a, and the length of the phase delay line 6 between the two second germanium telluride films 8 is b. Excitation of the germanium telluride film at a specific position is achieved by an excimer pulse laser and a mask. Therefore, on the basis of a simple square ring body 5 structure loaded with a phase delay line 6, flexible dual-frequency regulation can be achieved by embedding a germanium telluride film and switching its state, satisfying the smooth coverage of the 0-360° reflection phase in the two frequency bands, and the loss is less than 0.5dB.

[0043] The reflectarray antenna 1 is composed of a plurality of reflectarray units 2 based on germanium telluride according to the reflectarray compensation phase distribution. In order to convert the incident spherical wave into a plane wave, the required reflection phase corresponding to each reflectarray unit 2 on the reflectarray antenna 1 at different frequencies can be calculated by the following formula:

[0044] , is the frequency of reflector array element 2, is the direction in which the reflection forms the main beam, is the position coordinate of reflector array element 2, is the free-space wave number at that frequency, is at frequency When the phase center of the feed source is The distance between the feed source and the reflective array unit 2 is different at different frequencies.

[0045] The feed source feeding form of the millimeter-wave frequency multiplexing reflectarray antenna 1 based on germanium telluride is not limited to the horn feed and the vertical incidence feeding mode. When other types of feed sources adopt the inclined incidence feeding mode, the millimeter-wave frequency multiplexing reflectarray antenna composed of the reflectarray unit based on germanium telluride of the present invention still has excellent performance.

[0046] The dielectric substrate 3 used by the reflective array unit 2 includes but is not limited to LTCC low temperature co-fired ceramic substrate / PCB printed circuit board / quartz glass and the like.

[0047] The structure of the present invention is explained below with reference to specific embodiments.

[0048] Embodiment 1: Reflection array unit 2:

[0049] like Figure 2 and 3 The three-segment delay line reflector array unit 11 is shown. The side length of the dielectric substrate 3 is L sub is [0.1λ,0.8λ], thickness H sub is [0.01λ,0.5λ], and the outer side length of the ring body 5 is L 1 is [0.05λ, 0.5λ], the inner side length of the ring body 5 L 2 is [0.01λ, 0.4λ], the length of the connecting section between the ring body 5 and the phase delay line 6 L d1 is [0.01λ,0.2λ], the length of the first delay line L d2 The interval is [0.05λ,0.5λ], and the length of the second delay line is L d3 The interval is [0.05λ,0.5λ], and the length of the third delay line is L d4 The width of the interdigital first germanium telluride film 7 is [0.05λ, 0.5λ]. g w is [0.001λ,0.1λ], length g l is [0.005λ,0.1λ].

[0050] In this embodiment, the specific length of the phase delay line 6 of the reflective array unit 2 and the position of the second germanium telluride film 8 responsible for phase control are determined according to the required phase values ​​of the reflective array unit 2 at two frequencies obtained by the reflection phase calculation. The length of the phase delay line corresponding to different frequencies is different.

[0051] In this embodiment, the shapes of the ring body 5 and the phase delay line 6 can be different, so as to further enhance the adjustment dimension of the reflection phase and obtain better design freedom.

[0052] In this embodiment, the specific dimensions of the reflective array unit 2 are as follows:

[0053] Medium side length L sub 3.7mm thickness H sub 0.8mm, the outer length of the ring body 5 L 1 is 1.75mm, the inner side length of the ring body 5 L 2 is 1.2 mm, the length of the connecting section between the ring body 5 and the phase delay line L d1 0.3mm, the length of the first delay lineL d2 The interval is [0.3,3.3] mm, and the length of the second delay line is L d3 The interval is [3.4,4.4] mm, and the length of the third delay line is L d4 The interval is [4.5,5] mm. The width of the interdigitated first germanium telluride film 7 g w 0.025mm, length g l It is 0.125mm.

[0054] In the above embodiments, the reflective array unit 2 is made of micro-nano processing, germanium telluride is prepared by magnetron sputtering, and the dielectric substrate is quartz glass. ε r is 3.78, the metal thickness is [0.005λ, 0.1λ], and the germanium telluride film thickness is [0.005λ, 0.1λ], where λ is the free space wavelength. The above given data parameters are the dimensions when the low frequency center frequency is 28GHz.

[0055] Embodiment 2: Millimeter-wave frequency multiplexing reflectarray antenna based on germanium telluride:

[0056] In this embodiment, Figure 1 as well as Figure 9-11 As shown in the overall structure diagram of the reflective array antenna 1 and the horn feed source 12, the X-axis direction of the dielectric substrate 3 is the vertical direction, the Y-axis direction is the horizontal direction, the unit origin is the center point of the dielectric substrate 3, and the XY coordinate system direction mentioned in this embodiment shall be subject to the attached figure.

[0057] like Figure 4 and 5 As shown, the center operating frequencies of the reflectarray unit 2 when the first germanium telluride film 7 is in the on state and the insulating state are 28 GHz and 38 GHz. The reflection phase curves of the two frequencies change smoothly from 0 to 360°, and the unit reflection loss is less than 0.5 dB, indicating that the reflectarray unit 2 of the present invention can effectively reduce the unit reflection loss, and further obtain a frequency multiplexing reflectarray antenna based on germanium telluride with high aperture efficiency.

[0058] like Figure 6 and 7 As shown, the mm-wave frequency multiplexing reflectarray antenna 1 based on germanium telluride has an array aperture size of 5541.77 mm. 2, the height of the horn feed 12 at 28GHz and 38GHz is 44mm and 72mm respectively, and the corresponding focal diameter ratio is 0.53 and 0.86. The peak gain at low frequency is 24.24dBi, the corresponding aperture efficiency is 44.7%, and the 3-dB and 1-dB gain bandwidths are 23.16% (25.2-31.8GHz) and 12.65% (27.4-31.1GHz) respectively. The peak gain at high frequency is 27.37dBi, the corresponding aperture efficiency is 52.8%, the 3-dB and 1-dB gain bandwidths are 27.08% (33.2-43.6GHz) and 14.9% (35.4-41.1GHz) respectively, and the E / H plane direction Figure 1 The consistency is good, achieving the reflective array effect with high gain and high aperture efficiency in the millimeter wave frequency band.

[0059] From the above, it can be seen that the millimeter-wave frequency multiplexing reflectarray antenna 1 based on germanium telluride of the present invention achieves the characteristics of high aperture efficiency in two millimeter-wave frequency bands, and proposes an independently adjustable method of phase and frequency based on germanium telluride. The excitation of germanium telluride at a specific position can be achieved through an excimer pulse laser and a mask, which greatly enhances the design freedom.

[0060] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited by the embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be equivalent replacement modes and shall be included in the protection scope of the present invention.

Claims

1. A reflective array unit based on germanium telluride, comprising a ring body (5) and two phase delay lines (6), characterized in that: Two first germanium telluride films (7) are embedded in the ring body (5), dividing the ring body (5) into two parts of equal length, each part of the ring body is connected to the middle of a phase delay line (6), and two second germanium telluride films (8) are embedded in the phase delay line (6), and the two second germanium telluride films (8) are symmetrical up and down with the middle of the phase delay line (6) as the center. The first germanium telluride film (7) and the second germanium telluride film (8) can be conductive or insulated, thereby changing the length of the ring body (5) to adjust the frequency of the reflective array unit (2), or changing the length of the phase delay line (6) to adjust the phase of the reflective array unit (2), and the regulation of frequency and phase is independent.

2. The germanium telluride-based reflective array unit according to claim 1, characterized in that: It also comprises a dielectric substrate (3) and a metal floor (4); the ring body (5) and the phase delay line (6) are both connected to the upper surface of the dielectric substrate (3); and the lower surface of the dielectric substrate (3) is connected to the metal floor (4).

3. The germanium telluride based reflectarray unit according to claim 1, characterized in that: The first germanium telluride film (7) and the second germanium telluride film (8) are interdigitated germanium telluride films.

4. The germanium telluride based reflectarray unit according to claim 1, characterized in that: The ring body (5) is a polygonal ring body or a circular ring, and the phase delay line (6) is a straight line or a bent line or a curve.

5. The germanium telluride based reflectarray unit according to claim 1, characterized in that: The ring body (5), phase delay line (6) and metal floor (4) are made of gold, silver or copper, and the dielectric substrate (3) is a low temperature co-fired ceramic substrate, a PCB board or a quartz glass board.

6. A millimeter-wave frequency multiplexing reflectarray antenna based on germanium telluride, characterized by: The invention comprises a plurality of reflective array units (2) and a feed source as claimed in claim 2, wherein the reflective array unit (2) forms a reflective array according to phase distribution, and the feed source is arranged near the reflective array for feeding the reflective array, and the reflective array converges electromagnetic waves to achieve broadband high gain for the electromagnetic waves.

7. The millimeter-wave frequency multiplexing reflectarray antenna based on germanium telluride according to claim 6, characterized in that: The required phases of the reflective array unit (2) at different frequencies are different, and the lengths of the phase delay lines (6) of the reflective array units (2) at different phases are different. The required phases of the reflective array unit (2) at different frequencies are calculated by the following formula: , is the frequency of the reflector array unit (2), is the direction in which the reflection forms the main beam, is the position coordinate of the reflector array unit (2), is the free-space wave number at that frequency, is at frequency When the phase center of the feed source is The distance between the reflective array unit (2) and the feed source is different at different frequencies. The length of the phase delay line (6) of the reflective array unit (2) is set.

8. The millimeter-wave frequency multiplexing reflectarray antenna based on germanium telluride according to claim 7, characterized in that: When the first germanium telluride film (7) of the reflective array unit (2) is turned on or insulated, the ring body (5) has two different frequencies, and the two frequencies correspond to two required phases, that is, to two lengths of the phase delay line (6). Assuming that the longer length is a and the shorter length is b, the total length of the phase delay line (6) of the reflective array unit (2) is a, and the length of the phase delay line (6) between the two second germanium telluride films (8) is b.

9. The millimeter-wave frequency multiplexing reflectarray antenna based on germanium telluride according to claim 6, characterized in that: The feed source is a horn feed source (12) or a dipole antenna or a patch antenna, and the feed source incident mode is vertical incidence or oblique incidence.

10. The millimeter-wave frequency multiplexing reflectarray antenna based on germanium telluride according to claim 7, characterized in that: When the length of the phase delay line (6) is greater than the length of the dielectric substrate (3), the phase delay line (6) is bent.

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