CN114204259A

CN114204259A - Antenna structure

Info

Publication number: CN114204259A
Application number: CN202210031674.2A
Authority: CN
Inventors: 洪敬榔
Original assignee: AU Optronics Corp
Current assignee: AU Optronics Corp
Priority date: 2021-04-01
Filing date: 2022-01-12
Publication date: 2022-03-18
Anticipated expiration: 2042-01-12
Also published as: CN114204259B

Abstract

An antenna structure comprises a first substrate, a second substrate, a first electrode layer, a second electrode layer, a liquid crystal layer and a reflecting layer. The first substrate and the second substrate are arranged oppositely. The first electrode layer and the second electrode layer are disposed on the first substrate and the second substrate, respectively. The second electrode layer is overlapped with the first electrode layer. The ratio of the area occupied by the first electrode layer to the area occupied by the second electrode layer is greater than or equal to 0.7 and less than 1. The liquid crystal layer is arranged between the first substrate and the second substrate and is positioned between the first electrode layer and the second electrode layer. The reflecting layer is arranged on one side of the second substrate, which is far away from the second electrode layer.

Description

Antenna structure

Technical Field

The present invention relates to mobile communication technologies, and in particular, to an antenna structure.

Background

With the commercialization of the fifth generation mobile communication technology (5G), applications such as telemedicine, VR live broadcast, 4K image live broadcast, smart home and the like have new development opportunities. Since 5G has high data rate, reduced latency, reduced energy, reduced cost, increased system capacity, and increased large-scale device connectivity, manufacturers in different fields can also perform cross-border alliances to jointly create a new generation of 5G ecochains. In order to increase the coverage of 5G millimeter waves, a reflective antenna is widely used.

Conventional reflective antennas can be classified into passive array antennas and active array antennas. The passive array antenna has a fixed electromagnetic wave receiving angle and an emitting angle due to a fixed antenna size. On the contrary, since the active array antenna has the phase modulation capability of the electromagnetic wave, the receiving angle and the emitting angle of the electromagnetic wave can be adjusted. However, such active array antennas are generally used in conjunction with phase shifters to modulate the phase of the electromagnetic wave. The larger the size of the array antenna, the higher the cost of using the phase shifters.

Disclosure of Invention

The invention provides an antenna structure which can be used for modulating the reflection frequency and phase of electromagnetic waves and has lower production cost.

The antenna structure comprises a first substrate, a second substrate, a first electrode layer, a second electrode layer, a liquid crystal layer and a reflecting layer. The first substrate and the second substrate are arranged oppositely. The first electrode layer and the second electrode layer are disposed on the first substrate and the second substrate, respectively. The second electrode layer is overlapped with the first electrode layer. The ratio of the area occupied by the first electrode layer to the area occupied by the second electrode layer is greater than or equal to 0.7 and less than 1. The liquid crystal layer is arranged between the first substrate and the second substrate and is positioned between the first electrode layer and the second electrode layer. The reflecting layer is arranged on one side of the second substrate, which is far away from the second electrode layer.

In view of the above, in the antenna structure according to an embodiment of the invention, the inductive loop formed by the first electrode layer and the second electrode layer can transmit the induced current with the specific resonant frequency, and the liquid crystal layer interposed between the two electrode layers can be used to modulate the current path length of the induced current, so as to modulate the reflection frequency and the phase of the electromagnetic wave. In addition, the ratio of the area occupied by the first electrode layer to the area occupied by the second electrode layer is more than or equal to 0.7 and less than 1, so that the bandwidth of the reflection frequency of the electromagnetic wave can be effectively increased.

Drawings

Fig. 1A and 1B are schematic cross-sectional and front views of an antenna structure according to a first embodiment of the present invention.

Fig. 2 is a graph of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 1A in different modes of operation.

Fig. 3A and 3B are schematic cross-sectional and front views of an antenna structure according to a second embodiment of the present invention.

Fig. 4 is a graph of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 3A in different modes of operation.

Fig. 5A and 5B are schematic cross-sectional and front views of an antenna structure according to a third embodiment of the present invention.

Fig. 6 is a graph of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 5A in different modes of operation.

Fig. 7A and 7B are schematic cross-sectional and front views of an antenna structure according to a fourth embodiment of the present invention.

Fig. 8 is a graph of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 7A in different modes of operation.

Fig. 9A and 9B are schematic cross-sectional and front views of an antenna structure according to a fifth embodiment of the present invention.

Fig. 10 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 9A in different modes of operation.

Fig. 11A and 11B are schematic cross-sectional and front views of an antenna structure according to a sixth embodiment of the present invention.

Fig. 12 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 11A in different modes of operation.

Fig. 13A and 13B are schematic cross-sectional and front views of an antenna structure according to a seventh embodiment of the present invention.

Fig. 14 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 13A in different modes of operation.

Fig. 15A and 15B are schematic cross-sectional and front views of an antenna structure according to an eighth embodiment of the present invention.

Fig. 16 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 15A in different modes of operation.

Fig. 17A and 17B are schematic cross-sectional and front views of an antenna structure according to a ninth embodiment of the present invention.

Fig. 18 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 17A in different modes of operation.

Fig. 19A and 19B are schematic cross-sectional and front views of an antenna structure according to a tenth embodiment of the present invention.

Fig. 20 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 19A in different modes of operation.

Fig. 21A and 21B are schematic cross-sectional and front views of an antenna structure according to an eleventh embodiment of the present invention.

Fig. 22 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 21A in different modes of operation.

Fig. 23A and 23B are schematic cross-sectional and front views of an antenna structure according to a twelfth embodiment of the invention.

Fig. 24 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 23A in different modes of operation.

Fig. 25A and 25B are schematic cross-sectional and front views of an antenna structure according to a thirteenth embodiment of the present invention.

Fig. 26 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 25A in different modes of operation.

Fig. 27A and 27B are schematic cross-sectional and front views of an antenna structure according to a fourteenth embodiment of the invention.

Fig. 28 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 27A in different modes of operation.

Fig. 29 is a graph of reflection coefficient S11 and phase versus frequency for the antenna structure of the alternative variant embodiment of fig. 27A in different modes of operation.

Fig. 30A and 30B are schematic cross-sectional and front views of an antenna structure according to a fifteenth embodiment of the present invention.

Fig. 31 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 30A in different modes of operation.

Fig. 32 is a graph of reflection coefficient S11 and phase versus frequency for the antenna structure of the alternative variant embodiment of fig. 30A in different modes of operation.

Fig. 33A and 33B are schematic cross-sectional and front views of an antenna structure according to a sixteenth embodiment of the present invention.

Fig. 34 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 33A in different modes of operation.

Description of reference numerals:

10A, 10B, 10C, 11A, 11B, 11C, 12A, 12B, 13A, 13B, 13C, 14A, 14B, 15, 16, 17: antenna structure

101: first substrate

102: second substrate

102 s: surface of

103: third substrate

110. 110A, 110B, 110D, 110E, 110F: a first electrode layer

111. 112, 111A, 112A, 121, 122, 115D, 125D, 115E, 125E, 115F, 125F: strip-shaped electrode

120. 120A, 120D, 120E, 120F: a second electrode layer

130. 130A: a third electrode layer

150: reflective layer

L: length of

LC: liquid crystal layer

W: width of

X, Y, Z: direction of rotation

Z1, Z2, Z3, Z1 ", Z2", Z3 ": region(s)

A-A ', B-B ', C-C ': cutting line

Detailed Description

As used herein, "about", "approximately", "essentially", or "substantially" includes the stated value and the average value within an acceptable range of deviation of the specified value as determined by one of ordinary skill in the art, taking into account the measurement in question and the specified amount of error associated with the measurement (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations of the stated value, or within, for example, ± 30%, ± 20%, ± 15%, ± 10%, ± 5%. Further, as used herein, "about", "approximately", "essentially", or "substantially" may be selected with respect to measured properties, cutting properties, or other properties, to select a more acceptable range of deviation or standard deviation, and not to apply one standard deviation to all properties.

In the drawings, the thickness of layers, films, panels, regions, etc. have been exaggerated for clarity. It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" or "connected to" another element, it can be directly on or connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly connected to" another element, there are no intervening elements present. As used herein, "connected" may refer to physical and/or electrical connections. Further, "electrically connected" may mean that there are other elements between the two elements.

Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings and the description to refer to the same or like parts.

Fig. 1A and 1B are schematic cross-sectional and front views of an antenna structure according to a first embodiment of the present invention. Fig. 2 is a graph of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 1A in different modes of operation. For clarity of presentation, fig. 1B only shows the first electrode layer 110, the second electrode layer 120, and the reflective layer 150 of fig. 1A.

Referring to fig. 1A and 1B, the antenna structure 10A includes a first substrate 101, a second substrate 102, a liquid crystal layer LC, a first electrode layer 110, and a second electrode layer 120. The first substrate 101 is disposed opposite to the second substrate 102. The material of the first substrate 101 and the second substrate 102 is, for example, glass, but not limited thereto. The liquid crystal layer LC is disposed between the first and

second substrates

101 and 102 and between the first and second electrode layers 110 and 120. The first electrode layer 110 is disposed on the first substrate 101 and between the liquid crystal layer LC and the first substrate 101. The second electrode layer 120 is disposed on the second substrate 102 and between the liquid crystal layer LC and the second substrate 102. The first electrode layer 110 overlaps the second electrode layer 120. Here, the overlapping relationship means that projections of the two electrode layers along the direction Z overlap. In the following paragraphs, unless otherwise mentioned, the overlapping relationship between the two components is also defined by the direction Z, and therefore, the description thereof is omitted.

In the present embodiment, the antenna structure 10A is adapted to receive an electromagnetic wave at one side of the first substrate 101 and reflect an electromagnetic wave with a specific frequency (or bandwidth) to the side of the first substrate 101. That is, the side of the first substrate 101 of the antenna structure 10A is a receiving side and a radiating side of an electromagnetic wave (e.g., millimeter wave). Compared with an antenna structure with only a single electrode layer, the antenna structure formed by stacking a plurality of electrode layers with slightly different sizes can have a wider bandwidth of reflection frequency.

It is particularly noted that the area of the orthographic projection of the first electrode layer 110 closer to the electromagnetic wave receiving side (or the first substrate 101) on the first substrate 101 is smaller than the area of the orthographic projection of the second electrode layer 120 farther from the electromagnetic wave receiving side on the first substrate 101. For example, the orthographic projection outlines of the first electrode layer 110 and the second electrode layer 120 on the first substrate 101 are both square and are distributed in the zone Z1 and the zone Z2, respectively, but not limited thereto. The ratio of the area of the region Z1 occupied by the first electrode layer 110 to the area of the region Z2 occupied by the second electrode layer 120 is designed to be greater than or equal to 0.7 and less than 1, so that the bandwidth of the reflection frequency of the electromagnetic wave can be effectively increased.

When an electromagnetic wave (for example, a millimeter wave) is irradiated from one side of the first substrate 101 to the antenna structure 10A, an induced current having a specific resonance frequency is generated in an induction loop formed by the first electrode layer 110 and the second electrode layer 120. Since the liquid crystal layer LC disposed between the first electrode layer 110 and the second electrode layer 120 can be electrically driven to change its effective dielectric constant, the length of the current path of the induced current can be electrically controlled to change, so as to modulate the frequency and phase of the electromagnetic wave radiated (or reflected) by the antenna structure 10A. Therefore, the first electrode layer 110 and the second electrode layer 120 may also serve as driving electrodes of the liquid crystal layer LC in addition to constituting an induction loop of the antenna structure 10A. That is, the electric field generated between the two electrodes can be used to drive the liquid crystal molecules (not shown) of the liquid crystal layer LC to rotate.

In the present embodiment, since the first electrode layer 110 and the second electrode layer 120 are respectively disposed on two opposite sides of the liquid crystal layer LC along the direction Z (i.e., the direction perpendicular to the surface of the first substrate 101), the antenna structure 10A is suitable for modulating the phase of the electromagnetic wave in the direction Z, but the invention is not limited thereto.

Referring to fig. 2, when the liquid crystal layer LC is not driven (i.e., the first electrode layer 110 and the second electrode layer 120 are not enabled), the curve C1a of the reflection coefficient S11 versus frequency and the curve C2a of the electromagnetic wave phase versus frequency of the antenna structure 10A are significantly different from those of the liquid crystal layer LC when driven, and the curve C1b of the reflection coefficient S11 versus frequency and the curve C2b of the electromagnetic wave phase versus frequency of the antenna structure 10A are also different. For example, for an electromagnetic wave whose phase falls around-160 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switching between the frequency 11.2GHz and the frequency 11.3 GHz. From another point of view, the maximum phase modulation amount Δ P1 that can be generated by driving or not driving the liquid crystal layer LC is about 70 degrees for electromagnetic waves having a frequency in the vicinity of 11.25 GHz.

Particularly, the antenna structure 10A can increase the reflection frequency bandwidth of 0.3GHz to 0.4GHz compared with the antenna structure formed by a single electrode layer through the arrangement of the double electrode layers. On the other hand, the antenna structure 10A of the present embodiment has a phase modulation capability without a phase shifter, so that it has a cost advantage compared to the conventional antenna structure, and is beneficial to the large-scale antenna structure.

Further, in order to increase the reflectivity of the antenna structure 10A for the target electromagnetic wave (e.g., millimeter wave), the antenna structure 10A further includes a reflective layer 150 disposed on a side of the second substrate 102 facing away from the second electrode layer 120. In the present embodiment, the reflective layer 150 is, for example, a metal conductive layer with a ground potential (ground), and covers the entire surface 102s of the second substrate 102 away from the second electrode layer 120, but not limited thereto.

The present disclosure will be described in detail below with reference to other embodiments, wherein like components are denoted by like reference numerals, and descriptions of the same technical content are omitted, and reference is made to the foregoing embodiments for omitting details.

Fig. 3A and 3B are schematic cross-sectional and front views of an antenna structure according to a second embodiment of the present invention. Fig. 4 is a graph of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 3A in different modes of operation. For clarity of presentation, fig. 3B only shows the first electrode layer 110A, the second electrode layer 120, and the reflective layer 150 of fig. 3A.

Referring to fig. 3A and 3B, the difference between the antenna structure 10B of the present embodiment and the antenna structure 10A of fig. 1A is: the first electrode layer has a different configuration. In the present embodiment, the first electrode layer 110A may have a plurality of first stripe electrodes 111 and a plurality of second stripe electrodes 112. The first stripe electrodes 111 and the second stripe electrodes 112 may be alternately arranged along the direction X and extend in the direction Y. It is particularly noted that the liquid crystal layer LC also fills the gaps between the bar-shaped electrodes, and the first bar-shaped electrodes 111 are electrically independent from the second bar-shaped electrodes 112.

That is, the first stripe electrodes 111 and the second stripe electrodes 112 may have different potentials, so that a lateral electric field may be generated between the first stripe electrodes 111 and the second stripe electrodes 112 to drive the liquid crystal layer LC. Therefore, the antenna structure 10B of the present embodiment is adapted to modulate the phase of the electromagnetic wave in the direction X. However, the present invention is not limited thereto. In other embodiments, the second electrode layer 120 may have a different potential from the first strip-shaped electrode 111 and the second strip-shaped electrode 112. Therefore, a vertical electric field can be generated between the first strip electrodes 111 (or the second strip electrodes 112) and the second electrode layer 120 to drive the liquid crystal layer LC. In other words, this driving method can modulate the phases of the electromagnetic wave in the Z direction and the X direction at the same time, which helps to increase the operational flexibility of the antenna structure.

Referring to fig. 4, in the present embodiment, when the liquid crystal layer LC is not driven (i.e. the first strip-shaped electrodes 111 and the second strip-shaped electrodes 112 are not enabled), the curve C3a of the reflection coefficient S11 versus frequency and the curve C4a of the electromagnetic wave phase versus frequency of the antenna structure 10B are significantly different from those of the liquid crystal layer LC when driven, the curve C3B of the reflection coefficient S11 versus frequency and the curve C4B of the electromagnetic wave phase versus frequency of the antenna structure 10B. For example, for an electromagnetic wave whose phase falls around-200 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switching between the frequency 12.75GHz and the frequency 12.85 GHz. From another point of view, the maximum phase modulation amount Δ P2 that can be generated by driving or not driving the liquid crystal layer LC is about 60 degrees for electromagnetic waves having a frequency in the vicinity of 12.8 GHz.

Fig. 5A and 5B are schematic cross-sectional and front views of an antenna structure according to a third embodiment of the present invention. Fig. 6 is a graph of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 5A in different modes of operation. For clarity of presentation, fig. 5B only shows the first electrode layer 110, the second electrode layer 120A, and the reflective layer 150 of fig. 5A.

Referring to fig. 5A and 5B, the difference between the antenna structure 10C of the present embodiment and the antenna structure 10A of fig. 1A is: the configuration of the second electrode layer is different. In the present embodiment, the second electrode layer 120A may have a plurality of first stripe electrodes 121 and a plurality of second stripe electrodes 122. The first stripe electrodes 121 and the second stripe electrodes 122 may be alternately arranged along the direction X and extend in the direction Y. It is particularly noted that the liquid crystal layer LC also fills the gaps between the bar-shaped electrodes, and the first bar-shaped electrodes 121 are electrically independent of the second bar-shaped electrodes 122.

That is, the first strip electrodes 121 and the second strip electrodes 122 may have different potentials, so that a transverse electric field may be generated between the first strip electrodes 121 and the second strip electrodes 122 to drive the liquid crystal layer LC. Therefore, the antenna structure 10C of the present embodiment is adapted to modulate the phase of the electromagnetic wave in the direction X. However, the present invention is not limited thereto. In other embodiments, the first electrode layer 110 may have a different potential from the first strip-shaped electrode 121 and the second strip-shaped electrode 122. Therefore, a vertical electric field can be generated between the first strip electrodes 121 (or the second strip electrodes 122) and the first electrode layer 110 to drive the liquid crystal layer LC. In other words, this driving method can modulate the phases of the electromagnetic wave in the Z direction and the X direction at the same time, which helps to increase the operational flexibility of the antenna structure.

Referring to fig. 6, in the present embodiment, when the liquid crystal layer LC is not driven (i.e. the first strip-shaped electrodes 121 and the second strip-shaped electrodes 122 are not enabled), the curve C5a of the reflection coefficient S11 versus frequency and the curve C6a of the electromagnetic wave phase versus frequency of the antenna structure 10C are significantly different from those of the liquid crystal layer LC when driven, the curve C5b of the reflection coefficient S11 versus frequency and the curve C6b of the electromagnetic wave phase versus frequency of the antenna structure 10C. For example, for an electromagnetic wave whose phase falls around-180 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switch between the frequency 14GHz and the frequency 14.3 GHz. From another point of view, the maximum phase modulation amount Δ P3 that can be generated by driving or not driving the liquid crystal layer LC is about 205 degrees for electromagnetic waves having a frequency in the vicinity of 14.15 GHz.

Fig. 7A and 7B are schematic cross-sectional and front views of an antenna structure according to a fourth embodiment of the present invention. Fig. 8 is a graph of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 7A in different modes of operation. For clarity of presentation, fig. 7B shows only the first electrode layer 110, the second electrode layer 120, the third electrode layer 130, and the reflective layer 150 of fig. 7A.

Referring to fig. 7A and 7B, the difference between the antenna structure 11A of the present embodiment and the antenna structure 10A of fig. 1A is: the antenna structure 11A may also optionally include a third electrode layer 130. In the present embodiment, the third electrode layer 130 can be disposed on a side of the first electrode layer 110 away from the second electrode layer 120. More specifically, the third electrode layer 130 is disposed on a surface of the first substrate 101 facing away from the first electrode layer 110, and completely overlaps the first electrode layer 110 and the second electrode layer 120.

That is, the third electrode layer 130 is closer to the receiving side of the electromagnetic wave than the first electrode layer 110. To further increase the bandwidth of the reflection frequency of the electromagnetic wave, the orthographic projection area of the third electrode layer 130 on the first substrate 101 can be smaller than the orthographic projection area of the first electrode layer 110 on the first substrate 101. For example, the orthographic projection outlines of the first electrode layer 110, the second electrode layer 120 and the third electrode layer 130 on the first substrate 101 are all square and are distributed in the zone Z1, the zone Z2 and the zone Z3, respectively, but not limited thereto. In other embodiments, at least one of the first electrode layer and the second electrode layer may also be distributed in the form of a plurality of stripe electrodes (as shown in fig. 3B and fig. 5B) in the region Z1 and the region Z2.

By designing the ratio of the area of the region Z3 occupied by the third electrode layer 130 to the area of the region Z1 occupied by the first electrode layer 110 to be greater than or equal to 0.7 and less than 1, the bandwidth of the reflection frequency of the electromagnetic wave can be effectively increased.

Referring to fig. 8, when the liquid crystal layer LC is not driven (i.e., the first electrode layer 110 and the second electrode layer 120 are not enabled), the curve C7a of the reflection coefficient S11 versus frequency and the curve C8a of the electromagnetic wave phase versus frequency of the antenna structure 11A are significantly different from those of the liquid crystal layer LC when driven, and the curve C7b of the reflection coefficient S11 versus frequency and the curve C8b of the electromagnetic wave phase versus frequency of the antenna structure 11A are also different. For example, for an electromagnetic wave whose phase falls around-220 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switching between the frequency 13.7GHz and the frequency 13.8 GHz. From another point of view, the maximum phase modulation amount Δ P4 that can be generated by driving or not driving the liquid crystal layer LC is about 57 degrees for electromagnetic waves having a frequency in the vicinity of 13.75 GHz.

Particularly, the antenna structure 11A can increase a reflection frequency bandwidth of about 0.6GHz compared with an antenna structure formed by a single electrode layer through the arrangement of three electrode layers. On the other hand, the antenna structure 11A of the present embodiment has a phase modulation capability without a phase shifter, and thus has a cost advantage compared to the conventional antenna structure, which is helpful for the large-scale antenna structure.

Fig. 9A and 9B are schematic cross-sectional and front views of an antenna structure according to a fifth embodiment of the present invention. Fig. 10 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 9A in different modes of operation. For clarity of presentation, fig. 9B only shows the first electrode layer 110A, the second electrode layer 120, the third electrode layer 130, and the reflective layer 150 of fig. 9A.

Referring to fig. 9A and 9B, the difference between the antenna structure 11B of the present embodiment and the antenna structure 11A of fig. 7A is: the first electrode layer has a different configuration. In the present embodiment, the first electrode layer 110A may have a plurality of first stripe electrodes 111 and a plurality of second stripe electrodes 112. The first stripe electrodes 111 and the second stripe electrodes 112 may be alternately arranged along the direction X and extend in the direction Y. It is particularly noted that the liquid crystal layer LC also fills the gaps between the bar-shaped electrodes, and the first bar-shaped electrodes 111 are electrically independent from the second bar-shaped electrodes 112.

That is, the first stripe electrodes 111 and the second stripe electrodes 112 may have different potentials, so that a lateral electric field may be generated between the first stripe electrodes 111 and the second stripe electrodes 112 to drive the liquid crystal layer LC. Therefore, the antenna structure 11B of the present embodiment is adapted to modulate the phase of the electromagnetic wave in the direction X. However, the present invention is not limited thereto. In other embodiments, the second electrode layer 120 may have a different potential from the first strip-shaped electrode 111 and the second strip-shaped electrode 112. Therefore, a vertical electric field can be generated between the first strip electrodes 111 (or the second strip electrodes 112) and the second electrode layer 120 to drive the liquid crystal layer LC. In other words, this driving method can modulate the phases of the electromagnetic wave in the Z direction and the X direction at the same time, which helps to increase the operational flexibility of the antenna structure.

Referring to fig. 10, in the present embodiment, when the liquid crystal layer LC is not driven (i.e. the first strip-shaped electrodes 111 and the second strip-shaped electrodes 112 are not enabled), the curve C9a of the reflection coefficient S11 versus frequency and the curve C10a of the electromagnetic wave phase versus frequency of the antenna structure 11B are significantly different from those of the liquid crystal layer LC when driven, the curve C9B of the reflection coefficient S11 versus frequency and the curve C10B of the electromagnetic wave phase versus frequency of the antenna structure 11B. For example, for an electromagnetic wave whose phase falls around-180 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switch between the frequency 11.7GHz and the frequency 11.8 GHz. From another point of view, the maximum phase modulation amount Δ P5 that can be generated by driving or not driving the liquid crystal layer LC is about 60 degrees for electromagnetic waves having a frequency in the vicinity of 12.8 GHz.

Fig. 11A and 11B are schematic cross-sectional and front views of an antenna structure according to a sixth embodiment of the present invention. Fig. 12 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 11A in different modes of operation. For the sake of clarity, fig. 11B shows only the first electrode layer 110, the second electrode layer 120A, the third electrode layer 130, and the reflective layer 150 of fig. 11A.

Referring to fig. 11A and 11B, the difference between the antenna structure 11C of the present embodiment and the antenna structure 11A of fig. 7A is: the configuration of the second electrode layer is different. In the present embodiment, the second electrode layer 120A may have a plurality of first stripe electrodes 121 and a plurality of second stripe electrodes 122. The first stripe electrodes 121 and the second stripe electrodes 122 may be alternately arranged along the direction X and extend in the direction Y. It is particularly noted that the liquid crystal layer LC also fills the gaps between the bar-shaped electrodes, and the first bar-shaped electrodes 121 are electrically independent of the second bar-shaped electrodes 122.

That is, the first strip electrodes 121 and the second strip electrodes 122 may have different potentials, so that a transverse electric field may be generated between the first strip electrodes 121 and the second strip electrodes 122 to drive the liquid crystal layer LC. Therefore, the antenna structure 11C of the present embodiment is adapted to modulate the phase of the electromagnetic wave in the direction X. However, the present invention is not limited thereto. In other embodiments, the first electrode layer 110 may have a different potential from the first strip-shaped electrode 121 and the second strip-shaped electrode 122. Therefore, a vertical electric field can be generated between the first strip electrodes 121 (or the second strip electrodes 122) and the first electrode layer 110 to drive the liquid crystal layer LC. In other words, this driving method can modulate the phases of the electromagnetic wave in the Z direction and the X direction at the same time, which helps to increase the operational flexibility of the antenna structure.

Referring to fig. 12, in the present embodiment, when the liquid crystal layer LC is not driven (i.e. the first strip-shaped electrodes 121 and the second strip-shaped electrodes 122 are not enabled), the curve C11a of the reflection coefficient S11 versus frequency and the curve C12a of the electromagnetic wave phase versus frequency of the antenna structure 11C are significantly different from those of the liquid crystal layer LC when driven, the curve C11b of the reflection coefficient S11 versus frequency and the curve C12b of the electromagnetic wave phase versus frequency of the antenna structure 11C. For example, for an electromagnetic wave whose phase falls around-190 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switching between the frequency 11.9GHz and the frequency 12.1 GHz. From another point of view, the maximum phase modulation amount Δ P6 that can be generated is about 180 degrees for an electromagnetic wave having a frequency in the vicinity of 12GHz, and whether the liquid crystal layer LC is driven or not.

Fig. 13A and 13B are schematic cross-sectional and front views of an antenna structure according to a seventh embodiment of the present invention. Fig. 14 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 13A in different modes of operation. For the sake of clarity, fig. 13B shows only the first electrode layer 110A, the second electrode layer 120A, the third electrode layer 130, and the reflective layer 150 of fig. 13A.

Referring to fig. 13A and 13B, the difference between the antenna structure 12A of the present embodiment and the antenna structure 11C of fig. 11A is: the first electrode layer has a different configuration. Specifically, in the present embodiment, the first electrode layer 110A and the second electrode layer 120A each have a plurality of stripe electrodes, for example: the first electrode layer 110A has a plurality of first stripe electrodes 111 and a plurality of second stripe electrodes 112, and the second electrode layer 120A has a plurality of first stripe electrodes 121 and a plurality of second stripe electrodes 122. It is particularly noted that the first stripe electrodes 121, the first stripe electrodes 111, the second stripe electrodes 122 and the second stripe electrodes 112 are alternately arranged along the direction X. That is to say, one first strip electrode 111 or one second strip electrode 112 is disposed between any two adjacent first strip electrodes 121 and second strip electrodes 122, and one first strip electrode 121 or one second strip electrode 122 is disposed between any two adjacent first strip electrodes 111 and second strip electrodes 112.

In the embodiment, the plurality of first stripe electrodes 111 and the plurality of second stripe electrodes 112 of the first electrode layer 110A do not overlap the plurality of first stripe electrodes 121 and the plurality of second stripe electrodes 122 of the second electrode layer 120A along the direction Z, but the invention is not limited thereto. In other embodiments, which are not shown, the plurality of strip-shaped electrodes of the first electrode layer may also partially overlap the plurality of strip-shaped electrodes of the second electrode layer.

Since the first electrode layer 110A of the present embodiment is similar to the first electrode layer 110A of fig. 9A, and the second electrode layer 120A of the present embodiment is similar to the second electrode layer 120A of fig. 11A, for a detailed description, refer to the related paragraphs of the foregoing embodiments, which are not repeated herein. Particularly, since the first electrode layer 110A and the second electrode layer 120A both have a plurality of strip-shaped electrodes, a portion of the liquid crystal layer LC located between the strip-shaped electrodes of the two electrode layers can be used to change the length of the current path of the induced current, which is helpful to increase the modulatable amplitude of the reflection frequency of the electromagnetic wave.

Referring to fig. 14, when the liquid crystal layer LC is not driven (i.e., the first electrode layer 110A and the second electrode layer 120A are not enabled), the curve C13a of the reflection coefficient S11 versus frequency and the curve C14a of the electromagnetic wave phase versus frequency of the antenna structure 12A are significantly different from those of the liquid crystal layer LC, and the curve C13b of the reflection coefficient S11 versus frequency and the curve C14b of the electromagnetic wave phase versus frequency of the antenna structure 12A are different from those of the liquid crystal layer LC. For example, for an electromagnetic wave whose phase falls around-230 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switch between the frequency 15.1GHz and the frequency 15.3 GHz. From another point of view, the maximum phase modulation amount Δ P7 that can be generated by driving or not driving the liquid crystal layer LC is about 70 degrees for electromagnetic waves having a frequency in the vicinity of 15.2 GHz.

Fig. 15A and 15B are schematic cross-sectional and front views of an antenna structure according to an eighth embodiment of the present invention. Fig. 16 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 15A in different modes of operation. For clarity of presentation, fig. 15B shows only the first electrode layer 110B, the second electrode layer 120A, the third electrode layer 130, and the reflective layer 150 of fig. 15A.

Referring to fig. 15A and 15B, the difference between the antenna structure 12B of the present embodiment and the antenna structure 12A of fig. 13A is: the configuration modes of the strip electrodes of the first electrode layer are different. Specifically, the extending directions (e.g., the direction X) of the first strip-shaped electrodes 111A and the second strip-shaped electrodes 112A of the first electrode layer 110B of the antenna structure 12B intersect the extending directions (e.g., the direction Y) of the first strip-shaped electrodes 121 and the second strip-shaped electrodes 122 of the second electrode layer 120A.

Therefore, compared with the antenna structure 12A in fig. 13A, the antenna structure 12B of the present embodiment has a larger modulation range for both the reflection main frequency and the phase of the electromagnetic wave. Referring to fig. 16, when the liquid crystal layer LC is not driven (i.e., the first electrode layer 110B and the second electrode layer 120A are not enabled), the curve C15a of the reflection coefficient S11 versus frequency and the curve C16a of the electromagnetic wave phase versus frequency of the antenna structure 12B are significantly different from those of the liquid crystal layer LC, and the curve C15B of the reflection coefficient S11 versus frequency and the curve C16B of the electromagnetic wave phase versus frequency of the antenna structure 12B are different from those of the liquid crystal layer LC. For example, for an electromagnetic wave whose phase falls around-200 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switching between the frequency 11.85GHz and the frequency 12.1 GHz. From another point of view, the maximum phase modulation amount Δ P8 that can be generated is about 180 degrees for an electromagnetic wave having a frequency in the vicinity of 12GHz, and whether the liquid crystal layer LC is driven or not.

Fig. 17A and 17B are schematic cross-sectional and front views of an antenna structure according to a ninth embodiment of the present invention. Fig. 18 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 17A in different modes of operation. For the sake of clarity, fig. 17B shows only the first electrode layer 110, the second electrode layer 120, the third electrode layer 130A, and the reflective layer 150 of fig. 17A.

Referring to fig. 17A and 17B, the main differences between the antenna structure 13A of the present embodiment and the antenna structure 11A of fig. 7A are: the third electrode layer is configured differently. Specifically, the third electrode layer 130A of the antenna structure 13A is disposed on a side of the second electrode layer 120 away from the first electrode layer 110. In the present embodiment, the antenna structure 13A further includes a third substrate 103, and the third electrode layer 130A is disposed between the second substrate 102 and the third substrate 103. The reflective layer 150 is disposed on a surface of the third substrate 103 facing away from the third electrode layer 130A. For example, the third substrate 103 may be a low dielectric loss substrate (e.g., a Rogers substrate), but is not limited thereto.

Since the third electrode layer 130A is farther from the receiving side (or the radiation side) of the electromagnetic wave than the first electrode layer 110 and the second electrode layer 120, the orthographic projection area of the third electrode layer 130A on the first substrate 101 is larger than the orthographic projection area of the second electrode layer 120 on the first substrate 101. For example, the orthographic projection outlines of the first electrode layer 110, the second electrode layer 120 and the third electrode layer 130A on the first substrate 101 are all square, and are distributed in the region Z1, the region Z2 and the region Z3 ″ respectively, but not limited thereto. By designing the ratio of the area of the region Z2 occupied by the second electrode layer 120 to the area of the region Z3 ″ occupied by the third electrode layer 130A to be greater than or equal to 0.7 and less than 1, the bandwidth of the reflection frequency of the electromagnetic wave can be effectively increased.

Referring to fig. 18, when the liquid crystal layer LC is not driven (i.e., the first electrode layer 110 and the second electrode layer 120 are not enabled), the curve C17a of the reflection coefficient S11 versus frequency and the curve C18a of the electromagnetic wave phase versus frequency of the antenna structure 13A are significantly different from those of the liquid crystal layer LC when driven, and the curve C17b of the reflection coefficient S11 versus frequency and the curve C18b of the electromagnetic wave phase versus frequency of the antenna structure 13A are also different. For example, for an electromagnetic wave whose phase falls around-200 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switching between the frequency 12.3GHz and the frequency 12.4 GHz. From another point of view, the maximum phase modulation amount Δ P9 that can be generated by driving or not driving the liquid crystal layer LC is about 50 degrees for electromagnetic waves having a frequency in the vicinity of 12.35 GHz.

Particularly, by arranging three electrode layers, the reflection frequency bandwidth of the antenna structure 13A can be increased by about 0.6GHz compared with the antenna structure formed by a single electrode layer. On the other hand, the antenna structure 13A of the present embodiment has a phase modulation capability without a phase shifter, so that it has a cost advantage compared to the conventional antenna structure, and is beneficial to the large-scale antenna structure.

Fig. 19A and 19B are schematic cross-sectional and front views of an antenna structure according to a tenth embodiment of the present invention. Fig. 20 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 19A in different modes of operation. For the sake of clarity, fig. 19B shows only the first electrode layer 110A, the second electrode layer 120, the third electrode layer 130A, and the reflective layer 150 of fig. 19A.

Referring to fig. 19A and 19B, the difference between the antenna structure 13B of the present embodiment and the antenna structure 13A of fig. 17A is: the first electrode layer has a different configuration. In the present embodiment, the first electrode layer 110A may have a plurality of first stripe electrodes 111 and a plurality of second stripe electrodes 112. The first stripe electrodes 111 and the second stripe electrodes 112 may be alternately arranged along the direction X and extend in the direction Y. It is particularly noted that the liquid crystal layer LC also fills the gaps between the bar-shaped electrodes, and the first bar-shaped electrodes 111 are electrically independent from the second bar-shaped electrodes 112.

That is, the first stripe electrodes 111 and the second stripe electrodes 112 may have different potentials, so that a lateral electric field may be generated between the first stripe electrodes 111 and the second stripe electrodes 112 to drive the liquid crystal layer LC. Therefore, the antenna structure 13B of the present embodiment is adapted to modulate the phase of the electromagnetic wave in the direction X. However, the present invention is not limited thereto. In other embodiments, the second electrode layer 120 may have a different potential from the first strip-shaped electrode 111 and the second strip-shaped electrode 112. Therefore, a vertical electric field can be generated between the first strip electrodes 111 (or the second strip electrodes 112) and the second electrode layer 120 to drive the liquid crystal layer LC. In other words, this driving method can modulate the phases of the electromagnetic wave in the Z direction and the X direction at the same time, which helps to increase the operational flexibility of the antenna structure.

Referring to fig. 20, in the present embodiment, when the liquid crystal layer LC is not driven (i.e. the first strip-shaped electrodes 111 and the second strip-shaped electrodes 112 are not enabled), the curve C19a of the reflection coefficient S11 versus frequency and the curve C20a of the electromagnetic wave phase versus frequency of the antenna structure 13B are significantly different from those of the liquid crystal layer LC when driven, the curve C19B of the reflection coefficient S11 versus frequency and the curve C20B of the electromagnetic wave phase versus frequency of the antenna structure 13B. For example, for an electromagnetic wave whose phase falls around-210 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switch between the frequency of 12.84GHz and the frequency of 13.05 GHz. From another point of view, the maximum phase modulation amount Δ P10 that can be generated by driving or not driving the liquid crystal layer LC is about 100 degrees for electromagnetic waves having a frequency in the vicinity of 12.96 GHz.

Fig. 21A and 21B are schematic cross-sectional and front views of an antenna structure according to an eleventh embodiment of the present invention. Fig. 22 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 21A in different modes of operation. For the sake of clarity, fig. 21B shows only the first electrode layer 110, the second electrode layer 120A, the third electrode layer 130A, and the reflective layer 150 of fig. 21A.

Referring to fig. 21A and 21B, the difference between the antenna structure 13C of the present embodiment and the antenna structure 13A of fig. 17A is: the configuration of the second electrode layer is different. In the present embodiment, the second electrode layer 120A may have a plurality of first stripe electrodes 121 and a plurality of second stripe electrodes 122. The first stripe electrodes 121 and the second stripe electrodes 122 may be alternately arranged along the direction X and extend in the direction Y. It is particularly noted that the liquid crystal layer LC also fills the gaps between the bar-shaped electrodes, and the first bar-shaped electrodes 121 are electrically independent of the second bar-shaped electrodes 122.

That is, the first strip electrodes 121 and the second strip electrodes 122 may have different potentials, so that a transverse electric field may be generated between the first strip electrodes 121 and the second strip electrodes 122 to drive the liquid crystal layer LC. Therefore, the antenna structure 13C of the present embodiment is adapted to modulate the phase of the electromagnetic wave in the direction X. However, the present invention is not limited thereto. In other embodiments, the first electrode layer 110 may have a different potential from the first strip-shaped electrode 121 and the second strip-shaped electrode 122. Therefore, a vertical electric field can be generated between the first strip electrodes 121 (or the second strip electrodes 122) and the first electrode layer 110 to drive the liquid crystal layer LC. In other words, this driving method can modulate the phases of the electromagnetic wave in the Z direction and the X direction at the same time, which helps to increase the operational flexibility of the antenna structure.

Referring to fig. 22, in the present embodiment, when the liquid crystal layer LC is not driven (i.e. the first strip-shaped electrodes 121 and the second strip-shaped electrodes 122 are not enabled), the curve C21a of the reflection coefficient S11 versus frequency and the curve C22a of the electromagnetic wave phase versus frequency of the antenna structure 13C are significantly different from those of the liquid crystal layer LC when driven, the curve C21b of the reflection coefficient S11 versus frequency and the curve C22b of the electromagnetic wave phase versus frequency of the antenna structure 13C. For example, for an electromagnetic wave whose phase falls around-200 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switching between the frequency 12.39GHz and the frequency 12.43 GHz. From another point of view, the maximum phase modulation amount Δ P11 that can be generated is about 30 degrees for an electromagnetic wave having a frequency in the vicinity of 12.37GHz, and whether the liquid crystal layer LC is driven or not.

Fig. 23A and 23B are schematic cross-sectional and front views of an antenna structure according to a twelfth embodiment of the invention. Fig. 24 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 23A in different modes of operation. For the sake of clarity, fig. 23B shows only the first electrode layer 110A, the second electrode layer 120A, the third electrode layer 130A, and the reflective layer 150 of fig. 23A.

Referring to fig. 23A and 23B, the main differences between the antenna structure 14A of the present embodiment and the antenna structure 11C of fig. 21A are: the first electrode layer has a different configuration. Specifically, in the present embodiment, the first electrode layer 110A and the second electrode layer 120A each have a plurality of stripe electrodes, for example: the first electrode layer 110A has a plurality of first stripe electrodes 111 and a plurality of second stripe electrodes 112, and the second electrode layer 120A has a plurality of first stripe electrodes 121 and a plurality of second stripe electrodes 122. It is particularly noted that the first stripe electrodes 121, the first stripe electrodes 111, the second stripe electrodes 122 and the second stripe electrodes 112 are alternately arranged along the direction X. That is to say, one first strip electrode 111 or one second strip electrode 112 is disposed between any two adjacent first strip electrodes 121 and second strip electrodes 122, and one first strip electrode 121 or one second strip electrode 122 is disposed between any two adjacent first strip electrodes 111 and second strip electrodes 112.

Since the first electrode layer 110A of the present embodiment is similar to the first electrode layer 110A of fig. 19A, and the second electrode layer 120A of the present embodiment is similar to the second electrode layer 120A of fig. 21A, for a detailed description, refer to the related paragraphs of the previous embodiments, which are not repeated herein. Particularly, since the first electrode layer 110A and the second electrode layer 120A both have a plurality of strip-shaped electrodes, a portion of the liquid crystal layer LC located between the strip-shaped electrodes of the two electrode layers can be used to change the length of the current path of the induced current, which is helpful to increase the modulatable amplitude of the reflection frequency of the electromagnetic wave.

Referring to fig. 24, when the liquid crystal layer LC is not driven (i.e., the first electrode layer 110A and the second electrode layer 120A are not enabled), the curve C23a of the reflection coefficient S11 versus frequency and the curve C24A of the electromagnetic wave phase versus frequency of the antenna structure 14A are significantly different from those of the liquid crystal layer LC, and the curve C23b of the reflection coefficient S11 versus frequency and the curve C24b of the electromagnetic wave phase versus frequency of the antenna structure 14A are also different. For example, for an electromagnetic wave whose phase falls around-210 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switch between the frequency 12.66GHz and the frequency 12.72 GHz. From another point of view, the maximum phase modulation amount Δ P12 that can be generated by driving or not driving the liquid crystal layer LC is about 30 degrees for electromagnetic waves having a frequency in the vicinity of 12.7 GHz.

Fig. 25A and 25B are schematic cross-sectional and front views of an antenna structure according to a thirteenth embodiment of the present invention. Fig. 26 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 25A in different modes of operation. For the sake of clarity, fig. 25B shows only the first electrode layer 110B, the second electrode layer 120A, the third electrode layer 130A, and the reflective layer 150 of fig. 25A.

Referring to fig. 25A and 25B, the difference between the antenna structure 14B of the present embodiment and the antenna structure 14A of fig. 23A is: the configuration modes of the strip electrodes of the first electrode layer are different. Specifically, the extending directions (e.g., the direction X) of the first strip-shaped electrodes 111A and the second strip-shaped electrodes 112A of the first electrode layer 110B of the antenna structure 14B intersect the extending directions (e.g., the direction Y) of the first strip-shaped electrodes 121 and the second strip-shaped electrodes 122 of the second electrode layer 120A.

Therefore, compared with the antenna structure 14A in fig. 23A, the antenna structure 14B of the present embodiment has a larger modulation range for both the reflection main frequency and the phase of the electromagnetic wave. Referring to fig. 26, when the liquid crystal layer LC is not driven (i.e., the first electrode layer 110B and the second electrode layer 120A are not enabled), the curve C25a of the reflection coefficient S11 versus frequency and the curve C26a of the electromagnetic wave phase versus frequency of the antenna structure 14B are significantly different from those of the liquid crystal layer LC, and the curve C25B of the reflection coefficient S11 versus frequency and the curve C26B of the electromagnetic wave phase versus frequency of the antenna structure 14B are different from those of the liquid crystal layer LC. For example, for an electromagnetic wave with a phase around-210 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switch between the frequency 12.8GHz and the frequency 13.0 GHz. From another point of view, the maximum phase modulation amount Δ P13 that can be generated by driving or not driving the liquid crystal layer LC is about 130 degrees for electromagnetic waves having a frequency in the vicinity of 12.9 GHz.

Fig. 27A and 27B are schematic cross-sectional and front views of an antenna structure according to a fourteenth embodiment of the invention. FIG. 27A corresponds to section line A-A' of FIG. 27B. Fig. 28 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 27A in different modes of operation. Fig. 29 is a graph of reflection coefficient S11 and phase versus frequency for the antenna structure of the alternative variant embodiment of fig. 27A in different modes of operation. For the sake of clarity of presentation, fig. 27B shows only the first electrode layer 110D, the second electrode layer 120D, and the reflective layer 150 of fig. 27A.

Referring to fig. 27A and 27B, unlike the antenna structure 10A of fig. 1B, in the present embodiment, the projection outlines of the area Z1 ″ occupied by the first electrode layer 110D and the area Z2 ″ occupied by the second electrode layer 120D of the antenna structure 15 on the first substrate 101 are rectangular, and both of the electrode layers are disposed in these areas in the form of a plurality of strip-shaped electrodes. For example, the first electrode layer 110D has a plurality of strip electrodes 115D, and the second electrode layer 120D has a plurality of strip electrodes 125D. The strip electrodes 115D and the strip electrodes 125D are alternately arranged along the direction Y, and the strip electrodes 115D are overlapped with the strip electrodes 125D along the arrangement direction (e.g., the direction Y). More specifically, these stripe electrodes correspond to the film thickness of the liquid crystal layer LC.

The

strip electrodes

115D and 125D may have different potentials, so that a transverse electric field may be generated between the

strip electrodes

115D and 125D to drive the liquid crystal layer LC. Therefore, the antenna structure 15 of the present embodiment is adapted to modulate the phase of the electromagnetic wave in the direction Y. It is to be noted that each of the above-described zone Z2 "and zone Z1" has a longer length along the arrangement direction of the strip-like electrodes, and has a shorter length in the extending direction of the strip-like electrodes. More specifically, zone Z2 "has a length L and a width W along direction Y and direction X, respectively, with length L being greater than width W. On the other hand, any two

adjacent stripe electrodes

115D and 125D have a distance G along the direction Y, and the ratio of the distance G to the length L is greater than 0 and less than 0.1. Accordingly, it can be ensured that the reflection frequency and phase of the electromagnetic wave can be modulated efficiently.

It should be noted that although the dotted frames for indicating the area Z1 ″ occupied by the first electrode layer 110D and the area Z2 ″ occupied by the second electrode layer 120D are slightly larger than the actual occupied areas of the first electrode layer 110D and the second electrode layer 120D for clarity, it should be understood that the dotted frames actually overlap the projection outlines of the electrode layers on the first substrate 101.

For example, in the present embodiment, the second substrate 102 may be a low dielectric loss substrate (e.g., a Rogers substrate), but is not limited thereto. Referring to fig. 28, when the liquid crystal layer LC is not driven (i.e. the

bar electrodes

115D and 125D are not enabled), the curve C27a of the reflection coefficient S11 versus frequency and the curve C28a of the electromagnetic wave phase versus frequency of the antenna structure 15 are significantly different from those of the liquid crystal layer LC when driven, and the curve C27b of the reflection coefficient S11 versus frequency and the curve C28b of the electromagnetic wave phase versus frequency of the antenna structure 15 are also different. For example, for an electromagnetic wave whose phase falls around-210 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switch between the frequency 15.8GHz and the frequency 16 GHz. From another point of view, the maximum phase modulation amount Δ P14 that can be generated by driving or not driving the liquid crystal layer LC is about 182 degrees for electromagnetic waves having a frequency in the vicinity of 15.9 GHz.

However, the present invention is not limited thereto. In another modified embodiment of fig. 27A, the second substrate 102 of the antenna structure may also be a glass substrate. Referring to fig. 29, when the liquid crystal layer LC is not driven (i.e. the

strip electrodes

115D and 125D are not enabled), the curve C29a of the reflection coefficient S11 versus frequency and the curve C30a of the electromagnetic wave phase versus frequency of the antenna structure are significantly different from those of the liquid crystal layer LC when driven, and the curve C29b of the reflection coefficient S11 versus frequency and the curve C30b of the electromagnetic wave phase versus frequency of the antenna structure are also different. For example, for an electromagnetic wave whose phase falls around-55 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switching between the frequency 18.6GHz and the frequency 18.7 GHz. From another point of view, the maximum phase modulation amount Δ P15 that can be generated by driving or not driving the liquid crystal layer LC is about 26 degrees for electromagnetic waves having a frequency in the vicinity of 18.6 GHz.

Fig. 30A and 30B are schematic cross-sectional and front views of an antenna structure according to a fifteenth embodiment of the present invention. FIG. 30A corresponds to section line B-B' of FIG. 30B. Fig. 31 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 30A in different modes of operation. Fig. 32 is a graph of reflection coefficient S11 and phase versus frequency for the antenna structure of the alternative variant embodiment of fig. 30A in different modes of operation. For the sake of clarity, fig. 30B shows only the first electrode layer 110E, the second electrode layer 120E, and the reflective layer 150 of fig. 30A.

Referring to fig. 30A and fig. 30B, the main differences between the antenna structure 16 of the present embodiment and the antenna structure 15 of fig. 27B are: the arrangement direction and the extension direction of the strip-shaped electrodes are different. Specifically, the plurality of strip electrodes 115E of the first electrode layer 110E and the plurality of strip electrodes 125E of the second electrode layer 120E of the antenna structure 16 are alternately arranged along the direction X and extend in the direction Y.

Referring to fig. 31, when the liquid crystal layer LC is not driven (i.e. the

strip electrodes

115E and 125E are not enabled), the curve C31a of the reflection coefficient S11 versus frequency and the curve C32a of the electromagnetic wave phase versus frequency of the antenna structure 16 are significantly different from those of the liquid crystal layer LC, and the curve C31b of the reflection coefficient S11 versus frequency and the curve C32b of the electromagnetic wave phase versus frequency of the antenna structure 16 are different. For example, for an electromagnetic wave whose phase falls around-180 degrees, whether the liquid crystal layer LC is driven or not can change the reflection main frequency of the electromagnetic wave, for example, switch between the frequency of 8.95GHz and the frequency of 9.0 GHz. From another point of view, the maximum phase modulation amount Δ P16 that can be generated by driving or not driving the liquid crystal layer LC is about 204 degrees for electromagnetic waves having a frequency in the vicinity of 8.98 GHz.

Therefore, the antenna structure 16 of the present embodiment has a smaller amount of modulation of the reflection frequency of the electromagnetic wave than the antenna structure 15 of fig. 27B, but has a larger amount of phase modulation of the electromagnetic wave than the antenna structure 15, with respect to the induced current flowing in the direction Y.

In the present embodiment, the second substrate 102 of the antenna structure 16 may be a low dielectric loss substrate (e.g., Rogers substrate). However, the present invention is not limited thereto. In another modified embodiment of fig. 30A, the second substrate 102 of the antenna structure may also be a glass substrate. Referring to fig. 32, when the liquid crystal layer LC is not driven (i.e. the

strip electrodes

115E and 125E are not enabled), the curve C33a of the reflection coefficient S11 versus frequency and the curve C34a of the electromagnetic wave phase versus frequency of the antenna structure are significantly different from those of the liquid crystal layer LC when driven, and the curve C33b of the reflection coefficient S11 versus frequency and the curve C34b of the electromagnetic wave phase versus frequency of the antenna structure are also different. For example, for an electromagnetic wave whose phase falls around-55 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switch between the frequency 17.2GHz and the frequency 17.36 GHz. From another point of view, the maximum phase modulation amount Δ P17 that can be generated by driving or not driving the liquid crystal layer LC is about 66 degrees for electromagnetic waves having a frequency in the vicinity of 17.27 GHz.

That is, when the material of the second substrate 102 in fig. 30A is replaced with glass from a low dielectric loss material, the reflection frequency modulation amount of the antenna structure for the electromagnetic wave increases, and the phase modulation amount for the electromagnetic wave decreases.

Fig. 33A and 33B are schematic cross-sectional and front views of an antenna structure according to a sixteenth embodiment of the present invention. FIG. 33A corresponds to section line C-C' of FIG. 33B. Fig. 34 is a plot of reflection coefficient S11 and phase versus frequency for the antenna structure of fig. 33A in different modes of operation. For the sake of clarity, fig. 33B shows only the first electrode layer 110F, the second electrode layer 120F, and the reflective layer 150 of fig. 33A.

Referring to fig. 33A and 33B, the difference between the antenna structure 17 of the present embodiment and the antenna structure 15 of fig. 27A is: the first electrode layer 110F of the antenna structure 17 does not overlap the second electrode layer 120F. In the present embodiment, the plurality of strip-shaped electrodes 115F of the first electrode layer 110F do not overlap the plurality of strip-shaped electrodes 125F of the second electrode layer 120F along the arrangement direction (e.g., the direction Y). That is, when the strip electrodes 115F have different potentials from the strip electrodes 125F, the electric field generated between the

strip electrodes

115F and 125F may have both vertical and horizontal components. The antenna structure 17 is thus adapted to modulate the phase of the induced current in the direction Z and the direction Y.

Referring to fig. 34, when the liquid crystal layer LC is not driven (i.e. the

strip electrodes

115F and 125F are not enabled), the curve C35a of the reflection coefficient S11 versus frequency and the curve C36a of the electromagnetic wave phase versus frequency of the antenna structure 17 are significantly different from those of the liquid crystal layer LC when driven, and the curve C35b of the reflection coefficient S11 versus frequency and the curve C36b of the electromagnetic wave phase versus frequency of the antenna structure 17 are also different. For example, for an electromagnetic wave whose phase falls around-180 degrees, whether the liquid crystal layer LC is driven or not may change the reflection main frequency of the electromagnetic wave, for example, switching between the frequency of 20.9GHz and the frequency of 21 GHz. From another point of view, the maximum phase modulation amount Δ P18 that can be generated by driving or not driving the liquid crystal layer LC is about 166 degrees for electromagnetic waves having a frequency in the vicinity of 20.97 GHz.

In summary, in the antenna structure of an embodiment of the invention, the inductive loop formed by the first electrode layer and the second electrode layer can transmit an induced current having a specific resonant frequency, and the liquid crystal layer sandwiched between the two electrode layers can be used to modulate the current path length of the induced current, so as to modulate the reflection frequency and phase of the electromagnetic wave. In addition, the ratio of the area occupied by the first electrode layer to the area occupied by the second electrode layer is more than or equal to 0.7 and less than 1, so that the bandwidth of the reflection frequency of the electromagnetic wave can be effectively increased.

Claims

1. An antenna structure comprising:

a first substrate;

a second substrate arranged opposite to the first substrate;

a first electrode layer disposed on the first substrate;

a second electrode layer disposed on the second substrate and overlapping the first electrode layer, wherein the ratio of the area occupied by the first electrode layer to the area occupied by the second electrode layer is greater than or equal to 0.7 and less than 1;

a liquid crystal layer arranged between the first substrate and the second substrate and between the first electrode layer and the second electrode layer; and

and the reflecting layer is arranged on one side of the second substrate, which is deviated from the second electrode layer.

2. The antenna structure of claim 1, wherein the first electrode layer or the second electrode layer has a plurality of strip electrodes, and the liquid crystal layer is located between the strip electrodes.

3. The antenna structure of claim 2, wherein the second electrode layer has the plurality of strip electrodes, the plurality of strip electrodes includes a plurality of first strip electrodes and a plurality of second strip electrodes, the plurality of first strip electrodes and the plurality of second strip electrodes are alternately arranged along a direction, and the plurality of first strip electrodes are electrically independent from the plurality of second strip electrodes.

4. The antenna structure of claim 1, further comprising:

and the third electrode layer is arranged on one side of the first electrode layer, which is far away from the second electrode layer.

5. The antenna structure of claim 4, wherein the first electrode layer or the second electrode layer has a plurality of strip electrodes, and the liquid crystal layer is located between the strip electrodes.

6. The antenna structure of claim 5, wherein the second electrode layer has the plurality of strip-shaped electrodes, the plurality of strip-shaped electrodes comprises a plurality of first strip-shaped electrodes and a plurality of second strip-shaped electrodes alternately arranged along a direction, and the first strip-shaped electrodes are electrically independent from the second strip-shaped electrodes.

7. The antenna structure of claim 4, wherein the first electrode layer and the second electrode layer each have a plurality of strip electrodes.

8. The antenna structure according to claim 7, wherein the extending direction of the strip-shaped electrodes of the first electrode layer intersects with the extending direction of the strip-shaped electrodes of the second electrode layer.

9. The antenna structure of claim 7, wherein the extending direction of the strip-shaped electrodes of the first electrode layer is parallel to the extending direction of the strip-shaped electrodes of the second electrode layer, and the strip-shaped electrodes of the first electrode layer and the strip-shaped electrodes of the second electrode layer are alternately arranged along a direction.

10. The antenna structure of claim 9, wherein the strip-shaped electrodes of the first electrode layer partially overlap the strip-shaped electrodes of the second electrode layer.

11. The antenna structure according to claim 4, wherein a ratio of an area occupied by the third electrode layer to an area occupied by the first electrode layer is greater than or equal to 0.7 and less than 1.

12. The antenna structure of claim 1, further comprising:

and the third electrode layer is arranged on one side of the second electrode layer far away from the first electrode layer.

13. The antenna structure of claim 12, wherein the first electrode layer or the second electrode layer has a plurality of strip electrodes.

14. The antenna structure of claim 13, wherein the first electrode layer has the plurality of strip-shaped electrodes, the plurality of strip-shaped electrodes comprises a plurality of first strip-shaped electrodes and a plurality of second strip-shaped electrodes alternately arranged along a direction, and the first strip-shaped electrodes are electrically independent from the second strip-shaped electrodes.

15. The antenna structure of claim 12, wherein a ratio of an area occupied by the second electrode layer to an area occupied by the third electrode layer is greater than or equal to 0.7 and less than 1.

16. The antenna structure of claim 12, wherein the first electrode layer and the second electrode layer each have a plurality of strip electrodes.

17. The antenna structure according to claim 16, wherein the extending direction of the strip-shaped electrodes of the first electrode layer intersects with the extending direction of the strip-shaped electrodes of the second electrode layer.

18. The antenna structure of claim 16, wherein the extending direction of the strip-shaped electrodes of the first electrode layer is parallel to the extending direction of the strip-shaped electrodes of the second electrode layer, the strip-shaped electrodes of the first electrode layer and the strip-shaped electrodes of the second electrode layer are alternately arranged along a direction, and the strip-shaped electrodes of the first electrode layer partially overlap with the strip-shaped electrodes of the second electrode layer.

19. The antenna structure of claim 1, wherein the first electrode layer has a plurality of first strip-shaped electrodes, the second electrode layer has a plurality of second strip-shaped electrodes, and the first strip-shaped electrodes and the second strip-shaped electrodes are alternately arranged along a direction.

20. The antenna structure of claim 19, wherein the first strip electrodes overlap the second strip electrodes along the direction.

21. The antenna structure of claim 20, wherein any two adjacent ones of the first strip-shaped electrodes and the second strip-shaped electrodes have a distance therebetween along the direction, the area occupied by the second electrode layer has a length along the direction, and a ratio of the distance to the length is greater than 0 and less than 0.1.

22. The antenna structure of claim 1 wherein the second substrate is a low dielectric loss substrate.