Antenna module having phase delay

Abstract

This antenna module comprises: a dielectric substrate; a liquid crystal layer disposed in the dielectric substrate or stacked thereon; an array antenna comprising a plurality of antenna elements arrayed in one axial direction on one surface of the dielectric substrate, and radiating wireless beamforming signals; and feeding structures disposed so as to connect antenna elements that are adjacent in the one axial direction from among the plurality of antenna elements. The liquid crystal layer is disposed to overlap the feeding structures, and the angle of orientation of the wireless beamforming signal may be changed to the one axial direction in accordance with the voltage applied to the liquid crystal layer.

Description

Antenna module with phase delay

[0001] The present specification relates to an antenna module having a phase delay. A specific implementation relates to an antenna module having an array antenna structure capable of beamforming with a phase delay.

[0002] Phased array antennas can adjust beam steering direction by electronically controlling the phase of radio waves on a per-element basis. This element-by-element phase control is typically implemented using phase shifters at the radio frequency (RF) level. These phase shifters increase the weight, size, and cost of the phased array antenna.

[0003] Meanwhile, a series-fed array antenna can be applied to implement an array antenna within a limited area. A series-fed array antenna is designed by arranging radiators connected in series along a transmission line at intervals of wavelength (λg) within the tube to generate an in-phase current distribution. This allows for high radiation gain in the forward direction of the array antenna, but limits beam steering to a single axis during beam scanning.

[0004] The purpose of this specification is to provide an antenna module having an array antenna structure capable of beam forming within a limited area.

[0005] The purpose of this specification is to provide an antenna module having an array antenna structure capable of two-dimensional beam forming while minimizing the number of phase control circuits in a frequency band of millimeter waves or higher.

[0006] The purpose of this specification is to provide an antenna module having an array antenna structure capable of two-dimensional beam forming capable of DC blocking while optimizing RF performance in a frequency band of millimeter waves or higher.

[0007] To achieve the above or other purposes, an antenna module according to an embodiment includes: a dielectric substrate; a liquid crystal layer disposed within the dielectric substrate or laminated with the dielectric substrate; an array antenna including a plurality of antenna elements arranged in a uniaxial direction on one surface of the dielectric substrate and radiating a beamforming wireless signal; and feeding structures configured to connect adjacent antenna elements in the uniaxial direction among the plurality of antenna elements. The liquid crystal layer is disposed to overlap the feeding structures, and a directivity angle of the beamforming wireless signal in the uniaxial direction can be changed according to a voltage value applied to the liquid crystal layer.

[0008] According to an embodiment, the plurality of antenna elements may include first to eighth antenna elements. A feeding line may be connected so that an RF signal is applied to the first antenna element disposed on one side of the plurality of antenna elements. A signal connection line may be connected so that a DC voltage is applied to the eighth antenna element disposed on the other side of the plurality of antenna elements.

[0009] According to an embodiment, the feed structure may include a first feed structure formed between the first and second antenna elements to a seventh feed structure formed between the seventh and eighth antenna elements. The liquid crystal layer may include a first region to a seventh region disposed in a lower region of the first feed structure to the seventh feed structure so as to overlap the first feed structure to the seventh feed structure.

[0010] According to an embodiment, the plurality of antenna elements may be arranged in a plurality of columns and rows in the one-axis direction and the other-axis direction to form a two-dimensional array antenna. The first region may be formed to overlap the first feed structure between the first antenna element and the second antenna element between the first row to the eighth row in the other-axis direction. The seventh region may be formed to overlap the seventh feed structure between the seventh antenna element and the eighth antenna element between the first row to the eighth row.

[0011] The technical effects of an antenna module having such a phase delay are as follows.

[0012] According to an embodiment, beamforming is possible within a limited area through an array antenna having a liquid crystal layer and a phase delay feed structure.

[0013] According to an embodiment, two-dimensional beamforming is possible in a frequency band of millimeter waves or higher while minimizing the number of phase control circuits through an array antenna having a liquid crystal layer and a phase delay feed structure.

[0014] According to an embodiment, signal separation is enabled between a signal connection line transmitting a DC signal and an RF signal terminal, thereby enabling two-dimensional beam forming capable of DC blocking while optimizing RF performance in a frequency band of millimeter waves or higher.

[0015] Further scope of the applicability of this specification will become apparent from the detailed description below. However, since various changes and modifications within the spirit and scope of this specification will be apparent to those skilled in the art, it should be understood that the detailed description and specific examples, such as preferred embodiments, are given by way of example only.

[0016] FIG. 1 illustrates the structure of an array antenna module including a plurality of elements according to the present specification.

[0017] Figure 2 shows a structure implemented with a reflective RIS and a transparent RIS according to the present specification.

[0018] FIG. 3 illustrates an antenna module implemented as a two-dimensional array antenna according to one embodiment of the present specification.

[0019] FIG. 4 illustrates an antenna module implemented as a two-dimensional array antenna according to another embodiment of the present specification.

[0020] Fig. 5 shows a cross-sectional view of a portion of the antenna module of Figs. 3 and 4.

[0021] Figure 6 shows the structure and electrical characteristics of a signal connection line in which a radial stub is formed.

[0022] Figure 7 shows feed lines having multiple sub-patterns and coupling patterns.

[0023] Figure 8 shows the electrical characteristics according to the feed lines of Figure 7.

[0024] Figure 9 is an enlarged drawing of a feed structure connecting adjacent antenna elements in an array antenna in which multiple antenna elements are arranged in a single-axis direction.

[0025] FIGS. 10A to 10C illustrate power supply structures including vertical stub patterns according to embodiments.

[0026] Figure 11 shows slow-wave structures according to embodiments.

[0027] Figure 12 shows the propagation delay coefficient according to the impedance ratio in the slow-wave structure according to the present specification.

[0028] Figures 13a to 13c show the phase delay characteristics of the feed structure as the dielectric constant and the length of the longest vertical stub pattern are changed according to embodiments.

[0029] Figure 14 shows an equivalent circuit of a power supply structure including adjacent stub patterns of Figures 13a to 13c.

[0030] Figure 15 shows a radiation pattern formed by beamforming in the first axis direction by varying the dielectric constant of the liquid crystal layer.

[0031] Figure 16 shows a radiation pattern formed by beamforming in the second axis direction by varying the dielectric constant of the liquid crystal layer.

[0032] Hereinafter, an antenna module having a phase delay according to the present specification will be described.

[0033] In this regard, a module including a plurality of elements according to the present specification may be referred to as a phase delay array antenna module. The antenna module may be configured to include a plurality of radiators and a phase delay element capable of implementing phase delay. The phase delay element may be implemented as a feed structure of a specific structure without separate electronic components such as a phase shifter.

[0034] The array antenna module can be configured to support 6G wireless communication services. In this regard, the array antenna module can be configured to operate in the millimeter wave band or the 10 GHz band. The array antenna module can be applied to mobile communication antennas, vehicle antennas, or satellite communication antennas.

[0035] 6G wireless communication services aren't limited to electronic devices like mobile terminals or video display devices. They can also be applied to fully autonomous vehicles, artificial intelligence (AI) robots, and electronic devices supporting the augmented and virtual reality (AR / VR)-based metaverse.

[0036] FIG. 1 illustrates the structure of an array antenna module, which is a module including a plurality of elements according to the present specification. Referring to FIG. 1, the array antenna module (1000) may be configured as an array antenna (1100) including a plurality of elements (1100-1 to 1100-8). The number of the plurality of elements is not limited to eight and may vary depending on the application.

[0037] The antenna module (1000) may be configured as a one-dimensional array antenna in which a plurality of elements are arranged in one axial direction. As another example, the antenna module (1000) may be configured as a two-dimensional array antenna in which a plurality of elements are arranged in one axial direction and another axial direction perpendicular thereto.

[0038] The spacing (G1) between the plurality of elements (1100-1 to 1100-8) can be implemented as a numerical value related to a wavelength corresponding to an operating frequency. Each of the plurality of elements (1100-1 to 1100-8) can be operably coupled to a phase delay element (1150-1 to 1150-8). The phase delay elements (1150-1 to 1150-8) can be formed as a feed structure having a phase delay. The phase delay elements (1150-1 to 1150-8) can be formed as a feed structure connecting adjacent antenna elements.

[0039] A transmission line (1200) connected to a plurality of elements (1100-1 to 1100-8) may be implemented as a waveguide, a microstrip line, a strip line, or a substrate integrated waveguide (SIW). Each of the plurality of elements (1100-1 to 1100-8) may be independently controlled to be turned on / off. Each of the plurality of elements (1100-1 to 1100-8) may be independently controlled to be turned on / off to adjust the beam forming direction of the antenna module (1000).

[0040] As the plurality of elements (1100-1 to 1100-8) are independently turned on / off, the phase of the signal applied to the plurality of elements (1100-1 to 1100-8) can be varied as illustrated in the transmission line (1200) of FIG. 1. As the interval between the on / off operations among the plurality of elements (1100-1 to 1100-8) decreases, the phase difference between adjacent elements increases. Accordingly, as the interval between the on / off operations among the plurality of elements (1100-1 to 1100-8) decreases, the beamforming angle increases.

[0041] Meanwhile, an antenna module comprising a plurality of antenna elements according to the present specification may be capable of phase adjustment when combined with a reconfigurable intelligent surface (RIS). In this regard, FIG. 2 illustrates a structure implemented with a reflective RIS and a transmissive RIS according to the present specification.

[0042] Referring to FIG. 2(a), the antenna module (1000) may be configured to include a reflective RIS (1000a) and at least one external antenna (1300). A wireless signal radiated from the external antenna (1300) may be configured to be reflected by the reflective RIS (1000a). The beamforming angle of the wireless signal may be varied by independently varying the on / off state of each element constituting the reflective RIS (1000a).

[0043] Referring to FIG. 2(b), the antenna module (1000) may be configured to include a transitive RIS (1000b) and at least one external antenna (1300). A wireless signal radiated from the external antenna (1300) may be configured to pass through the transitive RIS (1000b). The beamforming angle of the wireless signal may be varied by independently varying the on / off state of each element constituting the transitive RIS (1000b).

[0044] Hereinafter, an antenna module having a phase delay according to the present specification will be described. Specifically, FIG. 3 illustrates an antenna module implemented as a two-dimensional array antenna according to one embodiment of the present specification. FIG. 4 illustrates an antenna module implemented as a two-dimensional array antenna according to another embodiment of the present specification. FIG. 5 illustrates a cross-sectional view of a portion of the antenna module of FIGS. 3 and 4.

[0045] Specifically, Fig. 3 illustrates an antenna module having a structure in which a common stub is connected to a common feed line to which a plurality of antenna elements are combined. Fig. 4 illustrates an antenna module having a structure in which stubs are connected to feed lines connected to each of a plurality of antenna elements.

[0046] Referring to FIGS. 3 to 5, an antenna module having a phase delay structure according to the present specification will be described. The antenna module (1000) may be configured to include a dielectric substrate (1010), a liquid crystal layer (1020), an array antenna (1100), and feeding structures (1100f).

[0047] An antenna module having a phase delay structure according to the present specification can perform beamforming using a slow-wave structure and a liquid crystal medium. In this regard, by applying the slow-wave structure and the variable dielectric structure of the liquid crystal medium to the design of a series-fed antenna array, an antenna design capable of two-dimensional beam steering can be realized.

[0048] For series-fed array antennas, radiators are designed to be arranged serially along the transmission line at intervals of wavelength (λg) within the tube to generate an in-phase current distribution. This allows for high radiation gain in the forward direction of the array antenna, but limits beam steering to a single axis during beam scanning.

[0049] The proposed serial-fed array antenna implements a phase shift circuit based on a slow-wave structure, and utilizes liquid crystals to actively control the signal transmission phase. Therefore, two-dimensional beam steering is possible in the structure of the serial-fed array antenna.

[0050] In a series-fed array antenna according to the present specification, a plurality of antenna elements (1110 to 1180) constituting an array antenna (1100) may be arranged on one surface of a dielectric substrate (1010). A ground plane may be formed on the other surface of the dielectric substrate (1010) to provide a ground for the plurality of antenna elements (1110 to 1180). The antenna module (1000) of FIG. 3 may further include a feed line (1100f) and a signal connection line (SCL). The antenna module (1000) of FIG. 4 may further include a feed line (1100f) and a signal connection line (SCLb).

[0051] The liquid crystal layer (1020) may be any dielectric layer whose permittivity changes depending on the applied voltage. Since the permittivity of the liquid crystal layer (1020) may be changed, it may be referred to as a variable dielectric layer. The liquid crystal layer (1020) may be implemented so that the permittivity changes from a first permittivity value corresponding to a first voltage to a second permittivity value corresponding to a second voltage depending on the applied voltage. For example, the permittivity of the liquid crystal layer (1020) may change from 2.2 to 3.6, but is not limited thereto and may be changed depending on the application.

[0052] The liquid crystal layer (1020) may be disposed within the dielectric substrate (1010) or may be disposed to be laminated with the dielectric substrate (1010). The array antenna (1100) may include a plurality of antenna elements (1110 to 1180) arranged in one axial direction on one surface of the dielectric substrate (1010). The array antenna (1100) may be configured to radiate a beam-forming radio signal through the plurality of antenna elements (1110 to 1180).

[0053] The feeding structures (1100f) may be configured to connect adjacent antenna elements in a uniaxial direction among a plurality of antenna elements (1110 to 1180). The liquid crystal layer (1020) may be arranged to overlap the feeding structures (1100f). Depending on the voltage value applied to the liquid crystal layer (1020), the directionality angle of the beamforming wireless signal in a uniaxial direction may be changed.

[0054] Referring to FIG. 5, a liquid crystal layer (1020) may be disposed in a lower region in the Z-axis direction of a plurality of feed structures (1110f to 1140f) disposed on a front surface of a dielectric substrate (1010). A plurality of feed structures (1110f to 1140f) and a plurality of antenna elements (1110 to 1140) may be disposed on the front surface of the dielectric substrate (1010). A ground layer may be disposed on a rear surface of the dielectric substrate (1010). A liquid crystal layer (1020) may be disposed in a lower region of the first feed structure (1110f) to the fourth feed structure (1140f).

[0055] As the voltage applied to the liquid crystal layer (1020) in the lower region of the first feed structure (1110f) to the fourth feed structure (1140f) changes, the effective permittivity of the feed structures (1110f to 1140f) formed may change. Accordingly, the electrical length of the feed structures (1110f to 1140f) in the Y-axis direction may be varied. Accordingly, the phase difference between the antenna elements (1110 to 1140) between the feed structures (1110f to 1140f) may be varied, thereby changing the directionality angle of the antenna beam.

[0056] Referring to FIG. 5(a), the thickness of the liquid crystal layer (1020) may be formed to be the same as the first thickness (t1) of the dielectric layer (1010). Referring to FIG. 5(b), the thickness of the liquid crystal layer (1020) may be formed to be a second thickness (t2) that is smaller than the first thickness (t1) of the dielectric layer (1010).

[0057] Referring to FIGS. 3 to 5, a plurality of antenna elements (1110 to 1180) of an antenna module (1000) may be configured to include a first antenna element (1110) to an eighth antenna element (1180). A feeding line (FL) may be connected so that an RF signal is applied to the first antenna element (1110) disposed on one side of the plurality of antenna elements (1110 to 1180). A signal connection line (SCL, SCLb) may be connected so that a DC voltage is applied to the eighth antenna element (1180) disposed on the other side of the plurality of antenna elements (1110 to 1180).

[0058] The feed structure (1100f) may include a first feed structure (1110f) formed between the first and second antenna elements (1110, 1120) to a seventh feed structure (1170f) formed between the seventh and eighth antenna elements (1170, 1180). The liquid crystal layer (1020) may be arranged to overlap the first feed structure (1110f) to the seventh feed structure (1170f). The liquid crystal layer (1020) may include a first region (R1) to an eighth region (R8) arranged in a lower region in the Z-axis direction, which is the height direction of the first feed structure (1110f) to the seventh feed structure (1170f).

[0059] In an array antenna having a plurality of antenna elements, the feed structure (1100f) may be configured to include a plurality of stub patterns. In a 1x4 array antenna, the feed structure (1100f) may be configured to include a first feed structure (1110f) to a third feed structure (1130f). The first feed structure (1110f) to the third feed structure (1130f) may be referred to as a first stub pattern to a third stub pattern (1130f), respectively. The first feed structure (1110f) may be arranged to connect the other end of the first antenna element (1110) to one end of the second antenna element (1120). The second feed structure (1120f) may be arranged to connect the other end of the second antenna element (1120) to one end of the third antenna element (1130). A third feed structure (1130f) may be arranged to connect the other end of the third antenna element (1130) and one end of the fourth antenna element (1140).

[0060] In a 1x8 array antenna, the feed structure (1100f) may be configured to include the first feed structure (1110f) to the third feed structure (1130f) and the fourth feed structure (1140f) to the seventh feed structure (1170f) described above. The first feed structure (1110f) to the seventh feed structure (1170f) may be referred to as the first stub pattern and the seventh stub pattern, respectively. A detailed description of the first feed structure (1110f) to the third feed structure (1130f) is omitted as it has been described in the above paragraph. The fourth feed structure (1140f) may be arranged to connect the other end of the fourth antenna element (1140) to one end of the fifth antenna element (1150). A fifth feed structure (1150f) may be arranged to connect the other end of the fifth antenna element (1150) and one end of the sixth antenna element (1160). A sixth feed structure (160f) may be arranged to connect the other end of the sixth antenna element (1160) and one end of the seventh antenna element (1170). A seventh feed structure (1170f) may be arranged to connect the other end of the seventh antenna element (1170) and one end of the eighth antenna element (1180).

[0061] In the two-dimensional array antenna structure, the first region (R1) to the eighth region (R8) of the liquid crystal layer (1020) may be formed to overlap with the feeding structure (1110f). In this regard, a plurality of antenna elements (1110 to 1180) may be arranged in a plurality of columns and rows in one axial direction and the other axial direction to form a two-dimensional array antenna.

[0062] The first region (R1) of the liquid crystal layer (1020) may be formed to overlap the first feed structure (1110f) between the first antenna element (1110) and the second antenna element (1120) between the first row to the eighth row in the other axis direction. The second region (R2) may be formed to overlap the second feed structure (1120f) between the second antenna element (1120) and the third antenna element (1130) between the first row to the eighth row in the other axis direction. The third region (R3) may be formed to overlap the third feed structure (1130f) between the third antenna element (1130) and the fourth antenna element (1140) between the first row to the eighth row in the other axis direction. The fourth region (R4) may be formed to overlap the fourth feed structure (1140f) between the fourth antenna element (1140) and the fifth antenna element (1150) between the first to eighth rows in the other axis direction.

[0063] The fifth region (R5) of the liquid crystal layer (1020) may be formed to overlap the fifth feed structure (1150f) between the fifth antenna element (1150) and the sixth antenna element (1160) between the first to eighth rows in the other axial direction. The sixth region (R6) may be formed to overlap the sixth feed structure (1160f) between the sixth antenna element (1160) and the seventh antenna element (1170) between the first to eighth rows in the other axial direction. The seventh region (R7) may be formed to overlap the seventh feed structure (1170f) between the seventh antenna element (1170) and the eighth antenna element (1180) between the first to eighth rows in the other axial direction.

[0064] A first spacing (G1) between adjacent antenna elements in one axial direction of the array antenna (1100) can be formed as a value in a predetermined range based on a wavelength (λ) corresponding to an operating frequency. A second spacing (G2) between adjacent antenna elements in the other axial direction of the array antenna (1100) can be formed as a value in a predetermined range based on half of the wavelength corresponding to the operating frequency.

[0065] The liquid crystal layer (1020) forms a closed loop so that the liquid crystal material of the distribution can be uniformly distributed over the entire area. In this regard, the liquid crystal layer (1020) may further include an eighth region (R8) and a ninth region (R9). The eighth region (R8) of the liquid crystal layer (1020) may be formed to connect one end of the first region (R1) and one end of the seventh region (R7). The ninth region (R9) of the liquid crystal layer (1020) may be formed to connect the other end of the first region (R1) and the other end of the seventh region (R7).

[0066] The eighth region (R8) of the liquid crystal layer (1020) may be arranged in an upper region of the first to eighth antenna elements of the first row on the XY plane. The ninth region (R9) of the liquid crystal layer (1020) may be arranged in a lower region of the first to eighth antenna elements of the eighth row on the XY plane.

[0067] The liquid crystal layer (1020) of the antenna module (1000) may be provided with a hole into which liquid crystal is injected and a hole through which internal air is discharged to the outside. In this regard, the liquid crystal layer (1020) may be configured to include a first hole (HL1) and a second hole (HL2). The first hole (HL1) may be formed on one side of the eighth region (R8) so that liquid crystal may be injected into the liquid crystal layer (1020). The second hole (HL2) may be formed on the other side of the ninth region (R8) so that air within the liquid crystal layer (1020) may be discharged to the outside.

[0068] Referring to Fig. 3, in a two-dimensional array antenna structure, signal connection lines (SCL) can be formed as a single stub structure. In this regard, Fig. 6 illustrates the structure and electrical characteristics of a signal connection line in which a radial stub is formed. Fig. 6(a) illustrates a structure in which a radial stub (RST) is connected to one side of the signal connection line. Fig. 6(b) illustrates the reflection loss of the first port (Port 1) of the signal connection line of Fig. 6(a) and the insertion loss between the first and second ports (Port 1, Port 2).

[0069] Referring to Fig. 6, the return loss (S11) of the signal connection line to which the radial stub (RST) is connected has a value greater than or equal to -1 dB at 145-180 GHz. The insertion loss (S21) of the signal connection line to which the radial stub (RST) is connected has a value less than or equal to -10 dB. Therefore, the signal connection line to which the radial stub (RST) is connected can operate to block RF signals in the frequency band of 145-180 GHz. Accordingly, the signal connection line to which the radial stub (RST) is connected can transmit DC signals and block RF signals.

[0070] In this regard, a DC blocking circuit must be placed on the RF signal transmission line of a series-fed array antenna. This is to protect the electronic components that process and transmit the RF signal. A DC blocking circuit designed on a transmission line such as a microstrip line can equivalently function as a capacitor. Therefore, a chip capacitor can be used as a replacement for the DC blocking circuit. However, there is a problem that the electrical characteristics of commercial chip capacitors deteriorate in the millimeter-wave band, especially in the sub-THz band or higher. Therefore, it is necessary to implement it in the form of a distributed capacitor with a specific pattern shape on the PCB.

[0071] To achieve impedance matching, the length of the DC blocking circuit can be designed as λg / 4. Meanwhile, a wide cross-section area must be designed to ensure sufficient capacitance for DC blocking and RF transmission. Accordingly, the DC blocking circuit can operate as a high-pass filter, blocking DC signals and transmitting RF signals.

[0072] Referring to FIGS. 3 and 6, signal connection lines (SCL) may be connected to upper vertices of eighth antenna elements (1180) of the first to eighth rows. A radial stub (RST) formed with a first radius (r1) and a first angle may be connected to a point of a second signal connection line (SCL2) to which the signal connection lines (SCL) are connected. In this regard, the first radius (r1) of the radial stub (RST) may be formed within a predetermined range based on 1 / 4 of a wavelength corresponding to an operating frequency. The first angle of the radial stub (RST) may be formed within a range between 45 degrees and 135 degrees.

[0073] Referring to FIG. 4, in the two-dimensional array antenna structure, signal connection lines (SCLb) may be formed with a plurality of stub structures. Referring to FIGS. 4 and 6, the signal connection lines (SCLb) may be connected to the upper vertices of the eighth antenna elements (1180) of the first to eighth rows. A radial stub (RST) formed with a first radius (r1) and a first angle may be connected to each point of the signal connection lines (SCLb). In this regard, the first radius (r1) of the radial stub (RST) may be formed in a predetermined range based on 1 / 4 of the wavelength corresponding to the operating frequency. The first angle of the radial stub (RST) may be formed in a range between 45 degrees and 135 degrees. By applying different voltages to each of the signal connection lines (SCLb), the effective permittivity can be made different for each row from the first to the eighth row, thereby causing the antenna elements to operate differently for each row.

[0074] In a two-dimensional array antenna structure, each of the feed lines (FL) can be configured to include a plurality of sub-patterns and coupling patterns. In this regard, FIG. 7 illustrates feed lines having a plurality of sub-patterns and coupling patterns. FIG. 7(a) illustrates a feed line having two coupling patterns. FIG. 7(b) illustrates a feed line having three coupling patterns.

[0075] In this regard, the feed lines need to be implemented with RF choke circuits that transmit RF signals and block DC signals. It is necessary to place RF chokes so that they can contact all columns of the series-fed array antenna through which RF signals flow, thereby blocking the RF signal from being introduced into the DC signal source. The line through which the DC voltage is applied can be designed with a narrow line width below the critical value to have high impedance in the frequency band of the RF signal. Accordingly, the current leakage of the RF signal can be minimized. At this time, the closer the RF choke is placed to the antenna element, the more effective it is in reducing RF signal leakage. However, placing too many RF chokes can cause interference in some frequency bands, so the number of RF chokes should be limited to a certain number.

[0076] Referring to FIGS. 3, 4, and 7(a), each of the feed lines (FL) may include a first sub-pattern (FL1), a second sub-pattern (FL2), a first coupling pattern (FLc1), and a second coupling pattern (FLc2). Referring to FIGS. 3, 4, and 7(b), each of the feed lines (FL) may include a first sub-pattern (FL1), a second sub-pattern (FL2), a first coupling pattern (FLc1), a second coupling pattern (FLc2), and a third coupling pattern (FLc3).

[0077] Referring to FIGS. 3, 4, and 7, the first sub-pattern (FL1) is connected to the first antenna elements (1110) of the first to eighth rows, and may be formed with a predetermined length and width. The second sub-pattern (FL2) may be formed with a predetermined length and width and may be formed spaced apart from the first sub-pattern (FL1).

[0078] Referring to FIGS. 3, 4, and 7(a), the first coupling pattern (FLc1) may have one end connected to the end of the first sub-pattern (FL1). The other end of the first coupling pattern (FLc1) may be spaced apart from the end of the second sub-pattern (FL2) by a predetermined distance. The second coupling pattern (FLc2) may have one end connected to the end of the second sub-pattern (FL2). The other end of the second coupling pattern (FLc2) may be spaced apart from the end of the first sub-pattern (FL1) by a predetermined distance. The first coupling pattern (FLc1) and the second coupling pattern (FLc2) may be arranged in parallel. The first coupling pattern (FLc1) and the second coupling pattern (FLc2) may be formed with a length within a predetermined range based on 1 / 4 of the wavelength corresponding to the lowest frequency.

[0079] Referring to FIGS. 3, 4, and 7(b), the first coupling pattern (FLc1) may have one end connected to an end of the first sub-pattern (FL1). The second coupling pattern (FLc2) may be connected to one end of the second sub-pattern (FL2) at a first point (Pc1). The third coupling pattern (FLc3) may be connected to one end of the second sub-pattern (FL2) at a second point (Pc2). The third coupling pattern (FLc3) may be arranged parallel to the first coupling pattern (FLc1) and the second coupling pattern (FLc2). The first coupling pattern (FLc1) may be arranged with a predetermined distance between the second coupling pattern (FLc2) and the third coupling pattern (FLc3).

[0080] Figure 8 shows the electrical characteristics according to the feed lines of Figure 7. Figure 8(a) shows the reflection loss (S11) and insertion loss (S21) of the feed line of Figure 7(a). Figure 8(b) shows the reflection loss (S11) and insertion loss (S21) of the feed line of Figure 7(b). The reflection loss (S11) of the feed line indicates the value at which the RF signal applied from the first port (Port 1) is reflected. The insertion loss (S21) of the feed line indicates the value at which the RF signal is transmitted from the first port (Port 1) to the second port (Port 2).

[0081] Referring to FIGS. 7(a) and 8(a), a feedline having two coupling patterns has a reflection loss (S11) of less than -10 dB and an insertion loss (S21) of less than -1 dB at 145-180 GHz. Referring to FIGS. 7(b) and 8(b), a feedline having three coupling patterns has a reflection loss (S11) of less than -10 dB and an insertion loss (S21) of less than -1 dB at 145-180 GHz. Therefore, a feedline having two or more coupling patterns can be configured to transmit an RF signal while blocking a DC signal in the 145-180 GHz frequency band.

[0082] Meanwhile, the feed structure according to the present specification may include a horizontal stub pattern connecting adjacent antenna elements and a vertical stub pattern perpendicular thereto. In this regard, FIG. 9 is an enlarged drawing of a feed structure connecting adjacent antenna elements in an array antenna in which a plurality of antenna elements are arranged in a single-axis direction.

[0083] By applying the slow-wave structure proposed in this specification to the design of a series-fed array antenna, the phase of the signal applied to the array elements can be controlled while maintaining the spacing between the array antenna elements. By using A, not only can the beam-shift shape be improved, but the array antenna can be designed to steer in a specific direction. In addition, by setting the aperture size of the array antenna differently, the beam width can be varied, and beam-steering and forming performances that are difficult to design with conventional series-fed array antennas can be implemented.

[0084] In this regard, FIGS. 10A to 10C illustrate feed structures including vertical stub patterns according to embodiments. Referring to FIGS. 10A to 10C, various design configurations of the slow-propagating structure proposed in the present specification are illustrated. Referring to FIGS. 3 and 10A to 10C, a slow-propagating structure can be implemented by a plurality of vertical stub patterns (VST) having multiple stages. As the number of stages increases, the phase delay effect of the feed structures improves. In addition, the phase delay effect of the wideband feed structures improves as one side and the other side become more symmetrical. In addition, the phase delay effect of the feed structures improves in the uniform type compared to the gradual type in which the length of the stub patterns increases. In addition, the phase delay effect of the feed structures improves as the length of the stub patterns increases. Meanwhile, the impedance matching characteristic of the gradual type improves in a wideband frequency compared to the uniform type.

[0085] A vertical stub pattern (VST) may be formed of a plurality of sub-patterns. Referring to FIGS. 9 and 10A, the vertical stub pattern (VST) may be configured to include a first sub-pattern (VST1) and a second sub-pattern (VST2). The first sub-pattern (VST1) may be formed with a first length (Lsa1, Lsb1, Ls1) in at least one of an upper or lower direction on the other axis from a first point of the horizontal stub pattern (HST). In this regard, the upper direction on the other axis may correspond to the upper direction of the Y-axis. The lower direction on the other axis may correspond to the lower direction of the Y-axis.

[0086] The second sub-pattern (VST2) may be formed with a second length (Lsa2, Lsb2, Ls2) parallel to the first sub-pattern (VST1) at a second point of the horizontal stub pattern (HST). The second sub-pattern (VST2) may be formed with a second length (Lsa2, Lsb2, Ls2) in at least one direction among an upper or lower direction on the other axis at the second point of the horizontal stub pattern (HST). In this regard, the upper direction on the other axis may correspond to the upper direction of the Y-axis. The lower direction on the other axis may correspond to the lower direction of the Y-axis.

[0087] Referring to Fig. 10a(a), the vertical stub pattern (VST) can be formed only in one of the upper or lower directions on the other axis. Therefore, the vertical stub pattern (VST) can be implemented with an asymmetric structure. In this regard, the first sub-pattern (VST1) and the second sub-pattern (VST2) can be formed only in one of the upper or lower directions on the other axis. The second length (Lsa2) of the second sub-pattern (VST2) can be formed to be longer than the first length (Lsa1) of the first sub-pattern (VST1).

[0088] Meanwhile, the vertical stub pattern (VST) may also be implemented with a symmetrical structure. Referring to FIG. 10a(b), the first sub-pattern (VST1) and the second sub-pattern (VST2) may be formed in the upper and lower directions on the other axis. In this regard, the second length (Lsb2) of the second sub-pattern (VST2) may be formed to be longer than the first length (Lsb1) of the first sub-pattern (VST1).

[0089] Referring to FIG. 10a(c), a first sub-pattern (VST1) and a second sub-pattern (VST2) may be formed in upper and lower directions on the other axis. In this regard, a second length (Ls2) of the second sub-pattern (VST2) may be formed to be identical to a first length (Ls1) of the first sub-pattern (VST1).

[0090] Referring to FIGS. 9 and 10b, the vertical stub pattern (VST) may be configured to include a first sub-pattern (VST1), a second sub-pattern (VST2), and a third sub-pattern (VST3). The first sub-pattern (VST1) may be formed with a first length (Lsa1, Lsb1, Ls1) in at least one direction of an upper or lower direction on the other axis at a first point of the horizontal stub pattern (HST). The second sub-pattern (VST2) may be formed with a second length (Lsa2, Lsb2, Ls2) parallel to the first sub-pattern (VST1) at a second point of the horizontal stub pattern (HST). The third sub-pattern (VST3) may be formed with a third length (Lsa3, Lsb3, Ls3) parallel to the first and second sub-patterns (VST1, VST2) at a third point of the horizontal stub pattern (HST). The third length (Lsa3, Lsb3, Ls3) of the third sub-pattern (VST3) may be formed to be longer than or equal to the second length (Lsa2, Lsb2, Ls2) of the second sub-pattern (VST2).

[0091] Referring to FIG. 10b(a), the vertical stub pattern (VST) can be formed in only one of the upper or lower directions on the other axis. Therefore, the vertical stub pattern (VST) can be implemented with an asymmetric structure. In this regard, the first sub-pattern (VST1), the second sub-pattern (VST2), and the third sub-pattern (VST3) can be formed in only one of the upper or lower directions on the other axis. The second length (Lsa2) of the second sub-pattern (VST2) can be formed to be longer than the first length (Lsa1) of the first sub-pattern (VST1). The third length (Lsa3) of the third sub-pattern (VST3) can be formed to be longer than the second length (Lsa2) of the second sub-pattern (VST2).

[0092] Meanwhile, the vertical stub pattern (VST) may be implemented as a symmetric structure. Referring to FIG. 10b(b), a first sub-pattern (VST1), a second sub-pattern (VST2), and a third sub-pattern (VST3) may be formed in upper and lower directions on the other axis. In this regard, a second length (Lsb2) of the second sub-pattern (VST2) may be formed to be longer than a first length (Lsb1) of the first sub-pattern (VST1). A third length (Lsb3) of the third sub-pattern (VST3) may be formed to be longer than a second length (Lsb2) of the second sub-pattern (VST2).

[0093] Referring to FIG. 10b(c), a first sub-pattern (VST1), a second sub-pattern (VST2), and a third sub-pattern (VST3) may be formed in upper and lower directions on the other axis. In this regard, a second length (Ls2) of the second sub-pattern (VST2) may be formed to be identical to the first length (Ls1) of the first sub-pattern (VST1). A third length (Ls3) of the third sub-pattern (VST3) may be formed to be identical to the second length (Ls2) of the second sub-pattern (VST2).

[0094] Referring to FIGS. 9 and 10c, the vertical stub pattern (VST) may be configured to include a first sub-pattern (VST1), a second sub-pattern (VST2), a third sub-pattern (VST3), and a fourth sub-pattern (VST4). The first sub-pattern (VST1) may be formed with a first length (Lsa1, Lsb1, Ls1) in at least one direction of an upper or lower direction on the other axis at a first point of the horizontal stub pattern (HST). The second sub-pattern (VST2) may be formed with a second length (Lsa2, Lsb2, Ls2) parallel to the first sub-pattern (VST1) at a second point of the horizontal stub pattern (HST). The third sub-pattern (VST3) may be formed with a third length (Lsa3, Lsb3, Ls3) at a third point of the horizontal stub pattern (HST) and parallel to the first and second sub-patterns (VST1, VST2). The fourth sub-pattern (VST4) may be formed with a fourth length (Lsa4, Lsb4, Ls4) at a fourth point of the horizontal stub pattern (HST) and parallel to the first to third sub-patterns (VST1, VST2, VST3). The third length (Lsa4, Lsb4, Ls4) of the fourth sub-pattern (VST4) may be formed to be longer than or equal to the third length (Lsa3, Lsb3, Ls3) of the third sub-pattern (VST3).

[0095] Referring to Fig. 10c(a), the vertical stub pattern (VST) can be formed in only one of the upper or lower directions on the other axis. Therefore, the vertical stub pattern (VST) can be implemented with an asymmetric structure. In this regard, the first sub-pattern (VST1), the second sub-pattern (VST2), the third sub-pattern (VST3), and the fourth sub-pattern (VST4) can be formed in only one of the upper or lower directions on the other axis. The second length (Lsa2) of the second sub-pattern (VST2) can be formed to be longer than the first length (Lsa1) of the first sub-pattern (VST1). The third length (Lsa3) of the third sub-pattern (VST3) can be formed to be longer than the second length (Lsa2) of the second sub-pattern (VST2). The fourth length (Lsa4) of the fourth sub-pattern (VST4) can be formed longer than the third length (Lsa3) of the third sub-pattern (VST3).

[0096] Meanwhile, the vertical stub pattern (VST) may be implemented as a symmetric structure. Referring to FIG. 10c(b), a first sub-pattern (VST1), a second sub-pattern (VST2), a third sub-pattern (VST3), and a fourth sub-pattern (VST4) may be formed in upper and lower directions on the other axis. In this regard, a second length (Lsb2) of the second sub-pattern (VST2) may be formed to be longer than a first length (Lsb1) of the first sub-pattern (VST1). A third length (Lsb3) of the third sub-pattern (VST3) may be formed to be longer than the second length (Lsb2) of the second sub-pattern (VST2). A fourth length (Lsb4) of the fourth sub-pattern (VST4) may be formed to be longer than a third length (Lsb3) of the third sub-pattern (VST3).

[0097] Referring to FIG. 10c(c), a first sub-pattern (VST1), a second sub-pattern (VST2), and a third sub-pattern (VST3) may be formed in upper and lower directions on the other axis. In this regard, a second length (Ls2) of the second sub-pattern (VST2) may be formed to be the same as the first length (Ls1) of the first sub-pattern (VST1). A third length (Ls3) of the third sub-pattern (VST3) may be formed to be the same as the second length (Ls2) of the second sub-pattern (VST2). A fourth length (Ls4) of the fourth sub-pattern (VST4) may be formed to be the same as the third length (Ls3) of the third sub-pattern (VST3).

[0098] Meanwhile, the spacing between sub-patterns of the vertical stub patterns of FIGS. 10A to 10C may be formed differently. In this regard, in order to place a stub pattern (1100f) including a plurality of sub-patterns within an area between adjacent antenna elements, the spacing between sub-patterns and / or the width of the sub-patterns may be designed to decrease as the number of sub-patterns increases.

[0099] The first sub-pattern (VST1) and the second sub-pattern (VST2) of FIG. 10a may be spaced apart by a first interval (Ga1). The first sub-pattern (VST1) and the second sub-pattern (VST2) of FIG. 5b may be spaced apart by a second interval (Gb1). The second sub-pattern (VST2) and the third sub-pattern (VST3) may be spaced apart by a third interval (Gb3). The second interval (Gb2) between the first sub-pattern (VST1) and the second sub-pattern (VST2) and the third interval (Gb3) between the second sub-pattern (VST2) and the third sub-pattern (VST3) may be set to be the same.

[0100] The second gap (Gb1) between the first sub-pattern (VST1) and the second sub-pattern (VST2) of FIG. 5b may be formed narrower than the first gap (Ga1) between the first sub-pattern (VST1) and the second sub-pattern (VST2) of FIG. 10a. The third gap (Gb2) between the second sub-pattern (VST2) and the third sub-pattern (VST3) of FIG. 10b may be formed narrower than the first gap (Ga1) between the first sub-pattern (VST1) and the second sub-pattern (VST2) of FIG. 10a. Meanwhile, the width of the first sub-pattern (VST1) of FIG. 5b may be formed narrower than the width of the first sub-pattern (VST1) of FIG. 5a. The width of the second sub-pattern (VST2) of FIG. 10b may be formed narrower than the width of the second sub-pattern (VST2) of FIG. 10a.

[0101] The first sub-pattern (VST1) and the second sub-pattern (VST2) of FIG. 10c may be spaced apart by a fourth interval (Gc1). The second sub-pattern (VST2) and the third sub-pattern (VST3) may be spaced apart by a fifth interval (Gc2). The third sub-pattern (VST3) and the fourth sub-pattern (VST4) may be spaced apart by a sixth interval (Gc3). The fourth interval (Gc1) between the first sub-pattern (VST1) and the second sub-pattern (VST2), the fifth interval (Gc2) between the second sub-pattern (VST2) and the third sub-pattern (VST3), and the sixth interval (Gc3) between the third sub-pattern (VST3) and the fourth sub-pattern (VST4) may be set to be the same.

[0102] The first sub-pattern (VST1) and the second sub-pattern (VST2) of FIG. 10b may be formed to have a fourth gap (Gc1) narrower than the second gap (Gb1) of the first sub-pattern (VST1) and the second sub-pattern (VST2) of FIG. 10c. The fifth gap (Gc2) of the second sub-pattern (VST2) and the third sub-pattern (VST3) of FIG. 10c may be formed to have a third gap (Gb2) of the second sub-pattern (VST2) and the third sub-pattern (VST3) of FIG. 10b. Meanwhile, the width of the first sub-pattern (VST1) of FIG. 10c may be formed to be narrower than the width of the first sub-pattern (VST1) of FIG. 5b. The width of the second sub-pattern (VST2) of FIG. 5c may be formed to be narrower than the width of the second sub-pattern (VST2) of FIG. 5b. The width of the third sub-pattern (VST3) of FIG. 10c may be formed narrower than the width of the third sub-pattern (VST3) of FIG. 5b.

[0103] Meanwhile, the length between adjacent sub-patterns in the feed structure (1100f) of the antenna module according to the present specification may be implemented within a certain range. In this regard, the second length (Lsa2, Lsb2, Ls2) of the second sub-pattern (VST2) may be formed to be 1 to 1.32 times the first length (Lsa1, Lsb1, Ls1) of the first sub-pattern (VST1). Meanwhile, the third length (Lsa3, Lsb3, Ls3) of the third sub-pattern (VST3) may be formed to be 1 to 1.32 times the second length (Lsa2, Lsb2, Ls2) of the second sub-pattern (VST3). Additionally, the fourth length (Lsa4, Lsb4, Ls4) of the fourth sub-pattern (VST4) may be formed to be 1 to 1.32 times longer than the third length (Lsa3, Lsb3, Ls3) of the third sub-pattern (VST3).

[0104] Meanwhile, the length of the longest sub-pattern in the feed structure (1100f) of the antenna module according to the present specification may be implemented to be no longer than a certain range greater than the length of the horizontal stub (HST). In this regard, the length of the longest sub-pattern among the sub-patterns of the vertical stub pattern (VST) may be formed to be no longer than 1.32 times the length of the horizontal stub pattern (HST).

[0105] Referring to FIG. 10a, the length of the longest sub-pattern (Lsa2, Lsb2, Ls2) among the sub-patterns of the vertical stub pattern (VST) may be formed to be 1.32 times or less of the length of the horizontal stub pattern (HST). Referring to FIG. 10b, the length of the longest sub-pattern (Lsa3, Lsb3, Ls3) among the sub-patterns of the vertical stub pattern (VST) may be formed to be 1.32 times or less of the length of the horizontal stub pattern (HST). Referring to FIG. 10c, the length of the longest sub-pattern (Lsa4, Lsb4, Ls4) among the sub-patterns of the vertical stub pattern (VST) may be formed to be 1.32 times or less of the length of the horizontal stub pattern (HST).

[0106] Meanwhile, in the array antenna structure of the antenna module according to the present specification, the spacing between adjacent antenna elements can be implemented within a predetermined range. In this regard, the spacing (G1) between the first antenna element (1110) and the second antenna element (1120) can be formed to be 0.8 times or more and 1.0 times or less of the wavelength corresponding to the operating frequency of the RF signal.

[0107] Meanwhile, the array antenna of the antenna module according to the present specification may include a plurality of antenna elements, for example, 4, 6, 8, 10, 12, 14, or 16 antenna elements. The plurality of antenna elements may include a first antenna element (1110) to an eighth antenna element (1180).

[0108] In the array antenna, the spacing (G1) between the second antenna element (1120) and the third antenna element (1130) may also be formed to be 0.8 times or more and 1.0 times or less of the wavelength corresponding to the operating frequency of the RF signal. Similarly, the spacing (G1) between the seventh antenna element (1170) and the third antenna element (1180) may also be formed to be 0.8 times or more and 1.0 times or less of the wavelength corresponding to the operating frequency of the RF signal.

[0109] Referring to FIGS. 3 to 7 and 9 to 10c, the feed structure (1100f) may include a horizontal stub pattern (HST) and a vertical stub pattern (VST). The horizontal stub pattern (HST) may be arranged in a uniaxial direction to connect adjacent antenna elements. The vertical stub patterns (VST) may be vertically connected to the horizontal stub pattern (HST) at different points on the horizontal stub pattern (HST).

[0110] Referring to FIG. 10A, the vertical stub patterns may be configured to include a first sub-pattern (VST1) and a second sub-pattern (VST2). The first sub-pattern (VST1) may be formed with a first length (Ls1) in an upper and lower direction on the other axis at a first point of the horizontal stub pattern (HST). The second sub-pattern (VST2) may be formed with a second length (Ls2) parallel to the first sub-pattern (VST1) at a second point of the horizontal stub pattern (HST). The first sub-pattern (VST1) may be arranged adjacent to the first antenna element (1110). The second sub-pattern (VST2) may be arranged adjacent to the second antenna element (1120).

[0111] Referring to FIG. 10b, the vertical stub patterns may be configured to include a first sub-pattern (VST1) to a third sub-pattern (VST3). The first sub-pattern (VST1) may be arranged adjacent to the first antenna element (1110). The third sub-pattern (VST3) may be arranged adjacent to the second antenna element (1120).

[0112] Referring to FIG. 10c, the vertical stub patterns may be configured to include a first sub-pattern (VST1) to a fourth sub-pattern (VST4). The third sub-pattern (VST3) may be formed with a third length (Ls3) parallel to the second sub-pattern (VST2) at a third point of the horizontal stub pattern (HST). The fourth sub-pattern (VST4) may be formed with a fourth length (Ls4) parallel to the third sub-pattern (VST3) at a fourth point of the horizontal stub pattern (HST). The first sub-pattern (VST1) may be arranged adjacent to the first antenna element (1110). The fourth sub-pattern (VST4) may be arranged adjacent to the second antenna element (1120).

[0113] Referring to FIGS. 3 to 7 and 9 to 10c, a liquid crystal layer (1020) may be disposed in a lower region in the Z-axis direction of a vertical stub pattern (VST) in an antenna module according to the present specification. In this regard, a region where the first sub-pattern (VST1) and the second sub-pattern (VST2) are disposed may be formed to overlap the first region (R1) to the seventh region (R7) of the liquid crystal layer (1020). Accordingly, the dielectric constant of the region where the first sub-pattern (VST1) and the second sub-pattern (VST2) are disposed may be varied depending on the voltage applied to the liquid crystal layer (1020), so that the directivity angle of a beam forming wireless signal in one direction may be changed.

[0114] The regions where the first to third sub-patterns (VST1) to (VST3) are arranged may be formed to overlap the first to seventh regions (R1) to (R7) of the liquid crystal layer (1020). Accordingly, the dielectric constant of the regions where the first to third sub-patterns (VST1) to (VST3) are arranged may be varied depending on the voltage applied to the liquid crystal layer (1020), thereby changing the direction angle of the beam forming wireless signal in one direction.

[0115] The regions where the first to fourth sub-patterns (VST1) to (VST4) are arranged may be formed to overlap the first to seventh regions (R1) to (R7) of the liquid crystal layer (1020). Accordingly, the dielectric constant of the regions where the first to fourth sub-patterns (VST1) to (VST4) are arranged may be varied depending on the voltage applied to the liquid crystal layer (1020), thereby changing the direction angle of the beam forming wireless signal in one direction.

[0116] Meanwhile, the feed structure of the antenna module having a phase delay according to the present specification can be implemented as a slow-wave structure having a phase delay by a variable dielectric layer such as a liquid crystal layer. In this regard, FIG. 11 shows slow-wave structures according to embodiments. FIG. 11(a) to FIG. 11(d) may be referred to as a tapered structure, a stepped structure, a meander structure, and a comb structure, respectively. Meanwhile, FIG. 12 shows a propagation delay coefficient according to an impedance ratio in a slow-wave structure according to the present specification.

[0117] Referring to FIGS. 9 to 11, a slow-wave structure may be implemented to delay the phase of a signal transmitted through a transmission line of a power supply structure (1100f). The slow-wave structure may be configured to delay the phase component of an output signal according to a slow-wave factor (SWF).

[0118] The feed structure (1100f) of FIGS. 9 to 10c can be implemented as a comb structure. The comb-shaped feed structure (1100f) has the best performance in terms of impedance matching and symmetry compared to other structures. The slow-wave structure can be formed with multiple stages having different impedances (Z) on a transmission line. The feed structures of FIGS. 10a to 10c are structures formed with 2, 3, and 4 stages, respectively.

[0119] It can be interpreted as a structure in which impedance stages consisting of RLC circuits are connected in series, equivalently in a structure in which the stages are arranged in a cross or repeat manner. At this time, in order to match the impedance of the entire transmission line, all stages (Z in case of 2 stages for calculation convenience) are connected. A Wow Z B (Z A < Z0< Z B ) must be equal to the characteristic impedance of the input / output transmission line (Z0=50Ω). At this time, the impedance ratio of each stage (Z B / Z A ) can be determined as in mathematical expression 1, the propagation delay factor (SWF).

[0120]

[0121] The impedance between adjacent vertical line structures in the comb structure of Fig. 11(d) is Z A and Z B, which can be referred to as . Referring to FIGS. 9 to 10c, 11(d) and 12, the impedance ratio (Z) of each stage B / Z A ) The larger the difference, the larger the propagation delay factor (SWF). Also, the larger the propagation delay factor (SWF), the larger the phase delay. As the phase delay is larger, a longer electrical length can be realized within a limited area between adjacent antenna elements.

[0122] Meanwhile, an antenna module equipped with a feed structure according to the present specification can be designed to have different phase delay characteristics as the length of the vertical stub pattern changes. In this regard, FIGS. 13a to 13c illustrate phase delay characteristics of the feed structure according to embodiments as the permittivity and the length of the longest vertical stub pattern change. Meanwhile, FIG. 14 illustrates an equivalent circuit of a feed structure including adjacent stub patterns of FIGS. 13a to 13c.

[0123] In a structure having three vertical stub patterns of FIG. 10b(b), different phase delay characteristics can be implemented by changing the permittivity and the length of the longest third vertical stub pattern (VST3).

[0124] Referring to FIG. 10b(b) and FIG. 13a, the length (Lsb3) of the third vertical stub pattern (VST3) is 2.8 mm, and the permittivity (DK) can be varied from 2.2 to 3.6. As the permittivity increases from 2.2 to 3.6, the phase delay value of the feed structure increases. By increasing the permittivity of the liquid crystal layer of the feed structure, the antenna elements can be arranged closer together or the beamforming range can be increased as the phase delay value increases. When Lsb3 = 2.8 mm, the maximum phase shift is 107 degrees as the permittivity increases from 2.2 to 3.6.

[0125] Referring to FIG. 10b(b) and FIG. 13b, the length (Lsb3) of the third vertical stub pattern (VST3) is 3.6 mm and the permittivity (DK) can be changed from 2.2 to 3.6. As the permittivity increases from 2.2 to 3.6, the phase delay value of the feed structure increases. In addition, as the length (Lsb3) of the third vertical stub pattern (VST3) increases, the phase delay value increases. Therefore, by increasing the length (Lsb3) of the third vertical stub pattern (VST3), the antenna elements can be arranged closer together or the beamforming range can be increased as the phase delay value of the feed structure increases. When Lsb3=3.6 mm, the maximum phase shift can increase to 121 degrees as the permittivity increases from 2.2 to 3.6.

[0126] Referring to FIG. 10b(b) and FIG. 13c, the length (Lsb3) of the third vertical stub pattern (VST3) is 4.4 mm and the permittivity (DK) can be changed from 2.2 to 3.6. As the permittivity increases from 2.2 to 3.6, the phase delay value of the feed structure increases. In addition, as the length (Lsb3) of the third vertical stub pattern (VST3) increases, the phase delay value increases. Therefore, by increasing the length (Lsb3) of the third vertical stub pattern (VST3), the antenna elements can be arranged closer together or the beamforming range can be increased as the phase delay value of the feed structure increases. When Lsb3 = 4.4 mm, the maximum phase shift can increase to 148 degrees as the permittivity increases from 2.2 to 3.6.

[0127] Fig. 14(a) illustrates a feed structure having adjacent vertical stub patterns as an equivalent circuit of an open stub microstrip resonator. Fig. 14(b) illustrates a feed structure having adjacent vertical stub patterns as an equivalent circuit of an RLC resonator.

[0128] Referring to FIGS. 13a to 13c and 14(a), one end and the other end of the horizontal stub pattern (HST) may correspond to the first port (Port 1) and the second port (Port 2). The input impedance of the horizontal stub pattern (HST) is the same as Z0. Depending on the line width of the horizontal stub pattern (HST), the impedance is Z m and the propagation constant is g m can be expressed as . Adjacent vertical stub patterns can correspond to the first and second stubs (Stub1, Stub2). Depending on the line width of the first stub (Stub1), Z s and the propagation constant is g s can be expressed as

[0129] Referring to FIGS. 13a to 13c and 14(b), one end and the other end of the horizontal stub pattern (HST) may correspond to the first port (Port 1) and the second port (Port 2). The input impedance of the horizontal stub pattern (HST) is equal to Z0. Depending on the line width of the horizontal stub pattern (HST), the impedance may be Z m and the propagation constant is g m can be expressed as . Adjacent vertical stub patterns can correspond to the first and second stubs (Stub1, Stub2).

[0130] A first stub (Stub1) may be configured to connect a first point of a horizontal stub pattern (HST) and ground. The first stub (Stub1) may be configured to include a first resistor (R1), a first inductor (L1), and a first capacitor (C1). One end and the other end of the first resistor (R1) may be connected to the first point of the horizontal stub pattern (HST) and one end of the first inductor (L1), respectively. One end and the other end of the first inductor (L1) may be connected to the other end of the first resistor (R1) and one end of the first capacitor (C1), respectively. One end and the other end of the first capacitor (C1) may be connected to the other end of the first inductor (L1) and ground, respectively.

[0131] The second stub (Stub2) may be configured to include a second resistor (R2), a second inductor (L2), and a second capacitor (C2). One end and the other end of the second resistor (R2) may be connected to a second point of the horizontal stub pattern (HST) and one end of the second inductor (L2), respectively. One end and the other end of the first inductor (L1) may be connected to the other end of the second resistor (R2) and one end of the second capacitor (C2), respectively. One end and the other end of the second capacitor (C2) may be connected to the other end of the second inductor (L2) and ground, respectively.

[0132] Meanwhile, beamforming of a two-dimensional array antenna is possible by varying the dielectric constant of the liquid crystal layer in an antenna module equipped with a power supply structure according to the present specification. In this regard, Fig. 15 shows a radiation pattern formed in the first axis direction by varying the dielectric constant of the liquid crystal layer. Fig. 16 shows a radiation pattern formed in the second axis direction by varying the dielectric constant of the liquid crystal layer.

[0133] Figures 15(a) to 15(d) show radiation patterns beam-formed at -45 degrees, -22.5 degrees, 0 degrees, and 45 degrees in the first axis (horizontal axis) direction, respectively. Referring to Figures 3, 4, 9, and 15, the first to seventh feed structures (1110f to 1170f) can be arranged in the Y-axis direction. As the permittivity of the liquid crystal layer (1020) under the feed structure (1100f) increases, the directivity angle of the radiation pattern in the horizontal axis direction changes from 0 degrees to -45 degrees (or 45 degrees).

[0134] Figures 16(a) to 16(c) show radiation patterns beam-formed at -30 degrees, 0 degrees, and 30 degrees in the vertical axis direction, respectively. In the array antennas of Figures 3, 4, and 9, beam-forming in the vertical axis direction can be achieved by applying different DC voltages to the eighth antenna element.

[0135] Alternatively, a separate phase control circuit may be added to the feed line (FL) of the array antenna of FIGS. 3, 4, and 9. By arranging the separate phase control circuit in the vertical axis direction, the directivity angle of the radiation pattern can be changed from 0 degrees to -30 degrees (or 30 degrees) in the horizontal axis direction. Therefore, in the present specification, the number of RF chains connected to the elements of the array antenna can be reduced. High radiation gain can be maintained while simplifying the separate phase control circuit. In addition, the antenna module having a phase delay according to the present specification is capable of beam scanning in two axes in two dimensions, not limited to a single axis in one dimension, during beam scanning.

[0136] The above describes an antenna module having a phase delay according to the present specification. The technical effects of the antenna module having a phase delay according to the present specification are as follows.

[0137] According to an embodiment, beamforming is possible within a limited area through an array antenna having a liquid crystal layer and a phase delay feed structure.

[0138] According to an embodiment, two-dimensional beamforming is possible in a frequency band of millimeter waves or higher while minimizing the number of phase control circuits through an array antenna having a liquid crystal layer and a phase delay feed structure.

[0139] According to an embodiment, signal separation is enabled between a signal connection line transmitting a DC signal and an RF signal terminal, thereby enabling two-dimensional beam forming capable of DC blocking while optimizing RF performance in a frequency band of millimeter waves or higher.

[0140] Further scope of the applicability of this disclosure will become apparent from the detailed description below. However, since various changes and modifications within the spirit and scope of this disclosure will become apparent to those skilled in the art, it should be understood that the detailed description and specific embodiments, such as the preferred embodiments of this disclosure, are given by way of example only. The detailed description should not be construed as limiting in any respect but rather as illustrative. The scope of this disclosure should be determined by a reasonable interpretation of the appended claims, and all changes coming within the scope of equivalents of this disclosure are intended to be embraced therein.

Claims

1. In the antenna module, dielectric substrate; A liquid crystal layer disposed within the dielectric substrate or laminated with the dielectric substrate; An array antenna comprising a plurality of antenna elements arranged in a uniaxial direction on one surface of the dielectric substrate and radiating a beamforming wireless signal; and It includes feeding structures configured to connect adjacent antenna elements in the uniaxial direction among the plurality of antenna elements, An antenna module in which the liquid crystal layer is arranged to overlap the power supply structures, and the direction angle of the beam forming wireless signal in the uniaxial direction is changed according to the voltage value applied to the liquid crystal layer.

2. In paragraph 1, The above plurality of antenna elements include first antenna elements to eighth antenna elements, A feeding line is connected so that an RF signal is applied to the first antenna element arranged on one side of the plurality of antenna elements, An antenna module in which a signal connection line is connected so that a DC voltage is applied to the eighth antenna element arranged on the other side among the plurality of antenna elements.

3. In paragraph 2, The above-mentioned feeding structure includes a first feeding structure formed between the first and second antenna elements and a seventh feeding structure formed between the seventh and eighth antenna elements, The liquid crystal layer includes first to eighth regions arranged in a lower region of the first to seventh feed structures so as to overlap the first to seventh feed structures, and the antenna module.

4. In paragraph 3, The above plurality of antenna elements are arranged in a plurality of columns and rows in the one-axis direction and the other-axis direction to form a two-dimensional array antenna, The first region is formed to overlap the first feed structure between the first antenna element and the second antenna element between the first row to the eighth row in the other axis direction, An antenna module in which the seventh region is formed to overlap the seventh antenna element between the first row to the eighth row and the seventh feed structure between the eighth antenna element.

5. In paragraph 4, The first spacing between adjacent antenna elements in the above uniaxial direction is a value within a predetermined range based on the wavelength corresponding to the operating frequency, An antenna module, wherein the second spacing between adjacent antenna elements in the above-described other axis direction is a value within a predetermined range based on half of the wavelength corresponding to the operating frequency.

6. In paragraph 4, The above liquid crystal layer, An eighth region formed to connect one end of the first region and one end of the seventh region; and An antenna module further comprising a ninth region formed to connect the other end of the first region and the other end of the seventh region.

7. In paragraph 4, A first hole formed on one side of the eighth region so that liquid crystal can be injected into the liquid crystal layer; and An antenna module including a second hole formed on the other side of the ninth region so that air within the liquid crystal layer can be discharged to the outside.

8. In paragraph 4, The above signal connection lines are connected to the upper vertices of the first antenna elements of the first to eighth rows, An antenna module, wherein a radial stub formed with a first radius and a first angle is connected to a point of a second signal connection line to which the above signal connection lines are connected.

9. In paragraph 4, The above signal connection lines are connected to the upper vertices of the first antenna elements of the first to eighth rows, An antenna module, wherein radial stubs formed at a first radius and a first angle are connected to each point of the above signal connection lines.

10. In paragraph 4, Each of the above feed lines, A first sub-pattern connected to the eighth antenna elements of the first to eighth rows and formed with a predetermined length and width; A second sub-pattern spaced apart from the first sub-pattern in the uniaxial direction and formed with a predetermined length and width; and A first coupling pattern having one end connected to an end of the first sub-pattern and the other end spaced apart from an end of the second sub-pattern; and A second coupling pattern is included, one end of which is connected to an end of the second sub-pattern and the other end is spaced apart from an end of the first sub-pattern, An antenna module wherein the first coupling pattern and the second coupling pattern are arranged in parallel and formed with a length within a predetermined range based on 1 / 4 of the wavelength corresponding to the operating frequency.

11. In paragraph 10, The second coupling pattern is connected to one end of the second sub-pattern at the first point. Further comprising a third coupling pattern connected to one end of the second sub-pattern and a second point, and arranged parallel to the first coupling pattern and the second coupling pattern; An antenna module, wherein the first coupling pattern is arranged with a predetermined interval between the second coupling pattern and the third coupling pattern.

12. In paragraph 4, The above power supply structure is, a horizontal stub pattern arranged in the uniaxial direction to connect the adjacent antenna elements; and An antenna module comprising vertical stub patterns vertically connected to the horizontal stub at different points on the horizontal stub pattern.

13. In paragraph 12, The above vertical stub patterns are, A first sub-pattern formed with a first length in the upper and lower directions on the other axis at a first point of the horizontal stub pattern; and An antenna module comprising a second sub-pattern formed with a second length parallel to the first sub-pattern at a second point of the horizontal stub pattern.

14. In paragraph 13, The above vertical stub patterns are, A third sub-pattern formed with a third length parallel to the second sub-pattern at a third point of the horizontal stub pattern; and A fourth sub-pattern is formed with a fourth length parallel to the third sub-pattern at the fourth point of the horizontal stub pattern, An antenna module, wherein the first sub-pattern is arranged adjacent to the first antenna element, and the fourth sub-pattern is arranged adjacent to the second antenna element.

15. In paragraph 14, The area where the first to fourth sub-patterns are arranged is formed to overlap with the first to seventh areas of the liquid crystal layer, An antenna module in which the dielectric constant of the region where the first to fourth sub-patterns are arranged is changed according to the voltage applied to the liquid crystal layer, thereby changing the direction angle of the beam forming wireless signal in the uniaxial direction.

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