Series-fed directional pattern patch antenna

Abstract

The application discloses a series feeding directional pattern shaped patch antenna, which is a compact, low-cost, high-gain and arbitrary beam shape realizable series feeding antenna, and achieves the purpose of miniaturization of the shaped antenna. The antenna comprises a dielectric substrate, a feeding line, a plurality of radiation patches and a metal grounding plate. The dielectric substrate comprises oppositely arranged top and bottom surfaces; the feeding line and the radiation patches are attached to the top surface of the dielectric substrate; and the metal grounding plate is attached to the bottom surface of the dielectric substrate. The plurality of radiation patches are distributed along the feeding line, and a slot structure one is formed on the radiation patches; and a slot structure two is formed at a set position of the feeding line. The application realizes the accurate control of the amplitude and phase of the unit through the special design of the series feeding antenna and the radiation unit, so as to achieve the purpose of realizing arbitrary beam shaping of the microstrip traveling wave series feeding antenna.

Description

Technical Field

[0001] This invention relates to the field of antenna technology, and more specifically to a series-fed pattern-shaped patch antenna. Background Technology

[0002] Series-fed patch antennas offer advantages such as compact structure, simple fabrication, low cost, and ease of integration, making them widely used in wireless communication, target detection, remote sensing, and other applications. However, due to the difficulty in precisely controlling the amplitude and phase of the radiating elements and other unknown factors, existing series-fed patch antennas primarily focus on sidelobe suppression for pattern control, making it difficult to achieve effective beamform control.

[0003] Applications such as traffic monitoring radar and autonomous driving assistance radar require antennas with high gain, compact structure, low cost, and a specified beamform, necessitating precise amplitude and phase control of the shaped array. Traditional methods for amplitude and phase control via parallel feeding are simple in design, but the parallel feeding network is bulky, has high spurious emissions, and is not conducive to system miniaturization.

[0004] Therefore, how to achieve arbitrary beamforming while ensuring system miniaturization, and how to achieve precise control of the amplitude and phase of the array radiation elements, has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a series-fed pattern-shaped patch antenna, which is a miniaturized, low-cost, high-gain antenna array capable of arbitrary beamforming, thus achieving the goal of miniaturization of shaped antennas.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: a series-fed pattern-shaped patch antenna, comprising a dielectric substrate, a feed line, multiple radiating patches, and a metal ground plane.

[0007] The dielectric substrate includes a top surface and a bottom surface disposed opposite to each other; both the feed line and the radiating patch are attached to the top surface of the dielectric substrate; and the metal ground plane is attached to the bottom surface of the dielectric substrate.

[0008] Multiple radiating patches are distributed along the feed line; a slotted structure is formed on the radiating patches.

[0009] Furthermore, by designing the shape and size of the radiating patch, it is made to operate in a resonant state.

[0010] Furthermore, the projection length of the radiating patch on the feed line is taken as the width of the radiating patch; by designing the shape of the radiating patch and adjusting its width, the radiation amplitude of the radiating patch can be adjusted.

[0011] Furthermore, the radiation phase of the radiation patch can be adjusted by regulating the distance between adjacent radiation patches.

[0012] Preferably, multiple radiating patches are disposed on the same side or both sides of the feed line.

[0013] Furthermore, a matching unit is connected to the end of the feeder to absorb and radiate the remaining energy in the feeder.

[0014] Preferably, the slot structure is formed on one end of the radiating patch that is connected to the feed line, in order to reduce the width of the connection line between the radiating patch and the feed line.

[0015] Preferably, the slot structure is located on the radiating patch at the end furthest from the feed line.

[0016] Furthermore, the feed amplitude and feed phase of each radiating patch are obtained through pattern synthesis calculation with the beam shape requirement as the optimization objective.

[0017] Furthermore, a second slot structure is opened at a set position on the feed line to weaken the standing wave energy in the feed line. The number of slot structures is less than or equal to the number of radiating patches.

[0018] Beneficial effects:

[0019] 1. The series-fed pattern-shaped patch antenna provided by this invention has the following advantages: This invention achieves precise control of element amplitude and phase through a special design of the series-fed antenna and its radiating patch, thereby achieving arbitrary beamforming in a microstrip traveling-wave series-fed antenna. This invention utilizes a microstrip series-fed antenna to achieve precise beamforming, and by using series feeding, the size of the shaped antenna is greatly reduced, which is beneficial for the miniaturization and lightweight design of millimeter-wave radar.

[0020] 2. The series-fed pattern-forming patch antenna provided by the present invention has a matching unit connected at the end of the feed line and perpendicular to the radiating patch, which is used to absorb the remaining energy in the feed line to achieve traveling wave excitation. The main polarization direction of the matching unit is perpendicular to the main polarization direction of the radiating patch. Its beneficial effect is that it avoids the influence of the radiated energy of the matching unit on the pattern.

[0021] 3. The series-fed pattern-shaped patch antenna provided by this invention has several slot structures etched on the feed line at positions close to a specific radiating patch to suppress the reflected energy of the radiating patch. Its beneficial effect is that, without affecting the amplitude distribution of the microstrip series-fed pattern-shaped patch antenna, it suppresses the standing wave component in its feed line, enhances the purity of traveling wave excitation, and achieves precise phase control of the microstrip series-fed antenna. Attached Figure Description

[0022] Figure 1This is a simulation structure diagram of a 16-element series-fed pattern-shaped patch antenna provided in Embodiment 1 of the present invention, where Dn represents the distance between the center of the rectangular slot and the corresponding radiating patch feed center;

[0023] Figure 2 This is a comparison diagram of the surface current distribution of the radiating patch in a 16-element series-fed pattern-shaped patch antenna according to Embodiment 1 of the present invention and the surface current distribution of a traditional rectangular radiating patch.

[0024] Figure 3 This is a simulated radiation pattern of the H-plane of the radiating patch in a 16-element series-fed pattern-shaped patch antenna provided in Embodiment 1 of the present invention.

[0025] Figure 4 This is a comparison diagram of the adjustable radiation energy range of the radiating patch in a 16-element series-fed pattern-shaped patch antenna according to Embodiment 1 of the present invention and the adjustable radiation energy range of a traditional rectangular radiating patch.

[0026] Figure 5 This is a comparison of the simulated normalized radiation pattern, PSO synthesized radiation pattern, and target beamforming curve of a 16-element series-fed pattern-shaped patch antenna operating at 80 GHz, provided in Embodiment 1 of the present invention. The H-plane beamforming surface is shown in the figure. Figure 1 Mid-horizontal direction;

[0027] Figure 6 The simulated H-plane radiation patterns of a 16-element series-fed pattern-shaped patch antenna provided in Embodiment 1 of the present invention at operating frequencies of 79, 80, and 81 GHz reflect the antenna's gain and beam pointing within the operating frequency band.

[0028] Figure 7 The simulation results of the reflection parameter S11 of a 16-element series-fed pattern-shaped patch antenna provided in Embodiment 1 of the present invention;

[0029] Figure 8 This is a simulation structure diagram of a 16-element series-fed pattern-shaped patch antenna provided in Embodiment 2 of the present invention, where Dn represents the distance between the center of the elliptical slot and the corresponding radiating patch feed center;

[0030] Figure 9 This is a comparison of the simulated normalized radiation pattern, PSO synthesized radiation pattern, and target beamforming curve of a 16-element series-fed pattern-shaped patch antenna operating at 80 GHz, provided in Embodiment 2 of the present invention. The H-plane beamforming surface is shown in the diagram. Figure 8 Mid-horizontal direction;

[0031] Figure 10The simulation results of the reflection parameter S11 of a 16-element series-fed pattern-shaped patch antenna provided in Embodiment 2 of the present invention;

[0032] Figure 11 Other forms of arrays that may implement beamforming provided by the present invention.

[0033] Figure 12 Other optional forms of the radiation patch provided by the present invention. Detailed Implementation

[0034] The following is in conjunction with the appendix Figure 1-12 The present invention provides a more comprehensive description of the microstrip series-fed shaped antenna and its design method, along with specific embodiments. The advantages and features of the invention will become clearer from the following description.

[0035] The series-fed pattern-shaped patch antenna provided by the present invention includes: a dielectric substrate 1, a feed line 2, multiple radiating patches 3, and a metal ground plane.

[0036] The dielectric substrate 1 includes a top surface and a bottom surface disposed opposite to each other; the feed line 2 and the radiating patch 3 are both attached to the top surface of the dielectric substrate 1; and the metal ground plane is attached to the bottom surface of the dielectric substrate 1.

[0037] Multiple radiating patches 3 are distributed along the feed line 2, and slot structures 31 are formed on the radiating patches 3. In this embodiment of the invention, the radiating patches 3 can be patches of various shapes, and the shapes of the radiating patches on the same feed line 2 can be different, such as... Figure 12 As shown, the radiating patch can be rectangular, trapezoidal, or elliptical.

[0038] In this embodiment of the invention, the shape and size of the radiating patch 3 are designed to make the radiating patch 3 operate in a resonant state. In a specific embodiment provided by the invention, the length from the edge of the feed line 2 to the upper edge of the radiating patch 3 is used as the current path length of the radiating patch. The shape and size of the radiating patch 3 are designed to adjust the current path length of the radiating patch, thereby making the radiating patch 3 operate in a resonant state.

[0039] The projection length of the radiating patch 3 on the feeder 2 is used as the width of the radiating patch. By designing the shape of the radiating patch 3 and adjusting its width, the radiation amplitude of the radiating patch can be adjusted. The radiation phase of the radiating patch is adjusted by adjusting the distance between adjacent radiating patches 3. Multiple radiating patches 3 are arranged on the same side or both sides of the feeder 2, and the radiating patch 3 at the very end of the feeder 2 is used to absorb and radiate the remaining energy in the feeder.

[0040] The function of the etched groove structure 31 on the radiating patch is to constrain the current flow direction, thereby reducing the cross-polarization of the radiating patch. The groove structure 31 on the radiating patch 3 can have various shapes, and its location is not limited. It can be located at the connection between the radiating patch 3 and the feed line 2, or at the upper end of the radiating patch 3. For example, the groove structure 31 can be located on the connection line between the radiating patch 3 and the feed line 2. In this case, the groove structure 31 reduces the width of the connection line between the radiating patch 3 and the feed line 2. For example, in a specific embodiment of the present invention, by creating the groove structure 31 at the connection line between the radiating patch and the feed line, the width of the connection line is made less than 1 / 3 of the width of the radiating patch. To achieve good beamforming characteristics, the cross-polarization of the radiating patch within the beamforming angle range should generally be lower than -10dB. The lower the cross-polarization, the better for achieving beamforming. Alternatively, the groove structure 31 can also be located on the end of the radiating patch away from the feed line.

[0041] Cross-polarization is suppressed on the radiating patch 3 by etching groove structure 31. The design principle is as follows:

[0042] 1) Reduce the width of the connection line between the radiating patch 3 and the feed line 2 (the width of the connection line should generally be less than 1 / 3 of the patch width) so that the current flow in the feed line turns and flows into the radiating patch as close as possible to perpendicular to the feed line.

[0043] 2) Constrain the oscillation direction of the current on the radiating patch 3 so that the radiating current oscillates as close as possible to the direction perpendicular to the feed line;

[0044] 3) The slot structure 31 will affect the radiation power of the radiation patch 3. When optimizing the cross polarization of the radiation patch 3, the radiation power should be taken into account.

[0045] Alternatively, a matching unit 4 can be set at the end of feed line 2 to realize the traveling wave mode of the series feed array. This mode can also be realized by loading other structures, such as connecting the metal strip to the metal ground plane through metal vias to guide the remaining energy in the feed line into the ground plane.

[0046] Specific methods for controlling radiation amplitude distribution:

[0047] Preferably, the width of the radiation patch is adjusted to achieve the corresponding radiation amplitude, and the specific calculation process is as follows:

[0048] 1) Based on the energy distribution relationship of each radiating patch, the amplitude distribution of the radiating patch is converted into the coupling power CP distribution, where CP is the ratio of the energy of the input radiating patch to the radiated energy of the radiating patch.

[0049] 2) The S11 and S21 parameters of radiating patches of different widths were obtained through the radiating patch simulation model, and the coupling power CP corresponding to radiating patches of different widths was calculated:

[0050] CP = (1 - |S11|) 2 -|S21| 2 / |S21′| 2 )×100%

[0051] Where S21′ is the S21 parameter of the microstrip line of the same length as in the unit simulation model, representing the transmission line loss in the radiating patch model. Alternatively, the transmission line loss can be ignored depending on the situation.

[0052] CP = (1 - |S11|) 2 -|S21| 2 )×100%

[0053] 3) Based on the coupling power CP distribution corresponding to the amplitude distribution in 1), and combined with the coupling power CP corresponding to different width radiating patches obtained in 2), determine the unit width corresponding to the radiation amplitude of the radiating patch.

[0054] Specific methods for controlling radiation phase distribution:

[0055] Several radiating patches 3 are alternately distributed vertically (or on one side) on both sides of the feed line 2, with the radiating patches 3 spaced at approximately 1 / 2λ intervals. g Based on this, it moves a certain distance, which is calculated from the radiation phase of the radiation patch 3. Specifically, the moving distance Mn is calculated from the phase value β required to achieve cosecant squared shaping. n The calculation yields: Mn = β n / π*Sp(or Mn=β) n / (2*π)*Sp);Sp is the spacing between adjacent radiating patches 3 when in-phase excitation is achieved.

[0056] In this embodiment of the invention, in order to weaken the standing wave energy in the feeder, a second groove structure 21 is opened at a set position on the feeder 2. Specifically, the second groove structure 21 can be opened around the selected radiating patch 3. The number of second groove structures 21 is less than or equal to the number of radiating patches 3. The shape of the second groove structure 21 can be rectangular, elliptical, triangular, etc.

[0057] The size of the slot structure 21 and its distance Dn from the radiating patch 3 are determined by element simulation to minimize the element reflection coefficient S11. Specifically, the radiating patch and a section of feed line connected to it are used as the element model.

[0058] 1) Take a microstrip line of the same length as the feed line in the unit model, etch a groove structure on it, and simulate to obtain the reflection coefficient S of the microstrip line. 11s By changing the size of the second slot structure on the microstrip line, when S 11s Amplitude and corresponding unit model reflection coefficient S 11eWhen the amplitudes are equal, the size of the second slot structure on the microstrip line at this point is taken as the initial size of the second slot structure in the element model. The size of the second slot structure refers to the dimensions related to its shape. For example, when the second slot structure is rectangular, its size represents its length and width; when it is triangular, its size represents its base and height; and when it is elliptical, its size represents its short side and wide side. That is, for different shapes of the second slot structure, the size is represented by the dimensions that best characterize its structural size.

[0059] 2) Determine the distance Dn between the slot structure 21 and the nearest radiating patch 3: Dn=[±π-(∠S 11e -∠S 11s )]×λ g ÷4π, where ∠S 11e Let ∠S be the phase of the reflection coefficient of the unit model. 11s λ represents the phase of the reflection coefficient of the microstrip line in the second etched trench structure; g Waveguide wavelength;

[0060] 3) Based on the initial size of the second slot structure, the size of the second slot structure is optimized by overall simulation of the radiating patch and the second slot structure, so that its overall reflection coefficient S11 reaches the minimum value at the designed frequency.

[0061] Example 1:

[0062] This embodiment provides a 16-element cascaded fed pattern-shaped patch antenna, such as... Figure 1 As shown, the antenna includes: a dielectric substrate 1, including a top surface and a bottom surface opposite to the top surface; a feed line 2, 16 radiating patches 3, and a matching unit 4, all attached to the top surface of the dielectric substrate; and a metal ground plane attached to the bottom surface of the dielectric substrate. The radiating patches 3 are fixed on both sides of the feed line, and the feed line 2 is connected to the matching unit 4. Rectangular slots 21 are etched on the feed line near specific radiating patches 3. The antenna dimensions are 20.8mm * 2.64mm.

[0063] Please continue to refer to this. Figure 1 The dielectric substrate 1 has a relative permittivity of 3.04 and a thickness of 0.127 mm; the feed line 2, the radiating patch 3, the matching unit 4 and the metal ground plane are made of copper foil with a thickness of 18 μm; the feed line 2 has a width of 0.3 mm and a characteristic impedance of 50 Ω.

[0064] Please continue to refer to this. Figure 1 The 16 radiating patches 3 have two "L-shaped" groove structures 31 engraved on the traditional rectangular patches to suppress unit cross-polarization and widen the range of radiated energy regulation.

[0065] Figure 2 , Figure 3The cross-polarization characteristics of the radiating patch 3 in this embodiment are explained by the surface current distribution and the unit radiation pattern, respectively. Figure 2 This is a comparison of the surface current of radiating patch 3 and a traditional rectangular radiating patch at 80 GHz. Figure 2 The two "L-shaped" groove structures 31 restrict the surface current of the radiation patch 3 to the vertical direction, so most of the radiation energy is excited by the surface current in the vertical direction, resulting in higher polarization purity. In contrast, the surface current of the traditional rectangular unit has strong lateral and vertical components, resulting in low polarization purity, which is not conducive to obtaining the amplitude and phase values ​​required for shaping. Figure 3 Simulated radiation patterns on the 3H plane of radiating patches with different element widths. Figure 3 This indicates that within the adjustable radiated power range, with a unit width of [0.65, 0.95] mm, the cross-polarization energy of radiating patch 3 is at least 20 dB lower than the main polarization energy at normal phi = 0°, and cross-polarization is greatly suppressed. At the same time, the normalized radiation patterns of radiating patches of different widths tend to be consistent, reducing the difficulty of phase control of the radiating patch of the series-fed antenna.

[0066] Figure 4 The adjustable radiation power range corresponds to that of the radiating patch 3 and the traditional rectangular radiating patch. Figure 4 It is noted that the adjustable radiation power range of the radiating patch 3 is [7.1%, 35.4%], while the adjustable radiation power range of the traditional rectangular patch is [5.4%, 15.4%]. The adjustable radiation power range of the radiating patch 3 is approximately three times that of the traditional radiating patch.

[0067] To achieve cosecting square shaping of the H-plane radiation pattern of the series-fed pattern-shaping patch antenna in this embodiment, the amplitude and phase distribution of the 16 radiating patches are optimized based on the pattern product principle.

[0068] Please continue to refer to this. Figure 1 Sixteen radiating patches are alternately distributed vertically on both sides of the feed line. The length of each radiating patch is Le = 1.17 mm, approximately half the waveguide wavelength. The radiating patches are moved a distance Mn from the initial spacing Sp = 1.17 mm. Mn is determined by the desired phase value β. n The calculation yields: Mn = β n / pi*Sp. The cell width is calculated from the amplitude value required to implement cocutter squared shaping, and the specific calculation method is as follows:

[0069] 1. Based on the energy distribution relationship of each radiating patch, the amplitude distribution of the radiating patch is transformed into the element coupling power CP distribution:

[0070] 2: The S-parameters of radiating patches of different widths were obtained through element simulation, and their coupling power CP was calculated.

[0071] CP = (1 - |S11|)2 -|S21| 2 / |S21′| 2 )×100%

[0072] Wherein, S21′ is the S21 parameter of the microstrip line of the same length as in the unit simulation model.

[0073] 3: Based on 1 and 2, determine the cell width corresponding to the radiation amplitude of the radiation patch.

[0074] Please continue to refer to this. Figure 1 The matching unit 4 is connected to the end of the feed line 2, enabling the series-fed antenna of this embodiment to operate in traveling wave mode. Simultaneously, several rectangular slots 21 of different sizes are etched on the feed line at a specific distance from the specific radiating patch 3. The rectangular slots S11 have the same amplitude and opposite phase to the radiating patch S11. The size of the rectangular slots controls the amplitude of S11, and the distance Dn from the radiating patch controls the phase of S11. Thus, without significantly affecting the antenna amplitude distribution, the standing wave energy in the feed line is greatly suppressed, and the purity of the traveling wave energy is greatly improved. This is a prerequisite for precise control of the amplitude and phase of the radiating patch.

[0075] Figure 5 This is a comparison of the simulated normalized radiation pattern of the target beamforming curve, the integrated radiation pattern, and the series-fed radiation pattern of the 16-radiating patch antenna H-plane beamforming surface in this embodiment. Figure 5 This demonstrates that within the shaping range, the synthesized radiation pattern, the simulated radiation pattern, and the target shaping curve perfectly match, indicating a good shaping effect for the microstrip antenna. The simulated radiation pattern of the H-plane of the microstrip series-fed antenna in this example is essentially consistent with the synthesized radiation pattern, indicating that the actual amplitude and phase distribution of the 16 radiating patches is basically consistent with the theoretical amplitude and phase, demonstrating precise control of the amplitude and phase within the microstrip antenna.

[0076] Figure 6 The H-plane radiation patterns of the series-fed pattern-shaped patch antenna in this embodiment at 79 GHz, 80 GHz, and 81 GHz are shown. Figure 6 Note that at the center frequency of 80GHz, the gain of the series-fed shaped antenna in this embodiment is 15.2dB, and the beam pointing is in the normal direction. Within the 79-81GHz operating frequency band, the antenna gain is above 14.5dB, and the beam pointing deflects by an average of 1.2° per megahertz.

[0077] Figure 7 Corresponding to the matching performance of the antenna in this embodiment, Figure 7 This indicates that the antenna matching bandwidth is between 75.6GHz and 83.2GHz, which can cover the 79-81GHz shaped frequency band, proving that it meets the usage requirements in terms of operating frequency.

[0078] This embodiment achieves cocutter square beamforming by using a microstrip series-fed patch antenna, with an antenna gain of 15dB, meeting the gain requirements. The antenna size is 20.8mm*2.64mm, meeting the miniaturization design requirements, which is beneficial for the miniaturization and lightweight design of 80GHz traffic radar.

[0079] Example 2:

[0080] A 16-radiating patch antenna with series-fed pattern shaping, such as... Figure 8 As shown, the antenna includes: a dielectric substrate 1, including a top surface and a bottom surface opposite to the top surface; a feed line 2, 16 radiating patches 3, and a matching unit 4, all attached to the top surface of the dielectric substrate; and a metal ground plane attached to the bottom surface of the dielectric substrate. The 16 radiating patches 3 are fixed to one side of the feed line, and the feed line 2 is connected to the matching unit 4. An elliptical groove structure 21 is etched near a specific radiating patch 3 on the feed line. The antenna dimensions are 39.48 mm * 1.47 mm.

[0081] Please continue to refer to this. Figure 8 The dielectric substrate 1 has a relative permittivity of 3.04 and a thickness of 0.127 mm; the feed line 2, radiating patch 3, matching unit 4, and metal ground plane are made of copper foil with a thickness of 18 μm; the feed line 21 has a width of 0.3 mm and a characteristic impedance of 50 Ω. The 16 radiating patches 3 have the same shape as in Example 1.

[0082] To achieve cosecant square shaping of the H-plane radiation pattern of the series-fed shaped antenna in this embodiment, the amplitude and phase distribution of the 16 radiating patches are optimized based on the radiation pattern product principle. The amplitude and phase control concept in this embodiment is the same as in Embodiment 1. The difference is that, during phase control, the radiating patches are moved a distance Mn from the initial spacing Sp = 2.38 mm (approximately one waveguide wavelength): Mn = β n / (2*pi)*Sp.

[0083] Please continue to refer to this. Figure 8 The matching unit 4 is connected to the end of the feed line 2, enabling the series-fed antenna in this embodiment to operate in traveling wave mode. Simultaneously, several elliptical slot structures 21 of different sizes are etched on the feed line at a specific distance from the specific radiating patch 3. The elliptical slot structures 21 have the same function as the rectangular slot structure 2 in Embodiment 1.

[0084] Figure 9 The H-plane radiation pattern of the series-fed pattern-shaped patch antenna corresponding to this embodiment at 80 GHz. Figure 9 It is noted that at the center frequency of 80GHz, the gain of the series-fed shaped antenna in this embodiment is 13.2dB, with good cross-polarization characteristics, beam pointing approximately in the normal direction, and beamforming is achieved in the range of [-40° to 0°].

[0085] Figure 10 Corresponding to the matching performance of the antenna in this embodiment, Figure 10 This indicates that the antenna matching bandwidth is between 78.4GHz and 82.2GHz, which can cover the 79-81GHz shaped frequency band.

[0086] This embodiment also achieves cosecting square beamforming by using a microstrip series-fed patch antenna.

[0087] It should be noted that the above-described preferred embodiments of the present invention are only used to more fully and thoroughly disclose the content of the present invention, and are not intended to limit the conditions for implementing the present invention. Any increase or decrease in the number of units, modification of the structure, change in proportion or size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention. For example, the slot structure 21 on the feed line can be a rectangle as in Embodiment 1, an ellipse as in Embodiment 2, or a triangle, etc. It can be added near all the radiating patches or near some of the radiating patches, such as... Figure 11 The shape of the radiation patch can be the shape shown in Embodiments 1 and 2, or it can be as follows: Figure 12 The shape shown or other shapes are acceptable; the number of radiating patches can be changed according to needs; the means of implementing traveling wave mode are not limited to termination matching units. The last radiating patch can be used as a matching unit to achieve traveling wave excitation, or the energy from the end of the feeder can be introduced into the ground plane through metal vias to achieve traveling wave excitation, such as... Figure 11 Furthermore, even when there are a large number of radiating patches, the energy reflection at the end of the feed line can be ignored without any processing, thus achieving traveling wave excitation. Finally, based on the above-mentioned beamforming method for series-fed patch antennas, not only can the cosecant square beamforming in the embodiments be achieved, but it should also be able to achieve other arbitrary beamforming methods.

[0088] In summary, although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as a limitation of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A series-fed pattern-forming patch antenna, characterized in that, include: The dielectric substrate (1), feed line (2), 16 radiating patches (3) and metal ground plane; The dielectric substrate (1) includes a top surface and a bottom surface disposed opposite to each other; the feed line (2) and the radiating patch (3) are both attached to the top surface of the dielectric substrate (1); the metal ground plane is attached to the bottom surface of the dielectric substrate (1); The 16 radiating patches (3) are distributed along the feed line (2); a slot structure (31) is formed on the radiating patch (3); By designing the shape and size of the radiating patch (3), the radiating patch (3) is made to work in a resonant state; The projection length of the radiating patch (3) on the feed line (2) is taken as the width of the radiating patch; by designing the shape of the radiating patch (3) and adjusting the width of the radiating patch, the radiation amplitude of the radiating patch can be adjusted. The width of the radiation patch is used to adjust the corresponding radiation amplitude. The specific calculation process is as follows: 1) Based on the energy distribution relationship of each radiating patch, the amplitude distribution of the radiating patch is converted into the coupling power CP distribution, where CP is the ratio of the energy input to the radiating patch to the radiated energy of the radiating patch; 2) The S11 and S21 parameters of radiating patches with different widths were obtained through the radiating patch simulation model, and the coupling power CP corresponding to radiating patches with different widths was calculated: in, The S21 parameter is the same as that of the microstrip line of the same length in the unit simulation model, representing the transmission line loss in the radiating patch model, when the transmission line loss is not considered: 3) Based on the coupling power CP distribution corresponding to the amplitude distribution in 1), and combined with the coupling power CP corresponding to different width radiating patches obtained in 2), determine the unit width corresponding to the radiation amplitude of the radiating patch; The radiation phase of the radiation patch is adjusted by adjusting the distance between adjacent radiation patches (3); the specific method for controlling the radiation phase distribution is as follows: Several radiating patches (3) are alternately distributed on both sides of the feed line (2) or on one side, with the radiating patches (3) spaced at intervals. Based on this, it moves a certain distance, which is calculated from the radiation phase of the radiation patch (3), specifically: the moving distance Phase value required to achieve cosecant square shaping The calculation yielded: or ; To achieve the spacing between adjacent radiating patches (3) during in-phase excitation; Waveguide wavelength; Slot structure 21 is opened at the feed line projection positions of the radiating patches (3) at the 2nd, 6th, 8th, 9th, 11th-14th to suppress the reflected energy of the radiating patches (3), thereby weakening the standing wave energy in the feed line. Without affecting the amplitude distribution of the microstrip series feed pattern shaped patch antenna, the purity of the traveling wave excitation is enhanced, and the precise control of the phase of the microstrip series feed antenna is realized. The shape of slot structure 21 is rectangular, elliptical or triangular. The size of the second groove structure (21) and the distance between the second groove structure (21) and the radiating patch (3). Through element simulation, it was determined that the goal of element simulation is to minimize the element reflection coefficient S11. Specifically, the element model is a radiating patch and a section of feed line connected to it. 1) Take a microstrip line of the same length as the feed line in the unit model, etch a groove structure on it, and simulate to obtain the reflection coefficient of the microstrip line. By changing the size of the second slot structure on the microstrip line, when Amplitude and corresponding unit model reflection coefficient When the amplitudes are equal, the size of the second slot structure on the microstrip line at this time is taken as the initial size of the second slot structure in the unit model. The size of the second slot structure refers to the size related to the shape of the second slot structure. When the second slot structure is rectangular, the size of the second slot structure represents its length and width. When the second slot structure is triangular, the size of the second slot structure represents its base and height. When the second slot structure is elliptical, the size of the second slot structure represents its minor axis and major axis. That is, for the second slot structure of different shapes, the size that can characterize its structural size characteristics is taken to characterize the size of the second slot structure. 2) Determine the distance between the second groove structure (21) and the nearest radiating patch (3). : ,in, The phase of the reflection coefficient of the unit model. The phase of the reflection coefficient of the microstrip line in the second etched groove structure; Waveguide wavelength; 3) Based on the initial size of the second slot structure, the size of the second slot structure is optimized by overall simulation of the radiating patch and the second slot structure, so that its overall reflection coefficient S11 reaches the minimum value at the designed frequency.

2. The series-fed pattern-forming patch antenna as described in claim 1, characterized in that, By designing the shape and size of the radiating patch (3), the radiating patch (3) is made to work in a resonant state. Specifically, the length from the edge of the feed line (2) to the upper edge of the radiating patch (3) is taken as the current path length of the radiating patch. The shape and size of the radiating patch (3) are designed to adjust the current path length of the radiating patch so that the radiating patch (3) works in a resonant state. The radiation amplitude and radiation phase of each radiating patch (3) are obtained by radiation pattern synthesis calculation with the beam shape requirement as the optimization target.

3. The series-fed pattern-forming patch antenna as described in claim 1, characterized in that, The end of the feed line (2) is connected to a matching unit (4) for absorbing and radiating the remaining energy in the feed line.

4. The series-fed pattern-forming patch antenna according to claim 1, characterized in that, The groove structure (31) is opened on one end of the radiating patch (3) and connected to the feed line, and is used to reduce the width of the connection line between the radiating patch (3) and the feed line (2).

5. The series-fed pattern-forming patch antenna according to any one of claims 1 to 3, characterized in that, The slot structure (31) is located on the radiating patch (3) at one end away from the feed line.

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