A two-dimensional beam scanning antenna based on frequency adjustment and electrical adjustment
By combining a one-dimensional linear array architecture with an electrically adjustable radiation pattern module and frequency adjustment, a compact design and flexible switching of a two-dimensional beam scanning antenna are achieved, solving the problems of complex structure and single-direction scanning in existing technologies, and realizing lightweight and fast two-dimensional beam scanning.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- QIANYUAN NATIONAL LABORATORY
- Filing Date
- 2026-02-27
- Publication Date
- 2026-05-19
AI Technical Summary
Existing two-dimensional beam scanning antennas are complex in structure, high in cost, large in size, and difficult to achieve beam scanning in two-dimensional space in a compact structure. Traditional leaky wave antenna arrays occupy a large area and require a complex feeding network. Moreover, existing technologies can only achieve beam scanning in one direction.
A one-dimensional linear array architecture is adopted, and the dispersion effect of the leaky antenna is used to achieve one-dimensional beam scanning. Another-dimensional beam scanning is achieved in the orthogonal direction through an electrically adjustable pattern reconfigurable module. By combining frequency adjustment and electrical signal adjustment, the on and off states of the PIN diodes are controlled to achieve two-dimensional beam scanning.
It achieves flexible and fast beam scanning in a two-dimensional space with a compact structure, reduces antenna size and weight, is suitable for lightweight equipment platforms, and requires only two sets of bias voltages to achieve flexible radiation state switching.
Smart Images
Figure CN121748783B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of communication and radar detection technology, specifically relating to a two-dimensional beam scanning antenna based on frequency adjustment and electronic modulation. Background Technology
[0002] Beam-scanning antennas play a crucial role in communication and radar detection systems. They enable dynamically variable beam radiation to adapt to real-time changes in the communication or detection area. Currently, phased array antennas are commonly used for beam scanning; however, their high cost, system complexity, and large size and weight make them unsuitable for all applications. Leaky-wave antennas achieve beam scanning by adjusting the frequency to change the equivalent phase difference between elements. This avoids the use of phase shifters, power dividers, and other similar components. Employing a cascaded feeding method, they have a simple structure and meet the urgent need for low-cost, lightweight beam-scanning antennas in modern communication and radar systems, making them suitable for mass production.
[0003] To achieve beam scanning in two-dimensional space, leaky wave antennas typically require expanding the antenna structure from a one-dimensional linear array to a two-dimensional planar array. For example, patent document CN116345188A discloses a two-dimensional frequency scanning leaky wave antenna array and a two-dimensional frequency scanning method. However, planar array leaky wave antennas occupy significantly more area and require complex feeding networks. Therefore, how to achieve beam scanning in two-dimensional space with a leaky wave antenna while maintaining a compact and simple structure is of significant research importance.
[0004] Patent document CN111682314A discloses a dual-polarized electrically controlled beam scanning leaky antenna. It controls the beam scanning range by setting varactor diodes on the first periodic antenna radiation structure plate and the second periodic antenna radiation structure plate, and using a microcontroller to control the capacitance value of the varactor diodes. However, it can only achieve beam scanning in one direction along the Y-axis. Summary of the Invention
[0005] In view of the above, the purpose of this invention is to provide a two-dimensional beam scanning antenna based on frequency adjustment and electrical modulation, which overturns the traditional planar array architecture of two-dimensional beam scanning leaky wave antennas and adopts a linear array architecture instead. Utilizing the dispersion effect of the leaky wave antenna in the wave propagation direction, beam scanning is achieved based on frequency adjustment; electrically modulated pattern reconfigurable modules are arranged in directions orthogonal to the wave propagation direction, and beam scanning in the orthogonal direction is achieved based on electrical signal modulation. This enables beam scanning along two orthogonal directions, thus widening the beam scanning range.
[0006] To achieve the above-mentioned objectives, an embodiment provides a two-dimensional beam scanning antenna based on frequency adjustment and electrical modulation, comprising:
[0007] At least two periodic units arranged on a substrate and cascaded along the wave propagation direction;
[0008] Each periodic unit includes a leaky wave antenna module arranged along the wave propagation direction, which utilizes the dispersion effect of the leaky wave antenna to achieve one-dimensional beam scanning in the wave propagation direction based on frequency adjustment;
[0009] Each periodic unit also includes electrically adjustable pattern reconfigurable modules arranged in a direction orthogonal to the wave propagation direction, which achieve another-dimensional beam scanning in the orthogonal direction based on electrical signal adjustment.
[0010] Preferably, the leaky antenna module includes a section of meandering parallel double line, a pair of wide microstrip lines connected to the meandering parallel double line, and a pair of microstrip stubs connected to the meandering parallel double line and extending in opposite directions.
[0011] Preferably, the meandering parallel double lines are printed on the upper and lower surfaces of the substrate as upper and lower supports, respectively. The current amplitudes of the upper and lower supports are the same but the phases are opposite, so they only transmit signals and do not generate radiation.
[0012] Preferably, the pair of wide microstrip lines are printed on the upper surface of the substrate and are symmetrical about the central axis of the unit, providing current polarization components along the wave propagation direction and introducing periodic perturbations to form a periodic leaky antenna, thereby enabling one-dimensional beam scanning as the frequency changes.
[0013] The wide microstrip line causes a change in the phase difference between the upper and lower branches of the meandering parallel double line. To compensate for the phase difference change caused by the wide microstrip line, a pair of microstrip stubs extending in opposite directions are set in each periodic unit. The microstrip stubs are set on the lower surface of the substrate. The opposite extension directions of the microstrip stubs cause their current distributions to cancel each other out, which does not affect the radiation response of the antenna, so that the upper and lower branches of the meandering parallel double line are restored to an opposite phase relationship.
[0014] Preferably, the electrically tunable pattern reconfigurable module includes two pairs of semi-circular microstrip lines, each pair of semi-circular microstrip lines includes two semi-circular microstrip lines, the upper and lower branches of the semi-circular microstrip lines are respectively arranged on the upper and lower surfaces of the substrate, and the two pairs of semi-circular microstrip lines are mirror-symmetrical about the wave propagation direction.
[0015] Each pair of semi-circular microstrip lines has a metal through-hole at the end, which connects each pair of upper and lower semi-circular microstrip lines.
[0016] Each pair of semi-circular microstrip lines is connected to a pair of connecting microstrip lines by meandering parallel double lines.
[0017] Preferably, each pair of connected microstrip lines is provided with a PIN diode, and the on / off state of each PIN diode is controlled by different control voltages to control the excitation state of the semi-ring microstrip line, thereby forming different radiation responses and realizing beam scanning in orthogonal directions.
[0018] Preferably, the periodic elements at the beginning and end are also equipped with adapters. The adapter at the beginning (such as the adapter on the left) feeds the entire antenna, while the adapter at the end (such as the adapter on the right) connects to a standard load to absorb residual energy and prevent residual energy from returning to the feed end and damaging the radiation performance. The inner core of both the beginning and end adapters is connected to the upper metal layer of the substrate, and the outer core is connected to the lower metal layer of the substrate.
[0019] This invention relates to a two-dimensional beam scanning antenna based on frequency adjustment and electrical regulation. Within the operating frequency band (2.4 GHz to 3.4 GHz), four typical frequency points are selected. As the frequency increases, the radiated beam gradually scans from the y < 0 region to the y > 0 region. By adjusting different combinations of two sets of control voltages, the on / off states of two sets of PIN diodes are controlled, achieving the switching of the radiated beam between the x < 0 and x > 0 regions. By combining frequency adjustment and control voltage regulation, this invention achieves... φ - Beam scanning in a two-dimensional planar space.
[0020] Compared with the prior art, the beneficial effects of the present invention include at least the following:
[0021] The two-dimensional beam scanning antenna provided by this invention adopts a one-dimensional linear array architecture, realizing beam scanning in two-dimensional space. Compared with the traditional two-dimensional beam scanning antenna adopting a two-dimensional area array structure, this new design brings a significant reduction in antenna size and weight. Furthermore, it adopts a single-layer PCB board structure, making it suitable for placement in lightweight and miniaturized equipment platforms.
[0022] The two-dimensional beam scanning antenna provided by this invention uses only two sets of bias voltages. Combined with the frequency scanning characteristics of the leaky antenna, it can achieve beam scanning in two-dimensional space, and the radiation state switching is flexible and fast. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] Figure 1 This is a schematic diagram of the structure of the two-dimensional beam scanning antenna on the substrate provided in the embodiment, where (a) and (b) are top views of the upper structure and the lower structure, respectively;
[0025] Figure 2 These are the S-parameter curves of the two-dimensional beam scanning antenna provided in the embodiment;
[0026] Figure 3 This is the radiation response of the two-dimensional beam scanning antenna provided in the embodiment in the xoz plane at two electrically tunable modes and two high and low critical frequency points;
[0027] Figure 4 This is the normalized radiation pattern of the two-dimensional beam scanning antenna provided in the embodiment at four typical frequency points in two electrically tunable modes, in the plane of θ=90°.
[0028] Figure 5 The curves showing the peak gain of the two-dimensional beam scanning antenna provided in the embodiment as a function of frequency in two electrically adjustable modes are shown.
[0029] Note: 1-Substrate, 2-SMA connector 1, 3-SMA connector 2, 4-PIN diode S1, 5-PIN diode S2, 6-Control voltage V1, 7-Control voltage V2, 8-Wavy parallel double line, 9-Metal via, 10-Wide microstrip line, 11-Semi-ring microstrip line, 12-Connecting microstrip line, 13-Microstrip stub. Detailed Implementation
[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of this invention.
[0031] like Figure 1 As shown, the two-dimensional beam scanning antenna based on frequency adjustment and electronic modulation provided in the embodiment includes at least two periodic units arranged on the substrate 1 and cascaded along the wave propagation direction. The wave propagation direction can be the y-axis, and the direction orthogonal to the y-axis is the x-axis. In this case, the two-dimensional beam scanning antenna can be composed of five periodic units cascaded along the y-axis.
[0032] In this embodiment, each periodic unit includes a leaky wave antenna module arranged along the wave propagation direction, which utilizes the dispersion effect of the leaky wave antenna to achieve one-dimensional beam scanning in the wave propagation direction based on frequency adjustment. It also includes electrically adjustable pattern reconfigurable modules arranged in a direction orthogonal to the wave propagation direction, which achieve another-dimensional beam scanning in the orthogonal direction based on electrical signal adjustment.
[0033] In this embodiment, the leaky antenna module includes a meandering parallel double line 8, a pair of wide microstrip lines 10 connected to both ends of the meandering parallel double line 8, and microstrip stubs 13 connected to the meandering parallel double line 8 and extending in opposite directions.
[0034] Among them, the meandering parallel double line 8 serves as the transmission structure. It is divided into two branches and printed on the upper and lower surfaces of the substrate 1 respectively. The present invention bends the straight parallel double line to transform it into a meandering shape, thereby reducing the spacing between adjacent units, suppressing the grating lobe effect, and expanding the beam scanning range.
[0035] The portions of the meandering parallel double line 8 printed on the upper surface of the substrate 1 and the portions printed on the lower surface of the substrate 1 are labeled as the upper branch and the lower branch, respectively. The current amplitudes of the upper branch and the lower branch are the same, but their phases are opposite. Therefore, the currents distributed on the meandering parallel double line 8 cancel each other out. The meandering parallel double line 8 itself only serves the function of signal transmission and does not generate radiation.
[0036] Wide microstrip lines 10 are printed on the upper surface of substrate 1. A pair of wide microstrip lines 10 are provided in each periodic cell. These two wide microstrip lines are symmetrical about the central axis of the cell. They introduce periodic current elements along the y-axis to the two-dimensional beam scanning antenna, thereby forming a periodic leaky antenna, so that the two-dimensional beam scanning antenna has the function of performing one-dimensional beam scanning (yz plane) with frequency variation.
[0037] Because the loading of the wide microstrip line 10 on the upper branch of the meandering parallel double line 8 disrupts the anti-phase relationship between the upper and lower branches of the meandering parallel double line 8, a pair of microstrip stubs 13 extending in opposite directions are provided in each periodic unit. The microstrip stubs 13 are located on the lower surface of the substrate 1 to compensate for the phase difference change between the upper and lower branches of the meandering parallel double line 8 caused by the loading of the wide microstrip line 10, thus restoring the anti-phase relationship between the upper and lower branches of the meandering parallel double line 8. Since the microstrip stubs 13 extend in opposite directions, their current distributions cancel each other out and do not affect the radiation response.
[0038] In this embodiment, the electrically tunable pattern reconfigurable module includes two pairs of semi-circular microstrip lines 11. Each pair of semi-circular microstrip lines 11 includes two semi-circular microstrip lines. The upper and lower branches of the semi-circular microstrip lines are respectively arranged on the upper and lower surfaces of the substrate 1. These two pairs of semi-circular microstrip lines 11 are located at the central axis of each periodic unit and are mirror-symmetrical about the y-axis.
[0039] Each pair of semi-annular microstrip lines 11 has a metal through hole 9 at its end, so that each pair of upper and lower semi-annular microstrip lines 11 are connected.
[0040] In the meandering parallel double line 8, equal-amplitude and opposite-currents are distributed on the upper and lower branches. Each pair of semi-ring microstrip lines 11 is connected to the meandering parallel double line 8 through a pair of connecting microstrip lines 12. Thus, the meandering parallel double line 8 can provide differential feed signals to the upper and lower branches of the connected semi-ring microstrip lines 11, thereby exciting the semi-ring microstrip lines 11 to form... φ - A current loop in the plane is equivalent to a magnetic current element along the z-axis.
[0041] A PIN diode is set in each connecting microstrip line 12. The two sets of PIN diodes arranged in the x<0 and x>0 regions are denoted as PIN diode S1 4 and PIN diode S2 5, respectively. For a two-dimensional beam scanning antenna containing 5 periodic elements, each set contains 10 PIN diodes. The on and off states of the two sets of PIN diodes are controlled by two different bias voltages V1 and V2, respectively, so as to control the current distribution on the connecting microstrip line.
[0042] By controlling the current distribution on the microstrip line 12 connected in the x<0 and x>0 regions, the excitation state of the semi-ring microstrip line 11 in the x<0 and x>0 regions can be controlled, thereby forming different equivalent magnetic flux elements.
[0043] In ESC mode 1, the bias voltage V1 is 0V, and the bias voltage V2 is a forward bias voltage of approximately 3V; therefore, PIN diode S14 is in the open state, and PIN diode S25 is in the closed state. In ESC mode 2, the bias voltage V1 is a forward bias voltage of approximately 3V, and the bias voltage V2 is 0V; therefore, PIN diode S14 is in the closed state, and PIN diode S25 is in the open state.
[0044] The equivalent magnetic flux elements formed under the two electrically controlled modes are in opposite directions. The equivalent magnetic flux element along the z-axis formed by the semi-toroidal microstrip line 11 in the excited state and the current element along the y-axis formed by the wide microstrip line 10 constitute a complementary radiation element pair. When the equivalent magnetic flux element phase flips (phase change 180°)... ° When the PIN diodes are switched on and off, the corresponding radiation response will also point in the opposite direction. Therefore, by controlling the on and off states of the two sets of PIN diodes, the excitation state of the semi-ring microstrip line can be controlled, exciting different periodic complementary radiation pairs, forming different radiation responses, and thus forming beam scanning switching in the xz plane.
[0045] In summary, by combining frequency adjustment and electronic adjustment, the embodiments of the present invention can achieve beam scanning in two-dimensional space.
[0046] The following section selects 2.4GHz to 3.4GHz as the operating frequency band and demonstrates the performance parameters of the embodiments of the present invention within this operating frequency band.
[0047] Figure 2 The S-parameter curves of the two-dimensional beam scanning antenna of the present invention are shown, including | S 11 |and| S 21 |Curve, Figure 2 In the middle, the vertical axis is | S 11 | (dB) or | S21 | (dB), the horizontal axis represents frequency (GHz). Due to the non-perfectly symmetrical antenna structure, the S-parameter curves of electrically tunable mode 1 and electrically tunable mode 2 do not completely overlap. However, in both electrically tunable modes, the required parameters within the operating frequency band can be met. S 11 The impedance is less than -9 dB, demonstrating good impedance matching performance in both electrically adjustable modes.
[0048] Figure 3 This paper demonstrates the radiation response of the two-dimensional beam scanning antenna of the present invention in the xoz plane at two high and low critical frequencies and in two electrically adjustable modes. In electrically adjustable mode 1, the radiated beam always points to the x>0 region; in electrically adjustable mode 2, the radiated beam always points to the x<0 region. This verifies that beam switching in the xz plane is achieved through electrically adjustable methods in the embodiments of the present invention.
[0049] Figure 4 The invention demonstrates the two-dimensional beam scanning antenna at four typical frequency points and in two electrically adjustable modes. θ =90 ° Normalized radiation pattern in the plane. In Mode 1, as the operating frequency increases, the radiation beam gradually changes from -8... ° Continuous scanning up to 26 ° In mode 2, as the operating frequency increases, the radiation beam gradually changes from -172... ° Continuous scanning up to 154 ° .
[0050] Figure 5 The peak gain curves of the two-dimensional beam scanning antenna of the present invention are shown in two electrically tunable modes. Figure 5 In the figure, the vertical axis represents peak gain (dBi), and the horizontal axis represents frequency (GHz). Similarly, due to the asymmetrical antenna structure, the peak gain curves of Mode 1 and Mode 2 do not completely overlap, but the trend of peak gain with frequency in both electrically tunable modes is basically the same, with the peak gain fluctuating in the range of 3.5dBi to 7.3dBi within the operating frequency band.
[0051] Depend on Figures 2-5 In conclusion, the embodiments of the present invention achieve effective two-dimensional beam scanning by combining frequency adjustment and electrical signal adjustment.
[0052] The specific embodiments described above illustrate the technical solution and beneficial effects of the present invention in detail. It should be understood that the above description is only the most preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, additions, and equivalent substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A two-dimensional beam scanning antenna based on frequency adjustment and electrical modulation, characterized in that, include: At least two periodic units arranged on a substrate and cascaded along the wave propagation direction; Each periodic unit includes a leaky wave antenna module arranged along the wave propagation direction, which utilizes the dispersion effect of the leaky wave antenna to achieve one-dimensional beam scanning in the wave propagation direction based on frequency adjustment; Each periodic unit also includes electrically modulated pattern reconfigurable modules arranged in a direction orthogonal to the wave propagation direction, which achieve another-dimensional beam scanning in the orthogonal direction based on electrical signal modulation; The electrically tunable pattern reconfigurable module includes two pairs of semi-circular microstrip lines. Each pair of semi-circular microstrip lines includes two semi-circular microstrip lines. The upper and lower branches of the semi-circular microstrip lines are respectively arranged on the upper and lower surfaces of the substrate. The two pairs of semi-circular microstrip lines are mirror-symmetrical about the wave propagation direction. Each pair of semi-circular microstrip lines has a metal through-hole at the end, which connects each pair of upper and lower semi-circular microstrip lines. Each pair of semi-circular microstrip lines is connected to a meandering parallel double line via a pair of connecting microstrip lines.
2. The two-dimensional beam scanning antenna based on frequency adjustment and electrical modulation according to claim 1, characterized in that, The leaky antenna module includes a section of meandering parallel double line, a pair of wide microstrip lines connected to the meandering parallel double line, and a pair of microstrip stubs connected to the meandering parallel double line and extending in opposite directions.
3. The two-dimensional beam scanning antenna based on frequency adjustment and electrical modulation according to claim 2, characterized in that, The meandering parallel double lines are printed on the upper and lower surfaces of the substrate as upper and lower supports. The current amplitudes of the upper and lower supports are the same but the phases are opposite. They only transmit signals and do not generate radiation.
4. The two-dimensional beam scanning antenna based on frequency adjustment and electrical modulation according to claim 2, characterized in that, The pair of wide microstrip lines are printed on the upper surface of the substrate and are symmetrical about the central axis of the unit. They provide current polarization components along the wave propagation direction and introduce periodic perturbations to form a periodic leaky antenna, thereby enabling one-dimensional beam scanning as the frequency changes.
5. The two-dimensional beam scanning antenna based on frequency adjustment and electrical modulation according to claim 2, characterized in that, The microstrip stubs are disposed on the lower surface of the substrate to compensate for the phase difference change between the upper and lower branches of the meandering parallel double line caused by the loading of the wide microstrip line, so that the upper and lower branches of the meandering parallel double line are restored to an opposite phase relationship.
6. The two-dimensional beam scanning antenna based on frequency adjustment and electronic modulation according to claim 1, characterized in that, Each pair of connected microstrip lines is equipped with a PIN diode, and the on / off state of each PIN diode is controlled by different control voltages to control the excitation state of the semi-ring microstrip line, thereby forming different radiation responses and realizing beam scanning in orthogonal directions.
7. The two-dimensional beam scanning antenna based on frequency adjustment and electronic modulation according to claim 1, characterized in that, The periodic elements at the beginning and end are also equipped with adapters. The adapter at the beginning feeds the entire antenna, while the adapter at the end connects to a standard load to absorb the remaining energy and prevent the remaining energy from returning to the feed end and damaging the radiation performance.
8. The two-dimensional beam scanning antenna based on frequency adjustment and electrical modulation according to claim 7, characterized in that, The adapter includes an SMA connector.