A frustum-based conformal phased array and beamforming method

Abstract

The application discloses a kind of based on conical frustum conformal phased array and road beam forming method, belong to radar technical field, solve the technical problem that current technique cannot carry out unit beam screening discrimination in conformal array beam synthesis.The method includes: step 1, according to the structural characteristics of conical frustum conformal phased array, along the circumferential sector and upper and lower conical frustum division subarray and numbering;Step 2, extract current conical frustum phased array beam pointing angle step 3, according to the screening situation of unit on beam pointing direction, open the radio frequency transceiver channel of unshielded antenna unit, close the radio frequency transceiver channel of shielded antenna unit;Step 4, considering the factors of random feed phase, phase error compensation, find out the wave control code C (n) of the nth element in conical frustum array relative to reference unit;Step 5, and road echo is received by all subarrays of conical frustum phased array Echo superposition formation.The application realizes the shape of and road beam based on conical frustum conformal phased array.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radar, in particular to a sum-difference beam forming method based on a conical frustum conformal phased array. BACKGROUND

[0002] Phased array antenna has the ability of fast changing of beam pointing and beam shape, easy to form multiple beams, and can realize signal power synthesis in space. These characteristics make phased array antenna widely used in radar, communication, electronic warfare, navigation and other fields. At present, the phased array antennas used in these fields are basically planar phased array antennas, which install each unit in the array antenna on the surface of the platform, and the surface of the array antenna is consistent with the shape of the platform, which can form a "conformal array antenna".

[0003] Due to the limitations of structure and performance, the conventional planar antenna system has been difficult to meet the needs of development. Compared with the traditional planar phased array, the conformal phased array has better scanning beam characteristics in terms of scanning range and simultaneous multi-target.

[0004] Cone is a typical conformal body representative, and the key technology of its beam forming can have good commonality with other conformal bodies. The conformal phased array based on the surface of the conical frustum can have the ability of large-angle scanning and forward detection at the same time.

[0005] Sum-difference monopulse angle measurement is one of the main ways for radar to realize angle measurement. The basic principle is to process the received radar target echo, construct sum and difference road patterns, form sum-difference echo information, and use the difference between the target echo information in the sum and difference roads to extract the angle of the target deviating from the beam pointing axis through a specific algorithm model, so as to obtain the target angle.

[0006] On the conformal curved surface, due to the different positions of each antenna element, the unit direction pointing is inconsistent, and at the same time in wide-angle scanning, there are problems such as structure blocking in the beam scanning process. Only using a fixed sum-difference beam forming network cannot meet the beam forming demand, and even there may be a problem of forming a difference pattern.

[0007] Therefore, in order to meet the demand of conformal phased array monopulse angle measurement, it is necessary to dynamically select and combine each subarray in the beam switching process to form the sum-difference beam of the conformal phased array. SUMMARY

[0008] In view of the above analysis, the present application aims to provide a sum-difference beam forming method based on a conical frustum conformal phased array, to solve the problem of phased array sum and pattern synthesis under conformal array condition.

[0009] The purpose of the present application is mainly realized by the following technical scheme:

[0010] This invention provides a sum-path beamforming method based on a frustum-shaped conformal phased array, comprising the following steps:

[0011] Step 1: Based on the structural characteristics of the frustum conformal phased array, divide the circumferential sector and the upper and lower frustums into subarrays and number them;

[0012] Step 2: Extract the current frustum phased array beam pointing angle

[0013] Step 3: Based on the obstruction status of the antenna elements in the beam pointing direction, open the RF transceiver channel of the unobstructed antenna elements and close the RF transceiver channel of the obstructed antenna elements.

[0014] Step 4: Considering the factors of random phase feeding and phase error compensation, calculate the wave control code C(n) of the nth element in the frustum array relative to the reference element.

[0015] Step 5: The echo is formed by superimposing the echoes received by all subarrays of the frustum phased array.

[0016] Furthermore, in step 1, when dividing the frustum conformal phased array into subarrays, sectors are divided along the circumferential direction from the projection plane of the frustum conformal phased array perpendicular to the rotation axis, serving as subarray partitions. Then, the frustum conformal phased array is further divided into subarrays with a plane parallel to the bottom plane of the frustum as the boundary. Thus, each smallest partition module is a subarray that makes up the frustum conformal phased array.

[0017] Furthermore, in step 2, the beam pointing of the truncated conical conformal phased array is described using a right-handed coordinate system. The off-axis angle θ of the beam pointing of the truncated conical conformal phased array is the angle between the beam pointing direction vector and the z-axis. The value increases as the angle with the z-axis increases, and the value range is [0°, 180°].

[0018] Furthermore, in step 2, the azimuth angle of the frustum conformal phased array beam is... The angle between the projection vector of the beam pointing direction vector onto the xoy plane and the x-axis increases with the counterclockwise direction, and its value ranges from -180° to 180°.

[0019] Furthermore, in step 3, the antenna elements are attached to the surface of the frustum. For the frustum phased array, the switching state of each antenna element can be independently controlled by the TR component.

[0020] Furthermore, in step 3, the occlusion status of antenna element n is determined by the unit vector normal to element n. With beam pointing unit vector inner product Decision, if Then antenna element n is not blocked; if Then antenna element n is blocked;

[0021] where θ L is the single antenna element switch threshold angle, which is determined by the amplitude of the antenna element pattern in the direction deviating from the normal direction.

[0022] Further, in step 4, the wave control code C(n) of the nth element in the frustum array relative to the reference element is calculated.

[0023] C(n) = δ i，j - X(n)α - y(n)β - z(n)γ

[0024] wherein,

[0025] α = k sin(θ) cos(φ), which is given by signal processing;

[0026] which is given by signal processing;

[0027] γ = k cos(θ), which is given by signal processing;

[0028] n is the element number in the frustum array;

[0029] k = 2π / λ;

[0030] θ is the included angle between the beam pointing direction and the Z axis in the spherical coordinate system;

[0031] is the included angle between the projection of the beam pointing direction in the XOY plane and the X axis;

[0032] δ i,j is the initial phase of the antenna feeder;

[0033] [x(n) y(n) z(n)] is the position coordinate of the nth element.

[0034] Further, in step 1, when the subarray division is performed, the sectors are divided along the circumferential direction as seen from the projection plane of the frustum rotation axis, as the subarray division; then the frustum conformal phased array is divided into subareas by a plane parallel to the bottom plane of the frustum, and thus each minimum division module is a subarray of the frustum conformal phased array.

[0035] Further, in step 1, as seen from the projection plane xoy perpendicular to the rotation axis z, the frustum conformal phased array is uniformly divided into 8 sectors along the circumferential direction, and on this basis, the upper and lower frustums are divided into two layers along the plane parallel to the xoy plane, and finally 16 subarrays are formed.

[0036] Further, in step 3, the antenna element pattern sharply attenuates in the region deviating from the normal direction by 70°, which is defined as having no contribution to the pattern, and the element switch threshold angle θ is defined.L The value is 70°, according to which the state of each antenna unit switch is controlled.

[0037] Compared with the prior art, the present application can achieve at least one of the following beneficial effects:

[0038] (1) The present application realizes that in the synthesis of a conformal array beam, the blocking condition of a unit beam can be judged, and the unit beam in the blocked part is turned off, thereby avoiding the influence of the blocked beam on the precision.

[0039] (2) The present application superimposes the echo signals of all numbered subarrays to obtain the cone-shaped conformal phased array and the echo signal.

[0040] (3) The present application improves the phase accuracy between beams through phase control, thereby improving the working precision of the phased array.

[0041] In the present application, the above-mentioned technical solutions can be combined with each other to realize more preferred combination schemes. Other features and advantages of the present application will be described in the subsequent specification, and some advantages will become apparent from the specification or will be understood by implementing the present application. The purpose and other advantages of the present application can be achieved and obtained through the contents specifically indicated in the specification, examples and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0042] The drawings are only for the purpose of illustrating specific embodiments and are not considered as limiting the present application, and in the entire drawings, the same reference signs represent the same parts.

[0043] Figure 1 is a 45° half-cone-angle 384-unit cone-shaped conformal phased array schematic diagram provided by an embodiment of the present application;

[0044] Figure 2 is Figure 1 the subarray division top view of the cone-shaped conformal phased array 16 shown in the figure;

[0045] Figure 3a is a polar coordinate system definition schematic diagram adopted by the cone-shaped conformal phased array provided by the present application;

[0046] Figure 3b is a cone-shaped conformal phased array beam pointing azimuth angle definition schematic diagram provided by the present application;

[0047] Figure 4 is a cone-shaped conformal phased array and difference beam forming logic schematic diagram provided by an embodiment of the present application. DETAILED DESCRIPTION

[0048] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0049] This invention provides a dynamic arraying method based on a frustum-shaped conformal phased array and difference beamforming, specifically including the following steps:

[0050] Step 1: Based on the structural characteristics of the frustum conformal phased array, divide the circumferential sector and the upper and lower frustums into subarrays and number them.

[0051] Specifically, a frustum-shaped conformal phased array, or an envelope-stretching deformable body based on it, can be considered a rotational structure. When dividing the array into subarrays, sectors are divided along the circumference from the projection plane perpendicular to the rotation axis, serving as subarray partitions. Further, the frustum-shaped conformal phased array is divided into subarrays using planes parallel to the bottom plane of the frustum as boundaries. Thus, each smallest partition module constitutes a subarray of the frustum-shaped conformal phased array.

[0052] by Figure 1 Taking the frustum conformal phased array shown as an example, Figure 1 The diagram shows a 384-element frustum-shaped phased array with a 45° half-cone angle. Viewed from the xoy plane (perpendicular to the z-axis of rotation), it is uniformly divided into eight sectors along the circumference, each sector being 45°. Further, two layers of frustums are formed along a plane parallel to the xoy plane. The upper half-frustum forms eight sectors (1, 2, 3, 4, 5, 6, 7, 8), and the lower half-frustum forms eight sectors (9, 10, 11, 12, 13, 14, 15, 16), resulting in a total of 16 subarrays. Each subarray is numbered as follows: Figure 2 The top view of the truncated conical conformal phased array is shown. Starting from the subarray closest to the x-axis on the upper truncated conical array, the arrays are numbered counterclockwise.

[0053] Step 2: Extract the current frustum conformal phased array beam pointing angle

[0054] Specifically, the beam pointing of the truncated conical conformal phased array is defined using polar coordinates, as shown in Figure 3(a). The coordinate system is a right-handed system. The off-axis angle θ of the truncated conical conformal phased array beam pointing is the angle between the beam pointing direction vector and the z-axis, increasing with the angle between the vector and the z-axis, and ranging from [0°, 180°]. The azimuth angle of the truncated conical conformal phased array beam pointing... The angle between the beam pointing direction vector and the x-axis is the projection vector of the beam pointing direction vector onto the xoy plane. The angle increases with the counterclockwise direction and the value ranges from [-180° to 180°], as shown in Figure 3(b).

[0055] Step 3, according to the shielding condition of the unit in the beam pointing direction, the radio frequency transceiver channel of the unshielded antenna unit is opened, and the radio frequency transceiver channel of the shielded antenna unit is closed.

[0056] Specifically as follows: the antenna unit is attached to the frustum surface, for the phased array, the switching state of each antenna unit can be independently controlled by the TR component. First, according to the shielding condition of the unit in the beam pointing direction, the radio frequency transceiver channel of the unshielded antenna unit is opened, and the radio frequency transceiver channel of the shielded antenna unit is closed.

[0057] The shielding condition of the antenna unit n can be determined by the inner product of the normal unit vector of the antenna unit n and the beam pointing unit vector If , the antenna unit n is not shielded, and its radio frequency channel can be opened; if , the antenna unit n is shielded, and its radio frequency channel needs to be closed; wherein θ L is the antenna unit switching threshold angle, which is determined by the amplitude of the antenna unit pattern away from the normal direction. Taking the frustum conformal phased array with

[0058] structure as an example, the antenna unit pattern sharply attenuates in the region away from the normal direction by 70°, which is considered to have no contribution to the pattern, so the switching threshold angle θ L of the unit is taken as 70°, and the switching state of each antenna unit is controlled accordingly. Figure 1 It should be noted that the present application adopts conformal arrangement of antenna units, compared with the prior art, the present application solves the problem of shielding of the conformal body to the antenna unit after conformal arrangement of the antenna unit.

[0059] Step 4, according to random phase feeding, phase error compensation and other factors, the wave control code C(n) of the n-th array element in the frustum array relative to the reference unit is obtained;

[0060] C(n) = δ i，j -X(n)α-y(n)β-z(n)γ

[0061] In the formula,

[0062] α = ksin(θ)cos(φ), which is given by signal processing;

[0063]

[0064] which is given by signal processing; γ = kcos(θ), which is given by signal processing;

[0065] n-the array element number in the frustum array;

[0066]

[0067] ​k = 2π / λ;

[0068] θ is the angle between the beam direction and the Z-axis in spherical coordinates;

[0069] The angle between the projection of the beam onto the XOY plane and the X-axis;

[0070] δ i,j This represents the initial phase of the antenna feeder;

[0071] [x(n)y(n)z(n)] represents the position coordinates of the nth array element.

[0072] Step 5: The echo is formed by superimposing the echoes received by all subarrays of the frustum phased array.

[0073] Specifically as follows: Figure 1 Taking the frustum conformal phased array as an example, based on step 3, the echo signals of all subarrays numbered 1 to 16 are superimposed to obtain the frustum conformal phased array and the echo signal.

[0074] The obtained frustum conformal phased array and path echo signals are used to select the differential beamforming mode to enter based on the beam pointing off-axis angle and the threshold angle of the forward / lateral scanning mode.

[0075] In forward scan mode, viewed from the xoy plane (projection plane perpendicular to the z-axis of rotation) of the frustum-shaped conformal phased array, the angle of deviation from the x-axis of the projection of each sector subarray along the generatrix boundary line onto the xoy plane is used as the boundary angle for switching array modes. Regarding the current azimuth angle satisfy boundary angle The corresponding boundary line is the dividing line between the two sets of subarray regions that form the azimuth difference, and the boundary line perpendicular to it is the dividing line between the two sets of subarray regions that form the pitch difference.

[0076] For example, with Figure 1 Taking a frustum-shaped conformal phased array as an example, the subarray is divided into 8 large sectors along the circumference, with boundary angles... The values ​​are -135°, -90°, -45°, 0°, 45°, 90°, 135°, and 180°.

[0077] like Figure 4 As shown, the current azimuth angle When, select The corresponding boundary line is the azimuth difference dividing line. If the corresponding boundary line is the azimuth difference boundary line, the azimuth difference echo signal is formed by the difference between the (5, 6, 7, 8, 13, 14, 15, 16) subarray and the (1, 2, 3, 4, 9, 10, 11, 12) subarray, and the elevation difference echo signal is formed by the difference between the (3, 4, 5, 6, 11, 12, 13, 14) subarray and the (1, 2, 7, 8, 9, 10, 15, 16) subarray.

[0078] the current azimuth angle , select the corresponding boundary line is the azimuth difference boundary line, the corresponding boundary line is the elevation difference boundary line, the elevation difference echo signal is formed by the difference between the (1, 6, 7, 8, 9, 14, 15, 16) subarray and the (2, 3, 4, 5, 10, 11, 12, 13) subarray, and the azimuth difference echo signal is formed by the difference between the (4, 5, 6, 7, 12, 13, 14, 15) subarray and the (1, 2, 3, 8, 9, 10, 11, 16) subarray.

[0079] the current azimuth angle , select the corresponding boundary line is the azimuth difference boundary line, the corresponding boundary line is the elevation difference boundary line, the elevation difference echo signal is formed by the difference between the (5, 6, 7, 8, 13, 14, 15, 16) subarray and the (1, 2, 3, 4, 9, 10, 11, 12) subarray, and the azimuth difference echo signal is formed by the difference between the (3, 4, 5, 6, 11, 12, 13, 14) subarray and the (1, 2, 7, 8, 9, 10, 15, 16) subarray.

[0080] the current azimuth angle , select the corresponding boundary line is the azimuth difference boundary line, the corresponding boundary line is the elevation difference boundary line, the elevation difference echo signal is formed by the difference between the (4, 5, 6, 7, 12, 13, 14, 15) subarray and the (1, 2, 3, 8, 9, 10, 11, 16) subarray, and the azimuth difference echo signal is formed by the difference between the (2, 3, 4, 5, 10, 11, 12, 13) subarray and the (1, 6, 7, 8, 9, 14, 15, 16) subarray.

[0081] the current azimuth angle or , select the corresponding boundary line is the azimuth difference boundary line, If the corresponding boundary line is the azimuth difference boundary line, the azimuth difference echo signal is formed by the difference between the (1, 2, 3, 4, 9, 10, 11, 12) subarray and the (5, 6, 7, 8, 13, 14, 15, 16) subarray.

[0082] the current azimuth angle at this time, the If the corresponding boundary line is the azimuth difference boundary line, the azimuth difference echo signal is formed by the difference between the (1, 2, 3, 4, 9, 10, 11, 12) subarray and the (5, 6, 7, 8, 13, 14, 15, 16) subarray. the current azimuth angle

[0083] at this time, the If the corresponding boundary line is the azimuth difference boundary line, the azimuth difference echo signal is formed by the difference between the (1, 2, 3, 4, 9, 10, 11, 12) subarray and the (5, 6, 7, 8, 13, 14, 15, 16) subarray. the current azimuth angle at this time, the

[0084] If the corresponding boundary line is the azimuth difference boundary line, the azimuth difference echo signal is formed by the difference between the (1, 2, 3, 4, 9, 10, 11, 12) subarray and the (5, 6, 7, 8, 13, 14, 15, 16) subarray. the current azimuth angle at this time, the If the corresponding boundary line is the azimuth difference boundary line, the azimuth difference echo signal is formed by the difference between the (1, 2, 3, 4, 9, 10, 11, 12) subarray and the (5, 6, 7, 8, 13, 14, 15, 16) subarray.

[0085] If the lateral scanning mode is used, the elevation difference echo signal is formed by the difference between the upper and lower two conical frustums, and according to the azimuth angle determine the group array scheme participating in the synthesis of the azimuth difference echo signal respectively, synthesize the elevation difference and azimuth difference echo signals, and enter the subsequent signal processing flow.

[0086] Specifically, in the lateral scanning mode, the pitch difference echo is obtained by subtracting the subarray echoes from both sides of the upper and lower frustum interface. Looking from the xoy plane, the projection of each sector subarray along its generatrix boundary line onto the xoy plane perpendicular to the rotation axis z, the angle deviating from the x-axis is used as the boundary angle for switching array modes. Regarding the current azimuth angle satisfy boundary angle The corresponding boundary line is the dividing line between the two sets of subarray regions that form the azimuth difference.

[0087] by Figure 1 Taking a frustum-shaped conformal phased array as an example, the subarray is divided into 8 large sectors along the circumference, with boundary angles... The values ​​are -135°, -90°, -45°, 0°, 45°, 90°, 135°, and 180°. According to the upper and lower frustums, along the plane parallel to the xoy plane, it is divided into upper and lower frustums, and finally a total of 16 subarrays are formed.

[0088] like Figure 4 As shown, the current azimuth angle When, select The corresponding boundary line is the azimuth difference boundary line. The azimuth difference echo signal is formed by the difference between the (5, 6, 7, 8, 13, 14, 15, 16) subarray and the (1, 2, 3, 4, 9, 10, 11, 12) subarray.

[0089] When the front azimuth angle When, select The corresponding boundary line is the azimuth difference boundary line. The azimuth difference echo signal is formed by the difference between the (4, 5, 6, 7, 12, 13, 14, 15) subarray and the (1, 2, 3, 8, 9, 10, 11, 16) subarray.

[0090] When the front azimuth angle When, select The corresponding boundary line is the azimuth difference boundary line. The azimuth difference echo signal is formed by the difference between the (3, 4, 5, 6, 11, 12, 13, 14) subarray and the (1, 2, 7, 8, 9, 10, 15, 16) subarray.

[0091] When the front azimuth angle When, select The corresponding boundary line is the azimuth difference boundary line. The azimuth difference echo signal is formed by the difference between the (2, 3, 4, 5, 10, 11, 12, 13) subarray and the (1, 6, 7, 8, 9, 14, 15, 16) subarray.

[0092] When the front azimuth angle or When, select The corresponding boundary line is the azimuth difference boundary line, and the azimuth difference echo signal is formed by the difference between the (1, 2, 3, 4, 5, 6, 7, 8) subarray and the (9, 10, 11, 12, 13, 14, 15, 16) subarray.

[0093] The current azimuth angle At this time, the (1, 2, 3, 4, 5, 6, 7, 8) subarray is selected The corresponding boundary line is the azimuth difference boundary line, and the azimuth difference echo signal is formed by the difference between the (1, 2, 3, 8, 9, 10, 11, 16) subarray and the (4, 5, 6, 7, 12, 13, 14, 15) subarray.

[0094] The current azimuth angle At this time, the (1, 2, 3, 4, 5, 6, 7, 8) subarray is selected The corresponding boundary line is the azimuth difference boundary line, and the azimuth difference echo signal is formed by the difference between the (1, 2, 7, 8, 9, 10, 15, 16) subarray and the (3, 4, 5, 6, 11, 12, 13, 14) subarray.

[0095] The current azimuth angle At this time, the (1, 2, 3, 4, 5, 6, 7, 8) subarray is selected The corresponding boundary line is the azimuth difference boundary line, and the azimuth difference echo signal is formed by the difference between the (1, 6, 7, 8, 9, 14, 15, 16) subarray and the (2, 3, 4, 5, 10, 11, 12, 13) subarray.

[0096] In the prior art, the phased array antennas used in the application field of phased array antennas are basically planar phased array antennas, each unit in the array antenna is installed on the surface of the platform, the surface of the array antenna is consistent with the shape of the platform, and a "conformal array antenna" can be formed. Due to the limitations of structure and performance, the conventional planar antenna system has been difficult to meet the development needs. Compared with the traditional planar phased array, the conformal phased array has better scanning beam characteristics in terms of scanning range and simultaneous multi-target. For the conical surface conformal phased array, the conical surface conformal phased array can have large-angle scanning and forward detection capabilities. The sum-difference monopulse angle measurement is one of the main ways for radar to realize angle measurement. The basic principle is to process the received radar target echo, construct sum and difference road patterns, form sum and difference echo information, and use the difference between the target echo information in the sum and difference roads to extract the angle of the target deviating from the beam pointing axis through a specific algorithm model, so as to obtain the target angle. On the conformal surface, due to the different positions of the antenna elements, the unit direction pointing is inconsistent, and at the same time in the process of wide-angle scanning, there are problems such as structure blocking in the process of beam scanning. Using a fixed sum-difference beam forming network cannot meet the beam forming demand, and even there may be a problem of being unable to form a difference pattern. Compared with the prior art, the present application can always form a good array and difference pattern, obtain sum, pitch difference and azimuth difference echo signals, and solve the problem of being unable to form a difference beam caused by the structure blocking in the process of beam scanning of the conformal phased array, by designing the array subarray division and dynamically adjusting the range and combination form of the subarray participating in the sum-difference beam forming according to the radar beam pointing direction in a certain logical way.

[0097] Firstly, in the conformal array beam synthesis, the present application can judge the blocking condition of the unit beam and close the unit beam of the blocked part, so as to avoid the influence of the blocked beam on the precision. In addition, by designing the array subarray division, the present application improves the phase accuracy between beams through phase control, thereby improving the working precision of the phased array, obtaining a combined beam with high precision, and subsequently dynamically adjusting the range and combination form of the subarray participating in the sum-difference beam forming according to the radar beam pointing direction in a certain logical way, so as to always form a good array and difference pattern, obtain sum, pitch difference and azimuth difference echo signals, and solve the problem of being unable to form a difference beam caused by the structure blocking in the process of beam scanning of the conformal phased array.

[0098] By designing the array subarray division, the present application can dynamically select and combine each subarray in the process of beam switching to form the sum-difference beam of the conformal phased array, and can meet the monopulse angle measurement demand of the conformal phased array.

[0099] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A method of conical frustum conformal phased array and road beamforming, characterized in that, The method comprises the following steps: Step 1, according to the structure characteristics of the conical conformal phased array, sub-arrays are divided along the circumferential sectors and upper and lower conical frustums and numbered; Step 2, extract current frustum phased array beam pointing angle ; In the step 2, the conical conformal phased array beam pointing direction description adopts a right-hand system coordinate form, and the conical conformal phased array beam pointing off-axis angle is an angle between the beam pointing direction vector and the z-axis, and the value increases with the increase of the angle with the z-axis, and the value range is [0°, 180°]; In the step 2, the frustum conformal phased array beam pointing azimuth angle is the included angle between the projection vector of the beam pointing direction vector in the xoy plane and the x axis, which increases in the counterclockwise direction, and the value range is [-180°, 180°]; Step 3, according to the shielding condition of the unit in the beam pointing direction, the radio frequency receiving and transmitting channels of the antenna units not shielded are opened, and the radio frequency receiving and transmitting channels of the antenna units shielded are closed; In step 3, the occlusion status of antenna element n is determined by the unit vector normal to element n. With beam pointing unit vector inner product Decision, if Then antenna element n is not blocked; if If n is blocked, then antenna element n is blocked; where, The switching threshold angle of the antenna element is determined by the magnitude of the antenna element pattern in the direction deviating from the normal direction. The antenna units are attached to the surface of the conical frustum, and for the conical phased array, the switch state of each antenna unit is independently controlled by the TR component; Step 4, considering the factors of random phase feeding and phase error compensation, the wave control code of the nth element in the conical array relative to the reference element is calculated ; Step 5, the sum of the echoes received by all sub-arrays of the conical phased array forms a range echo; The obtained range echo signal of the conical conformal phased array is selected according to the beam pointing off-axis angle and the threshold angle size of the forward / lateral scanning mode to enter the difference beam synthesis mode; The difference beam synthesis mode includes a forward scanning mode and a lateral scanning mode. In forward scan mode, viewed from the xoy plane (projection plane perpendicular to the z-axis of rotation) of the frustum-shaped conformal phased array, the angle of deviation from the x-axis of the projection of each sector subarray along the generatrix boundary line onto the xoy plane is used as the boundary angle for switching array modes. Regarding the current azimuth angle ,satisfy boundary angle The corresponding boundary line is the dividing line between the two sets of subarray regions that form the azimuth difference, and the boundary line perpendicular to it is the dividing line between the two sets of subarray regions that form the pitch difference. If the side scan mode is used, the pitch difference echo signal is composed of the difference between the upper and lower conical frustum, and according to the azimuth angle , the group array scheme participating in the synthesis of the azimuth difference echo signal is determined respectively, the pitch difference and azimuth difference echo signals are synthesized, and the subsequent signal processing flow is entered; in the side scan mode, the pitch difference echo is obtained by differencing the subarray echoes on both sides of the upper and lower conical frustum interface; from the projection of the conical frustum conformal phased array on the projection plane xoy perpendicular to the rotation axis z, the projection of the generatrix boundary line of each sector subarray on the xoy plane is taken as the boundary angle of switching the group array mode ; for the current azimuth angle , the boundary angle corresponding to the boundary line satisfies , and the boundary line is the boundary line of the two groups of subarray regions for forming the azimuth difference.

2. The frustum-based conformal phased array and road beamforming method of claim 1, wherein, In the step 1, when the sub-array division of the conical conformal phased array is performed, from the projection plane of the conical conformal phased array perpendicular to the rotation axis, sectors are divided along the circumferential direction as sub-array partitions, and then the conical conformal phased array is divided into sub-regions with a plane parallel to the bottom plane of the conical frustum as a boundary, so that each minimum partition module is a sub-array of the conical conformal phased array.

3. The frustum conformal phased array and sum wave beam forming method of claim 2, wherein, In the step 4, the wave control code of the nth element in the frustum array relative to the reference element satisfies: （1） In the formula, given by the signal processing; given by the signal processing; given by the signal processing; n is the number of the array element in the conical array; ； is the angle between the beam pointing and the Z axis in the spherical coordinate system; is the angle between the projection of the beam pointing on the XOY plane and the X axis; is the initial phase of the antenna feeder line; [x(n) y(n) z(n)] is the position coordinates of the nth array element.

4. The frustum-based conformal phased array and road beamforming method of claim 3, wherein, In the step 1, when the sub-array division is performed, from the projection plane of the conical frustum, sectors are divided along the circumferential direction as sub-array partitions; then the conical conformal phased array is divided into sub-regions with a plane parallel to the bottom plane of the conical frustum as a boundary, so that each minimum partition module is a sub-array of the conical conformal phased array.

5. The frustum conformal phased array and road beamforming method of claim 4, wherein, In the step 1, the conical conformal phased array is uniformly divided into 8 sectors along the circumferential direction, and on this basis, the conical conformal phased array is divided into upper and lower conical frustums along a plane parallel to the xoy plane, so that 16 sub-arrays are finally formed.

6. The frustum-based conformal phased array and road beamforming method according to any one of claims 1 to 5, characterized in that, In the step 3, the antenna element pattern is sharply attenuated outside the region of 70° from the normal, defined as no contribution to the pattern, defining the element switch threshold angle The value 70° is taken, by which the state of each antenna element switch is controlled.

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