A vector antenna array for measuring waves coming from any angle in space

Abstract

The application discloses a vector antenna array for measuring waves coming from any angle in space, and belongs to the technical field of antenna engineering, the field of radio detection and the field of electronic countermeasure. The application uses wideband dipole antennas to receive waves coming from a wide frequency band, uses wideband dipole antennas to be placed in cross to form a defective vector antenna to realize lossless receiving of the electric field of the waves, uses two defective vector antennas to form a vector antenna array to complete estimation of the angle of arrival of the waves coming from any direction, and uses the information of the angle of arrival as a basis to combine the electric field intensity components of the waves received by each wideband dipole to realize extraction of the polarization information of the waves. The antenna unit adopted by the application has simple structure and is easy to process and assemble. When used, the direction of the waves is not limited, there is no dead angle for measurement, and complete information of the frequency, the angle of arrival and the polarization of the waves can be extracted. The application can measure the frequency, the angle of arrival and the polarization of the waves coming from any direction.

Description

Technical Field

[0001] This invention belongs to the fields of antenna engineering technology, radio detection, and electronic countermeasures. It relates to a vector antenna array with a simple structure that can measure the frequency, direction, and polarization of incoming waves with a 4π spherical aspect ratio in any direction. Background Technology

[0002] Traditional radio direction finding systems are passive electronic devices that can detect electromagnetic signals emitted by enemy radio equipment without emitting any themselves, making them highly stealthy and extremely valuable on the modern battlefield. However, traditional radio direction finding systems can only detect the frequency and direction of incoming enemy signals, not their polarization. Achieving effective countermeasures requires a significant investment of resources when only the frequency and direction of the incoming signal can be determined. Conversely, simultaneously detecting the frequency, direction, and polarization of the incoming signal allows for a much more efficient countermeasure. Therefore, radio equipment capable of simultaneously measuring the frequency, direction, and polarization of incoming signals has immense military value.

[0003] Currently, equipment used for measuring the frequency and direction of incoming waves can be mainly classified into the following types according to their system: 1. Amplitude comparison direction finding system: The working principle of the amplitude comparison direction finding system is based on the directional characteristics of the direction finding antenna array or antenna during the propagation of the radio wave. It determines the direction of the incoming wave by measuring the difference in amplitude of the received signal from different directions. 2. Watson-Watt direction finding system: The Watson-Watt direction finder is actually also an amplitude comparison direction finding system, but it does not use direct or indirect antenna pattern rotation during direction finding. Instead, it calculates or displays the arctangent value. 3. Interferometer direction finding system: The direction finding principle of the interferometer direction finding system is based on the fact that when radio waves from different directions arrive at the direction finding antenna array, the phases received by each direction finding antenna element in space are different, and therefore the phase differences between them are also different. By measuring the phase of the incoming wave and the phase difference, the direction of the incoming wave can be determined. 4. Doppler direction finding system. The Doppler direction finding system works on the principle that when a radio wave encounters a direction finding antenna moving relative to it during propagation, the received signal produces the Doppler effect. Measuring the frequency shift caused by the Doppler effect determines the direction of the incoming wave. To obtain the frequency shift caused by the Doppler effect, there must be relative motion between the direction finding antenna and the radio wave being measured. This is usually achieved by the direction finding antenna moving at a sufficiently high speed in the receiving field. The Doppler frequency shift (increase) is greatest when the direction finding antenna moves completely in the direction of the incoming wave. 5. Ulanweiber direction finding system. The Ulanweiber direction finding system uses a large-foundation direction finding antenna array, with multiple antennas erected in a circle. The incoming wave signal passes through a rotatable angle meter, phase shift circuit, and summing circuit to form a summing pattern, which is then fed to the receiver. By rotating the angle meter and the summing pattern, the direction of the incoming wave is determined. 6. Time difference of arrival direction finding system. The direction finding principle of the time-of-arrival (TOA) direction finding system is based on the difference in arrival time of radio waves at each direction finding antenna element in the array, thus determining the direction of arrival. It is similar to phase-comparison direction finding, but the parameter measured here is the time difference, not the phase difference. This system requires the measured signal to have a specific modulation scheme. 7. Spatial spectrum estimation direction finding system. The spatial spectrum estimation direction finding system works by measuring the arrival parameters of an element or multiple radio wave field in a multi-element antenna array with known coordinates. These parameters are then converted and amplified by a multi-channel receiver to obtain a vector signal. This vector signal is sampled and quantized into a digital signal array, which is then sent to a spatial spectrum estimator. A defined algorithm is used to calculate the arrival direction, elevation angle, polarization, and other parameters of each radio wave.

[0004] All the direction-finding methods listed above can only measure the frequency and direction of the incoming wave, but cannot obtain the polarization of the incoming wave. However, the vector antenna array of this invention, when connected to a common multi-channel broadband receiver, can simultaneously measure the frequency, direction, and polarization of incoming waves from any direction by simply combining it with relevant algorithms.

[0005] Traditional radio direction finding equipment uses scalar antennas or scalar antenna arrays. Limited by the radiation patterns of scalar antennas and arrays, the angular measurement range of traditional radio direction finding equipment is limited, making it impossible to achieve complete angular coverage of 4π spherical degrees. The vector antenna of this invention, when measuring the angle of arrival of an incoming wave, has no restrictions on the direction of the incoming wave; it can measure incoming waves from any direction within 4π spherical degrees. Simultaneously, this vector antenna can also extract the polarization information of the incoming wave, a capability not found in traditional radio direction finding equipment. Summary of the Invention

[0006] Based on the prior art, this invention proposes a vector antenna array that can be used for simultaneous frequency, direction, and polarization measurement. This vector antenna array, together with a multi-channel broadband receiver, forms a complete radio detection system. This system can detect incoming waves from any direction within a 4π spherical radius of space, extracting their frequency, angle of arrival (AOA), and polarization information.

[0007] The technical solution adopted in this invention is: a vector antenna array for measuring incoming waves at arbitrary angles in space, the antenna array being composed of two identical incomplete vector antenna elements; the incomplete vector antenna element is composed of three identical broadband dipole antennas;

[0008] The broadband dipole antenna includes: a radiating patch, a dielectric substrate, and a metal grounding layer; the radiating patch is disposed on one surface of the dielectric substrate, and the metal grounding layer is disposed on the other surface of the dielectric substrate; the radiating patch is composed of a rectangular region and an isosceles wedge region spliced ​​together, the bottom edge of the isosceles wedge region contacts one side of the rectangular region, and the top of the isosceles wedge region extends outward by an additional microstrip line protrusion; the metal grounding layer is a "U"-shaped patch, and the corresponding position of the "U"-shaped patch surrounds the isosceles wedge region of the radiating patch;

[0009] The missing vector antenna includes: three broadband dipole antennas placed in a crisscross pattern, the extensions of the axes of symmetry of these three broadband dipole antennas intersecting at a point; the plane formed by the axes of any two broadband dipole antennas is perpendicular to the axis of symmetry of the third broadband dipole antenna.

[0010] The vector antenna array includes: a missing vector antenna element one and a missing vector antenna element two. The smallest outer cube of the two missing vector antenna elements does not touch.

[0011] Furthermore, the isosceles wedge-shaped region of the radiating patch in the broadband dipole antenna is an isosceles trapezoid, or a deformation of the isosceles trapezoid, wherein the waist of the deformed isosceles trapezoid is a curve.

[0012] Furthermore, the axes of symmetry of the three broadband dipole antennas in the incomplete vector antenna are mutually perpendicular.

[0013] Furthermore, the positional relationship between the missing vector antenna element one and the missing vector antenna element two is one of the following positional relationships;

[0014] 1. The position of the second incomplete vector antenna element is obtained by translating the first incomplete vector antenna element along the axis of symmetry of a radiating patch;

[0015] 2. Suppose that the missing vector antenna element 1 includes broadband dipole antenna 1, broadband dipole antenna 2, and broadband dipole antenna 3, and the axis of symmetry of broadband dipole antenna 2 is perpendicular to the plane formed by the axes of symmetry of broadband dipole antenna 1 and broadband dipole antenna 3; the missing vector antenna element 2 includes broadband dipole antenna 4, broadband dipole antenna 5, and broadband dipole antenna 6, and the axis of symmetry of broadband dipole antenna 5 is perpendicular to the plane formed by the axes of symmetry of broadband dipole antenna 4 and broadband dipole antenna 6; the plane formed by the axes of symmetry of broadband dipole antenna 1 and broadband dipole antenna 3 in the missing vector antenna element 1 is parallel to the plane formed by the axes of symmetry of broadband dipole antenna 4 and broadband dipole antenna 6 in the missing vector antenna element 2, and broadband dipole antenna 2 and broadband dipole antenna 5 are located outside the two planes;

[0016] 3. The positional relationship between the missing vector antenna element 1 and the missing vector antenna element 2 in positional relationship 3 is obtained by translating the missing vector antenna element 2 along the axis of symmetry of the broadband dipole antenna 4 or the broadband dipole antenna 6, based on positional relationship 2.

[0017] This invention employs a broadband dipole antenna as the antenna element of a detrimental vector antenna. Three broadband dipole antennas are interleaved to form a detrimental vector antenna element, and two detrimental vector antenna elements are placed at a certain distance to form a vector antenna array. The broadband dipole antenna has a very wide operating bandwidth, allowing the vector antenna array to measure incoming waves over a wide frequency range. For two detrimental vector antenna elements placed at a certain distance to form a vector antenna array, for a wave arriving from any direction with a 4π spherical aspect ratio, there is a path difference upon arrival at the two detrimental vector antenna elements, allowing the measurement of the angle of arrival (Angle of Arrival). Based on the obtained AnAngle of Arrival information, the three broadband dipole antennas forming the detrimental vector antenna element can all receive the electric field component of the incoming wave. By combining the AnAngle of Arrival information with the electric field vector synthesis, the polarization information of the incoming wave can be obtained. This invention can measure the frequency, AnAngle of Arrival, and polarization of waves arriving from any direction. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the broadband dipole antenna in an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of a partial vector antenna consisting of three broadband dipole antennas.

[0020] Figure 3This is a schematic diagram of a vector antenna array composed of two incomplete vector antenna elements.

[0021] Figure 4 is the standing wave ratio of the broadband dipole antenna.

[0022] Figure 5 This is the radiation pattern of a broadband dipole antenna.

[0023] Figure 6 This is a schematic diagram of a modified re-radiating patch for a broadband dipole antenna.

[0024] Figure 7 This is a schematic diagram of a modified version of a depleted vector antenna array consisting of two depleted vector antennas. Detailed Implementation

[0025] The structure of the broadband dipole antenna element in this embodiment is shown below. Figure 1 The broadband dipole antenna element measures 265mm × 105mm × 1.6mm. The antenna operates at frequencies between 385MHz and 640MHz, with a standing wave ratio (VSWR) less than 2.0 within this frequency band (see figure). The broadband dipole antenna element has a three-layer structure: a radiating element layer, a dielectric substrate layer, and a metal ground layer. The dielectric substrate is made of FR4 material with a relative permittivity of 4.4 and a thickness of 1.6mm.

[0026] Radiation unit layer.

[0027] The radiating unit layer is a copper foil with a thickness of 0.035mm, and its shape is obtained by cutting two right-angled trapezoids of the same size from a rectangle. The dimensions of the rectangle are 265mm × 88mm, the lower base of the two right-angled trapezoids is 122mm, the upper base is 4mm, and the height is 42mm.

[0028] The radiating layer formed by removing the two right-angled trapezoids allows the dipole antenna element to achieve good impedance matching over a wide frequency band.

[0029] Metallic strata.

[0030] The metal grounding layer is also a copper foil with a thickness of 0.035mm, and its shape is "U". It is obtained by cutting out a small rectangle from a large rectangle. The large rectangle measures 105mm × 93mm, and the small rectangle measures 82mm × 80mm.

[0031] The U-shaped metal grounding layer is used as the ground for a broadband dipole antenna. Using this shape can effectively reduce the length of the antenna.

[0032] Defective vector antenna.

[0033] The incomplete vector antenna consists of three broadband dipole antennas. Broadband dipole antenna one and broadband dipole antenna two are located in the same plane, with an angle of 135° between their axes. Broadband dipole antenna three is perpendicular to the plane containing broadband dipole antenna one and broadband dipole antenna two. The axes of broadband dipole antenna one, broadband dipole antenna two, and broadband dipole antenna three are located at the same point.

[0034] Three broadband dipole antennas placed in a crisscross pattern can achieve complete reception of the electric field components of waves arriving from any direction.

[0035] Vector antenna array.

[0036] The vector antenna array is a two-element array composed of two incomplete vector antenna elements, with the two incomplete vector antennas spaced 1900mm apart. The broadband dipole antennas 1, 2, and 3 of incomplete vector antenna 1 are parallel to the broadband dipole antennas 1, 2, and 3 of incomplete vector antenna 2.

[0037] The purpose of spacing two incomplete vector antennas that make up a vector antenna array is to obtain the path difference of the incoming wave and provide phase information for measuring the angle of arrival.

[0038] The vector antenna array consists of two incomplete vector antennas, which in turn are composed of three intersecting broadband dipole antennas. The broadband dipole antennas operate within a bandwidth of 385MHz-640MHz. (See...) Figure 4 Its gain is greater than 2.0 dBi throughout the entire operating frequency band, see... Figure 5 This broadband dipole antenna can effectively receive incoming waves with frequencies ranging from 385MHz to 640MHz. When two incomplete vector antennas are spaced 1900mm apart to form a vector antenna array, this array can achieve frequency, angle of arrival, and polarization measurements for incoming waves from any direction.

[0039] Compared to traditional radio direction-finding antenna arrays, vector antennas have no blind spots in direction finding, and can measure the polarization information of the incoming wave simultaneously with angle and frequency measurement. Only by obtaining the frequency, angle of arrival, and polarization information of the incoming wave can a complete understanding of the incoming wave be truly achieved.

Claims

1. A vector antenna array for measuring incoming waves at arbitrary angles in space, the antenna array being composed of two identical incomplete vector antenna elements; the incomplete vector antenna element is composed of three identical broadband dipole antennas; The broadband dipole antenna includes: A radiating patch, a dielectric substrate, and a metallic grounding layer; the radiating patch is disposed on one surface of the dielectric substrate, and the metallic grounding layer is disposed on the other surface of the dielectric substrate; The radiating patch is composed of a rectangular area and an isosceles wedge-shaped area. The bottom edge of the isosceles wedge-shaped area contacts one side of the rectangular area, and the top of the isosceles wedge-shaped area extends outward with an additional microstrip protrusion. The metal grounding layer is a "U"-shaped patch, and the corresponding position of the "U"-shaped patch surrounds the isosceles wedge-shaped area of ​​the radiating patch. The incomplete vector antenna includes: three broadband dipole antennas placed intersecting each other, the extensions of the axes of symmetry of the three broadband dipole antennas intersecting at a point; wherein the plane formed by the axes of any two broadband dipole antennas is perpendicular to the axis of symmetry of the third broadband dipole antenna; The vector antenna array includes: a first incomplete vector antenna element and a second incomplete vector antenna element, wherein the smallest outer cube of the two incomplete vector antenna elements does not contact each other.

2. A vector antenna array as described in claim 1 for measuring frequency, angle of arrival, and polarization of waves arriving at arbitrary angles in space, characterized in that, The isosceles wedge-shaped region of the radiating patch in the broadband dipole antenna is an isosceles triangle, or a deformation of the isosceles triangle, wherein the legs of the deformed isosceles triangle are curves.

3. A vector antenna array as described in claim 1 for measuring frequency, angle of arrival, and polarization of waves arriving at arbitrary angles in space, characterized in that, The axes of symmetry of the three broadband dipole antennas in the incomplete vector antenna are perpendicular to each other.

4. A vector antenna array as described in claim 1 for measuring frequency, angle of arrival, and polarization of waves arriving at arbitrary angles in space, characterized in that... The positional relationship between the first incomplete vector antenna element and the second incomplete vector antenna element is one of the following positional relationships; 1. The position of the second incomplete vector antenna element is obtained by translating the first incomplete vector antenna element along the axis of symmetry of a radiating patch; 2. Suppose that the incomplete vector antenna element 1 includes broadband dipole antenna 1, broadband dipole antenna 2, and broadband dipole antenna 3, with the axis of symmetry of broadband dipole antenna 2 perpendicular to the plane formed by the axes of symmetry of broadband dipole antenna 1 and broadband dipole antenna 3; the incomplete vector antenna element 2 includes broadband dipole antenna 4, broadband dipole antenna 5, and broadband dipole antenna 6, with the axis of symmetry of broadband dipole antenna 5 perpendicular to the plane formed by the axes of symmetry of broadband dipole antenna 4 and broadband dipole antenna 6; the plane formed by the axes of symmetry of broadband dipole antenna 1 and broadband dipole antenna 3 in the incomplete vector antenna element 1 is parallel to the plane formed by the axes of symmetry of broadband dipole antenna 4 and broadband dipole antenna 6 in the incomplete vector antenna element 2, and broadband dipole antenna 2 and broadband dipole antenna 5 are located outside the two planes; 3. The positional relationship between the incomplete vector antenna element 1 and the incomplete vector antenna element 2 in positional relationship 3 is obtained by translating the incomplete vector antenna element 2 along the axis of symmetry of the broadband dipole antenna 4 or the broadband dipole antenna 6, based on positional relationship 2.

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