Optimization method based on phase consistency of interferometer in complete machine in compact space

Abstract

The invention provides an interferometer phase consistency optimization method based on a compact space complete machine, relates to an interferometer direction finding technology, and belongs to the field of electronic countermeasures. According to the method, a metal cavity is designed around an interferometer array, and the interferometer array is arranged in the metal cavity, so that the interferometer array isolates a compact space complete machine environment and mirror reflection caused by an antenna housing; wave-absorbing materials are pasted on the four walls of the metal cavity, and gaps of the interferometer units at the bottom of the metal cavity are filled with foam wave-absorbing materials. According to the invention, the phase consistency optimization problem of the interferometer in a compact space complete machine can be solved.

Description

Technical Field

[0001] The invention mainly relates to an interferometer direction-finding technology, proposes an optimization method for the phase consistency of an interferometer in a compact space whole machine, and belongs to the field of electronic countermeasures. Background Art

[0002] In the rapidly developing modern war, various advanced airborne and shipborne weapon systems often require reconnaissance and guidance from electronic countermeasure systems, highlighting the criticality of direction finding systems. However, with the continuous optimization and iteration of direction finding platforms, the layout conditions of direction finding antenna arrays have become increasingly demanding, the installation space of interferometers has been repeatedly compressed, and the compact whole machine environment interacts with antennas, resulting in large variations in electrical performance between antennas.

[0003] The conventional method for optimizing the lateral phase consistency of the interferometer is to perform phase calibration in a large microwave darkroom. However, phase calibration can only adjust the phase at a single angle and has no effect on the phase consistency at other azimuth angles. There is currently no suitable optimization method for optimizing the effect of multipath reflection in a complex environment on the phase consistency between units through array design. Summary of the invention

[0004] The present invention aims to optimize the phase consistency of the interferometer in a compact space machine by optimizing the design of the traditional interferometer to meet the requirements of direction finding in a compact machine space. The present invention can be applied to direction finding problems in a variety of complex machine environments.

[0005] The above purpose is achieved through the following technical solutions: The present invention provides an optimization method based on the phase consistency of an interferometer in a compact space complete machine. The method comprises the following steps: designing a metal cavity around an interferometer array and placing the interferometer array in the metal cavity so that the interferometer array is isolated from the compact space complete machine environment and the mirror reflection caused by the antenna cover; the four walls of the metal cavity are pasted with absorbing material, and the bottom of the metal cavity is filled with a foam absorbing material to fill the interferometer unit gap.

[0006] Furthermore, the interferometer array adopts log-periodic antenna units or slot-line antenna units.

[0007] Furthermore, the metal cavity is made of parallel planar aluminum or copper metal materials.

[0008] Furthermore, the absorbing material is made of broadband rubber absorbing material.

[0009] Furthermore, the absorbing material is a rubber absorbing material with a thickness of 1 mm; and the bottom of the metal cavity is filled with a foam absorbing material with a thickness of 10 mm.

[0010] Compared with the prior art, the present invention has the following significant advantages: 1. The present invention adds parallel metal cavities around the array on the basis of the traditional interferometer, and adds absorbing materials inside the metal cavity to optimize the phase consistency of the compact space. The parallel metal cavity ensures the consistency of the mirror reflection between the interferometer antenna units as much as possible relative to the irregular whole machine environment. At the same time, the metal cavity can effectively isolate the mirror reflection caused by the antenna cover from the multiple mirror reflections that affect the antenna through the irregular whole machine environment. At the same time, the bottom of the antenna array is filled with foam absorbing materials to reduce the influence of the reflected waves caused by the metal floor. With the present invention, the disordered phase consistency between the interferometer units affected by the whole machine is greatly improved, and the phase difference of each unit in the azimuth range of ±45° in the full frequency band of 2Ghz~18GHz in the compact whole machine space is basically within ±20°. The present invention meets the urgent needs of the interferometer direction-finding platform, and its implementation can improve the working ability of the equipment and has important military benefits.

[0011] 2. The present invention has a wide range of applicable platforms, a simple structure, and is easy to process, and can meet the direction finding requirements of a variety of complex whole machine environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is an outline diagram of the optimization method of the interferometer phase consistency in a compact space machine according to the present invention; Figure 2 It is a top view of the array of the optimization method of the interferometer phase consistency in a compact space machine according to the present invention; Figure 3 It is a side view of the array of the optimization method of the interferometer phase consistency in a compact space complete machine according to the present invention; Figure 4 (a), (b), and (c) show the phase consistency of a conventional compact spatial interferometer at 2 GHz, 9 GHz, and 18 GHz, respectively; Figure 5 (a), (b), and (c) in the figure respectively show the phase consistency of the interferometer at 2 GHz, 9 GHz, and 18 GHz after optimization based on the phase consistency of the compact space machine of the present invention; Explanation of the reference numerals in the figure: 1. interferometer array; 2. metal cavity; 3. absorbing material; 4. foam absorbing material; 5. metal base plate. DETAILED DESCRIPTION

[0013] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0014] refer to Figure 1-3 Described are the three-dimensional schematic diagram, top view and side view of the model of the optimization method for the phase consistency of the interferometer in a compact space machine proposed by the present invention.

[0015] like Figure 1-3As shown, the optimization method of the interferometer phase consistency in a compact space whole machine of the present invention designs a metal cavity 2 around the interferometer array 1 and places the interferometer array in the metal cavity so that the interferometer array is isolated from the compact space whole machine environment and the mirror reflection caused by the antenna cover; the four walls of the metal cavity 2 are pasted with absorbing material 3, and the bottom of the metal cavity 2 is filled with foam absorbing material 4 to fill the interferometer unit gap.

[0016] The interferometer array in this embodiment is designed as a four-element interferometer array with specific frequency band and size requirements. According to the product requirements for gain, interferometer unit spacing and power resistance, a metal logarithmic periodic antenna unit is designed. In this embodiment, four logarithmic periodic antenna units are arranged in a line according to the predetermined interferometer baseline to form an interferometer array; a metal cavity is added around the array and placed vertically on the metal base plate 5. The size of the metal cavity is determined according to the overall environment optimization to ensure that the messy mirror reflections between the four logarithmic periodic antennas in the compact space are transformed into relatively consistent mirror reflections; a rubber absorbing material with a thickness of 1 mm is pasted on the four walls inside the metal cavity. This absorbing material is selected after optimization simulation comparison of several absorbing materials available on the market for the frequency band range of the interferometer array by bringing in the electromagnetic parameters of the absorbing material, which can improve the influence of the introduction of the metal cavity on the phase consistency between the interferometer units; the bottom is filled with a foam absorbing material with a thickness of 10 mm to reduce the mirror reflection of the metal base plate. The foam absorbing material is also selected after simulation screening and comparison to ensure that the phase consistency of the interferometer antenna array is optimized.

[0017] Figure 4 The phase consistency of the interferometer units at different frequencies in a conventional compact space environment shows that the phase consistency between the units in the azimuth range of ±45° deteriorates to about 70° at 2GHz, the worst consistency is about 30° at 9GHz, and the consistency is about 20° at 18GHz. This is because the wavelength of 2GHz is longer than that of 18GHz and is more susceptible to the complex environment of the whole machine. It is manifested as follows: when the four-element interferometer array is working, electromagnetic waves are generated and radiated in all directions. In a conventional compact space environment, the metal structures around the interferometer will reflect a large number of electromagnetic waves, and due to the irregularity of the structure and arrangement of the metal structures, the four logarithmic periodic antenna units are affected by different electromagnetic wave reflections, which affects the phase consistency between the units.

[0018] Figure 5The optimized phase consistency of the interferometer phase consistency in a compact space machine shows that the phase consistency between units within the range of ±45° in the azimuth angle is within 20° at 2GHz, 9GHz, and 18GHz. It is manifested as follows: when the four-element interferometer array (1) is working, electromagnetic waves are generated and radiated in all directions. After the optimization of this patent, a planar metal cavity (2) is added around the array. The metal cavity is placed parallel to the logarithmic periodic antenna unit, so that the surrounding environment of the four logarithmic periodic units is relatively consistent, which optimizes the consistency of the mirror reflection between the units. At the same time, the height of the metal cavity is slightly higher than the metal structural parts around the interferometer. In this way, the multiple mirror reflections caused by the irregularity of the metal structural parts and the arrangement in the compact space machine will be blocked by the metal cavity, which greatly ensures that the interferometer array unit is not restricted by the installation environment. Adding rubber absorbing material to the bottom of the metal cavity and adding foam absorbing material to optimize the effect of the mirror reflection of the metal cavity and the metal bottom plate on the phase consistency between the units.

[0019] The present invention proposes an optimization method based on the phase consistency of the interferometer in a compact space machine, which is widely applicable to platforms, has a simple structure, is easy to process, isolates the influence of the environment on the phase consistency between the interferometer units, and can meet the direction finding requirements of various complex machine environments; the antenna array of the present invention has good phase consistency between the units in the full frequency band, and the phase difference of each unit within the azimuth angle range of ±45° is basically within ±20°; The terms involved in the present invention are explained as follows: Phase consistency: The consistency of the phase difference between each antenna element in the array, that is, .

[0020] Phase consistency processing method: Read the phase data of the four antennas. For example, take antenna No. 1 as the reference, and subtract the phase data of antenna No. 2 at the same angle at the same frequency point from its phase data, and you will get the phase consistency of interferometer units No. 1 and No. 2 at the same frequency at different azimuth angles. Similarly, you can get the phase consistency data of interferometer units No. 2 and No. 3, and No. 3 and No. 4.

Claims

1. An optimization method based on the phase consistency of the interferometer in a compact space machine, characterized in that: The method is as follows: a metal cavity is designed around the interferometer array and the interferometer array is placed in the metal cavity so that the interferometer array is isolated from the compact space environment and the mirror reflection caused by the antenna cover; the four walls of the metal cavity are pasted with absorbing materials, and the bottom of the metal cavity is filled with foam absorbing materials to fill the interferometer unit gap.

2. The optimization method based on interferometer phase consistency in a compact space machine according to claim 1, characterized in that: The interferometer array adopts logarithmic periodic antenna units or slot line antenna units.

3. The optimization method based on interferometer phase consistency in a compact space machine according to claim 1 or 2, characterized in that: The metal cavity is made of parallel planar aluminum or copper metal materials.

4. The optimization method based on interferometer phase consistency in a compact space machine according to claim 1 or 2, characterized in that: The wave absorbing material is made of broadband rubber wave absorbing material.

5. The optimization method based on interferometer phase consistency in a compact space machine according to claim 4, characterized in that: The absorbing material is a rubber absorbing material with a thickness of 1 mm; the bottom of the metal cavity is filled with a foam absorbing material with a thickness of 10 mm.

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