Modular esm antenna cover electrical performance testing device and method

Abstract

The application belongs to the field of antenna cover electrical performance test, and relates to a modular ESM antenna cover electrical performance test device and method. The device comprises a large crossbar, a small crossbar, a tail support, an antenna array erection assembly and an antenna cover erection assembly. The large crossbar is provided with a male or female lug at both ends for connection with a rotary table. The middle part of the large crossbar is provided with a plurality of square lugs, and the square lugs are connected with longitudinal rods. The longitudinal rods are divided into two groups of inside and outside, and there are four longitudinal rods in total. The two longitudinal rods on the inside are used for connection with the antenna array erection assembly, and the two longitudinal rods on the outside are used for connection with the antenna cover erection assembly. The connection form of the small crossbar is the same as that of the large crossbar. The lower end of the tail support is connected with the rotary table through bolts. The device has the advantages that the antenna array and the antenna cover have high installation precision during the antenna cover electrical performance test, the installation and adjustment method of the antenna array and the antenna cover is simple during the symmetrical antenna cover test, the adjustment process is convenient, and the test efficiency and accuracy are high.

Description

Technical Field

[0001] This invention belongs to the field of radome electrical performance testing, and relates to a modular ESM radome electrical performance testing device and method. Background Technology

[0002] ESM radomes are primarily used for the aerodynamic layout of antenna pods in airborne electronic support systems (AFSS), and are a major component of AFSS. The electrical performance of the ESM radome directly affects the performance of the AFSS. Therefore, accurately evaluating the electrical performance parameters of the ESM radome is particularly important. An ESM radome electrical performance testing device is designed specifically for this purpose. Its main function is to mount the ESM antenna and ESM radome on a test turntable, with the relative mounting positions of the ESM antenna array and ESM radome on the turntable consistent with their relative installation positions on the aircraft. By testing the radiation pattern parameters of each element of the ESM antenna array in both radome and uncovered states, the electrical performance indicators of the ESM radome can be evaluated through mathematical calculations.

[0003] Because the ESM radomes installed on the left and right wingtips of the aircraft have dihedral angles in both the yaw and vertical directions, and the ESM antenna arrays are divided into a forward and a rear antenna arrays with an angle of 45° along the wingspan axis, and the distances from the forward and rear antenna arrays to the wingtip radome separation surface are not unequal, the existing electrical performance testing equipment for ESM radomes made of wood suffers from complex, time-consuming, and low-precision adjustments to the right wingtip radome installation position when replacing it after testing the electrical performance of the left ESM radome. This significantly affects testing efficiency and accuracy. Summary of the Invention

[0004] A modular ESM radome electrical performance testing device includes a large horizontal bar 1, a small horizontal bar 2, a tail support 3, an antenna array mounting assembly 4, and an antenna radome mounting assembly 5. The large horizontal bar 1 has irregularly shaped lugs at both ends for connection to a turntable. The middle of the large horizontal bar 1 has several square lugs connected to longitudinal bars. The longitudinal bars are divided into two symmetrical groups, inner and outer, totaling four. The two inner longitudinal bars are connected to the antenna array mounting assembly 4, and the two outer longitudinal bars are connected to the antenna radome mounting assembly 5. The small horizontal bar 2 has the same connection method as the large horizontal bar 1. The lower end of the tail support 3 is connected to the turntable by bolts, and the upper end is supported by four adjusting bolts at the bottom of the two inner and two outer longitudinal bars respectively. The antenna array mounting assembly 4 includes an antenna support, an antenna bracket, and a... The antenna support is bolted to two inner longitudinal rods on one side and bolted to one side of the antenna bracket on the other side. The antenna bracket is bolted to the antenna connector on the other side. The antenna connector's profile matches the antenna structure. The radome mounting assembly 5 includes a separation surface support and a separation surface assembly. One side of the separation surface support is connected to the outer longitudinal rod, and the other side is connected to the separation surface assembly. The separation surface assembly includes a separation panel, a small-end locator, a large-end locator, an upper pressure plate, and a lower pressure plate. In the yaw direction, the separation panel has a large-end locator facing upwards and a small-end locator facing upwards. The upper and lower ends of the working surface of the separation panel are respectively equipped with upper and lower pressure plates, two of each. Their profiles match the outer contour of the radome, and the radome is bolted together.

[0005] Both the upper and lower pressure plates are provided with U-shaped holes, which are connected to the separation panel by bolts, allowing for fine adjustment of the relative positions of the upper and lower pressure plates on the separation panel.

[0006] The separation panel has positioning lines at its upper and lower ends, which are used to align with the heading feature points on the radome.

[0007] Both the small-endian and large-endian positioners are equipped with positioning lines for alignment with the upper and lower feature points on the radome.

[0008] The areas where the upper and lower pressure plates connect to the radome are equipped with rubber pads to protect the radome connection surfaces.

[0009] The separation panel is made of wood to reduce the impact of electromagnetic wave reflection on the test.

[0010] The length of the large horizontal bar 1 is greater than the length of the small horizontal bar 2, and the length requirement should match the shape of the turntable structure.

[0011] A method for testing the electrical performance of a modular ESM radome:

[0012] In use, first fix the large horizontal bar 1, small horizontal bar 2, and tail support 3 to the blind holes with internal threads on the horizontal rolling ring structure of the receiving turntable with bolts. Then, connect the assembled antenna mounting assembly 4 and radome mounting assembly 5 to the large horizontal bar 1, small horizontal bar 2, and tail support 3 respectively using the method in the technical solution. Connect the front antenna array and the rear antenna array to the 16 through holes of the front and rear forked horizontal plates of the antenna connector 4d with 16 bolts. The transmitting antenna is mounted on the transmitting turntable at the transmitting end. The transmitting antenna and the receiving antenna array are at the same height. The transmission and reception distance between the transmitting antenna and the receiving antenna array should meet the far-field test conditions (i.e., (where L is the distance between the transmitting and receiving antennas, D is the antenna aperture, and λ is the operating wavelength). Connect the multi-channel elements of the front and rear antenna arrays to the multi-channel input terminals of the microwave matrix switch via RF cables. Use calibration components to perform open-circuit, short-circuit, and through-port calibration of the vector network analyzer. Start the turntable and control the microwave matrix switch to time-divisionally acquire a set of amplitude and phase pattern data received by each element of the front and rear antenna arrays when the array is unshielded. Then, set up the left wingtip on the device according to the method in the technical solution of an ESM radome electrical performance testing device. Start the turntable and control the microwave matrix switch to time-divisionally acquire a set of amplitude and phase pattern data received by each element of the receiving antenna array when the array is shrouded. Change the pitch angle of the turntable until all unshielded and shrouded data acquisition is completed. Calculate the relevant electrical performance parameters of the left wingtip using mathematical methods.

[0013] During the electrical performance testing of the right wingtip radome, the front and rear antenna arrays must be detached from the antenna connector 4d of the antenna mounting assembly 4, and the antenna connector 4d must be removed. The symmetrical component of the upper antenna connector 4d must be replaced, and the front and rear antenna arrays must be installed on the symmetrical component of the antenna connector 4d. The separation surface assembly 5c must be detached from the radome mounting assembly 5, and the symmetrical component of the upper separation surface assembly 5c must be installed. The turntable is started, and the control system controls the microwave matrix switch to switch the multiplexer to collect multiple sets of amplitude and phase radiation pattern data at various pitch angles with and without the radome. The relevant electrical performance parameters of the right wingtip radome are obtained through mathematical calculation.

[0014] Technical effect

[0015] Its advantages are that the antenna array and radome have high installation accuracy during radome electrical performance testing, and the installation and adjustment methods for symmetrical radome are simple and convenient during radome testing, resulting in high testing efficiency and accuracy. Attached Figure Description

[0016] This invention includes 9 figures, and the figures and their descriptions are as follows:

[0017] Figure 1 This is a schematic diagram of the modular ESM radome electrical performance testing device.

[0018] Figure 2 Here is the outline of the main horizontal bar 1;

[0019] Figure 3 Here is the outline of the small horizontal bar 2;

[0020] Figure 4 The outline of the tail support 3;

[0021] Figure 5 Schematic diagram of antenna mounting component 4;

[0022] Figure 6 4D outline of the antenna support;

[0023] Figure 7 Schematic diagram of component 5 for mounting the radome;

[0024] Figure 8 This is the outline drawing of the separation surface assembly 5c;

[0025] Figure 9 This is a schematic diagram of a modular ESM radome electrical performance testing device mounted on a rotating ring on a turntable, with the radome mounted on top. Detailed Implementation

[0026] like Figure 1 As shown, a modular ESM radome electrical performance testing device is provided, comprising: a large horizontal bar 1, a small horizontal bar 2, a tail support 3, an antenna array mounting assembly 4, and a radome mounting assembly 5; wherein, the antenna array mounting assembly 4 includes longitudinal bars 4a1 and 4a2, an antenna support 4b, an antenna bracket 4c1 and 4c2, and an antenna connector 4d (symmetrical left and right parts); the antenna mounting assembly 5 includes longitudinal bars 5a1 and 5a2, separation surface supports 5b1 and 5b2, and a separation surface assembly 5c (symmetrical left and right parts); wherein, the separation surface assembly 5c includes a separation panel 5c1, a small end positioner 5c2, a large end positioner 5c3, upper pressure plates 5c4 and 5c5, and lower pressure plates 5c6 and 5c7.

[0027] Both the large horizontal bar 1 and the small horizontal bar 2 have one irregularly shaped lug welded to each end of the narrow lower side of the rectangular aluminum profile. Each irregularly shaped lug has one triangular reinforcing rib welded to each side of the wide side of the rectangular aluminum profile. Each irregularly shaped lug has two through holes, for a total of eight through holes. Four square lugs are welded to the narrow upper side of the rectangular aluminum profile. Each square lug has four through holes, for a total of sixteen through holes. The large horizontal bar 1 and the small horizontal bar 2 are fixed to the blind holes with internal threads on the turntable's horizontal rolling ring using eight bolts through the eight through holes of the four irregularly shaped lugs. Thirty-two bolts are used to connect the large horizontal bar 1 and the small horizontal bar 2 to the antenna array mounting assembly 4 and the radome mounting assembly 5, respectively, through the 32 through holes of the eight square lugs. Their functions are twofold: first, to provide a reference for the installation of the antenna array mounting assembly 4 and the radome mounting assembly 5; and second, to provide a bridge between the antenna array mounting assembly 4 and the radome mounting assembly 5 and the turntable's horizontal rolling ring.

[0028] The tail support 3 is welded together from two upper and lower flat plates, two horizontal and vertical supports in the middle, and two vertical and horizontal supports. The upper flat plate has four through holes; the two middle through holes are bolted to the antenna array mounting assembly 4, and the two side through holes are bolted to the radome mounting assembly 5. The lower flat plate has two through holes, which are bolted to the blind holes with internal threads on the turntable's horizontal rolling ring. Its function is to provide tail support for the antenna array mounting assembly 4 and the radome mounting assembly 5, increasing their rigidity and reducing their deformation under different postures during turntable operation.

[0029] The antenna array mounting assembly 4 consists of longitudinal rods 4a1 and 4a2, antenna support 4b, antenna brackets 4c1 and 4c2, and antenna connector 4d. The longitudinal rod 4a1 has two square lugs welded to the lower narrow side of a rectangular aluminum profile, each lug having four through holes, for a total of eight through holes. Three rectangular lugs are welded to each of the left and right sides of the rectangular aluminum profile, flush with the upper narrow side, each lug having two through holes, for a total of twelve through holes. The longitudinal rod 4a2 has the same structure as 4a1. The antenna support 4b is a welded component. Its structure consists of a rectangular base plate with a U-shaped opening, with two vertical rectangular aluminum profiles welded to the left and right sides of the rear. A hollow triangular reinforcing rib is welded to the front of each of the two vertical rectangular aluminum profiles, and a triangular reinforcing rib is welded to the rear of each. A rectangular plate with a U-shaped opening is welded to the front of the upper side of the two vertical rectangular aluminum profiles. Eight through holes are machined on each of the front and rear sides of the rectangular base plate with the U-shaped opening, for a total of 16 through holes. Six through holes are machined on each of the top, bottom, left, and right sides of the rectangular plate with the U-shaped opening, for a total of 12 through holes. During manufacturing, the perpendicularity of the lower plate to the two vertical rectangular aluminum profiles must be ensured. Antenna bracket 4c1 is a CNC machined part. Its structure consists of two milled flat plates with reinforcing ribs on the front and back sides of a rectangular aluminum alloy piece. The reinforcing ribs run through the front and back, forming two angled T-shapes. Three angled rectangular holes are milled in the middle of the T-shaped vertical plates to reduce weight. Three through holes are machined on the left and right sides of the rear plate, for a total of six through holes. Four through holes are machined at the four corners of the front plate. Parallelism of the front and rear plates must be ensured during machining. Antenna bracket 4c2 has the same structure as 4c1. Antenna connector 4d is a CNC machined part. Its structure consists of a rectangular aluminum alloy piece milled into an irregular shape. The rear of this irregular shape is a rectangular vertical plate. Two through holes are machined at each of the four corners of the rectangular vertical plate, for a total of eight through holes. A horizontal plate with reinforcing ribs, perpendicular to the vertical plate, is milled at the top and bottom center of the rectangular vertical plate. A 90° V-shaped notch is milled at the front end of the horizontal plate away from the vertical plate, causing the horizontal plate to bifurcate at 45° to the left and right. One triangular and one trapezoidal weight-reducing cavity are milled at the front and rear forks of the horizontal plate. Four through holes are machined on each side of the two parallel edges of the front and rear forks of the horizontal plate at a 45° angle to the central reinforcing rib, for a total of 16 through holes. The front and rear antenna arrays are mounted on the lower part of the front and rear forks of the horizontal plate using eight bolts. Two antenna connectors 4d are machined, symmetrically arranged.During the assembly of the antenna array mounting component 4, 16 bolts are used to connect the 16 through holes of the 8 rectangular lugs on the upper middle rear part of the longitudinal rods 4a1 and 4a2 to the 16 through holes of the lower rectangular plate of the antenna support 4b welded component. 6 bolts are used to connect the 6 through holes on each of the left and right sides of the upper rectangular plate of the antenna support 4b welded component to the 6 through holes of the rear vertical plate of the antenna brackets 4c1 and 4c2 machined parts. 4 through holes on each of the front plate of the antenna brackets 4c1 and 4c2 machined parts are used to connect the 8 through holes on the rear vertical plate of the antenna connector 4d irregular part to the 8 through holes of the rear vertical plate of the antenna connector 4d irregular part via 8 bolts. After the antenna array mounting component 4 is assembled, 16 bolts are used to connect the 16 through holes of the 4 square lugs on the lower part of the longitudinal rods 4a1 and 4a2 to the 16 through holes of the 4 square lugs on the upper narrow side of the rectangular aluminum profiles of the large horizontal rod 1 and the small horizontal rod 2.

[0030] The antenna radome mounting assembly 5 consists of longitudinal rods 5a1 and 5a2, separation surface supports 5b1 and 5b2, and separation surface assembly 5c (symmetrical left and right parts). The separation surface assembly 5c includes a separation panel 5c1, a small-end positioner 5c2, a large-end positioner 5c3, upper pressure plates 5c4 and 5c5, and lower pressure plates 5c6 and 5c7. The structures of longitudinal rods 5c1 and 5c2 are the same as those of longitudinal rod 4a1. The separation surface support 5b1 is a welded component. Its structure consists of a vertical rectangular aluminum profile welded to the middle and rear part of the upper surface of a rectangular base plate; a hollow triangular reinforcing rib welded to the front part of the lower side of the vertical rectangular aluminum profile; a triangular reinforcing rib welded to the rear part; and a rectangular lug welded to the upper left side of the vertical rectangular aluminum profile, flush with the front surface. Eight through holes are machined on both sides of the front and rear parts of the rectangular base plate; and three through holes are evenly distributed along the center line of the rectangular lug's length. During manufacturing, the perpendicularity between the lower rectangular base plate and the vertical rectangular aluminum profile must be ensured. The structure of the separation surface support 5b2 is symmetrical to that of 5b1. The separation surface assembly 5c is an assembly, and the separation panel 5c1 is a CNC machined part, characterized by a rectangular plate with a hollowed-out center, providing installation space for the antenna mounting assembly 4; dihedrals conforming to structural requirements are machined along the front-back and up-down directions on the upper surface of the hollowed-out rectangular plate; three through holes with countersunk holes are evenly distributed on the upper surface of the hollowed-out rectangular plate along the height direction on the left and right sides, and four U-shaped weight-reducing holes are machined along the inner side of the three countersunk through holes on the left and right sides; three blind holes with internal threads are machined horizontally in the middle of the upper and lower two U-shaped holes on the left and right sides, which are connected to the small end positioner 5c2 and the large end positioner 5c3 respectively; Six through holes are machined on the upper and lower sides of the rectangular plate with a hollowed-out center, along the outer contour of the radome, for connecting the upper pressure plates 5c4 and 5c5 and the lower pressure plates 5c6 and 5c7. Positioning lines for the radome's forward and backward positions are engraved vertically along the center of the left and right sides of the upper surface of the rectangular plate with a hollowed-out center, corresponding to the feature points of the upper and lower contours of the radome. The small-end positioner 5c2 is a CNC machined part. Its structure consists of a rectangular aluminum alloy profile machined into a tapered Z-shaped plate, with the sharp edge of the tapered small end rounded. Three through holes with countersunk grooves are machined along the horizontal line at the center of the upper and lower ends of the Z-shaped plate, which are connected to three blind holes with internal threads on the left side of the separation panel 5c1 via bolts. Scale lines are present on the upper surface of the Z-shaped plate, corresponding to the feature points of the small end contour of the radome. The structure of the large-end positioner 5c3 is similar to that of the small-end positioner 5c2, except that the length is different. The three through holes of the large end of the Z-shaped plate are connected to the three blind holes with internal threads on the right side of the separation panel 5c1 by bolts. The scale lines on the upper surface of the Z-shaped plate correspond to the feature points of the outline of the large end of the radome.The upper pressure plate 5c4 is a CNC machined part. Its structure consists of a rectangular aluminum alloy piece machined into an approximately L-shape. One outer side of the L-shape is machined into an arc surface to fit the outer contour of the radome. A U-shaped elongated hole is machined along the transverse direction of this side, through which bolts are used to connect it to the mounting holes of the radome. Rubber is applied to the arc surface to prevent damage to the paint layer on the radome surface. On the other side of the L-shape, three vertical U-shaped holes are machined longitudinally, which are connected to three through holes on the outer side of the radome's outer contour line on the separation panel 5c1 via three bolts. The structures of the upper pressure plates 5c5, lower pressure plates 5c6, and 5c7 are similar to those of the upper pressure plate 5c4, except that the curvature of the arc surface is slightly different. Two separation panel components 5c are machined, symmetrically arranged on the left and right sides. When the radome mounting assembly 5 is assembled, 16 bolts are used to connect the 16 through holes of the 8 rectangular lugs on the upper middle and rear part of the longitudinal rods 5a1 and 5a2 to the 16 through holes of the lower rectangular plate of the separation surface support 5b1 and 5b2 welded parts; 6 bolts are used to connect the 3 through holes of the rectangular lugs on the upper part of the separation surface support 5b1 and 5b2 to the 6 countersunk through holes on the left and right sides of the separation panel 5c1 of the separation surface assembly 5c.

[0031] The essence of radome electrical performance testing is to assess the impact of the radome on the antenna's radiation or reception characteristics, thereby evaluating the radome's electrical performance parameters. When using the radiation pattern method, the amplitude and phase parameters of the antenna radiation patterns with and without the radome are collected, and performance indicators such as radome transmittance, beamwidth variation, and phase consistency of each element in the antenna array are obtained through mathematical calculations. During testing, the relative installation positions of the antenna and radome must meet the technical specifications; this is a fundamental requirement for radome electrical performance testing. A modular ESM radome electrical performance testing device is designed to meet this fundamental requirement; its structural schematic diagram and external view are attached. Figure 1 ~Attached Figure 9 .

Claims

1. A modular ESM radome electrical performance testing device, characterized in that, The system includes a main horizontal bar, secondary horizontal bars, a tail support, an antenna array mounting assembly, and a radome mounting assembly. The main horizontal bar has shaped lugs at both ends for connection to the turntable. Several square lugs are located in the middle of the main horizontal bar, connecting to longitudinal bars. The longitudinal bars are divided into two symmetrical groups (inner and outer), totaling four. The two inner longitudinal bars connect to the antenna array mounting assembly, and the two outer longitudinal bars connect to the radome mounting assembly. The secondary horizontal bars are connected in the same way as the main horizontal bar. The lower end of the tail support is bolted to the turntable, and the upper end is supported by four adjusting bolts at the bottom of the two inner and two outer longitudinal bars. The antenna array mounting assembly includes an antenna support, an antenna bracket, and antenna connectors. One side of the antenna support is bolted to the two inner longitudinal bars, and the other side is bolted to one side of the antenna bracket. The other side of the antenna bracket is bolted to the antenna connectors. The antenna connectors are shaped to match the antenna... The structures are mutually matched. The radome mounting assembly includes a separation surface support and a separation surface assembly. One side of the separation surface support is connected to the outer longitudinal rod, and the other side is connected to the separation surface assembly. The separation surface assembly includes a separation panel, a small-end locator, a large-end locator, an upper pressure plate, and a lower pressure plate. In the directional direction, the separation panel has a large-end locator facing upwards at the front and a small-end locator facing upwards at the rear. The upper and lower ends of the working surface of the separation panel are respectively equipped with upper and lower pressure plates, with two of each. Their shapes match the outline of the radome and are connected to the radome by bolts. Both the upper and lower pressure plates have U-shaped holes, which are connected to the separation panel by bolts, allowing for fine adjustment of the relative positions of the upper and lower pressure plates on the separation panel. The upper and lower ends of the separation panel are respectively equipped with positioning lines for alignment with the directional feature points on the radome. The small-end locator and the large-end locator are also equipped with positioning lines for alignment with the upper and lower feature points on the radome.

2. The modular ESM radome electrical performance testing device according to claim 1, characterized in that, The areas where the upper and lower pressure plates connect to the radome are equipped with rubber pads to protect the radome connection surfaces.

3. The modular ESM radome electrical performance testing device according to claim 1, characterized in that, The separation panel is made of wood.

4. The modular ESM radome electrical performance testing device according to claim 1, characterized in that, The length of the large horizontal bar is greater than the length of the small horizontal bar, and the length requirement should match the shape of the turntable structure.

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