Core technology: spherical near field (near and far field conversion)
The testing of phased array antennas with thousands of wave position directional maps is a serious constraint to R&D and production efficiency. General Test Systems (GTS) has introduced the RaySpirit® 8000, a high-precision phased-array multi-wavelength fast test system for phased-array antennas, based on a high-precision spherical near-field system, which enables continuous sampling of phased-array antennas of up to 1.5m aperture in a space of 8 x 6 x 5m. Through the microsecond timing control of the test software and the phased-array wave controller, up to thousands of wave positions can be tested simultaneously with just one 3D scan. Compared to traditional testing methods, the test efficiency is increased by more than several tens of times. In addition, the system creatively implements G/T value testing in near-field conditions, reducing test complexity and constraints.
Rapid multi-wavelength, multi-beam testing
Testing with a spherical near field can be accelerated in two ways.
(1) Multi-frequency point, multi-channel, multi-beam pointing fast testing
Active phased arrays usually have multiple frequency points, test channels, and beam-pointing states. Using ordinary measurement systems, each antenna state needs to be tested separately, which is inefficient for testing. The system uses the test software to interact with the phased array wave controller in real-time and combines multi-channel switching and instrument multi-frequency sampling to finally achieve a microsecond timing control automation test of the whole test process. The test can be completed simultaneously for multiple frequency points, multiple beams, and up to thousands of wave positions in just one 3D scan, increasing the test efficiency by tens of times compared to traditional test methods.
Assuming a switching time of 400us, a scan of one section within ±90° will take less than 6 minutes for 1000 wave positions.
Low cross-polarised corrugated horn
The measurement probe uses a corrugated horn antenna developed by General Test (GTS) for spherical near-field test systems. Several product models cover the different millimeter wave test bands from 1 to 50 GHz. The probe consists of a corrugated horn and an orthogonal mode coupler to realize the dual polarisation function of the antenna and greatly improve the testing efficiency. The antenna design specifications are benchmarked against international advanced probe antenna specifications, with world-leading performance in wide-angle cross-polarisation design. The dual-polarisation corrugated horn has good purity of wide-angle cross-polarisation, symmetrical beam, low side flap, and low return loss in a wide frequency range, which can significantly improve the accuracy of low cross-polarisation measurement of large parts under test. The antenna is machined to a high precision of ±0.01mm and the quality and roughness of the inner edges of the part are strictly controlled by special machining, resulting in a smooth machined surface and eliminating the effect of burrs on cross-polarisation.
Fully automated testing
The test system is fully automated and has a task batching function. After the first assembly and connection of the component under test, channel switching (multi-beam), test frequency switching, transceiver mode switching and batch processing of the different tasks set up can be realised in the software side to realise unattended testing throughout the automation.
Easy installation of phased arrays
The test system is designed with a distributed sampling and positioning structure, separating the pitch and azimuth axes. The vertical curved guideway structure enables the pitch angle to be scanned, while the horizontal turntable enables the orientation of the measured part to be rotated. This makes it extremely easy to set up the active phased-array antenna, which has a lot of cables and components, as the measured part only needs to rotate in one dimension in the horizontal plane. The plane near field, direct far field, tight field are faced with vertical installation and cable winding problems, inconvenient installation, long lead time, low reliability.
High testing accuracy
(1) Side flap and cross-polarisation uncertainty: 1dB@-20dB; 1.5dB@-30dB; 3dB@-40dB
(2) Peak Gain Uncertainty: 0.3dB
(3) System stability: ±0.1dB (amplitude), 2° (phase)
(4) Phase centre uncertainty: 2mm
(5) G/T value test uncertainty: 0.5dB
High precision positioning systems
The core component of the RaySpirit® 8000 is a high-precision standardized track with a positioning accuracy of better than 0.02°, a stable construction, high load capacity, and extreme reliability and durability. The gauging probe is moved for sampling using a slider mounted on a curved track. An azimuthal turntable is set at the center of the curved track. Due to the horizontal mounting surface of the turntable, it is very convenient for the installation and testing of active phased array antennas containing complex ground inspection equipment. At the same time, the turntable can also be moved in two dimensions in the horizontal plane with an accuracy of better than 0.01mm for fine adjustment of the position of the measured parts.
One-stop multifunctional testing
The test system covers most of the testing scenarios for phased array antennas, enabling one-stop testing. In addition to the basic near- and far-field directional map test, it also features a phase center test function. The integrated post-processing algorithm can use the directional map results for calculations without the need for an additional phase center test. In addition, the RaySpirit® 8000 offers the innovative implementation of EIRP testing and G/T testing in near-field conditions, eliminating the need for constant transitions of the test piece to meet different test requirements.
New clean wave absorbing materials
(1) High power resistance for starboard high-power phased arrays: 20kW/m2 (cellular), 1200W/m2 (EPP)
(2) High flame retardant grade: Class A (Honeycomb), Class B (EPP)
(3) Class 100,000 cleanliness: suitable for clean room environments
(4) High environmental adaptability: no powder loss, no moisture absorption, long life