Core technology: Spherical near-field (near- and far-field conversion)
+ fast calibration of flat fields
The RayVerse® 10KP is designed for the rapid calibration and testing of large phased-array arrays from S-band to W-band, where the development and production of large phased-array antennas require amplitude-phase calibration and testing of the resulting multiple wave position directional maps.
General Test Systems' (GTS) first integrated system for rapidly phased array calibration and testing consists of two main subsystems: Firstly, the phased array calibration system (planar near-field) link, which includes the low-frequency link and spread spectrum link at the DUT side, and the low-frequency link and frequency link at the probe side of the planar scanning frame, including instruments, frequency heads, switches, amplifiers, and other components to realize the phased array calibration function. The second is the phased array test system (spherical near-field) link, including the low-frequency link and spread spectrum link at the end of the component under test, and the low-frequency link and frequency link at the end of the arc scanning frame probe, including the instrument, frequency head, switch, amplifier, and other components, to achieve the phased array directional map test, EIRP test, G/T value test and other functions.
With fault diagnosis function
The system is equipped with a cell diagnostic function. Through fast unit channel calibration, the amplitude and phase information of the array can be obtained and the relevant parameters can be kicked out. Based on the phased array cell coordinate information, the array model is built and the channel information is displayed graphically, the effect is shown in the figure.
Unit diagnostic effect (part of the unit is closed in the center area on the right)
Highly capable of testing at remote wavelengths
The spherical near-field test system is not limited by the scanning range and theoretically supports the scanning of any angle range on the global surface, therefore it is not limited by the type of component under test and can test any type of antenna with any beam pointing, and the test accuracy is not reduced by the far beam.
Easy installation and erection
The solution places the reflective surface on top of the darkroom and, with the rocker arm for scanning the sphere, the measured part is simply placed flat on the 1D orientation table, making it easy to operate. It also simplifies the test process by eliminating the need for precise positioning of the test piece as in a planar near-field, which greatly reduces the preparation time for mounting and positioning before the test.
The use of spherical near-field testing allows for speed improvements in two areas.
(1) Multi-frequency point, multi-channel and multi-wavelength fast testing
The system interacts with the phased-array wave controller in real-time through the test software, and combines multi-channel switching and instrument multi-frequency point sampling, ultimately realizing microsecond timing control automation testing for the entire test process. During testing, multiple frequency points, multiple beams, and up to thousands of wave positions can be tested simultaneously with just one 3D scan, which increases the testing efficiency by tens of times compared to traditional testing methods.
(2) Easy installation, no need for accurate alignment
The spherical near-field uses a swing-arm structure for spherical scanning, and the test piece only needs to be placed flat on the 1D azimuthal turntable, making it easy to set up. In addition, the spherical near-field scanning does not require precise alignment of the measured part, but simply places it roughly in the static zone, calculates the required sampling density using the equation λ/D (minimum spherical diameter D), and performs the near and far field transformation. The whole installation process saves several hours compared to a planar near-field.
High safety factor
(1) System components are selected to meet the corresponding national standards
(2) Thermal imaging is used for 7 x 24 hour monitoring and real-time reporting of monitoring data
(3) The system is equipped with smoke and dust detection capability, detecting the smoke and dust concentration in the system in real time and keeping records at the same time, and automatically alarming when the smoke concentration is detected to exceed the standard.
High calibration accuracy
(1) Sampling accuracy does not decrease as the scanning range increases
With a spherical near-field test system, the probe is always pointing towards the part under test when it is being scanned. Theoretically, the same accuracy can be guaranteed at any angle of sampling, unlike in planar near-field, where the probe cannot be pointed squarely at the test object as the scanning range is extended, and the directional map changes and cross-polarisation deteriorate, leading to a reduction in test accuracy.
(2) International top-level wide-angle low cross-polarisation corrugated horn probe
The test probe has a great impact on the test accuracy of the near-field scanning system. The cross-polarisation performance of ordinary dual-polarised horn antennas cannot meet the requirements of use, so corrugated horn antennas with better cross-polarisation suppression are usually used. However, the corrugated horn antenna is difficult to design and complex to process, and few domestic antennas can be designed and developed, and usually only at the apex of the corrugated horn antenna can get good cross-polarization performance, it is difficult to achieve good cross-polarisation in a wide range of angles.
In addition, with conventional corrugated horn, there is a difference between the E and H sides of the phase center, resulting in large differences in horizontal and vertical polarization.
GTS has developed and designed its corrugated horn feeders with low cross-polarisation over a wide angle range. The cross-polarisation performance of approximately -40dB can be maintained over a range of ±20°, and the phase fluctuation between the E- and H-plane is less than 5° over a range of ±50°, providing excellent symmetry. These two features are among the best in the world. The high phase stability over a wide frequency band ensures low phase fluctuations in the static region, the high edge irradiation level (wide beam) results in low amplitude fluctuations in the static region, and the integrated design with absorbing material (the outer side can be covered with absorbing material) results in an overall low RCS characteristic of the feed source.
Comparison of planar near-field, tight-field and this solution
Wide angle low cross polarisation corrugated horn probe