Design Of RCS Measurement Transceiver Isolation System Based On Compact Field

Radar Cross Section(RCS)measurements currently play an important role in scientific research in the areas of radar system design,target detection and research into military weapons stealth technology.A quasi-optical device form of RCS measurement transceiver isolation system is designed in this paper based on a large laboratory size,high aperture utilization triple reflector tight field system.The tight field measurement method,with a stable and controlled measurement environment,reduces the amount of indoor space occupied and provides the flat incident wavefront required for RCS measurements in a limited space.Considering that the single-reflector compact field has been used to measure RCS because of the low utilization rate of its quiet zone,can not well control the emission field strength distribution,in addition,there are processing and error problems,this paper chooses the three-reflector compact field as the platform for RCS measurement,solving the inherent deficiencies of the single-reflector compact field.In the terahertz band,waveguide device processing difficulties can not meet the needs of high frequency band RCS measurement,so in this paper,the quasi-optical system design is used.In this paper,the Faraday rotator,wire gate polarizer,dual mode cone horn and orthogonal mode coupler are simulated and designed respectively based on RCS measurement principle.The Faraday rotator with a multi-matching layer structure reduces the reflection from the air layer compared to the single layer structure and reduces the loss of the system;the line gate polarizer with high polarization is designed to verify the performance of the system in the W-band;the dual-mode cone horn feeder with high electric field coupling and good symmetry is designed to reduce the processing difficulty of the feeder used in RCS measurements;in addition,the high-band W-band cross-gate type orthogonal mode coupler is also designed.A quasi-optical RCS transceiver and transmitter isolation system is proposed using the designed device.The isolation system is designed based on the characteristics of a tight field and can be extended to the terahertz frequency band,with low processing difficulty and high cross-polarization isolation.In this paper,the simulation verifies the feasibility of the system,so that the system cross-polarization isolation degree reaches 40dB,the isolation system in the main mirror 1m triple-reflector compact field system,the size of the quiet zone reaches 0.7m,compared to the single-reflector compact field system measurement,the quiet zone utilization rate is greatly improved.It concludes with a description of the issues,constraints and measurement methods that need to be addressed in the project to facilitate the evaluation of the entire system and to suggest new options for future RCS measurements.