The Development Of Handheld Absorbing Coating Tester

The rapid development of modern radio technology, has greatly promoted the world defense system's ability to search and tracking target, traditional combat weapon has been under more and more serious threat. Radar stealth technology, can significantly improve weapons' penetration ability, has become the most effective tactics technique in modern war. Absorbing material, can absorb the electromagnetic wave energy onto its surface, and make it into heat energy, or other forms of energy through the dielectric loss of itself. Daub absorbing material to the surface of weapons and equipment, can achieve the purpose of radar stealth. The great importance given to this method because of its simple construction, and its strong adaptability.Project aims to develop a hand-held absorbing coating tester, can measure the absorbing ability for C band(4GHz-8GHz),X band(8GHz-12GHz) and Ku band(12GHz-18 GHz) microwave flexibly,within a certain dynamic and error range.Tester is mainly divided into microwave probe, microwave module, data collection and processing module, human-computer interaction, the power supply system, PC software, charger seven parts. Microwave probe contains delay coaxial cable,waveguide, flange, realize the microwave signal conduction. Microwave modules,contains frequency synthesizer, mixer, pulse generator, echo door, control circuit, etc.,realize the implementation, modulation, detection, mixing output of microwave signal.Microwave module outputs a reference intermediate frequency signal, and an echo intermediate frequency signal. Acquisition and main control board adopts the ARM +FPGA dual processor mode, ARM as the main processor, responsible for equipment's main logic, FPGA as the coprocessor, responsible for digital signal processing, realize high-speed AD sampling, FIR filtering, orthogonal demodulation and IQ data storage,the two communicate through the FSMC bus. The human-computer interaction function, including OLED display, buttons and indicator lights. Equipment is powered by + 12.6 V lithium battery pack, produce the power required of each module by means of DC/DC or LDO chip. PC software responsible for the establishment of the measurement task, reflectivity calculation, the attenuation curve drawing,task interaction realized by SD memory card. Device charger contains AC - DC adapter and external charging dock, realize the charging management of lithium battery, as an attachment.After the test, the measurement error of RAM plates within a range of + / - 0.5 dB,and the tester can clearly distinguish between different models, whose absorbing coating thickness difference more than 0.05 mm, meet the demand of actual measurement. The development of absorbing coating tester,solves the problem of measuring the absorbing coatings that has been coated on the surface of equipments.Tester has the characteristics of easy to carry, simple operation, simplify the testing process, improve the production efficiency in a large extent.