Study On Projectile Gesture Testing Technology Based On S-band Microstrip Antenna

The various data of flying projectile is becoming increasingly important in practicalapplications. Currently, onboard attitude test system has been able to complete the parameters’collecting and storing. The evaluation of technical indicators has already been achieved.However, the device usually can not be recycled in time for various reasons, such as the longdistance and large range of flying bullets or shells, also high temperature and pressure at themoment of the shells landed. In practical applications, wireless real-time transmission ofonboard telemetry system has a more important strategic significance. Onboard antenna mustbe designed to adapt to high temperature, high impact, high electromagnetic interference ofthe flying projectiles. Microstrip antenna with a light weight, small size, low-polished surface,easy integration and other prominent advantages, is suitable for onboard attitude test.The paper studies the wireless transmission module and microstrip antenna theory,compares and analyzes of the antenna scheme, realizing the design of the S-band microstrippatch antenna. The wireless transmission part is constituted by hardware combination ofATmega8515+nRF2401+RFX2401. The using of coaxial line can achieve the feedback tothe antenna, and left circular polarization is formed by a cutaway square patch. Select thePTFE as the dielectric substrate, which has a high relatively dielectric constant. At lastconducting the performance simulation by using the ANSOFT HFSS13software. Theeffective working bandwidth of the antenna is2389～2413MHz, and the center frequency is2400MHz.The voltage standing wave is than2under the working frequency. The HFSSsimulation results shows the validity of the design.The hardware circuit uses ATmega8515microcontroller as a control unit, and nRF2401is selected as wireless data transfer. In order to increase the transmission distance and improvethe accuracy of data, the RFX2401chip, which having a power amplification, is added to thecircuit to ensure that data can be transmitted at least900m. Experimental results show that: this method can complete the wireless transmission ofdata successfully, as well as monitor and control the testing device, with the highanti-interference ability.