Wireless sensing system for environmental humidity and temperature monitoring

Aiming at the actual demand for monitoring environmental information,a wireless sensing system for temperature and relative humidity(RH)monitoring based on radio frequency(RF)technology and mobile network was designed.This paper introduces the architecture of the system.The system uses AVR micro controller unit(MCU),KYL-1020U RF module and SHT71 to complete real-time temperature and humidity monitoring,and uses SIM900A module to realize remote alarming and monitoring with short message system(SMS)through global system for mobile communication(GSM).Experimental results show that the designed system has good stability of measurement and real-time performance,and it can be used in some small temperature and humidity monitoring occasions.

耐高低温动态稳定射频旋转关节的设计

为了推动我国射频旋转关节技术的进步,促进各领域旋转射频通信系统的发展,展开了耐高低温动态稳定射频旋转关节的自主设计。该射频旋转关节进行了全温范围结构设计以及精心选材;根据高低温热胀冷缩的影响调整部分零件之间相互配合的尺寸公差以增大间隙;采用动态稳定内导体接触副补偿结构,保证接触副可靠接触,以避免旋转过程中因轴向跳动增大、磨损增大对使用寿命不利的情况;采用射频传输结构及补偿结构实现高频信号的传输。经相关性能测试,该射频旋转关节的工作温度达到-100~100℃,电压驻波比动态变化≤0.2,插入损耗动态变化≤0.5 dB,旋转寿命300万转,满足了耐高低温、动态稳定和安全可靠的设计要求。