求人翻译一段中文摘要(涉及电类知识)

In recent years, in the society some units developed in abundance, the production and the establishment use handset signal shield, the handset signal shield in the place which needed to protect, used in being forbid the mobile phone, thus eliminated the negative influence which the mobile phone produced, played the safety protection role. This article introduced briefly the handset signal shield's research background and the domestic research present situation, mainly elaborated the handset signal shield design and the manufacture principle, then elaborated and have compared several kind of handset signal shield technical program, as well as designed the concrete shield electric circuit according to the mission requirement, including the power unit electric circuit, the saw-tooth wave produced the electric circuit, the PLL electric circuit, and to shielded the electric circuit to carry on the analysis and the computation. Then to shields the electric circuit to carry on the debu