Research And Design Of The Method And Portable Instrument For Field Strength Measuring Of LF Time-code Signal

With the set up of the new time service system of low frequency time-code in our country, it is urgent need to research the method and instrument for field strength measuring of the LF time-code signal. In this paper, this problem is researched according to prevenient experience, and a small size & portable field strength meter for low frequency time-code signal is developed to meet the need of measuring.The main works and contributions can be summarized as follow:(1) The essential principle and theoretic base of field strength measuring is studied and analyzed, the method of implementation which based on the format and characteristic of low frequency time-code signal is given also. Further more, the method and flow for analog signal processing is researched.(2) The scheme and functional demand of field strength meter for low frequency time- code signal is given according to prevenient experience and the need of measuring. The select of CPU is completed, and the port of MCU each module will connect is also decided.(3) A field strength meter for low frequency time-code signal based on singlechip is developed, it has the function of field strength measuring, communication with PC, and battery monitoring. This instrument has the superiority of small size, convenient to take and displace, low power supply, easy to operation, low cost, etc. The method of hardware connecting and software design of the field strength meter is given respectively in chapter four and five. Some protocols involved, such as I2C bus, RS-232C & HDQ bus are discussed in detail.In all of this, research of the method for field strength measuring & design and implementation of the field strength meter based on singlechip for low frequency time-code signal are the main works I have done, they have been accomplished now. This field strength meter can complete the function of field strength measuring of low frequency time-cod signal credibly. Because of use the modules on the singlechip as more as possible, so it simplifies the circuit design, make the size of device smaller, and reduces the power supply effectively. This instrument can be used in large-scale measuring outdoor, can help to estimate the signal quality when install the time-code signal receive terminal, such as radio controlled timepieces, it has wide application perspective in the industrialization development of time service technology with low frequency time-code.