Research On Calibrating Signal Generation And The Monitoring System Of VHF Array Receiver

The occurrences of lighting are usually in company with unpredictable damage due to the intense electromagnetic waves, currents, heats caused by the lighting, which threaten the security of electrical power systems, communication networks and constructions fatally. In order to reduce the damages and protect safety and properties of people, many countries invest money and efforts in the field of lighting detection.As the front of the detection systems, the array signal receivers are the issues which appeal to the researchers. Under this circumstance, this thesis undertake the design of analog fronts for a lighting detection system, and finally accomplish qualified array signal receiver consisted of 8 analog channels.Among numerous performances, the identities of channels are given most attentions by the engineers. The designers must apply appropriate calibration algorithms in case the degradation of the performance of the direction finding caused by the array errors. This thesis discusses active calibration algorithm briefly and introduces several methods for calibrating signal generation, e.g. DDS. However, the drawback of DDS technic is evident. DDS technic will lead to large consumption of logic elements, in order to avoid this, this paper presents a kind of real-time signal generator based on true random generator. All internal modules of signal generator are presented elaborately, such as ring oscillator, low-pass filter and frequency spectrum shifting circuits.Moreover, in order to collection working condition and configure devices remotely, we must establish an appropriate monitoring system. This paper introduces a monitoring system in detail. The monitoring system can help user to monitor several system parameters, including the gain of each channel, frequency of local oscillation and the output of calibrating signal, and can communicate with PC via RS232 interface. The design has been divided into several independent function modules. This method strengthened the reconfiguration and portability of the system.