Marine Navigation Radar Signal Test System Design

Marine radar is a kind of significant radar which guarantees voyage security by playing an important role in marine offshore orientation, guiding ship’s entry and departure, navigating in narrow channel and avoiding collision. As the core component of Marine radar, frequency source’s function directly impacts the performance of marine radar. During the process of production and maintenance of marine radar, specific value in application is provided by developing cost effective, highly reliable, user-friendly frequency sources, which significantly improves the present development level of Chinese marine radar.The thesis put forward a practical measuring system project that can be used to test marine radar frequency source, which adopts disposable mixing RF signal technology in measurement within converting radar frequency signals into IF signals between30MHz and60MHz. In the design of the system, mixing module is composed by mixer and low noise figure are critical focus index during the design. This right oscillator source is a typical step local one based on phase-locked frequency synthesis technology, whose frequency and power can be adjusted by external keyboard, and frequency as well as power information showed by liquid crystal display(LCD). Close attention need to be pay towards low-phase noise in the design of local oscillator source. Considering rather high demanding towards the electromagnetic compatibility of the test system, independence module cavity is applied to the key part of RF module for the system in this paper, which prevents of test accuracy and precision from mutual interference. Meanwhile, difficulties are analyzed in details and matching solution are provided. Within tests for main standards are practiced and corresponding outcomes are presented. The test outcomes are:-3dBm to+1dBm for phase-locked output fundamental frequency signal power superior to-82dBc/Hz@1kHz for phase noise.9GHz to10GHz for LO frequency source output signal.+4.8dBm to+8.7dBm for signal power.7GHz to14GHz for mixing module working band,29dB for conversion gain,7dB for figure noise and advantage over50dB for the leak of LO power enter into IF.Finally, a RF signal with frequency of9.40GHz and power of-35.73dBm is put into the test system for analog measurement. The IF signal is exported with frequency of40MHz, power of-25.12dBm, phase noise of-61dBc/Hz@1kHz and spurious suppression of superior to30dB. According to the corresponding relationship between input and output signals, imported RF signal information can be gained due to the IF signal.Test result demonstrates that the marine radar frequency source test system designed here can measure the relative information of the RF signal in a rather precise way. Within cost effective, high reliable and user-friendly characteristics, anticipated designing target is fulfilled.