System considerations and VCO design for a local positioning system at 2.4 GHz for rescue of people on ships and in sea

In this paper a system for localization of passengers on ships and in the sea in case that passengers going overboard is described. System considerations taking into account parameters such as oscillation and modulation frequencies are conducted. The baseband architecture is discussed regarding necessary design tradeoffs for localization of a large amount of different passengers at a reasonable update time. A cross-coupled oscillator is implemented in 0.18 μm BiCMOS technology and optimized for the application as a reflector tag. According to measurements, the circuit provides an output power of 5 mW at 36 mW dc power resulting in a high efficiency of 14 % in continuous mode.