Design and Fabrication of the Loran Pulse Generator Based on PWM Method for LPS Navigation System

In this paper, the results of design and implementation of the laboratory subsystems are proposed for generating Loran pulse are proposed based on method of carrier’s pulse width change. In order to generate the desired pulse, a PWM signal is generated proportional to output voltage energy in each half-cycle and then it is applied to a class-D switching amplifier. The results show that by generating appropriate pulses in a digital FPGA subsystem for application in switching devices. It is possible to generate Loran pulse using only a single class-D amplifier, and the observed current in the load has the required standards for Loran transmitter. According to the performed measurements and calculations, the maximum zero crossing error in 4th to 12th half-cycle is 45ns and the band width of generated pulse will be 4 kHz. Moreover, MMSE and maximum error of peak points are 0.0092 and 0.025 in 8 first half-cycles, respectively, which they have fulfill the required standards of Loran pulse.