design and construction of a loran pulse based on pwm method for lps navigation system

in this paper, the results of design and implementation of the subsystems for generating loran pulse are proposed based on method of carrier’s pulse width change. in order to generate the desired pulse, firstly a pwm signal generated and then it is applied to a class-d switching amplifier. the results show that by generating appropriate pulses in 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. also mmse and maximum error of peak points in 8 first half-cycles are 0.0092 and 0.025 respectively which it complies with the required standards of loran pulse.