A 37 mW fully integrated GMSK modulator for DRRS standard in 0.6-μm digital CMOS process

A prototype Gaussian minimum key shifting (GMSK) modulator for digital radio relay systems (DRRSs) standard without any external component has been designed and simulated in the 1.4 GHz frequency band in a 0.6 μm CMOS process. The modulator including a compensation filter allows digital frequency modulation at 1.6 Mb/s. Using a low-power frequency divider and a low-power low-phase noise oscillator, the power consumption of the modulator is minimized. Transistor and system level simulations demonstrate that the modulator meets the performance requirements of the DRRS standard. Circuit simulation with a 0.6 μm CMOS technology shows that the power consumption of the modulator is 37 mW from a 3 V power supply.