CMOS UWB transmitter design

In an ultra-wideband (UWB) transmitter, an UWB pulse generator is one of the key components and performs an interface between the coded digital data stream and a UWB antenna. It is very challenging to design a UWB pulse generator because the time-width of UWB pulse is very short and its performance directly affects the UWB transmitter. To date, many circuits for generating UWB pulses have been traditionally proposed. Since the federal communications commission (FCC) revised its rules, the spectrum of UWB pulse has been much restricted. Now a new scheme has been demanded to satisfy the FCC regulation. Together, with abiding by the FCC rules, it is also significant to generate the UWB pulse with low power consumption. Moreover, it is advantageous that the UWB pulse generator is fabricated with standard CMOS technology for a low power and low cost device.; Recently it has been proposed that the fifth-order derivative of the Gaussian pulse complies with the FCC rules of 3.1 to 10.6-GHz. In this dissertation, the pulse combination method is proposed to design this pulse shape with low power technique. This method is analyzed and the analytical expression characterizing the output waveform is presented. The analytical solution closely matches with SPICE simulation and test results. CMOS UWB pulse generators using this method are designed with several functionalities: bi-phase and tunable time-width and amplitude. Since the power consumption is proportional to pulse repetition frequency (PRF), the proposed CMOS UWB pulse generators are much advantageous for low data rate wireless communications.; The developed CMOS UWB pulse generators are advanced to design a UWB transmitter. The prototype CMOS UWB transmitter for the Sub-GHz band is designed. It consists of the clock oscillator, pseudo-random code generator, and UWB pulse generator. The power consumption of the proposed CMOS UWB transmitter is no more than 1-mW when the PRF reaches to 7-MHz. The proposed UWB transmitter has the lowest power consumption in the published papers. Thus, the proposed low-cost low-power CMOS UWB transmitter is a good candidate for low data rate in short-range communications.