Design and Simulation of Impulse Radio UWB Transmitter with Differential Ring VCO

The Impulse Radio Ultra-Wide Band (IR-UWB) system used in low-power location-aware sensor networks is limited by signal power, inorder to avoid interference with existing licensed users. In addition, to increase battery life, the IR-UWB transmitter must be energy efficient. Hence, these two conditions limits the signal power and is an hindrance in increasing the range of communication. The range of communication can be increased by increasing the signal amplitude which in-turn fails to meet the FCC spectral limit of -41.3 dBm/MHz. In this paper, a CMOS UWB transmitter designed using a 0.18-μm process is presented for 3.1-5 GHz applications. The designed architecture improves the range of communication and nullifies the common mode temperature effect on frequency variations by exploiting the common mode noise cancellation technique using differential ring Voltage Control Oscillator (VCO). The spectral power of the impulse signal after increasing its amplitude has also been analyzed.