A single chip CMOS transmitter for UWB impulse radar applications

Ultra-wideband (UWB) radar has a vast application in civil engineering and industry, such as family surveillance, medical instrument, detecting live people buried under debris, movement sensors, microwave imaging, collision avoidance etc.. This work is about a pulse generating transmitter used in radar for the detection of human movement. There are several ways to generate pulses, such as using derivative of Gaussian pulses or digital combination methods, or the "carrier based UWB". Adopting ideas reported, we proposed an impulse radar (IR) transmitter architecture.The proposed transmitter uses the carrier based UWB pulse generation approach. By multiplying the triangular envelope to a continuous sinusoidal wave, the pulses are generated. Triangular shaped envelope, which provides the best side-lobe suppression, is generated by the envelope generator and a special mixer is designed to up-convert the envelope spectrum to the center frequency. Due to single-ended output, the two differential outputs of mixer go through a differential to single-ended converter to get the triangular shaped pulse with the desired spectrum. A two stage drive amplifier is designed to get the -2dBm output power into 50 ohm load.