A Power Efficient HBT Pulse Generator for UWB Radars

High-resolution radars require the transmission and reception of extremely high-bandwidth pulses. The generation of such pulses is a challenging task, especially for low power portable applications. In this paper we present a new approach to face this problem. The proposed approach uses a standard negative impedance LC oscillator to generate fully-differential pulses in the 6 to 8GHz frequency range. This circuit does not require pulse-shape filtering, leading to a high power efficiency of the generation process. It can also be easily modified to generate quadrature pulses. It can be used both in ultra-wideband transmitters and correlation receivers, allowing for the implementation of quadrature modulation schemes.