Circuit analysis and optimisation of the high-voltage high-efficiency IR-UWB pulse generator for ranging and radar application

摘要

An in-depth circuital analysis of an energy-efficient high peak power impulse radio ultra-wideband (IR-UWB) pulse generator monolithic microwave integrated circuit (MMIC) design is presented. The proposed IR-UWB pulse generation process is explained in detail. A trade-off between the peak output power level and the frequency of operation is discussed. The proposed circuit is optimised for the highest possible peak output power in the 3–5 GHz UWB band for ranging and radar application. The presented IR-UWB pulse former makes use of the cascode heterojunction bipolar transistor (HBT) configuration for signal scaling operation instead of the common emitter configuration. The proposed cascode pair configuration results in higher output voltage swing as well as reduced power consumption. The effect of coupling capacitors on amplification factor of the pulse former stages as well as impedance profile of the distributed transmission line is discussed in great detail. The temperature-dependent parasitic component in the proposed circuit is studied. Its effect on the transient behaviour of the proposed IR-UWB pulse generator is analysed, which is important for IR-UWB beamforming applications. The required mathematical model for the parasitic effect is derived and explained.