A 2nd derivative Gaussian UWB pulse transmitter design using a cross inductor

This paper presents a UWB pulse transmitter design using MOSIS/IBM 0.35μm CMOS process. A 2nd order derivative Gaussian pulse is generated using a Phase Detector (PD), which consists of a D-Latch with an effective phase difference of 46ps, and at the output an extra derivative circuitry exists. It generates pulses of 100ps width. The Gaussian impulse achieves a very small pulse width of about 200ps, and amplitude of 120mVpp. The complete circuit occupies a very small area of 63.4×42.4μm² without the PADs and inductor. The Sonnet tools were used to simulate and evaluate the performance of the novel cross inductor structure. In order to make a fair comparison, the new structure and conventional rectangular inductor were designed to get similar inductance value, and with the same segment width and spacing fixed at 10 μm. The result shows the feasibility to use the cross structure with an area of 160×140μm², while the square planar inductor would occupy an area of 180×180μm². Thus, the last one needs 45% more area than the cross inductor, so this cross inductor leads to an extra reduction in Silicon area, what is one of the main purposes of this work to get a small UWB transmitter. The compact shaper circuit and cross inductor has lead to the whole circuit area of only 0.0283mm² (about 20% of other published works).