ULTRA-WIDEBAND RADIO: UNCONVENTIONAL CIRCUIT SOLUTIONS FOR UNCONVENTIONAL COMMUNICATION.

The governing body in the United States, the Federal Communications Commission (FCC), has issued ultra-wideband regulations, under Part15 of the Commission's rules on April 22, 2002. Therefore, ultrawideband transmissions (intentional emissions) under certain frequency and power limitations have been permitted. The US has openly endorsed UWB based consumer products. Ultra-wideband offers significant contributions and advantages but simultaneously a number of challenges also need to be addressed. One of the key challenges is the co-design of an impulse generator and miniaturized antennas for ultra-wideband impulse radio. This has been designed and fabricated in 0.18μm CMOS technology. Measurements show the correct operation of the circuit for supply voltages of 1.8V and a power consumption of 45mW. The output pulse approximates a Gaussian monocycle having a pulse duration of about 375ps. Proper modulation of the pulse in time is confirmed [1]. In addition, to meet the stringent FCC stipulated frequency spectrum, an orthonormal [2] ladder filter with a Daubechies' impulse response is employed. The filter is implemented using novel 2-stage gm-C cells employing negative feedback. Simulation results in CMOS 0.13μm technology show that this pulse generator requires a total current of 30mA at a 1.2V power supply. The frequency coverage of the simulated waveform is about 85% of the FCC mask. [ABSTRACT FROM AUTHOR]