Tunable Pulse Generator for Ultra-Wideband Applications

For the first time, an ultra-wideband pulse generator is fabricated in GaAs HBT IC technology. The generator includes delay and differential circuits to convert a TTL input into an impulse signal and a Class-C amplifier to increase the pulse amplitude while compressing the pulse width. By adjusting the bias of the Class-C amplifier, the pulse amplitude can be varied linearly between 3.5 V and 11.5 V while maintaining the pulse width at 0.3 +/- 0.1 ns. Alternatively, the pulse width can be varied linearly between 0.25 ns and 0.65 ns, while maintaining the pulse amplitude at 10 +/- 1 V. Finally, the amplified impulse signal can be shaped into a monocycle signal by an L-C derivative circuit. These results compare well with that of pulse generators fabricated in GaAs HEMT, Si CMOS or Si discrete technologies.