Expansion and compression of analog pulses by bandwidth scaling of continuous-time filters

This paper demonstrates a completely on-chip implementation of expansion and compression of continuous-time, wideband, analog pulses. The input pulse is fed to a continuous-time filter whose delay exceeds the pulse duration. Once the pulse is completely inside the filter, it is stored in the form of the filter's state-variables, which can completely reconstruct the pulse. Instantaneously decreasing or increasing the filter's bandwidth at this instant results in the output pulse being expanded or compressed, respectively, compared with when the bandwidth is unchanged. A 1.6 mm2, 370 mW, 0.13 μ text{m} prototype has a delay filter whose bandwidth can be switched between 870 and 472 MHz. It achieves 1.8\times pulse expansion and 1.7\times pulse compression with an rms error which is 33 dB below the peak-peak pulse amplitude.