Time Domain Reconstruction of Incoherently Undersampled Periodic Waveforms Using Bandwidth Interleaving

Incoherent undersampling provides a low cost solution for wideband periodic waveform acquisition without the requirement for synchronization with the source clock. The bandwidth of a traditional incoherent undersampling based test setup is limited by the the bandwidth of the track and hold amplifier. In this work, a test setup is proposed combining incoherent undersampling and bandwidth interleaving to break the bandwidth barrier of the track and hold amplifier. The high frequency components of the signal waveform beyond the track and hold bandwidth are down converted using mixers and undersampled. While bandwidth interleaved frequency domain signal reconstruction techniques have been proposed before, this is the first time that fast time domain reconstruction techniques are used for periodic waveform reconstruction of wideband signals in the absence of any synchronization between the test signal and the tester oscillator/sampling clock over multiple frequency bands by choosing the local oscillator frequency to be a multiple of the sampling frequency. The periodic test signal waveform is acquired over multiple channels each covering only part of the total bandwidth of the signal. Feasibility of the proposed technique is shown through simulation and hardware results.