Reciprocity and Inter-Reciprocity: A Tutorial-Part II: Linear Periodically Time-Varying Networks

The second part of this two-part paper addresses reciprocity in linear periodically time-varying (LPTV) networks. We first give a brief overview of LPTV circuits and systems Using this, we derive the adjoint network, which naturally leads to the intriguing concept of time-reversal in the adjoint network. The frequency-reversal and transfer-function theorems are then derived. Finally, we derive some useful properties of LPTV circuits with sampled outputs. The theory is illustrated with examples.