Integrated SWIPT Receivers: Circuit Analysis and Performance Evaluation

The majority in existing energy harvesting (EH) models utilize complex analysis and often overlook the memory effects of the system’s low-pass filter (LPF). In this work, we aim to fill this gap and propose a simple yet effective approach to model the receiver’s output and capture the LPF’s memory. Specifically, we analyze two fundamental circuits: the half-wave rectifier (HWR) and the diplexer-based receiver (DBR). By using circuit analysis, we derive mathematical models for each receiver’s output, validated through circuit simulations. We then investigate these models in the context of integrated simultaneous wireless information and power transfer (SWIPT) receivers. For the HWR, we consider amplitude modulation and, using communication theory tools, we evaluate the performance in terms of bit error rate (BER) for both maximum likelihood (ML) and ML sequence detection (MLSD) schemes. Our results reveal the impact of memory-induced intersymbol interference on the BER and indicate that MLSD is necessary towards achieving higher data rates. For the DBR, we show that its LPF exhibits similar characteristics to the HWR yet is able to achieve better EH performance due to the lack of signal splitting. Finally, we explore the DBR’s band-pass filter output for information decoding, highlighting its capability to also use phase modulation. Clearly the DBR stands out as a more flexible receiver, while the HWR’s simple design makes it ideal for devices with limited resources.