On the Sideband Harmonics in Pulsed Frequency Diverse Arrays

Pulsed frequency diverse arrays (FDAs) have recently garnered significant research attention in radar and sensing applications due to their range-dependent radiation properties. However, the time-dependent nature of radiation can limit the benefits of FDAs. While recent methods have been proposed to mitigate this limitation and enhance the functionality of FDAs, there is an urgent need to better characterize their radiated power profile and specifically to address the substantial power losses in the sideband harmonics. In this paper, we bridge this gap in the literature by presenting a new closed-form expression for the sideband radiated power (SRP). Additionally, we explore practical limitations outlined in the existing literature that pertain to achieving time-independent radiation concerning SRP consumption. Finally, our theoretical analysis is supported by numerical examples. A noteworthy insight from our work is that treating pulsed FDA systems as time-independent may lead to unreliable conclusions, underscoring the importance of addressing the SRP issue in future research.