Near-field Harvesting Filter for Interference Resistance

The patent introduces a harvesting filter as an intermediary component between the near-field antenna and the energy harvesting circuit. This filter selectively passes certain frequency components while blocking others, acting as a mediator that separates desired communication signals from interfering electromagnetic energy. The filter has minima gains at blocking frequencies that align with interference sources, thereby reducing susceptibility to electromagnetic interference while maintaining communication reliability.

The patent applies local quality by making the harvesting filter's frequency response non-uniform, with specific minima gains positioned at blocking frequencies. Rather than treating all frequencies equally, the filter provides differentiated treatment: it blocks frequencies where interference is expected while allowing frequencies carrying desired communication signals to pass through. This localized frequency-selective filtering addresses the interference susceptibility problem without compromising overall communication reliability.

The patent segments the near-field energy spectrum into different frequency components using the harvesting filter. Instead of harvesting all near-field energy uniformly, the filter divides the energy into passed frequencies (which contain desired communication signals) and blocked frequencies (which are harvested by the energy harvesting circuit). This segmentation allows the system to simultaneously harvest energy from interfering frequencies while preserving communication signals, resolving the contradiction between energy harvesting efficiency and communication reliability.

The harvesting filter serves as an intermediary that separates the near-field energy into two distinct paths: one leading to the energy harvesting circuit and another leading to the communication receiver. By positioning the filter between the antenna and these two destinations, it enables selective routing of different frequency components, allowing energy harvesting without degrading communication signal quality.

The patent makes the near-field antenna system multi-functional by enabling it to simultaneously perform communication and energy harvesting operations. The harvesting filter, while adding complexity, enables the system to achieve two functions at once: filtering interference for improved communication reliability and directing energy to the harvesting circuit. This multi-functionality justifies the added complexity by providing dual benefits of interference resistance and energy efficiency.

The patent manages complexity by carefully controlling the filter's parameters, specifically positioning minima gains at blocking frequencies that match expected interference sources. Rather than implementing a complex wideband filter, the design uses targeted parameter adjustments in the filter's frequency response to achieve interference resistance with minimal added complexity. This parameter-based approach balances performance improvement with device simplicity.