In this paper, a novel synthesis technique for dual-frequency rectifier for ambient RF energy harvesting is proposed. For the first time, a fully distributed version of dual-frequency resistance compression network (RCN) is introduced. The proposed RCN utilizes the dual- frequency characteristic of the c-type coupled lines terminated into real impedance. The design technique is fully analytical based on closed-form design equations. Extensive simulations have been carried out to illustrate the proposed idea. The obtained results outperform the earlier reported lumped element network and provides a minimum 10% improvement in the RF-to-DC conversion efficiency at -20 dBm input power. The proposed technique can potentially serve as a starting point for the dual-frequency RF rectifier design.

In this paper, various ambient energy-harvesting technologies (solar, thermal, wireless, and piezoelectric) are reviewed in detail and their applicability in the development of self-sustaining wireless platforms is discussed. Specifically, far-field low-power-density energy-harvesting technology is thoroughly investigated and a benchmarking prototype of an embedded microcontroller-enabled sensor platform has been successfully powered by an ambient ultrahigh-frequency (UHF) digital TV signal (512-566 MHz) where a broadcasting antenna is 6.3 km away from the proposed wireless energy-harvesting device. A high-efficiency dual-band ambient energy harvester at 915 MHz and 2.45 GHz and an energy harvester for on-body application at 460 MHz are also presented to verify the capabilities of ambient UHF/RF energy harvesting as an enabling technology for Internet of Things and smart skins applications.

In this paper, we considered the possibility of using electricity harvested from the microwave field leaked from commercial microwave ovens. Our experimental results showed that the leakage received by a dipole antenna was about 0 dBm (1 mW) at a point 5 cm in front of the door. A rectenna consisting of a dipole antenna and charge pump can convert the leaked microwave energy into a DC current. When a microwave oven is operated for 2 min, 9.98 mJ of energy was harvested. We demonstrated that this energy is sufficient for powering a digital cooking timer to count down for 3 min and beep for 2.5 s. The operation of other kitchen devices was also demonstrated.

This paper discusses the evolution towards the first integrated radio-frequency identification (RFID)-enabled wireless sensor network infrastructure using ultra-high frequency/radio frequency (UHF/RF) RFID-enabled sensor nodes and inkjet-printed electronics technologies on flexible and paper substrates for the first time ever. The first sections highlight the unique capabilities of inkjet printed electronics as well as the benefits of using paper as the ultra-low-cost, conformal and environmentally friendly substrate for the mass-scale ubiquitous implementation of the first RFID-enabled wireless sensing applications. Various inkjet-printed antenna configurations are presented for enhanced-range compact RFID-enabled sensing platforms in “rugged” environments up to 7 GHz, followed by the discussion of their 2-D integration with integrated circuit (IC) and sensors on paper. This integration is extended to a power-scavenging “smart-shoe” batteryless integrated RFID module on paper that could be used for autonomous wearable sensing applications with enhanced range. The paper concludes discussing the details for establishing for the first time an asynchronous wireless link between the aforementioned RFID-tags and a widely used commercial wireless sensor network (WSN) mote using a simplified protocol; a paramount step that could potentially create ubiquitous ultra-low-cost sensor networks and large-scale RFID implementations eliminating the need of expensive RFID reader infrastructure and linking RFIDs to the mature level of WSNs.

In this paper, an overview of novel design and integration approaches for improved performance UHF radio frequency identification (RFID) tags with embedded power source and sensing capability is presented. Ultra-low-cost organic substrates, such as paper, with inkjet-printing capability are investigated for the UHF frequency band. The proposed technology could potentially revolutionize sensor nodes and RFID tags for various applications such as security, logistics, automotive and pharmaceutical.