Simultaneous wireless information and power transfer (SWIPT) is an emerging technology to connect and energize devices wirelessly, in the future Internet of Things (IoT) and wireless sensor networks (WSN). In this paper, we investigate two coherent detection schemes for integrated SWIPT receivers. At first, we examine a single input multiple output (SIMO) topology, with multiple rectennas at the receiver’s side, i.e. MRCA scheme. Targeting to reduce the decoding complexity, we further investigate a single input single output (SISO) topology, with one receive antenna connected to multiple rectifiers, i.e. MRCE scheme. A non-linear energy harvesting (EH) model, is considered for both schemes, by taking into account the sensitivity and saturation effects of rectifiers. With the use of maximum likelihood (ML) and soft decoding, energy detection is succeeded. An asymptotic analysis is conducted for both schemes, providing upper and lower bounds for EH and information decoding, respectively. Simulation and experimental results along with theoretical analysis, validate the enhanced performance of the proposed schemes.

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.

This paper presents a conformal, compact, omnidirectional, elliptical monopole antenna on liquid crystal polymer (LCP) which is studied mounted on a cylindrical surface and is proven to operate equally well compared to its planar rival. The presented return loss, gain and radiation pattern measurements demonstrate that the characteristics of the antenna are not compromised when the antenna is mounted on cylindrical surfaces of various radii when the direction of curvature is in the transverse direction. The presented study shows that the proposed antenna can be optimized and tested in planar shape and still be trusted to operate equally well under conditions like in wearable electronics, where their planar condition cannot be guaranteed.