The present era of digitization is looking forward to updating the manual system with automation. The chipless Radio Frequency Identification (RFID), a well-known wireless technology, eliminates the hurdle of human intervention and comes into the Automatic Identification (Auto-ID) technology market. Although the low cost of optical barcodes dominates them for many years, their restricted read distance, reduced information storing capacity, and significant manual involvement in their operation call out the need for an alternative. The conventional RFID overcomes all the above-mentioned shortcomings of an optical barcode. But the cost of the RFID is an important problem. This article reviews chipless RFID which benefits over existing Auto-ID technologies. An overview of the basic RFID system, categories of RFID tags, and a comparison of chipless and chipped RFID tags are outlined. Understanding the relevance of chipless RFID in the future, the classes of chipless RFID tags, the challenges that come across in designing a chipless RFID, the principle of operation of a backscattering chipless tag, and design parameters like Radar Cross Section (RCS) are discussed. This article throws light on RFID tag printing, data capturing techniques of chipless RFID, certain materials used for tag manufacturing, chipless RFID-based sensors, potential applications, followed by current challenges and future directions of chipless RFID tags.

Chipless RFID: A Unique Technology for Mankind

Performance improvements of perfluorosulfonic acid membranes, such as Nafion and Flemion, underline a need for dielectric characterization of these materials toward a quantitative understanding of the dynamics of water molecules and protons within the membranes. In this Article, a two-port transmission line technique for measuring the complex permittivity spectra of polymeric electrolytes in the microwave region is described, and the algorithms for permittivity determination are presented. The technique is experimentally validated with liquid water and polytertrafluoroethylene film, whose dielectric properties are well-known. Further, the permittivity spectra of dry and hydrated Flemion SH150 membranes are measured and compared to those of Nafion 117. Two water relaxation modes are observed in the microwave region (0.045−26 GHz) at 25 °C. The higher-frequency process observed is identified as the cooperative relaxation of bulk-like water, whose amount was found to increase linearly with water content in t...

http://ma.ecsdl.org/content/MA2010-01/25/1288.full.pdf

Two-Port Transmission Line Technique for Dielectric Property Characterization of Polymer Electrolyte Membranes

A new nonvolatile nanoionic switch is powered and controlled through wireless radio-frequency (RF) transmission. A thin layer of chalcogenide glass doped with a metal ion, such as silver, comprises the operational portion of the switch. For the switch to function, an oxidizable electrode is made positive (anode) with respect to an opposing electrode (cathode) when sufficient bias, typically on the order of a few tenths of a volt or more, is applied. This action causes the metal ions to flow toward the cathode through a coordinated hopping mechanism. At the cathode, a reduction reaction occurs to form a metal deposit. This metal deposit creates a conductive path that bridges the gap between electrodes to turn the switch on. Once this conductive path is formed, no further power is required to maintain it. To reverse this process, the metal deposit is made positive with respect to the original oxidizable electrode, causing the dissolution of the metal bridge thereby turning the switch off. Once the metal deposit has been completely dissolved, the process self-terminates. This switching process features the following attributes. It requires very little to change states (i.e., on and off). Furthermore, no power is required to maintain the states; hence, the state of the switch is nonvolatile. Because of these attributes the integration of a rectenna to provide the necessary power and control is unique to this embodiment. A rectenna, or rectifying antenna, generates DC power from an incident RF signal. The low voltages and power required for the nanoionic switch control are easily generated from this system and provide the switch with a novel capability to be operated and powered from an external wireless device. In one realization, an RF signal of a specific frequency can be used to set the switch into an off state, while another frequency can be used to set the switch to an on state. The wireless, miniaturized, and nomoving- part features of this switch make it suitable for applications such as integration into garments, RFID (radio-frequency identification) tags, and conformal structures (e.g., aircraft wings, sounding rockets contours, etc). In the case of RFID tags the innovation will provide countermeasures to attempts for identity theft and other uninvited attempts for retrieval of information. It could also be applicable to the automotive industry as well as the aerospace industry for collision avoidance and phased array radar systems, respectively

/pdf/wireless-chalcogenide-nanoionic-based-radio-frequency-switch-2rs27wa9y3.pdf

Wireless Chalcogenide Nanoionic-Based Radio-Frequency Switch

We present an electronically rewritable chipless RFID tag based on integrated nonvolatile Conductive Bridging Random Access Memory (CBRAM) RF switches. CBRAM is a nonvolatile memory technology, which is identified as an innovative RF switching solution in this decade. Reconfigurable resonator or RF encoding particle (REP) used in this tag is a closed-loop resonator integrated with two switches each to tune its electrical length, and encodes three states each, to represent more than one bit per REP. Presented tag is composed of three such REPs to represent a total of 27 unique states. This chipless RFID tag with CBRAM switches could be written/rewritten electronically using DC voltage pulses, to encode a desired code from a given combination. Thermal impression transfer printing is utilized for printing metallic layers of the presented chipless tag. Complete fabrication steps of presented tag with integrated CBRAM switches are carried out without any “clean room” processes. An insight to working mechanism of presented rewritable REPs using electrical models is included in this article. Proof of concept of a potential hybrid data encoding technique combining frequency shift coding and Radar Cross Section (RCS) magnitude level coding, through experimental studies, for presented REPs, is also given herewith.

/pdf/electronically-rewritable-chipless-rfid-tags-fabricated-160thxw4m8.pdf

Electronically Rewritable Chipless RFID Tags Fabricated Through Thermal Transfer Printing on Flexible PET Substrates

To date semiconductor switches are still the main enablers for electrical circuit and system reconfigurability. They however not only consume dynamic power but also dissipate static power, the former for performing on/off operation and latter for holding on/off state. These semiconductor devices are volatile and not energy efficient due to the need for holding voltage and can significantly increase the system power consumption where hundreds and thousands of switches are needed, such as in large reconfigurable intelligent surfaces and large antenna arrays. In this work, we report a non-volatile reconfigurable antenna that can switch between dual-band at 2.4 GHz and 5 GHz to a single band at 3 GHz. The measured results including reflection, gain and radiation patterns reveal promising performance, experimentally demonstrating a new approach of design and realization of RF switch integrated multi-band reconfigurable antennas. This zero-static power mechanism, along with easy fabrication on the flexible substrates would be very beneficial for Internet of Things (IoT) applications.

/pdf/non-volatile-rf-reconfigurable-antenna-on-flexible-substrate-13wli6cim0.pdf

Non-Volatile RF Reconfigurable Antenna on Flexible Substrate for Wireless IoT Applications

This article reports the first results of a Nafion®-based, solid state, non-volatile, electronically reconfigurable Radio Frequency (RF)-switch integrated to a co-planar waveguide transmission line (CPW) in shunt mode, on a flexible paper substrate. The switch is based on a metal–insulator–metal structure formed respectively using Silver–Nafion–aluminum switching layers. The presented device is fully passive and shows good performance till 3 GHz, with an insertion loss less than 3 dB in the RF-on state and isolation greater than 15 dB in the RF-off state. Low-power direct current pulses in the range 10 V/0.5 mA and −20 V/0.15 A are used to operate the switch. The device was fabricated in an ambient laboratory condition, without the use of any clean room facilities. A brief discussion of the results and potential application of this concept in a re-configurable chipless RFID tag is also given in this article. This study is a proof of concept of fabrication of electronically re-configurable and disposable RF-electronic switches on low cost and flexible substrates, using a process feasible for mass production.

https://hal.archives-ouvertes.fr/hal-01992062/document

Electronically Re-Configurable, Non-Volatile, Nano-Ionics-Based RF-Switch on Paper Substrate for Chipless RFID Applications

Electromagnetic Shielding Using Flexible Embroidery Metamaterial Absorbers: Design, Analysis and Experiments

In this paper, a target location scheme for multi-target localization in free space is proposed. It exploits the properties of directional modulated antenna radiation patterns which are synthesized using time-modulated arrays (TMAs). Here, we show that the TMAs can be made to synthesize directional modulation (DM) symbols concurrently upon multiple angular beams. Compared with previous DM works on target localization, our proposed system exhibits some promising features, such a <inline-formula> <tex-math notation="LaTeX">${i}$ </tex-math></inline-formula>) generating multiple beams simultaneously, enabling multiple targets detection at the same time along different angular directions, <italic>ii</italic>) allowing multiple access in frequency domain, <italic>iii</italic>) requiring only one radio frequency (RF) chain with a signal peak- to-average power ratio (PAPR) of 0 dB; <italic>iv</italic>) eliminating the azimuth ambiguity in mirror angular directions with respect to array boresight, <inline-formula> <tex-math notation="LaTeX">${v}$ </tex-math></inline-formula>) flexibly adjusting the target angular resolution, and <italic>vi</italic>) enabling beam steering without the need of phase shifters. The proposed technique is useful in various applications, such as tracking and controlling multiple drones, vehicles, and etc. It provides an alternative means in most of the Radar applications, and with the capability of wireless communication, it can be treated in the domain of waveform design for the Integrated Sensing and Communication (ISAC).

Target Localization Using Time-Modulated Directional Modulated Transmitters

Electrical resistance control programming of conductive bridging random access memory (CBRAM) radio frequency (RF) switches could benefit the development of electronically controlled non-volatile RF attenuators and other reconfigurable devices. The object of this study is to adapt a conventional CBRAM based memory cell to be used as an RF switch, and to demonstrate the feasibility of programming non-volatile RF CBRAM switches to achieve specific target resistances within a range of continuous values. The memory-RF technologic transition implies a drastic increase of the geometry in order to handle a much higher power, a decrease of the transition capacitance in order to operate at much higher frequencies, and a decrease of the LRS to a few ohms, which is critical for RF applications. These studies are initially performed on an in-house made RF CBRAM cell array at DC frequency, and then extended successfully to a co-planar waveguide (CPW) based shunt mode RF switch with an integrated CBRAM cell. Reliability of the proposed technique is validated through detailed analysis of factors like repeatability of the process, time stability of programmed states, and statistics of time taken to converge to a desired resistance value for an arbitrary RF CBRAM switch. 

/pdf/cbram-technology-transition-from-a-memory-cell-to-a-3oyvr5td.pdf

Jayakrishnan Methapettyparambu Purushothama

Papers

Electronically Re-Configurable, Non-Volatile, Nano-Ionics-Based RF-Switch on Paper Substrate for Chipless RFID Applications

Electronically Rewritable Chipless RFID Tags Fabricated Through Thermal Transfer Printing on Flexible PET Substrates

Electromagnetic Shielding Using Flexible Embroidery Metamaterial Absorbers: Design, Analysis and Experiments

Target Localization Using Time-Modulated Directional Modulated Transmitters

CBRAM technology: transition from a memory cell to a programmable and non-volatile impedance for new radiofrequency applications