Philippe Pannier

High-Gain Fully Printed Organic Complementary Circuits on Flexible Plastic Foils

We present several fully printed organic complementary circuits using n- and p-type organic thin-film transistors. n-Type and p-type devices are developed on a flexible polyethylene-naphthalate substrate. All organic layers are deposited using a low-cost screen-printing technique. The inverters show a high gain and a switching point at exactly VDD/2. A seven-stage voltage-controlled oscillator (VCO) is designed with an organic output buffer, using the n- and p-type organic transistors. This VCO oscillates at a frequency of 186 Hz. Finally, two complementary differential amplifiers with high gain and large bandwidth are presented. The amplifiers only draw a 1-μA current from a 40-V power supply.

Modeling and Design of CMOS UHF Voltage Multiplier for RFID in an EEPROM Compatible Process

Modeling and design of CMOS ultra-high-frequency (UHF) voltage multipliers are presented. These circuits recover power from incident radio frequency (RF) signal and supply battery less UHF RF identification (RFID) transponders. An analytical model of CMOS UHF voltage multipliers is developed. It permits to determine the main design parameters in order to improve multiplier performance. The design of this kind of circuits is then greatly simplified and simulation time is reduced. Thanks to this model, a voltage multiplier is designed and implemented in a low-cost electrically erasable programmable read-only memory compatible CMOS process without Schottky diodes layers. Measurements results show communication ranges up to 5 m in the U.S. standard.

Dual band mono-chip HF-UHF tag antenna

Nowadays, RFID systems are commonly used for tracking and identifying supplies or goods. Several RFID standards exist, each have advantages and drawbacks [1]. HF and UHF RFID standards are some of the most used. This paper presents the feasibility of a single chip dual band HF-UHF RFID tag antenna. Some research focused on dual band HF and UHF RFID [2–4]. Cost is a non negligible parameter in RFID tag antenna development. For this reason, multi-layered antennas and multi chip solutions are prohibited as presented in [2, 3]. The reason is that fabrication processes are too expensive to certify a low cost product. Tag exposed in [4] exposed a multi-band antenna fed by a single chip. These performances in the HF bands are classic for tag antennas operating in this frequency band. However, performances in UHF RFID band suffer from degradations especially the maximum gain.

Dual Band UHF and Microwave RFID Antenna

This paper presents a new topology for RFID antenna matched on all UHF and one of the microwave RFIDs band. The antenna can be implemented on different standards of tags sizes as credit card, 85 times 54 mm, or other common sizes 50 times 50 mm. The most criticals parameters of the antenna are studied in order to predict design rules for implemented different kind of dies on the antenna. Radiation pattern on UHF band is complementary to the radiation pattern on microwave band. The substrate is FR4, 0.8 mm, with epsivr = 4.4. Some purposes are made on future studied of a tri-band antenna on 13.56 MHz, all UHF and 2.45 GHz RFIDs band.

A temperature and gas sensor integrated on a 915MHz RFID UHF tag

We present a new battery-free RFID sensor which can be used as a node of a low cost sensor network. It can be used to detect either temperature and gas concentration, depending on the choice of the sensitive element. Its main features are a low consumption, a temperature sensibility range from 0 to 70 °C with a maximum reading distance of 7 m and an ammonia detection sensibility range from 0 to 10 ppm with a distance of 14 m. The circuit was layouted on ST Microelectronics 0.13 µm CMOS technology on a surface of 0.076 mm2

A resistant textile tag antenna for RFID UHF frequency band

Wearable textile systems are nowadays a fast growing field. Besides lower prices, wearable tags antenna have to resist laundry cycles which means high pressure, high temperature and humidity. This paper introduces a novel RFID textile tag antenna, made of two distinct antennas coupled together to protect UHF RFID system from environment stress : a circular small-loop antenna packaged with the RFID chip and a wideband log-periodic antenna made of electro-thread. Electric proprieties of the chip, the small-loop antenna and matching between both are shown. Used method to characterize electro-thread and the choice of electro-thread are presented. Finally the whole tag antenna is simulated and results are presented in part IV. In the UHF band we found the matched reflection coefficient less then -10 dB and the antennas half power beamdwith has 80°. According to Friis equation we can estimated the read range at 4 meters in the RFID UHF band.

Design of organic complementary circuits for RFID tags application

This paper presents organic complementary circuits that can be used in an all-organic sheet-to-sheet processed RFID tag on plastic foils. An integrated organic eight-stage rectifier reaching a 14 MHz maximum working frequency is presented, as well as a physical unclonable function generator able to generate a code depending on the organic process scattering.

Fast behavioral modeling of organic CMOS devices for digital and analog circuit applications

Organic thin film technologies have opened a new range of interest into the optoelectronics industry. Nevertheless the physics and devices modeling still present a lack of accuracy. In order to provide designers with the latest performances of our organic CMOS technology, we have compared the performances of a behavioral model to the public a-Si TFT model in terms of accuracy on device modeling and basic circuit simulations. Fully printed organic CMOS devices and circuits have been processed and characterized in order to validate our device models. In particular, measurements have been carried out on several digital circuits like inverters and ring oscillators. Analog circuits such as current mirrors and differential pairs have also been measured. Simulations of these circuits have been performed using the device behavioral model and the a-Si TFT one under common EDA commercial tools. We show that both kinds of models enable to reproduce the different simple CMOS circuits performances in static as well as in dynamic modes which can open the way for designing a wide range and more complex digital and analog organic applications.

RF energy harvester with sub-threshold step-up converter

An UHF RF energy harvester with integrated step-up converter is presented. This system is designed to overcome the limits of standard RF harvesters (namely low output voltage). This objective is obtained with an extra DC/DC converter that provides an extra voltage boost, with less than 10 nW of power consumption. The accurate sub-threshold analysis of this converter allowed a start-up voltage as low as 200 mV, without compromising the overall power efficiency. The final system is intended to provide an output voltage high enough to power standard common loads (ex. microcontroller) and, more in general, any IoT wireless sensor node, with a limited amount of received power. This is confirmed by experimental results: an output voltage above 1.2 V is obtained starting from a received power of about -24 dBm. The step-up converter area is only 230 μm × 375 μm.

Auto-tuning in passive UHF RFID tags

This paper presents a matching system which enhances compatibility of UHF RFID tags. It provides constant performance in every frequency band used in different countries. The bases of automatic tuning are presented here as well as a system architecture based on two PMOS capacitors. Simulations results from a prototype designed in a 0.18µm CMOS technology show that input power for all the bandwidth (860MHZ–960MHZ) is up to 3dB better with an auto-tuning system.