Transponder Performance Research Articles

Investigation of Factors Affecting the Performance of Textronic UHF RFID Transponders.

The aim of this paper is to demonstrate progress in textronic UHF RFID transponder (RFIDtex tag) technology. The fundamental idea behind the RFIDtex tag design involves galvanic separation between circuits of the sewn antenna and the chip, which are electromagnetically coupled through a system of inductive loops. To advance the development of this concept, it is crucial to detect factors affecting the performance of the transponders. To achieve this goal, a mathematical model of the textronic UHF RFID transponder was developed. It involves relationships that describe the impedance of each element, the mutual inductance of the loops, and the chip voltage, and it enables the exploration of the influence of these variables on general parameters such as impedance matching and read range. Various analytical and numerical approaches were considered to obtain the value of the mutual inductance of the loops. The dimensions and geometry of the antenna, as well as the matching circuit in the microelectronic module, were taken into account. Based on the mathematical model, it was determined that mutual inductance strongly affects the chip voltage for frequencies higher than 800 MHz. The calculations from the mathematical model were compared with numerical simulations. Experimental studies were also conducted to investigate how the transponder performance is affected by either the distance between the centers of the loops or the conductivity of the threads used to embroider the antenna. The measurement results allowed us to conclude that even small imperfections in the manufacturing of the transponder, which slightly increase the vertical or horizontal distance between the centers of the loops, cause a dramatic decrease in the mutual inductance and coupling coefficient, significantly impacting the transponder's performance.

Harmonic Balance/Full-Wave Analysis of Wearable Harmonic Transponder for IoT Applications

The article presents a novel design of a compact wearable harmonic transponder with double-plane symmetry, composed of a dual-band patch-type antenna loaded by an HSMS-2820 Schottky diode, operated as a proof of concept at ISM UHF 869 and 1734 MHz frequencies. The antenna is analyzed and optimized for a minimum ground plate size by means of the CST Microwave Studio electromagnetic simulator, and its reflection coefficient is incorporated into the equivalent circuit model for a combined harmonic balance (HB) and full-wave analysis using the AWR Microwave Office commercial simulator. The transponder performance, including the complex input impedance matching and conversion loss (CL) between the fundamental and second harmonic frequencies on the diode, was evaluated both in free space and when attached to a human muscle phantom. The total harmonic transponder CL, including diode CL, antenna transponder gains, and impedance mismatching, is 6.2 dB for an excitation power of −25 dBm at the antenna–diode interface. The measured reading distances are 9.0 and 8.8 m for equivalent isotropically radiated power (EIRP) <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$=20$ </tex-math></inline-formula> dBm when the transponder is placed in free space and on the human body, respectively. As a means of machine-to-person communication, the transponder is suitable for the Internet of Things (IoT) concept, e.g., for the identification of pedestrians in traffic, i.e., in a complex environment with unwanted radiation clutter and multipath fading.

Towards vendor-agnostic real-time optical network design with extended Kalman state estimation and recurrent neural network machine learning [Invited

The network operator’s call for open, disaggregated optical networks to accelerate innovation and reduce cost, make progress in the standardization of interfaces, and raise telemetry capabilities in optical network systems has created an opportunity to adopt a new paradigm for optical network design. This new paradigm is driven by direct measurement and continuous learning from the actual optical hardware deployed in the field. We report an approach towards practical, vendor-agnostic, real-time optical network design and network management using a combination of two learning models. We generalize our physics-based optical model parameter estimation algorithm using the extended Kalman state estimation theory and, for the first time, to the best of our knowledge, present results using real optical network field data. An observed 0.3 dB standard deviation of the difference between typical predicted and measured signal quality appears mostly attributable to transponder performance variance. We further propose using the physics-based optical model parameter values as inputs to a second learning model with a recurrent neural network such as a gated recurrent unit (GRU) to allocate the appropriate required optical margin relative to the typical signal quality predicted by the physics-based optical model. A proof of concept shows that for a dataset of 3000 optical connections with a wide variety of amplified spontaneous emission noise and nonlinear noise limited conditions, a 10-hidden-unit 2-layer GRU was sufficient to realize a margin prediction error standard deviation below 0.2 dB. This approach of measurement data-driven automated network design will simplify deployment and enable efficient operation of open optical networks.

Simulation of Optical ISL with 48 Transponders and Performance Analysis Using Ber and Q-Factor

Abstract In the present day world, the satellite technology is recording high growth rate on day to day basis through which the part played by optical wireless communication via satellite has been found to be playing an important role. The system has been evaluated by means of two methods. The first one being the communication system using 48 transponders in the satellite by means of Optisystem 15.2 software. The second one attributes to the concept of Satellite to Satellite Optical Wireless Communication (SSOWC) wherein 48 transponders are used by means of Optisystem 15.2 software. In this, the factors realized are Q-factor, bit error rate, effective noise band width and noise power. These factors were verified and analyzed to make use of satellite optical wireless communication of the respective transponder performance.

Probability of error for BPSK modulation from electrostatic interference [in orbital situation

In an orbital situation any spacecraft is bombarded by charged particles that span a broad range of energies. Some of the particles may be trapped within the materials of the spacecraft. Recent data indicates that an S-band phased-array antenna on a spacecraft may experience electrostatic discharges from such ion deposition at the elements of the array. These discharges may induce RF interference of sufficient magnitude to degrade transponder performance. This issue is addressed by considering the degradation to a binary phase shift keying (BPSK) signal. A simple model for the electrostatic phenomenon is described, and error probabilities are evaluated. The discharges and induced pulse rates are shown to be well below the interference level.

Intelligent fault isolation and diagnosis for communication satellite systems

NASA-Lewis Research Center recently completed the design of a Ka-band satellite transponder system, as part of the Advanced Communication Technology Satellite (ACTS) System. To enhance the reliability of this satellite, NASA funded The University of Akron to explore the application of an expert system, in order to provide this satellite with autonomous diagnosis capability. The result of this research was the development of a prototype diagnosis expert system, called Fault Isolation and Diagnosis EXpert (FIDEX). FIDEX is a frame-based system that uses hierarchical structures to represent such items as the satellite's subsystems, components, sensors, and fault states. This overall frame architecture integrates these hierarchical structures into a lattice that provides a flexible representation scheme and facilitates system maintenance. To overcome limitations on the availability of sensor information, FIDEX uses an inexact reasoning technique based on the incrementally acquired evidence approach that was developed by Shortliffe during his MYCIN project. The system is also designed with a primitive learning ability through which it maintains a record of past diagnosis studies. This permits it to search first for those faults that are most likely to occur. And finally, FIDEX can detect abnormalities in the sensors that provide information on the transponder's performance. This ability is used to first rule out simple sensor malfunctions. The overall design of the FIDEX system, with its generic structures and innovative features, makes it an applicable example for other types of diagnostic systems. This article discusses these aspects of FIDEX, and illustrates how they can be applied to fault diagnostics in other types of space systems.

Communications transponder performance for Japanese Communications Satellite-2 and prospects for future systems

Communications transponder for the Japanese Communications Satellite-2 (CS-2a and 2b) to be launched into a geostationary orbit by N-II launch vehicle in February and August, 1983, has been developed. The transponder is provided with six-channel K-band ( 30 20 GHz ) transponder including beacon transmitter, which operates in the highest frequency ranges ever utilized on an operational communications satellite, and two-channel C-band ( 6 4 GHz ) transponder. Receiver front end of the K-band transponder consists of a direct mixer followed by a 1.8 GHz IF amplifier and provides 8 dB noise figure. 20 GHz output power is 4 W by final amplification at 5-W TWTA. C-band transponder provides 4 dB noise figure and 4.3-W output power. Key factors for future high capacity transponder are also presented.

TDRSS Performance Evaluation for Shuttle Services Using Analytical Simulation

An analytical simulation package called LinCsim has been developed by LinCom Corporation for analytical verification of bit error rate and tracking service performance for both <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</tex> - and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Ku</tex> -band Shuttle user service through the Tracking and Data Relay Satellite System (TDRSS). The purpose of this effort was to provide a tool to assess overall system performances as well as the sensitivity to key subsystem parameters and to ensure compatibility of TDRSS and Shuttle transponder performance specifications. The evaluation is based on an analytical simulation, i.e., a combination of simulation techniques and analytical performance evaluation. This allows the use of a more realistic signal format than is possible with a purely analytical approach and maintains the advantage of short computation time. The Shuttle forward and return link models and the main features of the simulation are described. Sample results of the computer runs are provided for current power budgets and system design parameters.