Passive UHF RFID transponders are usually employed with balanced antennas optimized to match the complex conjugate of the chip impedance. Since the degree of impedance matching between the antenna and the chip determines the system performance, it is essential to validate the performance of the transponder through prototype measurements. In this paper, the design of a chip -based passive UHF RFID sensor transponder antenna and the measurement of its impedance is presented. Simulations were carried out in ANSYS High Frequency Structure Simulator (HFSS) and the input impedance of the antenna was matched with the conjugate impedance of the commercial RFID chip, Farsens Rocky100. A prototype of the antenna was fabricated and its input impedance was measured using image theory. The simulated and measured results are in good agreement, thus validating the antenna's performance. The S-11 < - 10 dB bandwidth of the antenna covers the entire UHF frequency band. Accordingly, the proposed antenna can be operated in any region within the aforementioned frequency band for RFID applications.

Currently, the inspection and verification of vehicle-related information are done by police inspectors using camera-based systems or manually.Though integrating video technology is more advantageous than manual operation, they do not perform accurately due to bad weather or driving styles.This paper presents the design of a compact, durable, battery-free, UHF RFID tag with enough memory to carry necessary information for automatic identification of traffic law enforcement applications.The vehicle owner can also be alerted when the tag is detected due to the visual indication facility.This tag's novel feature includes adapting a modified T-match structure to match the highly capacitive impedance of the chosen RFID sensor chip, i.e., Farsens Rocky100.In contrast to existing designs, the proposed tag contains no extra lumped components that necessitate an external impedance matching circuit.Instead, the input impedance was matched using an advanced T-match topology and by optimizing the antenna's geometrical features.Simulations were done in Ansys HFSS (High-Frequency Structure Simulator) whereas the dimensions of all the printed elements were fine-tuned using parametric optimization.The tag was fabricated on a low-cost FR4 substrate and measured.The tag with an overall size of 110 × 25 × 2.4 mm 3 can be detected by a conventional UHF RFID reader within a range of about 0.2 m-1 m.Due to the loop configuration, the tag exhibits a confined detection range while operating well within short ranges.

This paper presents the design of a battery-free chip-based UHF RFID sensor tag appropriate for temperature measurement inside a poultry egg incubator. The tag employs an EM4325 UHF RFID sensor chip that has a built-in temperature sensor. The antenna was connected to the chip via an internal impedance-matching circuitry and they were etched on an FR4 substrate. Tuning the antenna configuration to match the impedance of the chip and miniaturization of the tag size were performed using parametric optimization. Simulations were performed in ANSYS High-Frequency Structure Simulator (HFSS). The RFID tag, with a compact size of 75 × 20 × 1.6 mm 3 , performs well in terms of impedance matching, bandwidth, and radiation efficiency. Further, the proposed UHF RFID sensor tag demonstrates both far-field and near-field characteristics due to the antenna's dipole topology and loop structure respectively.

A non-uniformly meandered printed dipole antenna is proposed to be used as a passive Ultra High Frequency – Radio Frequency Identification (UHF RFID) chip-based sensor tag. A printed, modified dipole antenna, with an overall size of 130 × 25 × 1.6 mm3 was used as a reference antenna, and its size was reduced by 32% by folding dipole arms and employing a non-uniformly meandered structure. A double T-match structure was introduced to match the conjugate impedance of the RFID chip, i.e. Rocky100. Simulations were carried out in ANSYS High-Frequency Structure Simulator (HFSS), etching the antenna on FR4 substrate. The meandered antenna, with an overall dimension of 88 × 25 × 1.6 mm3, exhibits better performance than the reference antenna. The bandwidth of the antenna covers the whole UHF spectrum from 860 – 960 MHz while exhibiting an omnidirectional radiation pattern. The theoretical read range of the tag according to the Friis transmission equation is 10.6 m at EIRP of 4 W. The proposed tag can be used to develop chip-based passive UHF RFID sensor tags by integrating sensors to the Rocky100 chip.

This paper presents design of a printed dipole antenna suitable for RFID applications. The RFID chip of Farsens Rockyl00 with the input impedance of 64 - j 469 Ω at 868 MHz was used to develop a passive RFID sensor tag. The antenna was etched on an FR4 dielectric substrate with a relative permittivity of 4.4, loss tangent of 0.02, and thickness of 1.6 mm. Initially, a simple dipole antenna with a single T-match structure was designed having overall dimensions of 163 mm × 16 mm × 1.6 mm. The antenna was simulated in ANSYS High Frequency Structure Simulator (HFSS) and found that its impedance is 63.66 + j 130.56 Ω. Then the T-match was modified by adding another bridge parallel to the T-match and by folding the dipole. The dimensions of its structure were optimized by using parametric optimization to match the impedance. The impedance match between the proposed antenna and the chip concerning the power transmission coefficient is 0.998. The simulated S11 ≤ -10 dB bandwidth is 690 MHz - 970 MHz. The radiation patterns are omnidirectional with a gain of about 1.7 dB. The read range of the proposed antenna was computed and found as 2.36 m.

This article addresses the formulation and validation of a simple PC based software application developed for simulating commercially available solar panels. The important feature of this application is its capability to produce speedy results in the form of solar panel output characteristics at given environmental conditions by using minimal input data. Besides, it is able to deliver critical information about the maximum power point of the panel at a given environmental condition in quick succession. The application is based on a standard equation which governs solar panels and works by means of estimating unknown parameters in the equation to fit a given solar panel. The process of parameter estimation is described in detail with the aid of equations and data of a commercial solar panel. A validation of obtained results for commercial solar panels is also presented by comparing the panel manufacturers' results with the results generated by the application. In addition, implications of the obtained results are discussed along with possible improvements to the developed software application.