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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 mm³ 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. [ABSTRACT FROM AUTHOR]

A low-profile multi-polarized MIMO ultra-wideband antenna suitable for body-centric communications is reported. MIMO configuration is achieved using the symmetric heptagonal monopole (SHM) antenna, a mirrored SHM antenna, an asymmetric ruby-shaped monopole (ARSM) antenna, and a mirrored ARSM antenna placed over the modified C-shaped ground plane (MCGP). The proposed antenna elements are designed to achieve resonance for the entire ultra-wideband frequency range. The SHM antenna is coupled with a co-planar waveguide to produce linear polarization. An ARSM antenna generates circular polarization utilizing an asymmetric geometry both in the radiator and a truncated ground plane. Both the SHM antenna and an ARSM antenna are aligned face-to-face over an MCGP plane and good isolation >15 dB is realized between the antenna elements. The gain and total efficiency for linear polarized and the circularly polarized antennas are 3.05–4.8 dBi/48–66% and from 2.8 to 5 dBic/52 to 70.5%, respectively. The specific absorption rate values are evaluated to understand their suitability for WBAN communications. [ABSTRACT FROM AUTHOR]

There is a strong demand for compact and multiband antennas as wireless technologies become more integrated into automobiles. These antennas must be able to serve multiple services without compromising the size and installation space. In addition, the antenna incorporated should not affect the aesthetic appearance of the vehicle. This paper presents a compact multiple-input-multiple-output (MIMO) antenna working at 2.45 GHz (Wi-Fi/Bluetooth/RFID) and ultra-wideband (UWB) frequencies. A basic rectangular monopole with a self-complementary structure is used to design the antenna element. The size of the antenna element is 20 × 22 mm2. The proposed MIMO cube is developed with four antenna elements in cubical orientation to achieve compactness and better isolation. The overall dimension of the MIMO antenna is 35 × 22 mm2. The diversity antenna shows impedance bandwidth of 2.4–11.5 GHz and isolation of more than 20 dB. The envelope correlation coefficient (ECC) of the MIMO antenna is less than 0.2, diversity gain (DG) is greater than 9 dB, and total active reflection coefficient (TARC) and channel capacity loss (CCL) are less than −10 dB and 0.4 bits/s/Hz, respectively. The gain and efficiency are found to be greater than 1 dBi and 72%, respectively. [ABSTRACT FROM AUTHOR]

In the proposed research paper, a novel compact, ultra-wideband electronically switchable dual-band omnidirectional to directional radiation pattern microstrip planar printed rectangular monopole antenna (PRMA) has been presented. The proposed antenna system has an optimum size of 0.26 λ0 × 0.28 λ0. A combination of radiators, reflectors, and two symmetrical grounds does place on the same layer of the rectangular microstrip PRMA. The frequency agility and the radiation pattern from omnidirectional to directional are achieved using two SMD PIN diodes (SMP1340-04LF). The directional radiation patterns with 180° phase shifts are achieved at the C-band frequency spectrum. The parametric study of the proposed antenna system was performed for different design parameters, and the antenna characteristics were analyzed. An antenna prototype is fabricated using the printed circuit board etching method by using RMI UV laser etching and cutting tools. The measurements of the proposed antenna are conducted in an anechoic chamber to validate the simulations. There are three states of operations due to two SMD PIN diodes being used in switching circuits. In state-I, the proposed antenna radiates at 6.185 GHz (5.275–6.6 75 GHz) in the Ф = 270° direction with a gain of 2.1 dBi, whereas in state-II, it radiates at 5.715 GHz (5.05–6.8 GHz) in the Ф = 90° direction with a gain of 2.1 dBi. In state-III, the antenna exhibits the X-band frequency with center frequency at 9.93 GHz (8.845–10.49 GHz), and the omnidirectional pattern offers a gain of 4.1 dBi. The features of the proposed antenna are suitable for high-speed wireless sensor network communication in industries such as chemical reactors in oil and gas and pharmaceuticals. It is also well suited for IoT and 5G-sub-6-GHz applications. [ABSTRACT FROM AUTHOR]

An Ultra-Wide Band (UWB) Quasi Yagi antenna with beam steering property is reported in this paper for Wireless Body Area Network (WBAN) application. The proposed antenna has a driver dipole, micro-strip line to slot-line transition and four parasitic strips printed on a very thin substrate of thickness 0.2 mm. The coplanar strip-line (CPS) is used to connect the driver dipole to the slot-line. The proposed antenna has an improved bandwidth of 7.4 GHz along with unidirectional radiation pattern. The parasitic strips act as directors to attain high gain of 7.8 dBi with better directionality. The flexible and compact geometry with footprint of 34 mm × 30 mm makes the antenna suitable for body worn devices. Further to improve the communication between the sensor and the cluster node in WBAN, design of two element antenna array with footprint of 34 mm x 52.3 mm, is constructed to achieve beam steering and the performance metrics are evaluated. The proposed flexible antenna offers large gain and high impedance bandwidth simultaneously. The prototype of the simulated antenna is fabricated and the simulation results are validated using experimental measurements. The measurement and simulation results are found in good agreement. [ABSTRACT FROM AUTHOR]