This work presents a novel, low-cost frequency and pattern reconfigurable antenna for Internet of Vehicles (IoV) applications. The proposed design addresses the issue of using multiple antennas for different frequency bands to enable vehicles to communicate over several channels. Also, it relieves the need for a sophisticated beamforming network. The proposed radiating system comprises a simple segmented patch antenna (SPA) integrated with a few electronic switches to achieve frequency and pattern reconfiguration. The SPA consists of a radiating patch with two incorporated slots and two slits. Three p-i-n diodes are integrated into both slots to vary the shape of the patch to enable frequency reconfiguration at 4.1, 4.7, 5.0, and 5.7 GHz. Adopting the Yagi-Uda principle, two parasitic elements, functioning as either a reflector or a director, are positioned on both sides of the patch, facilitating the pattern reconfiguration. This novel SPA can scan its beam in twelve directions (0, ±38∘, ±50∘, ±63∘, ±90∘, ±143∘, 180∘) with a measured peak gain and efficiency of 4.2 dB and 92%, respectively. The proposed antenna is experimentally tested to validate the concept. Employing only five p-i-n diodes, this inexpensive antenna can radiate twelve distinguishable switchable beams, including broadside and end-fire radiation over four frequencies with acceptable gain, matching bandwidth, and efficiency. This makes the proposed antenna an excellent candidate for IoV applications.

In this paper, a novel stochastic geometry-based mathematical model is constructed to examine the performance of a millimeter-wave band joint radar communication (JRC) system. The proposed system comprises two sub-systems: the sensing sub-system, in which radar detects mobile users (MUs), and the communication sub-system, in which directional antennas establish communication with the detected users. Both function-alities operate simultaneously to reduce delay and accelerate beam alignment. The system is modeled under realistic fading channel conditions with distributed scatterers and interferers. Several system parameters are considered in the analytical model, including the density of MUs and clutter from surrounding scatterers, the radar cross section (RCS) fluctuations of the target and clutter, radar search time duration, antenna directivity, and bandwidth. The results reveal that the radar sensing sub-system has the greatest impact on the overall system performance, with radar search duration being a crucial parameter for maximizing the average system throughput.

This work proposes a novel millimeter-wave (mm-wave) wideband circularly polarized (CP) antenna array for Internet of Things (IoT) applications. The proposed design addresses the issues of having IoT sensors deployed in remote locations or over large geographical regions. Elliptically shaped dielectric resonator antennas (DRAs) are used as array elements to improve radiation characteristics and achieve circular polarization over a wide impedance bandwidth around 28 GHz. Two different sequential-phase corporate feed networks are studied and compared to obtain wider impedance, 3-dB gain, and axial ratio (AR) bandwidths. Furthermore, a ridge gap waveguide technique based on the low-cost PCB technology is adopted to reduce the transmission losses in the considered sequential-phase feed networks. The proposed mm-wave antenna exhibits an impedance bandwidth of 35% (28.1–40 GHz) and 3-dB gain bandwidth of 19.3% (27.6–33.5 GHz). The achieved 3-dB AR bandwidth is 22.6% (27.5–34.5 GHz). The proposed antenna was fabricated and measured, and good agreement between measured and simulated results was obtained. The reported results show that the suggested wideband CP mm-wave antenna has a lot of promise in preventing polarization mismatch losses between IoT devices and satellites caused by their varying orientations.

This article studies data aggregation in large-scale regularly deployed Internet of Things (IoT) networks. The data granularity, in terms of information content and temporal resolution, is parameterized by the sizes of the generated packets and the average interpacket generation time. The generated data packets at the devices are aggregated through static terrestrial gateways. Universal frequency reuse is adopted across all gateways and randomized scheduling is utilized for the IoT devices associated with each gateway. Such network model finds applications in environmental sensing, precision agriculture, and geological seismic sensing to name a few. To this end, we develop a novel spatiotemporal mathematical model to characterize the interplay between data granularity, transmission reliability, and delay. The developed model accounts for several IoT design parameters, which include packet sizes, average generation duty cycle, devices and gateways spatial densities, transmission rate adaptation, power control, and antenna directivity. For tractable analysis, we propose two accurate approximations, based on the Poisson point process (PPP), to characterize the signal-to-interference-plus-noise-ratio (SINR)-based transmission reliability. For the delay analysis, we propose a phase-type arrival/departure (PH/PH/1) queueing model that accounts for packet generation, transmission scheduling, and rate-sensitive SINR-based packet departure. The developed model is utilized to obtain the optimal transmission rate for the IoT devices that minimizes delay. The numerical results delineate the joint feasibility range of packet sizes and interarrival times for data aggregation and reveal significant gains when deploying directional antennas.

The design of a self-sustained cylindrical dielectric resonator antenna (DRA) fed by a printed ridge gap waveguide technology is presented. The antenna is designed to operate in the 60 GHz band. To avoid the difficulties of aligning the DRA above the coupling slot, a supporting structure made of the same DRA material is employed. This supporting structure is made by perforating the dielectric around the DRA to reduce its relative permittivity. Numerical results show an impedance bandwidth of 20.5 % from 54.3 to 66.7 GHz, and a 3-dB gain bandwidth covering the whole impedance bandwidth with a maximum gain of 9.5 dB at 62 GHz. The proposed self-sustained DRA is a strong candidate for 5thgeneration wireless communication devices as an array element.

In this work, a low profile, wide-band, dual standard, multiple-input-multiple-output (MIMO) antenna system is proposed for mobile applications. The MIMO antenna system consists of 4 monopole antenna elements for 4G standard covering different bands between 1900-3212 MHz and 3517-3712 MHz and 2 linear connected antenna arrays (LCA) for 5G standard covering 25.7-30.50 GHz band at mm-waves. This integrated MIMO antenna system is fabricated on an RO4350 substrate with εrequal to 3.5. The dimensions of the board are equal to 115×65×0.76 mm3which is a typical backplane size of a mobile handset. MIMO performance metrics such as envelope correlation coefficient and isolation are calculated and observed to be 0.16 and 13dB, respectively, at 4G bands and 0.0069 and 20dB at 5G band which shows good MIMO performances.

A novel 60 GHz dielectric resonator antenna (DRA) with wide circular polarization bandwidth is presented. The performance of a stair-like rectangular DRA with x-shaped feeding slot, which is fed with a printed ridge gap waveguide (PRGW) is analyzed. The antenna has a 10.9% circularly polarized bandwidth (axial ratio <; 3 dB) and 28% matching bandwidth (S11 <; -10 dB). The PRGW feeding technology ensures a low loss feeding mechanism with no radiation losses.