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In this paper an antenna module for automotive 5G communication is presented. The antenna is designed to cover all the 3GPP n258 frequency band i.e. from 24.25 GHz to 27.5 GHz. At these frequencies, the path loss and obstacles attenuation are high. For this reason, to reach an acceptable communication distance a relatively high gain is required. Furthermore, to achieve a more robust system to multipath interferences the antenna is designed to operate with dual linear polarization. The proposed antenna is composed by an array of 8 dual polarized stacked patches. Finally, in order to suppress the radiation pattern distortion due to surface waves (SWs) propagation, an Electronic Band Gap (EBG) structure is implemented. To validate the design a prototype has been realized and measured.

A low cost and low-profile multiband 3D antenna for roof-top vehicular applications is presented. The radiating element is obtained through a folded metal sheet shaping a geometry that makes the antenna works in the LTE (Long-Term Evolution) bands. Thanks to its particular shape and its small size the antenna can be positioned under the automotive common used shark-fin case. Furthermore, the design allows an easy industrialization process, using low cost material. In fact, the designed shape needs only to be cut and folded without any welding process. In addition to the designed antenna, simulations and measurements take into account another radiating element in order to analyze its behavior in a MIMO (Multiple-Input-Multiple-Output) configuration. For the proposed solution good performances have been demonstrated from both numerical and measurements results.

In this study, a low profile wideband 3D antenna for roof-top LTE vehicular applications is presented. The structure consists of folded metal sheets welded together building a geometry that allows covering two LTE bands: 700MHz–960MHz, 1700MHz–2700MHz. The shape and the size of the antenna allow to fit it under the shark-fin case, and thanks to the chosen material the production costs are low. Simulations and measurements have been performed taking into account two antennas working as a MIMO configuration. Both numerical and measurement results show good performances in terms of return loss, coupling and gain.

This paper describes the design of a new compact dual-band roof antenna (which is capable of operating in both U.S. and European mobile telephone bands) for automotive applications. The flipper shape of the antenna and its dimensional constrains are chosen according to prevailing automotive market trends. The chosen basic geometry of the radiating element is a planar printed monopole structured as a vertical fan with two narrow strips folding toward the ground plane and etched on a low-cost, medium-permittivity thin substrate. The geometrical variations of the basic radiating structure are introduced afterward to constrain the antenna shape under the assigned profile and to allow easy integration of a small Global Positioning System patch antenna without affecting radiation and bandwidth performances. The integration of a matching network directly over the etched monopole trace allows a good input matching over the lower and upper operative bands to be obtained, slightly affecting the radiation efficiency of the whole antenna.

This paper presents a recently built passive radar demonstrator, called the Software-defined Multiband Array Passive Radar (SMARP). This work has been conceived in the framework of the Italian National Plan for Military Research. The system is able to detect and track targets by exploiting DVB-T and UMTS transmitters. The system concept and the results are presented in this paper.

A coated conical antenna capable of wideband or dual band operation is here proposed and experimented. The antenna is intended for vehicular applications, where robustness and height reduction are a premium. Dielectric and magnetic coating of the radiating cone allows a two octave band operation, but only moderate size reduction. A more compact conical antenna, capable of dual-band operation, can be implemented at the expense of little reduction of radiation efficiency and gain by introducing distributed capacitive loading, a grounding strip and a proper matching network. The design procedure of the isolated antenna was essentially based on an analytical method, while the radiation behavior of the device mounted over a car roof was analyzed using a full-wave numerical approach based on the method of moments.

A challenging task in array design is to synthesize an array working at multiple frequencies within a large frequency band, with constraints imposed to the radiation pattern in terms of side lobe level (SLL). This kind of array synthesis requires a multi-objective approach since there is no single solution which can be considered the best at the multiple investigated frequencies for all the compulsory requirements. Therefore this class of problems, instead of a single one, is characterized by an ideal set of solutions, the Pareto front (PF), which comprises solutions over which no other solution of the population dominates [1]. This set provides a range of solutions for which no one can simultaneously satisfy the required performance but represents a tradeoff of the design requirements. Multi-objective genetic algorithms (MOAs) can be a useful tool for determining the Pareto front. They perform similarly to conventional genetic algorithms but they search for the set of solution which belongs to the PF, rather than providing only a single optimal solution. In particular, we have adopted a multi-objective genetic algorithm, called Non-dominated Sorting Genetic Algorithm (NSGA-II) [2] to optimize the array factor of a Spiral Array.

This paper reviews advances in vehicle mounted antennas developed into a long term R&D program in collaboration between the ASK Industries Group and the Microwave and Antenna Laboratory (LAM) of the University of Florence. Today an ever-increasing number of radio services have become available, therefore multifunction, multiband antenna systems are required. Examples are made of recently developed wideband, multi-band and multi-function automotive passive and active antenna systems for roof and internal mounting, designed to satisfy various attendant features such as compactness, radiation efficiency, robustness, aesthetic and aerodynamic profile and a low mass-production cost, that after all represents the most stringent requirement.

A microwave sensor designed to determine the complex permittivity of planar materials is proposed. The sensor is implemented using a full planar microstrip technology. The near fields of the ring resonator interact with the material under test (MUT) and the electrical characteristics of the resonator change. A scalar network analyzer is used to measure the resonant frequency and the corresponding amplitude of the transmission parameter for the fundamental mode. The complex permittivity is estimated by inverting the measured parameters using by an algorithm based on Artificial Neural Network (ANN). The proposed sensor is extremely compact and guarantees a good accuracy for low permittivity material. The design procedure is described and experimental results are reported validating the sensor performance.

We present a new coaxial antenna for microwave interstitial coagulative therapy, working at 2450 MHz and endowed with a miniaturized sleeve choke in order to reduce back heating effects and make the system response less dependent on the antenna insertion depth into the tissue; the way the choke is implemented makes the overall transversal size minimum and allows small adjustments of the choke section length even during operation. We describe the main technical features of the antenna and show experimental results clearly proving the choke effectiveness. Numerical simulations well agree with experimental data, confirming the suitability of the proposed device for minimally invasive medical applications.