This article presents the design and implementation of a high-gain tunable dual-band pattern reconfigurable antenna for vehicular communications. The proposed antenna consists of a slotted patch loaded with a double-side FSS acting as superstrate. The proposed slotted antenna operates at 2.45 and 3.5 GHz and the frequency tuning over the dual-band is accomplished by employing a varactor diode for tuning the center frequency from 2.41 to 2.62 GHz and from 3.38 to 3.65 GHz at lower and upper frequency bands, respectively. To obtain pattern reconfiguration, the slotted patch is divided into four regions by using two diagonal lines of vias. By properly choosing the excitation port combinations, 14 different radiation patterns are realized with a maximum realized gain of 8.4 and 7.9 dB. Further enhancement of gain is achieved using frequency-selective surface (FSS) screens which act as a partially reflecting surface. The unique feature of this design is to provide reflection coefficient with high reflectivity in two predetermined frequency ranges. The prototype antenna is fabricated and the measurement results are reported. The experimental results show that the prototype antenna with FSS offers tunable dualband with beam reconfigurable properties. K E Y W O R D Sfrequency-selective surface, multipattern antenna, pattern reconfiguration

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This article presents the design, fabrication, and testing of a broadband directional slot antenna and its application in a vehicular environment. The proposed antenna consists of a slot antenna fed by a simple microstrip line. Broadband impedance matching is achieved by replacing the conventional microstrip line with a modified microstrip line. The modified microstrip line consists of a microstrip line terminated with an impedance transformer and a square patch. The proposed antenna offers 76.9% bandwidth centered around 4.8 GHz covering most of the communication applications between 3 and 6.75 GHz. Furthermore, the antenna's radiation pattern is shaped to obtain the desired directional characteristics using a simple reflector and array of via holes. The typical gain enhancement is 2.45 dBi at 5 GHz. This gain enhanced slot antenna is further used to construct the four‐element MIMO antenna. The proposed MIMO antenna configuration offers omnidirectional coverage with realized antenna gain greater than 6 dBi making the antenna more suitable for the vehicular environment. The prototype antenna and the MIMO array are fabricated and measurement results are presented. The measurement results are in good agreement with the simulation results.

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