This paper proposes a 38 GHz multi-beam wide bandwidth antenna based on the substrate integrated waveguide (SIW) Butler matrix. The proposed Butler matrix removes the 0° phase shifter and only consists of −90° hybrid coupler, crossover, and −45° phase shifter. A 4 × 4 Butler matrix is combined with a patch antenna to form a multibeam-wide bandwidth antenna that can switch beam angle. The antenna is integrated based on the SIW structure to produce ideal beam directions of −45, 15, −14, and 44°, and has low side lobe characteristics, allowing the antenna to maintain good transmission quality. The antenna can cover 33–42 GHz from the simulation and measurement results, with an effective bandwidth of about 24%. The antenna is easily fabricated on a single-layer planar substrate and is cost-effective. In addition, the antenna complies with human body radiation standards and will be widely competitive in the millimeter-wave in the future.

This paper presents a multibeam dielectric rod antenna for mm-wave wireless power transfer (WPT) applications. The proposed solution utilizes its unique multibeam setup which allows the generation of adjustable beams simultaneously, without the need for an additional beamforming network. To enhance the compactness of the system, each Rexolite rod is fed through an annular slot etched on a Rogers RO4003. The generated beams are steered toward the desired directions by adjustment in the configuration of these rods. The final configuration consists of five rods that were fabricated and measured. In this configuration, a beam coverage between $-30^{\circ}$ and 30∘ can be obtained, while in the frequency of interest, a gain value above $12\,\mathrm{dBi}$ is achieved. With its adjustable configuration, the proposed solution can be adapted to different operating scenarios. Moreover, the low cost and flexibility of the solution make it a promising candidate for Radio Frequency Wireless Power Transfer (RF-WPT) Internet of things applications.

This paper presents a low-profile six-beam antenna implemented by a compact two-layer 6 × 6 beamforming network (BFN) and a 6 × 2 slot antenna in substrate integrated waveguide (SIW) technology. The main components of the proposed 6 × 6 BFN are 3 × 3 multi-aperture couplers, interlayer hybrid couplers, and several phase shifters which are embedded on two microwave substrates. The proposed antenna has been designed, simulated, and fabricated for the frequency range of 28–32 GHz. The size of this antenna is 82 × 31.8 × 0.787 mm3, which can be a suitable choice for 5G applications due to its compact dimensions compared to similar works. Prototype testing shows that the proposed structure presents a stable beamforming performance both in simulation and measurement with good agreement. The antenna generates six radiation beams in directions ±9°, ±30°, and ±54° with good return losses and isolations.