power divider, resulting in a 16-patch array antenna with a gain of 18.71 dBi, which was designed as a drone's rectenna [12]. Furthermore, a \(16\times 16\) transmitting array antenna operating in CP at 5.74 GHz formed a flat-top-beam, and a \(4\times 4\) receiving microstrip patch array was formed into a single rectenna for the drone [13]. In the MPT systems, integrating UAV trajectory with directional antenna orientation optimization has emerged as a significant innovation. This approach considerably enhances energy harvesting in UAV-enabled networks and mitigates long-distance radio frequency (RF) signal loss, thus significantly improving wireless power transfer (WPT) efficiency. The innovative mobile wireless-powered communication network (WPCN), employing an optimal transmission policy and a two-layer algorithm, represents a foundational step in this direction [14]. In [15; 16], a substantial enhancement in the efficiency of WPT was elucidated through the synergistic optimization of UAV flight trajectories and the orientation of directional antennas. This optimization not only augments energy harvesting capabilities within UAV-integrated networks but also effectively addresses the critical issue of long-distance radio frequency (RF) signal attenuation. The essence of minimizing misalignment losses between the transmitter and receiver lies in these advancements. The advent of beam steering (or tilting) antennas represents a critical solution to these losses, with the technology being adaptable through both mechanical and electronic implementations. Mechanical beam steering requires physical adjustment of the antenna, necessitating a complex installation framework that consequently increases the UAV's payload and power demands. On the other hand, electronic beam steering techniques, which modify the main beam's direction by altering the phase of each antenna element or subarray, offer a more streamlined and low-profile solution. This electronic modulation is facilitated by digital phase shifters [17], varactor diodes [18], and double-pole double-throw (DPDT) switches [19], enabling rapid and efficient adjustments that are crucial for active beam steering. However, implementing such antennas, especially receive antennas with high array circuitry, may increase the overall system cost and require additional power for the operation of the phase shifter, which could negatively affect the UAV's limited battery life. Electronically passive beam steering, in contrast, is less expensive, offers a lower profile, and has a simpler design than its active counterpart, eliminating the need for additional electronics. In [20], the main lobe is steered from 60\({}^{\circ}\) to 90\({}^{\circ}\) without additional electronics, using a parallel feeding network to minimize sidelobe levels. The design in [21] features index-modulated tilted-beam microstrip antennas with a 50\({}^{\circ}\) tilt and a 33.8% bandwidth enhancement. In [22], a symmetrically 45\({}^{\circ}\) dual-polarized rectenna array is introduced for wide-coverage MPT, incorporating differentially-feeding networks to achieve low insertion loss. A beam tilted at a 37\({}^{\circ}\) angle using phase adjustments in the transmission line is reported in [23], facilitating passive beam tilting while maintaining a low profile. Additionally, the series-fed antenna can implement electrically passive fixed-beam tilting while maintaining a low profile. [24] describes a series-fed microstrip array antenna with a 30-degree tilt, merging the radiation patterns of a patch and two monopoles. In [25], a broadband fixed-beam leaky-wave antenna (LWA) achieves stable beam angles of 0\({}^{\circ}\), 25\({}^{\circ}\), and \(-\)25\({}^{\circ}\) with gains up to 15.7 dBi over a 43% bandwidth. In [26], a series-fed dual-port array antenna is presented, achieving up to 44.6% efficiency and output power across a 90\({}^{\circ}\) angle range.