A wideband cup dielectric resonator antenna (CDRA) with a monopole-like mode is presented. A new coil feeding structure is used, creating an equivalent magnetic current loop above the ground plane, exciting the CDRA $\textrm {TM}_{01 \delta } $ mode and an equivalent electric dipole at the adjacent frequency band. Thus, a broad bandwidth is achieved from two adjacent resonances. A CDRA with $0.25\lambda _{0} $ diameter and $0.23\lambda _{0} $ height ( $\lambda _{0} $ is the center frequency free-space wavelength) is fabricated and measured. About 29% of −10 dB matching bandwidth (2.98–4.00 GHz) is achieved. The structure has a low cross-polarization level and stable radiation patterns within the entire operating bandwidth.

A broadband dual-polarized cup dielectric resonator antenna (CDRA) with stable omnidirectional radiation patterns is presented in this correspondence. Both omnidirectional horizontally polarized (HP) and vertically polarized (VP) radiation patterns can be attained by exciting electric-dipole/TM _01δ mode, TE _011+δ mode using a coil feeding structure and a planar feeding network, respectively. The coil feeding structure motivates the CDRA's mode and another equivalent electric dipole at nearby frequency to the CDRA mode to extend the bandwidth. A broadband TE _011+δ mode is excited by the planar feeding network using a double-tuned method. The CDRA is 0.48 λ ₀ ×0.18 λ ₀ (λ is the free-space wavelength at the center frequency). A prototype is fabricated and measured, achieving an HP bandwidth of 14.5% and a VP bandwidth of 29.8%. The overlapping bandwidth is 14.5% (3.26-3.77 GHz). The proposed antenna can be used in various wireless communications.

Part II investigates phase modulation as a low-complexity alternative to conventional phase shifters in pattern-reconfigurable antenna arrays. In the proposed architecture, phase formation originates from the direct reconfiguration of the driven radiation current and the induced parasitic current within each radiating element. This is achieved through a dual-phase control mechanism that independently tunes the intrinsic and deflection phases using separately biased PIN diodes integrated into the feeding branches and parasitic comb structures. The resulting discrete phase states provide a phase tuning range of up to 116° and enable subarray-level beamforming without continuous element-wise phase synthesis. Based on this concept, a 6-element discretized subarray is developed as the fundamental beamforming unit, offering three fixed beam states with simplified bias control. By adopting subarray-level beam-state selection, an 8×24 sparse dual-polarized array is constructed, enabling wide-angle two-dimensional scanning (±60° azimuth, ±10° elevation) while significantly reducing the number of RF chains. Despite the reduced channel count, the proposed architecture maintains comparable channel capacity, as validated through simulations and measurements, demonstrating its practicality for large-scale base station antenna arrays.

Dense direct-current (DC) bias routing and numerous radio-frequency (RF) choke inductors pose major challenges to the practical implementation of phase-shifter-free beam steering using PIN-controlled phase switching. To address this issue, a compact vertical DC biasing network is proposed, in which most DC bias lines are routed beneath the ground plane. The DC signals are fed to the PIN diodes through vertical bias lines passing through metallized vias in the dielectric substrate. This arrangement reduces routing congestion and simplifies array-level bias integration. The number of required RF choke inductors is decreased from 112 to 22 per dual-polarized element while preserving the required beam-steering functionality. For experimental validation, a 1 × 3 prototype operating at 3.5 GHz is fabricated and measured. The measured beam directions of −14°, 0°, and +14° agree well with simulations, confirming that the proposed bias network provides the phase control required for beam steering. The proposed network, therefore, offers a compact, low-complexity, and practical solution for scalable phase-shifter-free beam-steering systems.

A unified reconfigurable array architecture is proposed, supporting two-phase modulation mechanisms: element rotation and initial phase modulation. Both approaches enable subarray-level beam steering without needing phase shifters or complex feeding networks, facilitating large-scale array beam scanning with fewer radio frequency channels. An innovative beamforming method is introduced in Part I, leveraging element rotation within an N_s-element (6-element) linear subarray. Vertical partition scanning within ±θ_max (±10°) is achieved by presetting the tilt angles of the elements in the N_s-element subarray (6-element). A longer linear array of N_y-elements formed by M_s-subarrays is formed (N_y=M_s×N_s). A high-profile N_x×N_y array (8×24) of Yagi elements achieves two-dimensional beam scanning at 4.5 GHz with a grating lobe suppression algorithm. To generalize this approach, a theoretical framework is established that incorporates concepts such as phase smoothing region, deflection phase, intrinsic phase, and initial phase modulation, ultimately extending the rotation-based method into a universal initial phase control scheme. Simulation and measurement results confirm that replacing conventional small-ratio power dividers with 1-to-N_s equal-dividers preserves low sidelobe levels in vertical scanning, maintains original horizontal scanning performance, and achieves channel capacity parity with full-channel systems. Part II will further validate the approach by designing and implementing a dual-polarized base station antenna element with electronically tunable initial phase control.