Multi-mode CPW-fed dielectric resonator antenna array for high-gain THz wireless and ultra-sensitive sensing applications

Abstract This research presents a coplanar waveguide (CPW)-coupled single cylindrical dielectric resonator antenna (SCDRA) and extends the study to a four-element linear array circular dielectric resonator antenna (LACDRA) to enhance performance at terahertz (THz) frequencies. The design is optimized to operate around 4 THz, with additional resonances observed at 5 THz, 6 THz, and higher frequencies. A comprehensive parametric analysis is conducted to examine the influence of substrate thickness on resonant frequency and impedance matching. The standalone DRA exhibits multimode excitation, including HEM11, TM110, and TE111 modes, which contributes to wider operational bandwidth and stable gain performance. The radiation characteristics of the SCDRA reveal peak gains of 6.16 dB, 7.04 dB, and 8.31 dB at 4 THz, 5 THz, and 6 THz, respectively. To further enhance gain and directivity, a four-element LACDRA is proposed. This configuration achieves a maximum gain of 10.88 dB at 4.5 THz, along with improved polarization purity and reduced cross-polarization losses. The results demonstrate that CPW-fed DRAs offer a compact, efficient, and broadband solution, making them highly suitable for THz wireless communication, imaging systems, and biosensing applications.