ABSTRACT This study proposes a millimeter‐wave capsule antenna for wireless capsule endoscopy (WCE). The study addresses challenges such as high attenuation of millimeter‐wave channels within the body, the difficulty of integrating high‐gain antennas due to space constraints within the capsule, and the susceptibility of antennas to detuning and frequency shifts within the capsule shell and the human tissue environment. This paper integrates a 1 × 2 Yagi array, a microstrip T‐junction power divider, and a Yagi radiating structure onto a single planar substrate to achieve both high gain and wideband characteristics while maintaining miniaturization. The capsule shell was fabricated via SLA, and encapsulation measurements were performed to verify the design's feasibility. The antenna's measurement results cover 36.13–40.1 GHz, with a peak gain of 7.25 dBi, consistent with simulation results. Furthermore, power density (PD) simulations were conducted using a human body model to evaluate the feasibility of in vivo applications. Evaluation results show that the proposed antenna, even in a trim, unbent capsule configuration, maintains a stable operating frequency band and a well‐defined directional beam around 38 GHz. Therefore, this research contributes to improving signal penetration and communication robustness within the human body, making it suitable for millimeter‐wave wireless transmission in capsule systems.
Chung et al. (Wed,) studied this question.