Enhanced Radiation in a Millimeter-Wave Circularly Polarized On-Chip Bowtie Antenna Using a Low-Cost PCB Package

This paper presents a circularly polarized on-chip antenna (OCA) operating in the D-band for a fully integrated bidirectional transceiver in TSMC 40 nm bulk CMOS process. Circular polarization is achieved by arranging two pairs of antennas in an orthogonal configuration. The target design at 145 GHz features a compact hybrid structure that integrates a bowtie antenna with a PCB package. This configuration not only shields the antenna from environmental interference but also improves its radiation efficiency. The proposed OCA demonstrates a simulated gain of −1.4 dBi and a radiation efficiency of 32% at 145 GHz, along with a compact footprint of 0.4 × 0.4 mm2. To further enhance radiation efficiency and gain, the antenna elements are integrated into chip arrays. The OCA design presented in this work addresses key objectives in system design, including compactness, cost-effectiveness, and compatibility with existing technologies.