Dual-Fed Hollow Dielectric Antenna for Dual-Frequency Operation With Large Frequency Ratio

A new dual-fed dual-frequency antenna that integrates a microwave hollow dielectric resonator antenna (DRA) with a high-gain millimeter-wave dielectric Fabry-Perot resonator antenna (FPRA) is investigated. To obtain the dual-frequency operation, the dielectric and air regions of the hollow DRA are designed to satisfy the resonance condition of the FPRA. The DRA and FPRA are excited by a strip and a WR-34 waveguide, respectively. For demonstration, a prototype that covers both 2.4- and 24-GHz ISM bands was fabricated and tested. The S-parameters, radiation pattern, antenna gain, and antenna efficiency are studied, and reasonable agreement between the measured and simulated results is found.