A broadband antenna can transmit and receive radio signals across a broad frequency spectrum. The use of broadband millimeter-wave (mmWave) band antennas has garnered significant interest in wireless communication research. As a result, this type of antenna finds applications in television, radio broadcasting, and radar communication. The millimeterwave broadband antenna covers an extensive range of frequencies, leading to distinct design methodologies for such structures. The primary focus of this manuscript is to present a comprehensive overview of the recent developments in millimeter-wave antenna design, encompassing an in-depth analysis of the working principles of broadband antennas and their associated design characteristics. This review aims to shed light on the challenging path for antenna researchers and the potential enhancements achievable through broadband antenna technologies. Various applications, including enhanced wireless communication, high-definition and ultra-high-definition multimedia, and security signal intelligence, necessitate high data rates and significantly greater bandwidth. Consequently, a substantial demand for millimeter-wave broadband antennas can cater to these requirements.