Fully Packaged Wideband Circularly Polarized
Antenna for 60GHz Application

 As a result of the large bandwidth available, the 60 GHz ISM band is very attractive for a number of applications, including wireless personal-area networks (WPAN), local-area networks (WLAN), high definition multimedia, etc. In addition, due to the atmospheric absorption peak around 60 GHz, communication link at this band is inherently secure and has less interference among users, which are ideal for indoor applications. Therefore, as an important front-end component, mmWave antennas that are wideband, efficient and packaged to be compatible with integrated circuits are highly desirable. Moreover, previous wireless channel propagation studies have shown that circular polarization can effectively suppress multi-path fading and inter-symbol interference (ISI).

 This patch antenna incorporates a diagonal slot at the center and features a superstrate-substrate structure and an air cavity backing to achieve desired performances including wide bandwidth, high efficiency and low axial ratio. It is fully compatible with flip-chip mounted monolithic integrated circuits. The demonstrated antenna achieved an impedance bandwidth greater than 26%, a 6-dB axial ratio bandwidth of 22.7% and efficiency above 90% for the entire frequency range.