Compact dual-frequency antenna for 2.4/60 GHz applications

A compact dual-frequency antenna with two-port excitation and large frequency ratio is presented. It consists of a circularly-polarized (CP) microstrip patch antenna at 2.4 GHz and a linearly-polarized (LP) substrate-integrated cylindrical dielectric resonator antenna (DRA) at 60 GHz, resulting in a large frequency ratio of as high as 25. The two antenna parts are designed on a single substrate, giving a very compact structure. Slot-coupled source and probes are used to excite the upper-band DRA and the lower-band patch antenna, respectively. ANSYS HFSS was used to simulate the S-parameters, radiation patterns, antenna gains, and axial ratio (AR) (patch antenna part only) of the two antenna parts. The lower-band patch antenna has an impedance bandwidth of 17.3% and AR bandwidth of 15.3%, whereas the upper-band has an impedance bandwidth of 13.15%.