Dual-Band Structure-Shared Antenna With Large Frequency Ratio Using HMSIW Cavity

A dual band structure-shared antenna with large frequency ratio and omnidirectional pattern is proposed in this work. It's realized by a shorted monopole with wide band in microwave (MW) frequency band and two standing wave antennas based on half-mode substrate integrated waveguide (HMSIW) cavity in millimeter-wave (MMW) frequency band. The shorted monopole is implemented by double layer coplanar waveguide structure (DLCPW) so that cavity modes can be transmitted. There is a shorted via at the end of monopole in order to broaden working band. For sake of improving isolation between two bands, HMSIW cavity is integrated around the shorted via of monopole. Two MMW standing wave antennas are designed along the open side of HMSIW cavity, which have omnidirectional radiation pattern and compact size. Measured results showed that isolation between two feed-ports is more than 40 dB. The structure-shared antenna operates between frequency range of 2.04-4.12 GHz (67.53%) and 27.2-28.1 GHz, locating at sub-6GHz and MMW band, respectively.