Hybrid Antenna Using Open-Ended Slot for Integrated 4G/5G Mobile Application

This letter exploits a dual feature of rectangular open-ended ground slot to design an integrated 4G/5G antenna for mobile devices. In the proposed configuration, the antenna footprint of the 4G module is used for the installation of a 5G antenna module. While the entire rectangular slot is structured to operate at 800 MHz and 2 GHz, an array of 4-element Vivaldi antenna operating at 28 GHz is added within the slot space. This array provides end-fire radiation with 11 dBi peak realized gain. To validate the design concept, a prototype is fabricated on a RO-5880 substrate with an overall size of 150 × 75 × 0.51 mm3. The results show that the design covers two low frequency bands (from 770 to 810 MHz and from 1.9 to 2.6GHz) with less than -6dB reflection coefficient and a wideband millimeter-wave frequency range (from 26 to 32 GHz) with less than -7 dB reflection coefficient. A multiple-input-multiple-output (MIMO) configuration of the antenna is also realized with diversity performances verified.