Four-mode frequency reconfigurable antenna for 28 GHZ and 38 GHZ communication

This paper presents a four-mode frequency reconfigurable antenna design for 5G communication systems. The patch antenna approach has been chosen in the design steps and the proposed antenna contains two adjacent patches for corresponding operating frequencies. PIN diodes were located in the feeding line of each patch element to control the on or off state. There are four modes, which are OFF/OFF, OFF/ON, ON/OFF, and ON/ON modes, that correspond to no resonance, resonance at 38 GHz with −25 dB, resonance at 28 GHz with −16 dB and resonance at around 35.3 GHz with −22 dB, respectively. This approach paves the way for controlling the resonance point of an antenna element for 5G applications with high accuracy. The proposed antenna structure was fabricated and experimentally measured in a microwave laboratory to show the feasibility of the proposed idea, and the obtained experimental results are in good agreement with the numerical results.