Improving Fractional Bandwidth and Isolation Between Tx and Rx Antennas Using EBGs at X-band

In integrated sensing and communication (ISAC) applications, it is essential to have wide bandwidth and high isolation between transmitting (Tx) and receiving (Rx) antennas considering a full-duplex system. This paper demonstrates improved bandwidth and wideband isolation by employing sub-wavelength passive periodic structures, namely electromagnetic bandgap (EBG) structures at 10 GHz. The fabricated design exhibits a measured bandwidth of 1.89 GHz and a minimum isolation of around 42.4 dB at 0.5 λ<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> separation distance between antennas with the help of the EBG structures. The proposed method can be used as a wideband isolation solution for X-band applications maintaining a small package size. In addition to this, this technique doesn’t require active circuits and provides a cost-effective substitute for future 6G ISAC applications.