Isolation enhancement in a compact 2.4 GHz antenna pair for radar systems

In this paper, a compact antenna pair with a measured isolation of about -51 dB between the antenna pairs after fabrication is reported. Two ground plane slots of quarter wavelength at the design frequency, sharing a common ground plane, are used as a transmit-receive antenna pair. An isolation unit with both ground plane and microstrip plane structures is used to improve the isolation. The structure is compact and doesn’t require any lumped components or complex geometry to realize the isolation unit. The antenna pair radiates in the broadside direction (along the y-axis), and the top plane with the microstrip line can subsequently be used to integrate the radar circuit, facilitating a compact and fully functional transceiver design.