A dual mode log-periodic cavity-backed slot array

The log-periodic cavity-backed slot array (LPCBSA) is a wideband antenna that exhibits several attractive characteristics: (i) its planar structure allows it to be flush mounted on a vehicle and (ii) it is relatively easy to feed the antenna through integration with a planar circuit. This paper proposes a dual mode LPCBSA (DM-LPCBSA) which constitutes a variation on the LPCBSA that enables monopulse direction finding while maintaining the above advantages of the LPCBSA. The basic idea underlying the DM-LPCBSA is similar to that for the dual mode log-periodic dipole array: two LPCBSAs are combined together into a superstructure that can operate in sum and difference modes. This DM-LPCBSA antenna is highly suitable for wideband target identification purposes.