Stretchable Helical Antenna With an Inverted-F Feeding Structure for Man Overboard Devices

This letter proposes a design of a stretchable helical antenna with an inverted-F feeding structure to enhance the impedance matching characteristics and to reduce the size for maritime rescue man overboard (MOB) devices. The proposed antenna consists of a conical-shaped helical body, an inverted-F structure with metal posts and bolts, and a perforated printed circuit board (PCB). To enhance the durability, the metal posts and bolts are employed to tightly fix the helical radiator and the inverted-F feeding structure to the PCB. To verify the proposed antenna, an outdoor propagation test is performed on the MOB device. The results confirm that the proposed antenna with an inverted-F feeding structure is suitable for wireless communications in maritime rescue.