Concept Proposal of Rear Feed Log-Periodic Film Antenna Using Microstrip Lines

This paper presents a film antenna based on a log-periodic antenna, which has a wideband performance and unidirectional radiation. The proposed antenna is designed to operate from 0.7 to 6 GHz to cover 4G, 5G, and Wi-Fi bands. Generally, log-periodic antennas are fed from the tip of the antenna, and this is inconvenient for practical applications. The proposed antenna is fed from the rear of the antenna using microstrip lines printed on a polyethylene terephthalate (PET) film. The performance of the proposed antenna is examined by electromagnetic simulation. Antenna gains of 4 to 6 dB are obtained in a wide bandwidth from 0.7 to 6 GHz. The proposed antenna is cost effective and suitable for passive repeaters and Internet of Things (IoT) devices.