Axial Ratio-Bandwidth Enhancement of a Compact L Band Circularly Polarized Antenna Using a Simple Diagonal Slot and Corner Truncation

This paper presents the AR-bandwidth enhancement using a simple diagonal slot and corner truncation. The proposed antenna uses a double-stacked substrates, proximity coupling technique as a feeding line and circular polarization. The length of the feedline is a lambda /4 mm. This CP antenna has a compact size of 53.4 mm x 53.4 mm. The slotted-truncated patch gives a wider AR-bandwidth compared to the conventional patch. The untruncated conventional patch still has a linear polarization (AR > 40 dB), AR-bandwidth has not been established. By applying the corner truncation, the results show that CP antenna yields impedance bandwidth (S11 < -10 dB) of 94.78 MHz and AR-bandwidth of 73.46 MHz. In addition, the VSWR less than two is achieved in range of 1.21 GHz to 1.28 GHz (74.3 MHz). For the radiation pattern, it also generates a high gain of 5.68 dBi at the main beam. This proposed CP antenna has good performance and meet the requirement for L band application.