Compact Wideband Log Spiral Antenna with Circular Slots for S-Band Applications

In this paper, a compact log spiral antenna with slots on the spiral arm is designed to achieve wideband bandwidth and compact structure. These circular slots are also providing better impedance matching in terms of lower return loss. The introduction of slots increased the gain of the antenna. The proposed antenna has achieved a fractional bandwidth of 43.83 % over the S-band frequency range from 2.68 to 4 GHz. The radiation pattern is bidirectional along broadside direction. The gain of proposed antenna varies from 2.2 to 3.4 dBi over the S-band frequency range.