Compact circularly polarised microstrip antenna with bent slots

By embedding a group of four bent slots in a corner-truncated square microstrip patch, a single-feed compact circularly polarised microstrip antenna can easily be obtained. Results show that for a given circular polarisation (CP) operation, the proposed antenna can have an antenna size reduction of more than 50% as compared to the conventional CP design using a corner-truncated square patch without the slots. Moreover, the 50Ω feed position and truncated-corner size for achieving CP operation are found to be nearly independent of the bent slots introduced in the patch, which makes the proposed antenna easy to implement