Improved slow-wave active transmitting antenna with photonic band-gap and defected ground structure

This paper presents an improved active transmitting antenna. Defected ground structures (DGSs) are used to eliminate the higher mode radiation. Slow-wave propagation is realized by adopting DGS and photonic band-gap (PBG) structure, and consequently, size reduction is achieved. Suppression of the excited surface-waves of the patch antenna is realized by using an array of rectangular PBGs. Higher mode reduction is realized by using DGS. Measurement results are presented and discussed.