Characterization of horn antenna loaded with CLL unit cell

In this paper, a pyramidal horn antenna loaded with unit cell of metamaterial is proposed, designed and realized for L‐band that including terrestrial digital audio broadcasting T‐DAB, GPS, and GSM. The proposed antenna operates in the frequency range from 1.722 to 1.931 GHz. The metamaterial is fabricated on a printed circuit board as Capacitive Loaded Loop (CLL). The work aims to exhibit the advantage of metamaterial loaded inside the horn antenna in terms of the gain enhancement of the radiation pattern and the resonant frequency shift toward lower frequency. The retrieval technique used show that the constitutive parameters of the unit cell as CLL have a zero index metamaterial (ZIM) from 1.34 to 1.49 GHz and a near zero index of refraction from 1.495 GHz to 2 GHz, which is within the operating frequency of the horn antenna. The achieved results show that the total gain is improved over the frequency range. The simulation and the measurement are in good agreement.