| Popis: |
A composite right/left-hand microstrip leaky-wave antenna exhibits beam scanning from backward to forward end-fire directions and even through broadside as the frequency is swept over the left- and right- handed passbands. In this paper, we propose a novel leaky-wave antenna that possesses a pair of left/right-hand passbands and consequently has two frequencies where broadside radiation can be achieved. A generalized negative-refractive-index transmission-line (NRI-TL) unit cell suitable for this purpose was proposed in [1]. This design featured two left-handed bands and two right-handed bands; the conditions necessary for closing each of the two stopbands was also derived. The unit cell has been physically realized for a dual-band filter application using lumped elements [2], while a fully-printed unit cell has been reported in [3]; this latter work, however, did not achieve closure of either stopband and is thus unsuitable for the present dual-band leaky-wave application. To minimize both the cost and complexity of fabrication, fully-printed implementations are desirable. This paper therefore presents a fully-printed leaky-wave antenna based on the generalized NRI-TL which is capable of scanning from a backward to a forward direction and through broadside over two frequency bands. |
