Unequally Spaced and Excited Resonant Slotted-Waveguide Antenna Array Based on an Improved Resonant-Slot Coupled Cavity Chain Composite Right/Left-Handed Waveguide

This paper presents a new unequally spaced and excited resonant slotted-waveguide antenna array.It is realized by employing an improved resonant-slot coupled cavity chain composite right/lefthanded (CRLH) waveguide.As the CRLH waveguide works at the infinite wavelength frequency, all the slot elements along the waveguide wall are excited in-phase.Thus both the element spacings and excitation amplitudes are introduced into the synthesis to realize a resonant slotted-waveguide antenna array.A seven-element unequally spaced and excited antenna array which generates pencil beam is synthesized, simulated and fabricated.The results show, with comparison to the equally spaced but unequally excited resonant slotted-waveguide antenna array, the proposed unequally spaced and excited array produces a lower peak sidelobe level (PSLL).