Metamaterial dual-band Bandpass filters using CRLH zero-order-resonators and improving its intermediate stopband

Conventionally, BPF (Bandpass filter)s have been used as a core component for an RF communication system and designed based upon the half-wavelength resonator which also plays a critically important role in developing resonant antennas. Though the half-wavelength resonators are common and sweeping in the BPF and antenna development, they are pointed out with shortcomings such as giving rise to the spurious resonance known as harmonics and limitation in practical size-reduction. To circumvent the drawbacks, the concept of the CRLH-type metamaterial structures has been brought up and adopted to make resonance-based components to meet the design challenges[1–5]. This paper presents the design of a dual-band(GSM and ISM) microstrip BPF that comprises stop-band-embedded ZORs and the size-reduction and two desired passbands.