Experimental Realization of Tunable Transmission Lines Based on Single-Layer SIWs Loaded by Embedded SRRs
journal contributionposted on 26.04.2016, 00:00 by Farhad Farzami, Majid Norooziarab
Wave propagation in single layer substrate integrated waveguides (SIWs) loaded by embedded split-ring resonators (ESRRs) is discussed theoretically and experimentally. It is shown that the loaded SIW can support a backward-wave passband below the cutoff frequency (fc) of the host SIW or a stopband will appear above fc if the effective transversal permeability is negative. In addition, varactor-loaded ESSRs (VLESRRs) can show resonance frequency agility through a variable reverse bias voltage applied to the varactors. Next, VLESRRs are loaded in SIWs to realize transmission lines with either tunable passbands (stopbands) below (above) fc of the host SIWs. Both cases are considered in this paper. First, an SIW with fc=7 GHz is loaded by five VLESRRs showing a tunable passband below the cutoff from 1.5 to 4 GHz. Second, an SIW with fc=1.9 GHz and five VLESRRs is discussed where a tunable stopband is achieved above fc from 2 to 4 GHz. In both cases, the reverse-bias voltage applied to the varactors varies from 0 to 20 V. Finally, two fabricated prototypes are provided for each case to validate the analysis. The measured and simulated results are in good agreement.
rectangular waveguidesresonatorssubstrate integrated waveguidestransmission linesvaractorsSIWbackward-wave passbandfrequency 1.5 GHz to 4 GHzfrequency 7 GHzsingle layer substrate integrated waveguidestunable passbandstunable stopbandstunable transmission linesvaractor-loaded embedded split-ring resonatorsvoltage 0 V to 20 Vwave propagationCapacitanceMagnetic momentsPassbandPermeabilityPermittivityPropagationResonant frequencyBackward-wave passbandnarrow stopband or rejection band (notch)substrate integrated waveguide (SIW)tunable transmission line (TL)varactor-loaded embedded split-ring resonator (VLESRR)