1. Compact Wideband Bandpass Filter UsingStepped-Impedance Resonators and InterdigitalCoupling Structures EE 5601Akshay Soni Ashutosh Mehra

2. All same color holes (not black) are shorted together. All black holes are grounded.Wideband Bandpass Filter Next generation wireless communications need.l = 90 Strong couplingHigh Z TL Close spacing Low Z TL Fabrication difficulties Interdigital structure Strong coupling between stepped impedance resonators. Second passband is far away from the first passband. Provides a very compact structure. Folding provides additional size saving. We analyze the 4-pole Chebyshev Filter design Four stepped impedance resonators Each Interdigital coupled with others. Shorted All fingers shorts togetherto in bottom metalground layer Specifications Passband ripple of 0.05 dB Center frequency of 1.0102 GHz Fractional BW of 48% 3. All same color holes (not black) are shorted together. All black holes are grounded.Wideband Bandpass Filter Next generation wireless communications need. Strong coupling 14 Close spacing Fabrication difficulties Interdigital structure Strong coupling between stepped impedance resonators. Second passband is far away from the first passband. Provides a very compact structure. Folding provides additional size saving. We analyze the 4-pole Chebyshev Filter design2 Four stepped impedance resonators 3 Each Interdigital coupled with others. Specifications Passband ripple of 0.05 dB Center frequency of 1.0102 GHz Fractional BW of 48% 4. All same color holes (not black) are shorted together. All black holes are grounded.Wideband Bandpass Filter Next generation wireless communications need.Top Metal Layer View Strong coupling Close spacing Fabrication difficulties Interdigital structure Strong coupling between stepped impedance resonators. Second passband is far away from the first passband. Provides a very compact structure. Folding provides additional size saving. We analyze the 4-pole Chebyshev Filter design Four stepped impedance resonators Each Interdigital coupled with others. Specifications Passband ripple of 0.05 dB Center frequency of 1.0102 GHz Fractional BW of 48% 5. Issue of Multilayer and GroundingPublished Response The multi-layer structure is not well explained The grounding methodology is also not given We did a series of simulation, each going forover 30 hours. Simulation 1: Bottom layer forced groundOur IL = -20*log(mag(S21)) Result Eqn 30conductor2010dielectric 0 -10dB(S(2,1))dB(S(1,1)) -20 -30 75 No vias-40 50IL -50 No25 spurious -60passband0response0.61.1 1.4 -70responsefreq, GHz -80 0123 45 6 freq, GHz 6. Issue of Multilayer and Grounding Published Response The multi-layer structure is not well explained The grounding methodology is also not given We did a series of simulation, each going forEqn IL = -20*log(mag(S21)) over 30 hours. Simulation 2: With ground and manyOur Result grounding vias 0-10-20-30 dB(S(2,1)) dB(S(1,1))-4075-50 Ripples in50 IL-60 passband25 0 0.61.1 1.4Nice-70spurious freq, GHzground-8001 234 response 5 6 freq, GHz 7. Issue of Multilayer and Grounding Published Response The multi-layer structure is not well explained The grounding methodology is also not given We did a series of simulation, each going forover 30 hours. Simulation 3: With ground and lessgrounding vias Our Result Eqn IL = -20*log(mag(S21))0 -10 -20 -30dB(S(2,1))dB(S(1,1)) -4075 -5050 Bad passband IL25 -60 0 0.61.11.4 -70 freq, GHz -80 0 12 34 5 6 freq, GHz 8. 3 D Side view of the design 9. Thank You !!