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S-parameters from a RF Circuit - Circulator created from LC resonators

EduardoGS

Hello everyone.

I am trying to simulate, for my undergraduate thesis, a new RF circulator that was published by Nature Physics on article called "Magnetic-free non-reciprocity and isolation based on parametrically modulated coupled-resonator loops".

My doubt is how to create a setup that understands one RF signal (sweep from 140MHz to 200Mhz) modulated by a signal with fixed frequency (15Mhz) and that has phase 120º  difference between each one. After this, my goal is to plot S parameters and see the transmission from  port 1 to ports 2 and 3. My curent setup use QPSS and QPSP, but the results are not good.

I have the article and I can send to you to read and understand better the problem if you wish.

Best regards.

Parents

  • I was simulated again with your specifications. The results were the same, but the time of simulation was reduced.

    Here the input.scs:

    // Generated for: spectre
    // Generated on: Sep 26 22:40:41 2016
    // Design library name: TCC2
    // Design cell name: circulador_1_TB
    // Design view name: schematic
    simulator lang=spectre
    global 0
    parameters Fm=15.00000M Vm=600m C1=300p Cc=5.6p Cdcb=10u L1=270n L2=27n \
        Lc=1u Lrfc=2.7u Vdc=1.99 Frf=170M
    include "/usr/local/IC614/tsmc13/tsmc13rf/../models/tsmc13rf.scs"
    include "/home/eslam/TCC2/diode.scs"

    // Library name: TCC2
    // Cell name: varactor_SMV1237
    // View name: schematic
    subckt varactor_SMV1237 P_anode P_cathode
        D0 (net010 P_cathode) Diode_Model area=1
        R0 (net07 net010) resistor r=130.00m
        C0 (net07 P_cathode) capacitor c=9p
        L0 (P_anode net07) inductor l=1.7n
    ends varactor_SMV1237
    // End of subcircuit definition.

    // Library name: TCC2
    // Cell name: circulador_1
    // View name: schematic
    subckt circulador_1 Porta1 Porta2 Porta3 Porta4 Porta5 Porta6
        L14 (net30 Porta6) inductor l=Lrfc
        L13 (net33 0) inductor l=L1
        L12 (net27 Porta3) inductor l=Lc
        L11 (net27 net32) inductor l=L2
        L10 (net36 net27) inductor l=L2
        L9 (net24 Porta5) inductor l=Lrfc
        L8 (net34 0) inductor l=L1
        L7 (net21 Porta2) inductor l=Lc
        L6 (net21 net35) inductor l=L2
        L5 (net38 net21) inductor l=L2
        L4 (net18 Porta4) inductor l=Lrfc
        L3 (net15 Porta1) inductor l=Lc
        L2 (net31 net15) inductor l=L2
        L1 (net15 net39) inductor l=L2
        L0 (net37 0) inductor l=L1
        C11 (net30 net31) capacitor c=C1
        C10 (net30 net33) capacitor c=Cdcb
        C9 (net32 net30) capacitor c=C1
        C8 (net27 Porta3) capacitor c=Cc
        C7 (net24 net36) capacitor c=C1
        C6 (net24 net34) capacitor c=Cdcb
        C5 (net35 net24) capacitor c=C1
        C4 (net21 Porta2) capacitor c=Cc
        C3 (net15 Porta1) capacitor c=Cc
        C2 (net18 net37) capacitor c=Cdcb
        C1 (net18 net38) capacitor c=C1
        C0 (net39 net18) capacitor c=C1
        I7 (0 net30) varactor_SMV1237
        I4 (0 net24) varactor_SMV1237
        I0 (0 net18) varactor_SMV1237
    ends circulador_1
    // End of subcircuit definition.

    // Library name: TCC2
    // Cell name: circulador_1_TB
    // View name: schematic
    I4 (RF1 RF2 RF3 Vbias Vbias Vbias) circulador_1
    V0 (Vbias 0) vsource dc=Vdc type=dc
    PORT2 (RF3 0) port r=50 type=sine freq=Fm ampl=Vm sinephase=120 \
            fundname="Modulation"
    PORT0 (RF1 0) port r=50 type=sine freq=Fm ampl=Vm sinephase=0 freq2=Frf \
            dbm2=-101 sinephase2=0 fundname="Modulation" fundname2="RF"
    PORT1 (RF2 0) port r=50 type=sine freq=Fm ampl=Vm sinephase=-120 \
            fundname="Modulation"
    simulatorOptions options reltol=1e-3 vabstol=1e-6 iabstol=1e-12 temp=27 \
        tnom=27 scalem=1.0 scale=1.0 gmin=1e-12 rforce=1 maxnotes=5 maxwarns=5 \
        digits=5 cols=80 pivrel=1e-3 sensfile="../psf/sens.output" \
        checklimitdest=psf
    qpss  qpss  flexbalance=yes  oversample=[1  1]  funds=["Modulation"
    +     "RF"]  maxharms=[3  3]  errpreset=conservative  annotate=status
    qpsp  qpsp  sweeptype=absolute  start=140M  stop=200M
    +     portharmsvec=[0  0  0  0  0  0]  ports=[PORT0  PORT1  PORT2]
    +     donoise=no  annotate=status
    modelParameter info what=models where=rawfile
    element info what=inst where=rawfile
    outputParameter info what=output where=rawfile
    designParamVals info what=parameters where=rawfile
    primitives info what=primitives where=rawfile
    subckts info what=subckts  where=rawfile
    saveOptions options save=allpub

    Here is the result graphic with S11, S21 and S31:

    This result shows that circulator is not working as it should. The signal inserted on port 1 is returning on all range frequency and the port 2 is not receiving the signal (less than -10dB on all frequency range). Also the port 3 is receiving almost the same signal that port 2.

    Regards,

    Eduardo.

Reply

  • I was simulated again with your specifications. The results were the same, but the time of simulation was reduced.

    Here the input.scs:

    // Generated for: spectre
    // Generated on: Sep 26 22:40:41 2016
    // Design library name: TCC2
    // Design cell name: circulador_1_TB
    // Design view name: schematic
    simulator lang=spectre
    global 0
    parameters Fm=15.00000M Vm=600m C1=300p Cc=5.6p Cdcb=10u L1=270n L2=27n \
        Lc=1u Lrfc=2.7u Vdc=1.99 Frf=170M
    include "/usr/local/IC614/tsmc13/tsmc13rf/../models/tsmc13rf.scs"
    include "/home/eslam/TCC2/diode.scs"

    // Library name: TCC2
    // Cell name: varactor_SMV1237
    // View name: schematic
    subckt varactor_SMV1237 P_anode P_cathode
        D0 (net010 P_cathode) Diode_Model area=1
        R0 (net07 net010) resistor r=130.00m
        C0 (net07 P_cathode) capacitor c=9p
        L0 (P_anode net07) inductor l=1.7n
    ends varactor_SMV1237
    // End of subcircuit definition.

    // Library name: TCC2
    // Cell name: circulador_1
    // View name: schematic
    subckt circulador_1 Porta1 Porta2 Porta3 Porta4 Porta5 Porta6
        L14 (net30 Porta6) inductor l=Lrfc
        L13 (net33 0) inductor l=L1
        L12 (net27 Porta3) inductor l=Lc
        L11 (net27 net32) inductor l=L2
        L10 (net36 net27) inductor l=L2
        L9 (net24 Porta5) inductor l=Lrfc
        L8 (net34 0) inductor l=L1
        L7 (net21 Porta2) inductor l=Lc
        L6 (net21 net35) inductor l=L2
        L5 (net38 net21) inductor l=L2
        L4 (net18 Porta4) inductor l=Lrfc
        L3 (net15 Porta1) inductor l=Lc
        L2 (net31 net15) inductor l=L2
        L1 (net15 net39) inductor l=L2
        L0 (net37 0) inductor l=L1
        C11 (net30 net31) capacitor c=C1
        C10 (net30 net33) capacitor c=Cdcb
        C9 (net32 net30) capacitor c=C1
        C8 (net27 Porta3) capacitor c=Cc
        C7 (net24 net36) capacitor c=C1
        C6 (net24 net34) capacitor c=Cdcb
        C5 (net35 net24) capacitor c=C1
        C4 (net21 Porta2) capacitor c=Cc
        C3 (net15 Porta1) capacitor c=Cc
        C2 (net18 net37) capacitor c=Cdcb
        C1 (net18 net38) capacitor c=C1
        C0 (net39 net18) capacitor c=C1
        I7 (0 net30) varactor_SMV1237
        I4 (0 net24) varactor_SMV1237
        I0 (0 net18) varactor_SMV1237
    ends circulador_1
    // End of subcircuit definition.

    // Library name: TCC2
    // Cell name: circulador_1_TB
    // View name: schematic
    I4 (RF1 RF2 RF3 Vbias Vbias Vbias) circulador_1
    V0 (Vbias 0) vsource dc=Vdc type=dc
    PORT2 (RF3 0) port r=50 type=sine freq=Fm ampl=Vm sinephase=120 \
            fundname="Modulation"
    PORT0 (RF1 0) port r=50 type=sine freq=Fm ampl=Vm sinephase=0 freq2=Frf \
            dbm2=-101 sinephase2=0 fundname="Modulation" fundname2="RF"
    PORT1 (RF2 0) port r=50 type=sine freq=Fm ampl=Vm sinephase=-120 \
            fundname="Modulation"
    simulatorOptions options reltol=1e-3 vabstol=1e-6 iabstol=1e-12 temp=27 \
        tnom=27 scalem=1.0 scale=1.0 gmin=1e-12 rforce=1 maxnotes=5 maxwarns=5 \
        digits=5 cols=80 pivrel=1e-3 sensfile="../psf/sens.output" \
        checklimitdest=psf
    qpss  qpss  flexbalance=yes  oversample=[1  1]  funds=["Modulation"
    +     "RF"]  maxharms=[3  3]  errpreset=conservative  annotate=status
    qpsp  qpsp  sweeptype=absolute  start=140M  stop=200M
    +     portharmsvec=[0  0  0  0  0  0]  ports=[PORT0  PORT1  PORT2]
    +     donoise=no  annotate=status
    modelParameter info what=models where=rawfile
    element info what=inst where=rawfile
    outputParameter info what=output where=rawfile
    designParamVals info what=parameters where=rawfile
    primitives info what=primitives where=rawfile
    subckts info what=subckts  where=rawfile
    saveOptions options save=allpub

    Here is the result graphic with S11, S21 and S31:

    This result shows that circulator is not working as it should. The signal inserted on port 1 is returning on all range frequency and the port 2 is not receiving the signal (less than -10dB on all frequency range). Also the port 3 is receiving almost the same signal that port 2.

    Regards,

    Eduardo.

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