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

Andrew,

Sorry about the article. I read the "right and permissions" and I discovered that is illegal. Therefore, I removed from my dropbox.

About the simulation, my goal is: see the power to flow from port 1 to 2 or port 2 to 3 or port 3 to 1, but not in the reverse direction. Beyond that the results need to show the non-reciprocity, e.g., S11 = -20dB, S31 = -20dB and S21 = 0 dB when the frequency is 170MHz (with BW = 10Mhz), the RF signal is inserted at port 1 and Vdc=1.99V.

The varactor (SMV1237 - the same used on article) was made following the spice model. ( Follow the link: www.skyworksinc.com/.../Varactor_SPICE_Model_AN_200315C.pdf ). I made the simulations for to validate this model and my results are compatible with the one showed on spice model and with the description on article (C = 30pF when Vdc = 3V). The Diode_Model represents the diode used on varactor model designed. The "diode.scs" (represents Diode_Model) and "input_varactor.scs" (from varactor's testbench) were added on dropbox.

The figures on the folder contains the results of two situations. First one represents the case when no modulation signal was inserted. The article results shows that S21 are equal to S31 in that case described above. This means that without signal modulation this device behaves as power divider and not as a circulator. The second situation represents the case with the signal modulation and on this case, the device behaves as a circulator. The article reports that Vm = 0.6V (modulation signal voltage) and has no information about the RF signal. It also reports that Vdc = 1.99V (DC voltage inserted on ports 4 to 6 on the device). The Vdc is a frequency adjust. This means that if Vdc >= 1.73V and Vdc =< 4.50V the resonance zone is from 160Mhz to 210MHz. When Vdc=1.99 the device resonance zone is 170MHz.

On article besides the simulation it is contains the experimental setup. In this case, the signals RF and Modulation are generated by VNA (RF from 140MHz to 200Mhz) and Waveform generator (for 15MHz signal). The modulation signal is passes through a Power Divider and then by a Phase Shifter (because the three modulation signals need to have 120º on phase each other) and finally by a Diplexer. The low-pass ports of three diplexers receives the Modulation signals and the high-pass ports receives the VNA. Then the output of diplexer is connected at ports 1 to 3 of device.

I will change the setup with your specification as soon as possible and reports here.

Best regards,
Eduardo.

Andrew,

Sorry about the article. I read the "right and permissions" and I discovered that is illegal. Therefore, I removed from my dropbox.

About the simulation, my goal is: see the power to flow from port 1 to 2 or port 2 to 3 or port 3 to 1, but not in the reverse direction. Beyond that the results need to show the non-reciprocity, e.g., S11 = -20dB, S31 = -20dB and S21 = 0 dB when the frequency is 170MHz (with BW = 10Mhz), the RF signal is inserted at port 1 and Vdc=1.99V.

The varactor (SMV1237 - the same used on article) was made following the spice model. ( Follow the link: www.skyworksinc.com/.../Varactor_SPICE_Model_AN_200315C.pdf ). I made the simulations for to validate this model and my results are compatible with the one showed on spice model and with the description on article (C = 30pF when Vdc = 3V). The Diode_Model represents the diode used on varactor model designed. The "diode.scs" (represents Diode_Model) and "input_varactor.scs" (from varactor's testbench) were added on dropbox.

The figures on the folder contains the results of two situations. First one represents the case when no modulation signal was inserted. The article results shows that S21 are equal to S31 in that case described above. This means that without signal modulation this device behaves as power divider and not as a circulator. The second situation represents the case with the signal modulation and on this case, the device behaves as a circulator. The article reports that Vm = 0.6V (modulation signal voltage) and has no information about the RF signal. It also reports that Vdc = 1.99V (DC voltage inserted on ports 4 to 6 on the device). The Vdc is a frequency adjust. This means that if Vdc >= 1.73V and Vdc =< 4.50V the resonance zone is from 160Mhz to 210MHz. When Vdc=1.99 the device resonance zone is 170MHz.

On article besides the simulation it is contains the experimental setup. In this case, the signals RF and Modulation are generated by VNA (RF from 140MHz to 200Mhz) and Waveform generator (for 15MHz signal). The modulation signal is passes through a Power Divider and then by a Phase Shifter (because the three modulation signals need to have 120º on phase each other) and finally by a Diplexer. The low-pass ports of three diplexers receives the Modulation signals and the high-pass ports receives the VNA. Then the output of diplexer is connected at ports 1 to 3 of device.

I will change the setup with your specification as soon as possible and reports here.

Best regards,
Eduardo.