Timeline for How can I know the phase shift or phase delay of the SMA connector and RF port?
Current License: CC BY-SA 3.0
17 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Feb 11, 2015 at 8:26 | vote | accept | billyzhao | ||
| Feb 11, 2015 at 6:10 | comment | added | The Photon | If there's 30 cm of fiber optic cable between the modulator and analog circuit, that's even slower. The velocity factor of optical fiber is about 0.67. | |
| Feb 11, 2015 at 6:09 | comment | added | The Photon | 30 cm / (c * 0.85). 0.85 is a typical velocity factor for coaxial cable. It could vary from 0.65 to 0.9 though, so check your cable specs if you care about the difference. | |
| Feb 11, 2015 at 6:08 | comment | added | billyzhao | @ThePhoton: Yes. It is optical signal | |
| Feb 11, 2015 at 6:08 | comment | added | billyzhao | @ThePhoton: could you tell me how to calculate the 1.2ns? Thank you! | |
| Feb 11, 2015 at 6:07 | comment | added | The Photon | So the connection between the modulator and the analog circuit is an optical signal? | |
| Feb 11, 2015 at 6:06 | comment | added | billyzhao | @ThePhoton: the modulator is mach-zehnder modulator. Do you know it? I have learned that the modulator would not have problem in phase effect. Is it right? | |
| Feb 11, 2015 at 6:06 | comment | added | The Photon | Around 1.2 ns. So still practically nothing at 20 kHz. People who work in rf consider 20 kHz "practically DC". | |
| Feb 11, 2015 at 6:03 | comment | added | billyzhao | @ThePhoton: how serious would the phase effect caused by the cable be? | |
| Feb 11, 2015 at 6:01 | history | edited | billyzhao | CC BY-SA 3.0 | added 266 characters in body |
| Feb 11, 2015 at 6:01 | comment | added | The Photon | Also the modulator also probably has more phase effect than a single connector (doesn't it have connectors itself?) so if you're neglecting its delay, you really shouldn't worry about this connector. | |
| Feb 11, 2015 at 5:59 | comment | added | The Photon | The 30 cm cable has a much bigger phase effect than the sma connector. | |
| Feb 11, 2015 at 5:56 | comment | added | billyzhao | @ThePhoton：the SMA connector is part of the PCB board,and the board includes the MCU and the analogue circuit. About the cable, I don`t know what kind of it and I know less about the cable. It is about 30cm long. | |
| Feb 11, 2015 at 5:15 | comment | added | The Photon | Is the SMA connector part of the modulator or part of the MCU? What cables are connected between the MCU, the connector, and the modulator? | |
| Feb 11, 2015 at 5:12 | answer | added | The Photon | timeline score: 4 | |
| Feb 11, 2015 at 5:07 | answer | added | FullmetalEngineer | timeline score: 1 | |
| Feb 11, 2015 at 4:22 | history | asked | billyzhao | CC BY-SA 3.0 |