AD8302 phase detector for plasma power measurements of the RF-driven COST plasma jetAn easy-to-implement technique for measuring the dissipated plasma power of RF-excited plasmas at a frequency of 13.56 MHz is presented in this work. Specifically, the AD8302 phase detection board is used to measure the phase difference between voltage and current signals of the COST reference plasma jet. The system was characterised and power measurements were successfully carried out. Power curves of the COST-jet operated in pure helium and helium with 0.1 % of oxygen were well reproduced using the phase detection board. The current measurements were not disturbed by the addition of the circuit board and the ignition process as well as mode transition of the plasma are remarkably apparent in the phase measurements of the phase detection board. This work provides the basis for how the AD8302 phase detection board can be used for power measurements of RF-excited plasmas and what requires careful attention. This work is of particular interest for research groups, that would like to work with RF-driven plasmas, like the COST-jet, but are not able to perform power measurements involving fast and expensive oscilloscopes. However, the dissipated plasma power is the most important parameter when comparing different plasma sources or even comparing results produced by the same plasma but operated under different conditions. The measurement technique using the AD8302 phase detection board is easy to implement, requires no expensive oscilloscopes, and can be carried out in almost any laboratory that uses RF-driven plasma jets. Nevertheless, this method is only suitable for symmetrical waveforms and may lead to errors in the case of asymmetrical voltage and current waveforms. Care is required here, and proper calibration and a preliminary check of the waveforms must be carried out.

]]>AD8302 phase detectorCOST jetplasma diagnosticspower measurements5723328f-50f5-43dd-9a82-ab56539fc6a82026-04-24T08:26:51+02:002026-08-10T17:50:57+02:00EP2, PIPfigure 2 (a) calibration curves same cable lengthsCalibration curves of the phase detection board (three boards were tested) of two synchronised sinusoidal waveforms. (a) Same cable lengths for inputs A and B of the phase detection board.

]]>2026-08-10T17:37:31+02:002026-08-10T17:51:27+02:00text/plaintxt909https://rdpcidat.rub.de/dataset/ad8302-phase-detector-plasma-power-measurements-rf-driven-cost-plasma-jet/resource/244d5cfffigure 2 (b) calibration curves different cable lengthCalibration curves of the phase detection board (three boards were tested) of two synchronised sinusoidal waveforms. (b) Different cable lengths for inputs A (30 cm) and B (200 cm). Dashed lines are linear fits and dotted line shows the calibration curve of chip #2 with same cable length for comparison.

]]>2026-08-10T17:39:05+02:002026-08-10T17:51:27+02:00text/plaintxt1706https://rdpcidat.rub.de/dataset/ad8302-phase-detector-plasma-power-measurements-rf-driven-cost-plasma-jet/resource/9325a12ffigure 3 (a) power curves HePower curves of the COST-jet measured by the classical power detection and the AD8302 power detection (three boards were tested). Plasma was operated in (a) pure He and (b) He with 0.1 % O2 admixture. The shaded areas indicate an uncertainty range of 10 %.

]]>2026-08-10T17:40:56+02:002026-08-10T17:51:27+02:00text/plaintxt1661https://rdpcidat.rub.de/dataset/ad8302-phase-detector-plasma-power-measurements-rf-driven-cost-plasma-jet/resource/b421b1fcfigure 3 (b) power curves He+O2Power curves of the COST-jet measured by the classical power detection and the AD8302 power detection (three boards were tested). Plasma was operated in (a) pure He and (b) He with 0.1 % O2 admixture. The shaded areas indicate an uncertainty range of 10 %.

]]>2026-08-10T17:41:33+02:002026-08-10T17:51:27+02:00text/plaintxt1547https://rdpcidat.rub.de/dataset/ad8302-phase-detector-plasma-power-measurements-rf-driven-cost-plasma-jet/resource/311f409bfigure 4 (a) current curves HeCurrent as a function of applied voltage of the COST-jet measured by the classical power detection and the AD8302 power detection (three boards were
tested). Plasma was operated in (a) pure He and (b) He with 0.1 % O2 admixture. The shaded areas indicate an uncertainty range of 10 %.

]]>2026-08-10T17:42:10+02:002026-08-10T17:51:27+02:00text/plaintxt1742https://rdpcidat.rub.de/dataset/ad8302-phase-detector-plasma-power-measurements-rf-driven-cost-plasma-jet/resource/27548004figure 4 (b) current cuves He+O2Current as a function of applied voltage of the COST-jet measured by the classical power detection and the AD8302 power detection (three boards were
tested). Plasma was operated in (a) pure He and (b) He with 0.1 % O2 admixture. The shaded areas indicate an uncertainty range of 10 %.

]]>2026-08-10T17:42:35+02:002026-08-10T17:51:27+02:00text/plaintxt1525https://rdpcidat.rub.de/dataset/ad8302-phase-detector-plasma-power-measurements-rf-driven-cost-plasma-jet/resource/3165204dfigure 5 (a) phase shift curves HePhase shift as a function of applied voltage of the COST-jet measured by the classical power detection and the AD8302 power detection (three boards were tested). Plasma was operated in (a) pure He and (b) He with 0.1 % O2 admixture. Please note that the absolute values of the phase shift were obtained after calibration of the phase detection board and correcting for the induced artificial phase shift from the different cable length. More details are given in the experimental setup and calibration of the AD8302 board.

]]>2026-08-10T17:43:20+02:002026-08-10T17:51:27+02:00text/plaintxt2728https://rdpcidat.rub.de/dataset/ad8302-phase-detector-plasma-power-measurements-rf-driven-cost-plasma-jet/resource/5224e6c9figure 5 (b) phase shift curves He+O2Phase shift as a function of applied voltage of the COST-jet measured by the classical power detection and the AD8302 power detection (three boards were tested). Plasma was operated in (a) pure He and (b) He with 0.1 % O2 admixture. Please note that the absolute values of the phase shift were obtained after calibration of the phase detection board and correcting for the induced artificial phase shift from the different cable length. More details are given in the experimental setup and calibration of the AD8302 board.

]]>2026-08-10T17:43:50+02:002026-08-10T17:51:27+02:00text/plaintxt2479https://rdpcidat.rub.de/dataset/ad8302-phase-detector-plasma-power-measurements-rf-driven-cost-plasma-jet/resource/f9b54e12figures SI 1 (a)Output voltage of the phase detection board as a function of ffrequency of the input signals. Phase shifts of 0° and 90° were tested.

]]>2026-08-10T17:44:51+02:002026-08-10T17:51:27+02:00text/plaintxt573https://rdpcidat.rub.de/dataset/ad8302-phase-detector-plasma-power-measurements-rf-driven-cost-plasma-jet/resource/1e8bfabbfigures SI 1 (b)Output voltage of the phase detection board as a function of varying ratio in amplitude of iput signals A and B. Phase shifts of 0° and 90° were tested.

]]>2026-08-10T17:45:25+02:002026-08-10T17:51:27+02:00text/plaintxt537https://rdpcidat.rub.de/dataset/ad8302-phase-detector-plasma-power-measurements-rf-driven-cost-plasma-jet/resource/72dd5c58figure SI 2Detailed calibration curve in the range of ±15◦ phase shift shown by output voltage as a function of phase shift between the input signals A and B. The phase detection boards were tested.

]]>2026-08-10T17:45:49+02:002026-08-10T17:51:30+02:00text/plaintxt4201https://rdpcidat.rub.de/dataset/ad8302-phase-detector-plasma-power-measurements-rf-driven-cost-plasma-jet/resource/3868d1bcfigures SI 3Determination of the reference phase shift of the system measured by three phase detection boards. No feed gas was applied and the applied voltage was varied.

]]>2026-08-10T17:46:43+02:002026-08-10T17:51:30+02:00text/plaintxt2417https://rdpcidat.rub.de/dataset/ad8302-phase-detector-plasma-power-measurements-rf-driven-cost-plasma-jet/resource/0eba9d82DKANhttps://rdpcidat.rub.de