Two common PDN measurement questions: Page 4 of 5

May 20, 2015 //By Steve Sandler
Two common PDN measurement questions Steve Sandler provides answers two common PDN measurement questions.
Example measurements

In order to verify the measurement, several 2512 size resistors are mounted to circuit boards along with SMA connectors (see Figure 4). The 1 calibration resistor is connected in this setup picture. Three low value resistors, selected from the same vendor, are used to verify the measurement calibration.


Figure 4: The VNA and DC blockers are shown connected to a 2512 size 1Ohm resistor. Similar resistance values of 1m, 2m and 5m are shown in the foreground.

The pre- and post- calibration sweeps along with the measurement sweeps for 1m, 2m, and 5m resistance values are shown in Figure 5.

Figure 5: VNA measurement sweeps prior to calibration, after calibration and for the three low value resistors.

The post-calibration sweep is flat a 1 confirming the THRU calibration was performed and applied. The low frequency resistance values are reported as 1.2m, 2.3m, and 5.6m, while the corresponding inductance values are 420pH, 500pH, and 660pH respectively.

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