Measurement of group delay for a device under test (DUT). A test signal includes (i) a low frequency sine wave f.sub.LF, (ii) sine wave harmonics at a high frequency f.sub.HF, (iii) L pairs of sideband components at frequencies k.Math.f.sub.HF2.Math.f.sub.LF, where k odd, and M pairs of sideband components at frequencies k.Math.f.sub.HFf.sub.LF, where k is even. At DUT output, (i) phase .sub.LF at frequency f.sub.LF is measured, (ii) both sideband phase .sub.right(k) at frequencies k.Math.f.sub.HF+2.Math.f.sub.LF and phase .sub.left(k) at frequencies k.Math.f.sub.HF2.Math.f.sub.LF for odd k, are measured, and (iii) both sideband phases .sub.right(k) at frequencies k.Math.f.sub.HF+f.sub.LF and .sub.left(k) at frequencies k.Math.f.sub.HFf.sub.LF for even k, are measured. Group delay .sub.k at frequencies k.Math.F.sub.HF, are determined from: .sub.k=(.sub.right(k).sub.left(k)4.Math..sub.L)/(4.Math.f.sub.LF) for k odd, and .sub.k=(.sub.right(k).sub.left(k)2.Math..sub.L)/(2.Math.f.sub.LF) for k even.

Embodiments of the present invention provide techniques and methods for improving signal-to-noise ratio (SNR) when averaging two or more data signals by finding a group delay between the signals and using it to calculate an averaged result. In one embodiment, a direct average of the signals is computed and phases are found for the direct average and each of the data signals. Phase differences are found between each signal and the direct average. The phase differences are then used to compensate the signals. Averaging the compensated signals provides a more accurate result than conventional averaging techniques. The disclosed techniques can be used for improving instrument accuracy while minimizing effects such as higher-frequency attenuation. For example, in one embodiment, the disclosed techniques may enable a real-time oscilloscope to take more accurate S parameter measurements.

Embodiments of the present invention provide techniques and methods for improving signal-to-noise ratio (SNR) when averaging two or more data signals by finding a group delay between the signals and using it to calculate an averaged result. In one embodiment, a direct average of the signals is computed and phases are found for the direct average and each of the data signals. Phase differences are found between each signal and the direct average. The phase differences are then used to compensate the signals. Averaging the compensated signals provides a more accurate result than conventional averaging techniques. The disclosed techniques can be used for improving instrument accuracy while minimizing effects such as higher-frequency attenuation. For example, in one embodiment, the disclosed techniques may enable a real-time oscilloscope to take more accurate S parameter measurements.

A semiconductor device including power TSVs for stably supplying a power source is described. A semiconductor device includes a chip power pad placed in a first region of a chip, power through silicon vias (TSVs) connected to the chip power pad and placed in the second region of each of the chips, and metal lines configured to couple the chip power pad and the power TSVs.