Band Power Type (Markers)

Band Power Type parameter specifies whether to calculate the average power or average power density for the points within the band-power marker's boundaries.

Power - the VSA computes the average power
Density - the VSA computes the average power density using the same calculation as when Type is set to Power, except that the calculated band power is normalized by the width of the band.

For frequency-domain traces, the width of the band is specified by the left and right edges of the band-power marker. For time-domain traces, the entire measurement span is used as the width of the band.

The calculated band power is shown in the Markers Window, as well as in the marker readout above the trace grid when the band-power marker is the active marker.

For best accuracy with time-domain traces with sinusoidal, baseband waveforms, the width of the band power markers should be an integral number of cycles. For baseband analysis (the data is real, not complex), accuracy is degraded if an integral number of cycles is not used.

Band Power and Code Domain Data

For Code-domain trace data, band power is the sum of the power within the band power markers.

Band Power and OFDM Data

For some OFDM Orthogonal Frequency Division Multiplexing: OFDM employs multiple overlapping radio frequency carriers, each operating at a carefully chosen frequency that is Orthogonal to the others, to produce a transmission scheme that supports higher bit rates due to parallel channel operation. OFDM is an alternative tranmission scheme to DSSS and FHSS. data, band power is calculated from 2D average line, which is the average of all Z-axis points for each X-axis point in the trace. The applicable OFDM trace data include OFDM Error Vector Spectrum, OFDM Error Vector Time, OFDM IQ Meas, and OFDM IQ Ref trace data.

To match the trace data marker readout computation type when calculating band power, select Rms from the Calculate drop-down list.

Band Power and Units

Band power units can be %, dB, dBm deciBels referenced to a milliWatt: dB relative to 1 milliwatt dissipated in the nominal input impedance of the analyzer, dB/Hz, dB-Hz, Vrms, Vrms^2, watts, %rms, or %rms^2 depending on the current Trace Format, Band Power Type, and Band Power Calculation. The units may be preceded by "m" (milli), "u" (micro), or "n" (nano).