About ACP Multiband Measurements
Adjacent Channel Power (ACP Adjacent Channel Power: The power from a modulated communications channel that leaks into an adjacent channel. This leakage is usually specified as a ratio to the power in the main channel, but is sometimes an absolute power.) supports multiple spectrum bands as provided in the Power Spectrum Measurement. The typical customer use case is to measure ACP scenarios where a single carrier is less than the hardware's maximum IF bandwidth, but the total of all carriers and offsets extends beyond the hardware's maximum IF bandwidth.
See Making Power Spectrum Measurements for more information.
Selecting a Multiband Mode
Single Spectrum is the default, most intuitive behavior. A single acquisition is used to capture all data required by the measurement to cover the time and frequency region implied by aggregate carrier and offset configuration.
Spectrum Channel per Region allows ACP measurements where a single acquisition cannot make the measurement (a NO DATA indicator will be displayed with a reason indicating the problem). Choosing a distinct spectrum index per region allows the span constraint to be applied to the associated spectrum region rather than the aggregate requirements of all regions. Spectrum Channel per Region may be faster or provide better dynamic range if the offset and carrier regions include large gaps in frequency or have very different power levels.
ACP Multiband-Related Parameters
The following ACP parameters are used to configure the spectrum index per region for multiband (Spectrum Channel per Region) measurements:
Other Useful Parameters
Range - (Input > Analog > Range) Supports offsets and carriers that are widely spaced in frequency and power level.
Adjusting the Range setting implies attenuator changes during each measurement scan for some hardware, so care should be taken to minimize use of continuous measurement sweeps for this scenario to avoid undesired wear.
Extensions - (Input > Extensions) Instrument-specific Input Extension properties per spectrum region.
ResBW/Detectors - A subset of properties from the ResBW and Detectors panels (e.g., to enable different Points per spectrum region).
See Also
