There are a number of measurement applications where large amounts of data (often measured as fast as possible) at a single frequency/power level are needed. These applications usually involve collecting the data as some state of the DUT is changing (angle of an antenna in a range, state of a phase array module, bias state of a device, etc.) and that state can be changed fairly rapidly by an (often) external controller. As one might expect, synchronizing this DUT state with the data stream can be an important topic. Option 46 provides two separate Fast CW types that differ in terms of acquisition rates and how the data is output and processed:
Standard Fast CW
• This uses the standard MS464XX IF system which allows maximum acquisition rates of ~200,000 measurements/sec (and as slow as 1 measurement/sec). This mode is only available remotely to maximize speed and the display does not update in this mode.
• There are two main sub-modes: real-time streaming over the remote interface with unlimited data collection capabilities, and a buffered collection with a maximum buffer size of ~60 million measurements for a single S-parameter. (Buffer size is limited by system memory.)
Advanced Fast CW (Requires Option 35)
• This uses the high speed digitizer option to reach maximum acquisition rates of 100 million measurements/sec (adjustable to as slow as <4 million samples/sec). This mode is always buffered and is accessible from both the user interface and remotely.
• Raw data exporting is available as is pre-processing over variable measurement widths and time ranges.
• The maximum buffer size is 50 million measurements in each of four receiver channels (200 million measurements total) without the memory addition of Option 36 and 200 million measurements per receiver (800 million measurements total) with Option 36.
This chapter will discuss how these modes (and their various sub-modes work) along with some applications information.