IN Brief:
- FSWX-KM700 measures pulse timing, amplitude, shape, modulation, pulse trains, and differences between two measurement channels.
- The FSWX can analyse jammer input and output simultaneously using its dual-channel, phase coherent acquisition architecture.
- Triggering, long-capture statistics, and parameter trends are designed to expose intermittent errors in increasingly agile DRFM systems.
Rohde & Schwarz has added integrated pulse-analysis software to its FSWX signal and spectrum analyser, extending the instrument’s dual-channel, phase coherent architecture for radar and digital radio frequency memory testing. The FSWX-KM700 option measures jammer input and output signals in parallel, preserving the timing and phase relationship between the two channels inside one measurement environment.
Digital radio frequency memory, or DRFM, systems capture radar emissions, digitise them, and reproduce modified signals with controlled changes in delay, phase, and frequency. Verification therefore has to go beyond carrier frequency and output power. Pulse timing, envelope shape, modulation, repeatability, and the relationship between stimulus and response can all determine whether a generated signal behaves as intended.
FSWX-KM700 measures pulse width, amplitude, rise time, fall time, pulse repetition interval, duty cycle, shape, and overshoot. It also analyses complete pulse trains, extracting pulse repetition frequency spectra and pulse-to-pulse variation data. Supported waveform types include chirped pulses, pulse width modulation, pulse position modulation, and phase-modulated signals, allowing the same analysis environment to examine both pulse envelopes and modulation content.
Triggering can be based on amplitude, pulse width, pulse repetition interval, or user-defined patterns, making it possible to isolate selected events inside complex pulse sequences. Longer captures can aggregate measurements across many pulses to expose intermittent timing or modulation errors. Available displays include parameter trends, capture against time, pulse result and statistics tables, and magnitude, phase, and frequency against time, with channel delta information providing direct comparison between the input and output paths.
The measurement problem becomes harder as pulse widths shrink and modulation bandwidths increase. Trigger uncertainty, channel skew, analyser phase noise, and acquisition bandwidth can all obscure the behaviour being attributed to the device under test. Keeping the channels inside one phase coherent instrument simplifies part of that uncertainty budget because the two signal paths share a common acquisition architecture.
Simultaneous capture is important when the differences between two signals are themselves the measurement target. Separate acquisitions can introduce uncertainty if timing has to be reconstructed afterwards or if the device under test changes between captures. A phase coherent two-channel instrument retains the relative timing and phase information needed to analyse delay, modulation changes, and other behaviour introduced by the DRFM chain.
The option also extends a broader Rohde & Schwarz microwave test platform. The company recently extended its system amplification range to 53GHz, adding higher-frequency drive capability for radar, satellite, and telecoms test setups. FSWX-KM700 addresses the analysis end of the chain, concentrating pulse, pulse-train, modulation, and segmented-capture functions inside the signal analyser rather than requiring a separate pulse-analysis workflow.
Pulse-train statistics also help separate a one-off anomaly from systematic behaviour. A jammer may reproduce most pulses correctly but fail only at a particular repetition interval, modulation state, or transition between techniques. Trend displays and segmented captures give developers a way to correlate those failures over longer acquisitions without reducing the test to a single averaged result.
More agile radar waveforms make that integration increasingly useful. A DRFM system can reproduce a pulse correctly in one domain while introducing an unintended error in another, particularly when complex modulation and pulse-to-pulse changes are involved. Correlating envelope, timing, phase, frequency, and modulation behaviour makes it easier to isolate whether a deviation originated in capture, digital processing, conversion, or the output signal path.
The software approach also preserves the calibration and signal-path knowledge already associated with the FSWX hardware. Laboratories can keep the same front end and acquisition chain while adding a measurement application tailored to pulsed signals, reducing the number of separate instruments that have to be synchronised and maintained for one DRFM test setup.
Rohde & Schwarz will demonstrate the FSWX-KM700 at European Microwave Week 2026 at ExCeL London from 6 to 8 October. The new option is a software extension to an existing analyser rather than a separate instrument, allowing laboratories already using the FSWX platform to add dedicated pulse analysis without rebuilding the measurement chain around another acquisition system.
