Mixed-Mode

Spectral Dynamics’ Mixed-Mode is a true closed-loop controlled test in every respect. Tones, bands and the broadband base are each controlled to the specified shapes and tolerances.A multi-dimensional least squares approach is used in which Amplitude and Phase of Sine Tones are accommodated and true digital Tracking Filters are invoked as eeded during Sine sweeps or dwells.


Mixed-Mode Principal Features:

  • Independent definition of Broadband, Narrowband and Sine Tones.
  • Up to 50 controlled Narrowband or Sine Tone components.
  • Each Sine Tone can be defined with its own Profile of up to 40 breakpoints.
  • True Gaussian random signal generation for Broadband Random and Narrowbands. True, continuous Sine sweeps;not FFT-based steps.
  • Tones and Bands may sweep in the same or opposite directions and even cross each other during the sweeps. If a harmonic set of Tones is defined as stationary, the Tone drives remain in-Phase during a Mixed-Mode test.
  • Tones and Bands may have their sweeps stopped or reversed, individually, during a test and have their test levels lowered or shut off and then reestablished through operator control.
  • Automatic Test Scheduling of up to 100 Mixed-Mode test setups can be performed.
  • Test results may be displayed in real-time and/or stored to disk for all active channels.
  • Unique to JAGUAR, Mixed-Mode avoids the traditional problem of “hole” creation in the broadband random, sometimes referred to as a “traveling notch. ” By virtue of its ability to know in advance when and where the tones and/or narrow bands were to be located, Mixed-Mode modifies the reference at that unique location to allow the introduction of the new energy. Similarly, when the energy moves to a different location in the spectrum, the reference is instantly restored. In this way the “hole” never materializes.


Mixed-Mode is a Signature software package from Spectral Dynamics which provides great flexibility and on-line control of a wide variety of complex test scenarios.

Whether performing tests on automotive assemblies or recreating profiles from MIL-STD 810-F, JAGUAR Mixed-Mode provides the features, displays, real-time control and data results that are traditionally associated with Spectral Dynamics.

There are some vibration responses encountered in wheeled or tracked vehicles, helicopters and fixed-wing aircraft, airborne missiles and rapid- fire guns that almost defy description. These can create vibration levels of such a destructive nature that they must be very carefully simulated, or correlation to real-world events will be impossible and repeatability only a myth. These simulations often require a vibration combination which includes a broadband Random background, stationary or moving narrow bands of Random with sweeping or fixed Sine tones all mixed together. If sensitive electronics, such as Command/Control transceivers are subjected to these environments, it is crucial that a correct and repeatable control strategy be employed lest uncontrolled drive levels cause unwarranted damage to product and personnel.

The patented techniques employed by Spectral Dynamics assure that every element of the test is fully controlled and displayed. No open-loop summations here. Dynamic Signal Processing with true, digital Tracking Filters invoked where necessary creates an incredibly accurate simulation with real-time displays. And, individual Tones and Bands may be turned on and off or reversed in sweep direction during the live test.