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Question asked by JERRY_MARKETOS on Jul 26, 2005
Latest reply on Jul 26, 2005 by JERRY_MARKETOS
This information is intended to explain the difference between the HARBEC harmonic balance
nonlinear analysis engine and the SPECTRASYS spectral domain simulation engine.

[ Please note !!  If you have any questions about HARBEC, SPECTRASYS, or any other
parts of the GENESYS and SYSTEMVUE suite of products,  feel free to contact
us.  The array of product offerings has become substantial and we understand
sometimes the first question is "where do I start ?".  One nice thing with GENESYS is
that it all works together, and we can help you to make the right decisions. ]

The decision is not an "either-or" choice between HARBEC and SPECTRASYS,
because the two modules provide different functions in their analysis; HARBEC is useful
at the component and network level to perform a variety of nonlinear analyses, while
SPECTRASYS works at a higher level to make spectral domain analyses of systems
consisting of component and network blocks.


Harbec is a component level nonlinear analysis program.  It is used to characterize the nonlinear
performance of devices such as transistors, diodes, etc.  The device need not be alone for HARBEC
analysis.  For example, HARBEC is easily capable of analyzing an amplifier circuit consisting of a
transistor with associated bias components, inductors, capacitors, etc.  or networks consisting of
multiples of these (darlington, cascode etc.)  Additionally, HARBEC can analyze a circuit containing
any component for which there exists a valid nonlinear model.  GENESYS provides many generic
nonlinear models which can be tailored (user enters data) to characterize a specific device.  More
nonlinear models are also becoming available from device manufacturers, as they endeavor to make
it easier for engineers to integrate their components into new designs.

Harbec can apply multiple input tones, and its output results can be used to determine quantities
such as compression point, and second, third, fourth etc. order products.
(The highest order analyzed by HARBEC is user specifiable).

HARBEC is also the analysis engine within GENESYS that performs DC calculations
(node Voltages, currents, etc.)

HARBEC can also display waveforms in the time domain to observe clipping phenomena, etc.

HARBEC is not capable of performing system level analyses, or computing values for system level diagrams.


SPECTRASYS is a spectrum based system level analysis engine.  Information used to define performance
of the system blocks in SPECTRASYS is the type of information that comes out from HARBEC, or can be
(For example, device parameters such as compression point, gain, distortion information, noise information etc.)

SPECTRASYS can apply a broad spectrum of input signals to a given system, and then propagates the spectrum
from the input point to all other nodes.  SPECTRASYS can analyze systems with "loops" in the RF path, and
analyzes signals in both directions (out and back).  SPECTRASYS produces level diagrams, and has the ability to
"decompose" signal spurs;  that is, SPECTRASYS remembers and can be commanded to divulge all the contributing
components of a chosen signal spur;  it identifies where the signal energy originated in the system !

SPECTRASYS alone can not analyze a discrete amplifier (ie. made from discrete components) -
HARBEC is needed to do this.  SPECTRASYS presently does not show time domain responses (HARBEC does).

The common ground between SPECTRASYS and HARBEC is that both are capable of generating spectral plots;
HARBEC at the component level, and SPECTRASYS at the system level.

Although both analysis engines have many applications, it can be said that HARBEC is used for analysis and
development of component level circuits (amplifiers, detectors, mixers, etc.) while SPECTRASYS is used for
analysis of system level blocks, although it is acceptable for those system level blocks to contain discrete components.