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Preface

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Spectre^® circuit simulator or Spectre^® Accelerated Parallel Simulator (Spectre APS) base products with the Spectre RF analysis option provide simulation capabilities for RFIC designers. The simulators:

• Support efficient calculation of the operating point, transfer function, noise, and signal distortion of common RF and communication circuits, such as mixers, LNA, oscillators, sample and holds, and switched capacitor filters.
• Support a multi-technology simulation (MTS) mode that enables the simulation of systems consisting of blocks designed with different processes, such as RF System-in-Package (SIP).

This user guide assumes that you are familiar with:

• RF circuit design
• SPICE simulation
• Virtuoso^® Analog Design Environment (ADE)

The Spectre^® circuit simulator, the high performance Spectre^® APS, and the Spectre RF analysis options are part of the MMSIM (multi-mode simulation) portfolio and are accessible using individual a la carte licenses or MMSIM tokens. Note that mixing of tokens and a la carte license is not allowed. Table A-1 and Table A-2 show the capabilities offered with the base products Spectre circuit simulator or Spectre APS and the Spectre RF analysis option.

Table 0-1 Spectre^® Simulator with Spectre RF Analysis Option

Features
Transient Noise Analysis
DC, small-signal analyses and transient
Monte Carlo, DC mismatch, Parametric sweep
RF Harmonic Balance
RF Shooting Newton
Large-signal Analysis - Periodic and Quasi-periodic (HB, PSS and QPSS)
Noise Analysis - Periodic and Quasi-periodic (pnoise, QPNoise, sampled, jitter)
Small-signal Analysis - Periodic and Quasi-periodic (PAC, PXF, PSP, QPAC, QPXF, QPSP)
Periodic Stability Analysis (PSTB)
RF Transmission Line Library
Envelope Analysis (AM, PM, FM, Autonomous)
Wireless Analysis
Wireless Standard Sources (such as LTE, Zigbee, and 802.11n)
Rapid Distortion Analyses - Perturbation-based IP2 and IP3
Co-simulation with Simulink® from The MathWorks
MMSIM Toolbox for MATLAB® from The MathWorks

Table 0-2 Spectre^® Accelerated Parallel Simulator with Spectre RF Analysis Option

Features
All analysis and features in Spectre
RF Harmonic Balance
RF Shooting Newton
Large-signal Analysis - Periodic and Quasi-periodic (HB, PSS and QPSS)
Noise Analysis - Periodic and Quasi-periodic (pnoise, QPNoise, sampled, jitter)
Small-signal Analysis - Periodic and Quasi-periodic (PAC, PXF, PSP, QPAC, QPXF, QPSP)
Periodic Stability Analysis (PSTB)
RF Transmission Line Library
Envelope Analysis (AM, PM, FM, Autonomous)
Wireless Analysis
Wireless Standard Sources (such as LTE, Zigbee, and 802.11n)
Rapid Distortion Analyses - Perturbation-based IP2 and IP3

Cadence offers multi-core simulation up to 64 cores for Spectre RF analysis, enabled with the base product Spectre APS along with Spectre RF analysis and the Spectre CPU Accelerator options.

Please contact your account representative for more details on the licensing and packaging.

Using License Queuing

You can turn on license queuing by using the lqtimeout command line option:

spectre +lqtimeout time_in_seconds

If a license is not available when you begin a simulation job, the Spectre circuit simulator and Spectre APS wait in queue for a license for the specified time. If you specify the value 0 for this option, the Spectre circuit simulator waits indefinitely for a license. The lqtimeout option ha s no default value for the standalone Spectre circuit simulator. If you invoke Spectre through the Analog Design Environment, the default value for lqtimeout is 900 seconds.

You can use the lqsleep option to specify the interval (in seconds) at which the Spectre circuit simulator should check for license availability. The default value for lqsleep is 30 seconds.

spectre +lqsleep interval

For more information on any of the above options, see spectre -h.

Suspending and Resuming Licenses

You can direct Spectre and Spectre APS to release licenses when suspending a simulation job. This feature is aimed for users of simulation farms, where the licenses in use by a group of lower priority jobs may be needed for a group of higher priority jobs. To enable this feature, simply start Spectre with the +lsuspend command line option. In the Solaris environment, press ctrl+z to suspend the Spectre license. All licenses are checked in. To resume simulation, press fg. These keystrokes may not work if you have changed the default key bindings.

For information on tracking token licensing, see the Virtuoso® Software Licensing and Configuration Guide.

In Virtuoso^® Analog Design Environment, the lqtimeout and lqsleep options are controlled by the following options:

spectre.envOpts lsuspend boolean t

spectre.envOpts licQueueTimeOut string "900"

spectre.envOpts licQueueSleep string "30"

Related Documents for Spectre

This user guide contains information about the functionality. The following documents provide more information about the Spectre RF analysis option with Spectre, Spectre APS, and related products.

• The Spectre circuit simulator is often run within the analog circuit design environment, under the Cadence design framework II. To see how the Spectre circuit simulator is run under the analog circuit design environment, read the Virtuoso Analog Design Environment User Guide.
• To learn more about specific parameters of components and analyses, consult the Spectre online help (spectre -h).
• To learn more about the equations used in the Spectre circuit simulator, consult the Spectre Circuit Simulator Components and Device Models Manual.
• The Spectre circuit simulator also includes a waveform display tool, Virtuoso Visualization and Analysis tool, to use to display simulation results. For more information about the tool, see the Virtuoso Visualization and Analysis User Guide.
• For more information about using the Spectre circuit simulator with Verilog-A, see the Verilog-A Language Reference manual.
• For more information about RF theory, see Spectre Circuit Simulator RF Analysis Theory.
• For more information about how you work with the design framework II interface, see Cadence Design Framework II Help.
• For more information about specific applications of Spectre analyses, see The Designer’s Guide to SPICE & Spectre1.

Third Party Tools

To view any .swf multimedia files, you need:

• Flash-enabled web browser, for example, Internet Explorer 5.0 or later, Netscape 6.0 or later, or Mozilla Firefox 1.6 or later. Alternatively, you can download Flash Player (version 6.0 or later) directly from the Adobe website.
• Speakers and a sound card installed on your computer for videos with audio.

Typographic and Syntax Conventions

This list describes the syntax conventions used for the Spectre circuit simulator.

literal	Nonitalic words indicate keywords that you must enter literally. These keywords represent command (function, routine) or option names, filenames and paths, and any other sort of type-in commands.
argument	Words in italics indicate user-defined arguments for which you must substitute a name or a value. (The characters before the underscore (_) in the word indicate the data types that this argument can take. Names are case sensitive.
|	Vertical bars (OR-bars) separate possible choices for a single argument. They take precedence over any other character.
[ ]	Brackets denote optional arguments. When used with OR-bars, they enclose a list of choices. You can choose one argument from the list.
{ }	Braces are used with OR-bars and enclose a list of choices. You must choose one argument from the list.
...	Three dots (...) indicate that you can repeat the previous argument. If you use them with brackets, you can specify zero or more arguments. If they are used without brackets, you must specify at least one argument, but you can specify more.

The language requires many characters not included in the preceding list. You must enter required characters exactly as shown.

Kundert, Kenneth S. The Designer’s Guide to SPICE & Spectre. Boston: Kluwer Academic Publishers, 1995.
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