NEW EDA TOOLS TO ACCELERATE RF AND WIRELESS DESIGN CYCLES
Continued demand for wireless services has resulted in the need for large spectrum and new compression techniques to enhance capacity without sacrificing quality. Second-generation (2G), 2.5G and 3G digital wireless systems are being developed throughout the world to replace and supplement older systems.
Two new electronic design automation (EDA) products, GoldenGate/Sim; and GoldenGate/NN-Model Compiler, have been introduced that dramatically accelerate design cycles for RF and wireless communication designs. The tools are targeted to designers developing products for existing 2G and rapidly evolving 3G and Bluetooth communication standards.
GoldenGate/Sim is a comprehensive RF circuit and subsystem level simulation and analysis tool that offers a compelling alternative to products from established software suppliers. GoldenGate/Sim offers advanced, robust and accurate linear RF, harmonic balance and envelope circuit simulation tools with unique linear and nonlinear stability and phase noise analysis capabilities. In addition, it is seamlessly integrated into mainstream EDA environments from Cadence, Orcad, Synopsys and Elanix.
GoldenGate/NN Model Compiler is an innovative behavioral modeling tool, based on the company's patent-pending neural network technology that enables designers to accelerate RF circuit and subsystem simulation while maintaining circuit-level simulation accuracy. The GoldenGate/NN modeling tool significantly increases productivity of wireless system designers and enables them to handle complex designs by working at a higher level of abstraction, mixed with transistor-level designs.
So far, the world of RF design remains isolated from mainstream EDA flows and environments. The mission of these new products is to start breaking down the barriers that exist between tool flows, design environments, and design teams for the RF and baseband portions of communication system designs. Wireless designers face not only the challenge of unifying top-down and bottom-up tool flows, but also daunting design problems in system partitioning, intellectual property reuse, and exploding system and circuit complexity. The new tools simultaneously address these critical issues by integrating a productive modeling and simulation approach with the most popular environments for analog/mixed-signal, digital signal processing, and system architecture development.
GOLDENGATE/SIM FEATURES AND BENEFITS
GoldenGate/Sim version 2.0 features a unified simulation engine that supports multiple analysis methods including linear, nonlinear, harmonic balance, and envelope transient. The software is based on modern object-oriented architecture that allows faster development, easy maintenance and high quality software to better serve designers' long term needs.
sFig. 1 GoldenGate/Sim's envelope transient simulator used to perform accurate phase noise analysis.
Fig. 2 A GoldenGate/SIM representation of a complex modulation spectrum.
Among the many capabilities, GoldenGate simulators offer robust and accurate nonlinear analysis in deep power saturation, critical in designing amplifiers for CDMA and W-CDMA applications. It provides unique linear and nonlinear stability analysis especially for high Q circuits, and accurate nonlinear noise and near carrier phase noise analysis, including channel and 1/f noise. Figure 1 shows accurate phase noise analysis using the simulator's envelope transient simulator.
In addition, the simulator is capable of mixed-mode time and frequency domain analysis optimized for complex digitally modulated RF signals commonly used in 2G, 2.5G and 3G standards, and system-level functions at circuit level analysis, such as AM/AM, AM/PM, adjacent channel power ratio, signal-to-noise and noise power ratios, bit error rate, error vector magnitude, eye diagram, and constellation charts. Figure 2 shows GoldenGate/Sim used to analyze a complex modulation spectrum. GoldenGate also provides support for RF pulsed designs; amplifier and oscillator startup/power-up analysis; VCO, free-running and locked oscillator, and frequency multiplier analysis; and active/passive mixer analysis; as well as support for diverse substrate technologies such as GaAs, Si-bipolar, Si-CMOS, Si-BiCMOS, SiGe, hybrid, PCB and multichip module technologies. There is also extensive support of transmission line structures for stripline, microstrip, finline, suspended line and coplanar waveguide lines.
Fig. 3 A neural net model of an amplifier fed with a CDMA signal.
Fig. 4 The neural net modeler comparison of modeled data to measured data.
A BREAKTHROUGH NEURAL NETWORK MODELING COMPILER
GoldenGate/NN-Model Compiler represents a major breakthrough in modeling abstraction and accuracy for wireless system design. The company's patent-pending neural network techniques have been applied to accelerate simulation runtimes without compromising simulation accuracy.
No expertise in neural networks is required to use the pushbutton compiler which generates numerically efficient, C-language models from measured or simulated circuit response data. GoldenGate/NN-Model Compiler supports linear and nonlinear circuit modeling for components such as filters, amplifiers, mixers, multipliers and oscillators. Applying a block-based methodology, C models can be used in GoldenGate/ Sim or with other third-party simulators. The models improve simulation performance by up to 100 times versus traditional circuit simulation with accuracy between two and three percent of circuit/transistor level design. The models can be made parametric (for example, for gain, frequency and power compression) to facilitate design reuse for RF and wireless components. Figure 3 shows a neural network model of an amplifier fed with a CDMA signal where the model is more than 20 times faster than performing a full circuit envelope simulation. Figure 4 shows how the neural network modeler accurately models AM/AM and AM/PM data it is supplied with. The screen compares the modeled data to the original measured data the model was built from.
CONCLUSION
GoldenGate/Sim and GoldenGate/NN-Model Compiler represent a substantial leap forward in simulation and circuit modeling to solve the problems faced by today's wireless circuit and system designers. The integrated design environment allows much faster and easier simulation than traditional design environments.
GoldenGate/Sim version 2.0 is currently available priced at $55,000 for Unix platforms and between $10,000 and $40,000 for Windows platforms. GoldenGate/NN-Model Compiler is currently available on Unix and Windows platforms priced at $75,000. Additional information may be obtained from the company's Web site at www.xpedion.com.
Xpedion Design Systems Inc., Santa Clara, CA (408) 987-0603.