Agilent-ADS Cosimulation
The performance of electronic components within or around an optical communications system may have a significant impact on the performance of the system as a whole. In most optical communications systems simulations, the electrical components (drivers, coders, receivers, clock and data recovery) are treated as systems-level models representing the behavior of the electronics as equivalent noise, nonlinearity, gain and frequency-dependent functions.
A better understanding of the interactions between the electronic and photonic parts of a link can be obtained if full electronic circuit models can be incorporated directly into the systems simulation. Having full electronic models in the optical simulation also saves the time required for abstracting the electronic model to a behavioral model at each design iteration. Agilent's ADS provides a superb high-frequency electronic circuit design capability that is perfect for modeling the high-frequency circuits within optical communications systems. Furthermore, ADS has extensive libraries of components and materials for high-frequency design. Thus, VPIphotonics and Agilent have cooperated to provide ADS cosimulation with VPIphotonics' optical systems and components simulation tools. This interface calls the ADS simulator executable directly from VPItransmissionMaker or VPIcomponentMaker, so that the best technologies for photonic and electronic design work seamlessly together.
Electronics within Photonics Systems
With the help of the TC-ADS interface, it is now possible to provide the circuit design to the WDM systems design expert, who can use it to model the electrical component under investigation, e.g., an electrical amplifier or an electrical laser driver, within an arbitrary optical transmission system.
A typical workflow is illustrated in Figure 1. The electronic circuit design expert uses ADS to design a tentative electronic circuit for a photonic system. This becomes an Electronic Circuit Module that can be imported into a VPItransmissionMaker schematic by the WDM systems designer. When the WDM system simulation is run, ADS will take inputs from VPItransmissionMaker, then calculate the output waveforms of the electronic circuit and pass them back to VPItransmissionMaker. The systems performance might suggest that changes to the electronic circuit design are necessary. These changes are easily incorporated into the next WDM systems simulation, without having to create a new Electronic Circuit Module.
For a free copy of the cosimulation between VPItransmissionMaker / VPIcomponentMaker and Agilent ADS, contact support@VPIphotonics.com.
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Keywords:
ADS, Electronic, Cosimulation, RF, EDA