Today's RF amplifiers must meet challenging performance requirements such as bandwidth, efficiency, and linearity. The NI AWR software platform, with advanced design automation, robust harmonic-balance (HB) simulation for fast and accurate nonlinear analysis of RF/microwave circuits, and highly accurate device/circuit element models, provide designers with the tools to successfully bring products to market. (Image courtesy of ATL)
Accelerate design starts with powerful load-pull analysis and impedance-matching circuit synthesis.
Accurately predict nonlinear behavior, including gain compression and intermodulation distortion, with robust HB analysis.
Perform parametric design entry with an integrated schematic/layout editor, comprehensive element libraries, powerful graphing, customized scripting, optimization, and yield analysis.
Amplifier designs start with selection of an appropriate active device for the required frequency and performance targets, followed by the development of the necessary bias and impedance-matching circuitry. Biasing and load/source terminations have a strong influence over amplifier performance, hence design aids such as DC IV curve generation, load-pull analysis, and impedance-matching network synthesis play a critical role in accelerating early design activity.
New semiconductor technologies come with the challenge of accurately representing transistor parasitic, nonlinear, and thermal behaviors in order to provide accurate amplifier simulation. Software vendors must work closely with leading semiconductor foundries and load-pull test system manufacturers to ensure that robust, simulation-ready models of the latest semiconductor devices are available for amplifier design.
Prior to tapeout, amplifier performance must be verified through computer-aided simulation, which relies on specialized measurements such as noise figure (NF) and small-signal transmission and reflection parameters (S-parameters), as well as the nonlinear power, gain compression, and efficiency response to large-signal stimuli. HB techniques capture the nonlinear behavior of RF/microwave power amplifiers (PAs) in the frequency domain, and with the advent of digital-modulation for communications systems, amplifiers may also need to be analyzed using circuit envelope in order to simulate linearity metrics such as adjacent channel power ratio (ACPR) and error-vector magnitude (EVM).
Amplifier designers rely on RF-aware circuit simulation and frequency-dependent transmission line models, as well as circuit/electromagnetic (EM) co-simulation to provide embedded parasitic extraction and design verification. With hierarchical EM/circuit/system co-simulation, designers can perform in-situ EM analysis to capture and correct harmful parasitic couplings and resonances.
The NI AWR Design Environment platform provides a single, complete design environment that seamlessly integrates simulation and design technology and manages the circuit/system/EM components within a project, supporting schematic design entry and fully-synchronized physical design and layout.
Microwave Office circuit design software features APLAC multi-rate, transient, and transient-assisted HB, as well as time-variant (circuit envelope) analysis for linear and nonlinear circuit simulation of PAs and low-noise amplifiers (LNAs). Design aids include load-pull analysis, network synthesis (optional), design for manufacturing (optimization, yield, and statistical analysis), device libraries for printed-circuit board (PCB)-based designs, and process design kits (PDKs) for microwave monolithic integrated circuit (MMIC) and RFIC amplifiers.
The AXIEM 3D proprietary full-wave planar EM simulator is based on method-of-moments (MoM) fast-solver technology that readily analyzes on-chip passive structures, transmission lines, interconnects, vias, entire matching networks, and MMIC/RFIC amplifier packaging. Designers can extract S-parameters of passive structures directly embedded in an amplifier design and visualize fields and currents for potential resonances and other parasitics.
Visual System Simulator™ (VSS) system design software provides virtual test benches that support multiple wireless communications standards for linearity performance metrics such as ACPR and EVM. The software also offers modulation load-pull analysis for optimizing amplifier linearity for PAs.
The Analyst™ simulator with integrated 3D finite-element method (FEM) EM analysis enables designers to model 3D structures used in PCB- and IC-based amplifiers, including package and board interconnects, via fencing, wire bonds, air bridges, and ball grids.
Network synthesis automatically creates two-port, impedance-matching networks based on proprietary evolutionary EM optimization.
PDKs developed to work with NI AWR software are available from leading gallium arsenide (GaAs), gallium nitride (GaN), and silicon (Si) foundries.