Wireless and RF
Wireless and RF: RF device simulation, modeling and layout for RF silicon
Your RF silicon has to work at the frequency it runs, so Silvaco carries RF device simulation, S-parameter model fitting, circuit analysis and all-angle layout through one flow.
At radio frequency, small effects stop being small
Demand for connectivity across 5G, Wi-Fi and IoT keeps pulling device makers toward efficient high-frequency parts, and gallium nitride HEMTs and pHEMTs are one of the clearest cases. Every one of them ends up in an RF front end, right next to an antenna.
RF IC design sits closer to device physics than most markets do. Substrate parasitics count under small-signal conditions and count for more under large-signal drive. Drawn geometry behaves like part of the circuit, and the package brings effects of its own. A model fitted only at DC can miss every one of them. So device, model, circuit and layout have to move through development together, each tested at the frequency it will see.
Where Silvaco fits
Start at the transistor or at the front-end block. Each tool hands its result to the
next, and you check the model at frequency before any circuit depends on it.
Your input
The RF device or circuit
Transistor, substrate or front-end block
Technologies and devices
Where frequency changes the answer.
RF devices
You can build GaN HEMTs and pseudomorphic HEMTs in Victory Process, alongside the silicon BiCMOS, BCD and SiC technologies it covers for power and RF. Process simulation reaches RF MEMS devices too, variable capacitors among them.
Victory Device then models the silicon substrate beneath the circuit, in small- and large-signal operation. The same TCAD flow covers the effects that decide GaN RF performance: trap-driven drain-current dispersion in AlGaN/GaN HEMTs, and self-heating in high-power GaN HFETs.
Modeling at frequency
Utmost IV fits models to any mix of DC, capacitance, S-parameter and extracted data, and you can optimize each fit across devices, die, wafers and temperatures. If you model RF devices, S-parameter support is probably the first thing you check for.
For GaN, a TCAD simulation can be carried through to the large-signal model a circuit designer works with, and extraction covers the industry-standard ASM-HEMT compact model.
RF circuit analysis
SmartSpice places no restriction on the type of circuit analysis you run. For RF circuit simulation, SmartSpice RF adds harmonic balance for steady-state work on GHz-range circuits, covering noise, gain compression, harmonic distortion, intermodulation and oscillator phase noise. SmartSpice is certified on TSMC’s 0.18 µm mixed-signal/RF process PDK.
SmartView shows the results as Y and Z Smith charts, polar plots and constellation diagrams, and it reads Touchstone S-parameter files directly.
RF layout
Expert draws all-angle polygons for RF and microwave elements, inductors included, and its any-angle rulers keep measurements accurate once you leave the Manhattan grid.
SmartDRC/LVS supports specific devices drawn at any angle, so off-grid RF structures are verified with the rest of the design.
Applications
One flow, four RF jobs.
GaN RF power device development
HEMTs and pHEMTs for wireless links, built on the same gallium nitride physics that power switching uses.
RF compact model extraction
Models that hold at frequency, fitted to measured S-parameters alongside DC and capacitance curves.
RF and mixed-signal circuit simulation
LNAs, mixers and oscillators, taken from transient runs through to harmonic balance.
All-angle RF layout and verification
Spiral inductors and microwave elements drawn off the Manhattan grid and checked there.
GaN RF work on the record, and the reading behind it
Before you commit engineering time, you’ll want evidence from a company that builds GaN RF
parts, and papers you can check line by line.
Customer · GaN RF
February 2022
Wavetek
Adopted Victory TCAD for its GaN HEMT and pHEMT work in 5G, Wi-Fi and IoT.
“Silvaco's Victory TCAD platform gives us the ability to precisely model GaN device behavior under real-world conditions. This level of insight is critical for achieving the performance and reliability targets demanded by next-generation RF and power applications.”
Dr. Barry Lin, CTO, Wavetek
Webinar
February 2022
How Silvaco TCAD is at the Heart of Innovation in RF Devices
Substrates are a major source of parasitics at high frequency. Watch Victory Device model silicon substrates in small- and large-signal operation.
Webinar
February 2022
How to Use Device Simulation as a Tool for Understanding GaN HEMTs
Why GaN HEMTs need buffer layers, and how simulation explains dynamic on-resistance in GaN-on-Si power switches and dispersion in RF HEMTs on SiC.
Paper · PDF
February 2022
From TCAD simulations to large signal model for GaN RF device
A physics-based GaN device simulation, taken all the way to the large-signal model an RF designer drops into a circuit.
Application note · PDF
February 2022
Transceiver Block Simulation with SmartSpice RF
Dynamic range, sensitivity and selectivity set a microwave circuit's performance. This note simulates all three.
More on wireless and RF
Presentation · SURGE 2023
GaN Device Modeling for Power and RF Applications with Industry Standard ASM-HEMT Compact Model
Worked example
Worked example
IP brief · TSMC N3P
RF Mixer Schematic Simulation
Worked example
Extraction of Analog (RF) Design
Article · 2011
Thermal Optimization on GaN HFET Using Flip Chip and Through Wafer via Structures
Article · 2007
Trapping Effects in the Transient Response of AlGaN/GaN HEMT Devices
Article · 2005
Process Flow Simulation and Manufacture of Variable RF MEMS Capacitors
Article · 2004
Fast and Accurate Simulation of the Steady-State of Voltage Controlled Oscillators with SmartSpice-RF
Article · 2004
Silvaco’s RFIC Design Suite
Is simulation parting ways with your
bench data?
Send us the part you’re working on, a GaN device, a compact model or a front-end block, and
the point where simulation and measurement stop agreeing. An RF application engineer will
point to the step of the flow that closes that gap, on a case like yours.
Questions about wireless and RF design
What is different about RF device simulation?
It has to hold at frequency. Substrate parasitics become part of the circuit, more so under large-signal drive. Traps can make a GaN HEMT's drain current depend on what the device just did, and self-heating shifts performance at high power. RF device simulation has to capture all three, in the conditions the part will operate in.
How are RF compact models extracted?
From data taken at frequency as well as at DC. An RF model is fitted to S-parameter measurements alongside DC and capacitance curves, then checked across temperature and from device to device. For gallium nitride, a physics-based device simulation can feed the large-signal model directly, and ASM-HEMT is the industry-standard model to extract.
What are Smith and polar charts used for?
They put RF behavior in the form RF engineers design with. A Smith chart maps impedance or admittance, so you read matching networks and reflections straight off it. A polar chart shows magnitude and phase together. Silvaco plots both, next to the constellation diagrams you need for modulated signals.
Which RF device structures does Silvaco support?
Gallium nitride HEMTs and pHEMTs, high-power GaN HFETs, and power and RF parts built in silicon BiCMOS, BCD or SiC. The silicon substrates under RF circuits are modeled in small- and large-signal operation. Process simulation also reaches RF MEMS devices, variable capacitors among them.
How does this page relate to the Power Devices page?
Because at radio frequency, geometry is circuitry. The shape of an inductor, a transmission line or a microwave element sets its inductance, coupling and loss, and those shapes rarely sit on a 90-degree grid. Your layout tool has to draw them at any angle, and your verification has to check them there too.
Does Silvaco work at the leading edge nodes?
Both start from the same gallium nitride physics. Power Devices covers GaN, SiC and silicon parts built to switch power efficiently. Wireless and RF covers devices, models and circuits built for radio frequency, where S-parameters, substrate parasitics and layout geometry settle the result. A GaN HEMT can belong to either, depending on the job it does.
Related
Power Devices
TCAD development for SiC MOSFETs, GaN HEMTs and silicon IGBTs.
Victory Device
Device simulation for RF substrates and GaN
HEMTs.
Utmost IV
Model extraction with S-parameter
support.
SmartSpice
SPICE circuit simulation, with RF analysis in SmartSpice RF.
SmartView
Waveform analysis in Smith, polar and constellation views.
Expert
Custom layout for all-angle RF and microwave geometry.