Ansys Inc. · PDF file2 2012 ANSYS, Inc. November 14, ... – Fully automated HFSS port...

February 23, 2009 Inventory #002593

© 2012 ANSYS, Inc. Designer 8.0/HFSS 15.0 1 November 14, 2012

Large Scale EM Simulation

Ansys Inc.



Simulating a Large Scale EM Model

• Design and simulate a full assembly that is comprised of – A 10 GHz Voltage Controlled Oscillator – An Array of Dielectric Resonator Antennas – A Balanced Amplifier

• Individual components will be designed and key design

steps will be illustrated. The design tools are as follows. – VCO: HFSS for ECAD with Cadence Integration – Dielectric Resonator Antennas: HFSS – Balanced Amplifier: Designer circuit and HFSS for ECD in

Designer • Final assembly will be analyzed using HFSS for ECAD

within Designer



Extraction of a 10 GHz Voltage Controlled Oscillator using HFSS for ECAD with Cadence. This new capability allows Cadence users to create and setup on chip structures to be solved by HFSS while remaining within the Cadence Design Environment.

• Extracting a voltage controlled oscillator using the new HFSS for ECAD with Cadence Integration

Part One: Voltage Controlled Oscillator



Design Description

• Voltage Controlled Oscillator – Design 10 GHz Voltage Controlled Oscillator – Utilize the HFSS within Cadence functionality – Account for all parasitic effects from bondwires, leadframe, etc.



Design Flow from Cadence to HFSS Traditional Cadence/HFSS integration

GDS from Cadence

HFSS

Tech file for stack up for each gds file is needed

S-parameters

Equivalent circuit

Layout in Cadence

Create tech file only once for each process

Boundaries/materials/ports are automatically created in HFSS

Models

Manual annotation of models to Cadence environment

Automatic back-annotation of models to Cadence environment

Boundaries/materials/ports are manually created in HFSS

Tune the parameters

S- parameters Equivalent circuits

Solve

Solution setup is manually defined by user inside HFSS

Automatic solution setup that can be updated by user

HFS

S/C

adence Link



HFSS Solver on Demand within Ansoft Designer

• Enables users to: – Drive HFSS directly from the intuitive stack-up based layout interface of Ansoft Designer. – Set up ready-to-solve chip simulations directly from the Cadence Environment . – Create full 3-D HFSS models while working within Cadence layout tool.

• HFSS Solver on Demand Advantages: – Fully automated HFSS port creation and setup – Layout, Stackup, and Padstack Editors – Parametric Design Environment – Maintain Trace Characteristics and Nets from Layout – Hierarchical Design – Chip/Package/Board



HFSS for ECAD within Cadence

Cadence Environment

HFSS Model

HFSS/Cadence Integration

Model Back annotation



HFSS within Cadence: VCO

• Schematic and Layout:



1) Ports are automatically created 2) Option to Merge vias 3) Option to filter layout

Inductor capacitor

HFSS within Cadence: VCO Design Flow

HFSS/Cadence Link Non merged vias

Merged vias



VCO Design Back Annotation

HFSS symbol in schematic design



VCO Full Circuit Model

• Dynamically linked VCO Circuit and HFSS FEM Model



VCO Operating Frequency

200 MHz

550 MHz!

Red > Circuit Behavioral model Black > HFSS Inductor Model Blue > HFSS VCO Model



VCO Time Response

Red > Circuit Behavioral model Blue > HFSS Inductor Model Black > HFSS VCO Model



VCO Operating Frequency Tuning

• Varactors used to tune VCO Frequency to 10 GHz

VCO Frequency Response



Tuned VCO Final Results

• Results

VCO Frequency

VCO Transient Response

VCO Harmonics



Design of a 10 GHz dielectric resonator antenna using HFSS. Final antenna design will be incorporated into Designer and analyzed with HFSS for ECAD within Designer.

• Designing a Dielectric Resonator Antenna with HFSS

Part Two: Dielectric Resonator Antenna (DRA) Design



Motivations Behind The Use of DRA’s

• Dielectric resonator antennas (DRAs) are • alternatives to conventional antenna types • preferable for wireless communications systems due to

• their small size • high radiation efficiency (>98%) • wide impedance bandwidth • low ohmic loss…

• Can be made in various shapes for Antenna Applications :



Dielectric Resonators Uses

Dielectric Resonator Modes

High Q Modes Low Q Modes

Filtering & Oscillation Radiating Purposes

Dual Band Dielectric Resonator Antenna &

Filter

Dual Band Dielectric Resonator Antenna Dielectric Resonator Antenna

& Oscillator

Photos courtesy of Laila Salman PhD



Excitation Techniques

Aperture Coupling Probe Coupling Microstrip Line

Dielectric Image Guide Coupling

Coplanar Coupling

Dielectric Resonator Coupling Mechanisms

Photos courtesy of Laila Salman PhD



Design Procedure / Challenges

• Proper Design of a DRA follows the following steps

– Select the Mode of Interest & the Operating Frequency Range • Linearly polarized • 10 GHz

– Obtain Dielectric Resonator Design Parameters

• Rectangular dielectric resonator

– Choose the Appropriate Excitation Technique

• Stripline with transition to microstrip feed • Small patch excitation



Field Distributions in DRA

Electric Field Distribution inside the DR (Side View)

Magnetic Field Distribution inside the DR (Top View)



High Dielectric Substrate

Low Dielectric Substrate

Microstrip Coupling

Via Transition

Stripline Feed

Side View (Stackup)

Dielectric Resonator

Design Challenges – Coupling Technique

Microstrip-to-Stripline Transition



Antenna Directivity Patters (Plane Cuts) @ 10GHz

DRA Results



Final Single Element DRA Design

DR, єr = 10.2

Meander Strip Line Feeding Network

Opening in GND Plane

Wave Port Excitation with PEC Cap

Patch / Microstrip Coupling



Final Single Element DRA Results



Final Single Element DRA Results

10 GHz Antenna Gain Radiation Pattern

10 GHz Antenna Directivity 3D Polar Plot



Dielectric Resonators

a b

c

єr = 10.2

Four Element DR Antenna Array



Full Array Far Field Results



A 10 GHZ balanced amplifier will be designed within ANSYS Designer. This design will utilize the UMS design kit as well as the HFSS for ECAD functionality. This will enable engineers to combine both circuit and electromagnetic solver in a hybrid circuit/field solver simulation, providing maximum accuracy.

• Designing a balanced amplifier with Designer

Part Three: Balanced Amplifier Design



Ansoft Designer Overview

• Design Technology – Circuit & System Analysis

• Time and Frequency Domain – Electromagnetic Analysis – Access Multiple Solvers

• HFSS, PlanarEM, Nexxim and HSPICE

• Design Management – Hierarchical Schematic and Layout (2D/3D) – Design Exploration

• Parameterization, Optimization, Sensitivity & Statistical – Bi-directional Links to Field Solvers

• HFSS, PlanarEM, SIwave, Q3D, 2D Extractor – 3rd Party Links for Models and Geometry

• High Performance Computing (Multi-core/GPU)

00

0

0

0

0

0

0

1

2

3

U1Trans_1x2

1

2

3

U2Trans_1x2



Powerful New Importing Capability

• Links for Cadence Allegro/APD/Virtuoso – Run from either Cadence or Designer – Design cutouts and wirebonds for critical nets – Tightly couples ECAD, Circuits and HFSS

• Links for ODB++

– Common PCB Manufacturing format – Translation path for Mentor, Zuken, – Cadence, Altium, …



Design Description

•Balanced Amplifier • Combine two MMIC Amplifiers in parallel • Incorporate amplifiers in separate packages • Combine Amplifiers and 90° Hybrids on board • Include on-board biasing for amplifiers



Amplifier Schematic

• Three Gain stages separated by Wilkinson dividers

AMPNL

AMPNL

AMPNL

AMPNL

AMPNL

AMPNL

AMPNL

AMPNL



90º Hybrid Design Overview

• Hybrid Applications • Power Splitter / Combiner

• Load on one of the input / output ports, respectively

• Sum and Difference outputs • Two inputs to hybrid

• 90º Hybrid Features

• Power Splitter • Second input port is terminated • Quarter wavelength lines

• Series lines have lower impedance • Output ports are 90º out of phase with each other

4L

ZZ 0

λ=

=

4L

2ZZ 0

λ=

= /



90º Hybrid Design Overview

• Physical Modeling • Implement with transmission lines • Conserve space by bending series lines • Parameterize lengths and widths

• Analyze electromagnetically to account for all effects

• Optimize and Tune to 10GHz

5.00 7.50 10.00 12.50 15.00F [GHz]

-30.00

-25.00

-20.00

-15.00

-10.00

-5.00

0.00

Y1

BranchlineIdeal Linear Response ANSOFT

Curve InfodB(S(Port1,Port1))dB(S(Port1,Port2))dB(S(Port1,Port3))dB(S(Port1,Port4))



Hybrid Real Time EM Tuning

• Solved Parametrically • Tuned in real time

5.00 7.50 10.00 12.50 15.00F [GHz]

-35.00

-30.00

-25.00

-20.00

-15.00

-10.00

-5.00

0.00

Y1

Test HybridTuned Response ANSOFT

Curve InfodB(S(Port1,Port1))

Lambda4='144mil' Larm='125mil' W35='6.7mil'dB(S(Port1,Port2))



Lambda4='144mil' Larm='125mil' W35='6.7mil'

Lambda/4 = 144mil W35 = 6.7mil Larm = 125mil



Chip in Package on Board

• MMIC Amplifier in Package • MMIC Chips in QFN Package • 2 packaged amplifiers on FR-4

multi-layered board • Multiple wire bonds and vias in

package • Balanced Amplifier on Board

• Multiple SMT Components for bias

• Branchline 90 hybrids in stripline layer

• Vias, signal pads and interconnects

• HFSS – Solver on Demand • Board & package solved with

HFSS in Designer • Combined with power amps and

passives



Chip in Package On Board

Schematic Layout



Chip in Package on Board (3D View)



Full Board Linear Performance

• System Gain very close to ideal: 21.9dB



The individual components will now be combined into a full assembly and analyzed in Designer using both HFSS for ECAD and circuit solvers simultaneously

• Simulating the full assembly

Part Four: The Full Assembly



Design Description

• Full System • Create a full system based on combining the

• 10 GHz VCO output • Dielectric resonator antennas • Balanced amplifiers

• Solve entire system in Designer to establish 10

GHz performance metrics that include • Bondwire effects • Vias and transitions effects • Layout effects • Coupling effects



Full Assembly Semi-ideal Schematic



Full Assembly Layout

RF Feed

Balanced Amplifiers

Antenna Feed

Antenna



Overview: Package to Board



Full Assembly Profile

69.2G RAM



• Multi-Processing – Single workstation solution to increase the speed of the solver

• Spectral Decomposition Method (SDM) – Accelerates frequency sweeps by distributing the spectral content

across a network of processors

High Performance Computing

#cores Clock Time Delta

Reference 1 10 hours 1X

HPC Interpolating with MP

8 2.5 hours 4X

HFSS – HPC-MT Processor Performance* Up to 5x faster solver.

4 Cores

8 Cores

2 Cores

1 Core 1x

1.9x

3.6x

5.6x

(Baseline) No HPC



Full Assembly Performance

• Amplifier Gain & Return Loss • Gain, Harmonics

8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0F [GHz]

-40

-30

-20

-10

0

10

20

S-Pa

ram

eter

s (d

B)

SAS IP, Inc. Power Amp Buildup2Amplifier S-Parameters

10.0055

-33.1085

16.1469

-21.4064

Curve InfodB(S(Port1,Port1))

LinearFrequencydB(S(Port2,Port1))

LinearFrequencydB(S(Port2,Port2))

LinearFrequency



Full Assembly Performance

• Spectral Output

0.00 25.00 50.00 75.00 100.00 125.00 150.00Spectrum [GHz]

-375.00

-250.00

-125.00

0.00

dBm

(P(P

ort2

))

Power Amp Buildup2Spectrum P2m1 Curve Info

dBm(P(Port2))HB1Tone

Name X Ym1 10.0000 -13.8290



Output Power at Typical Port

BLUE – Full Board RED – Single Amplifier

-20 -15 -10 -5 0 5 10 15 20Pinput, dBm [dBm]

-5

0

5

10

15

20

25

30

35

Pout,

dB

m

Power Amp Buildup2Pout Vs Pin PPT

m1

Curve InfoP_in_dBm

HB1Tone Sw eep

Name X Y

m1 11.0 27.2



Far Field Performance Comparison

Antenna Alone Antenna with Board



Concluding Remarks

• Designer can be used to simulate designs that are: – Large to very large – Extremely complex

• High bondwire counts, many vias, many transitions, include finite dielectrics

– Are a combination of electromagnetic and circuit simulation

• Designer can be used as a central design schematic into which various engineers or engineering teams provide input

• Designer with HFSS for ECAD is a tool that allows engineers of any level to gain access to the power of HFSS

• The new Cadence Integration allows engineers to remain in the Cadence design environment but solve their structure electromagnetically with HFSS in an easy and seamless manner

Ansys Inc. · PDF file2 2012 ANSYS, Inc. November 14, ... – Fully automated HFSS port...

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