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12 Posts authored by: annamccowan Employee

Keysight EEsof EDA’s Advanced Design System (ADS) software can help you overcome your signal and power integrity challenges. As the world’s leading electronic design automation for RF/MW and high-speed digital applications, ADS features a host of new technologies designed to improve productivity, including two EM software solutions specifically created to help signal and power integrity engineers improve high-speed link performance in PCB designs. 

Below are ten ways ADS can solve your most common SI/PI Design Challenges.


1. ADS provides speed and accuracy for your SI EM characterization

Don't be slowed down by increasing data rates. ADS provides two EM analysis solutions - SIPro and PIPro - that are specifically designed to handle high data rates, without sacrificing accuracy or speed. The limiting factor of 3D-EM technology for SI analysis is simply the scale and complexity of PCB designs. However, SIPro focuses on enabling SI EM analysis of high-speed links on large, complex high-speed PCBs, while PIPro is used for PI EM analysis of power distribution networks, including DC IR drop analysis, AC PDN impedance analysis, and power plane resonance analysis. 


Figure 1. SIPro delivers results approaching the accuracy of full-wave 3D-EM solutions, but in a fraction of the time.


2. ADS simplifies the use of S-parameter files for your parts

Imagine you’ve just downloaded an S-parameter file for a part you are considering; in this case, a high-speed connector for a backplane. It has a large number of ports on it, so you want to first inspect the quality of the data and then use it in your simulation. How do you wire it up? Which ports are paired?

Traditionally, the answer might be to open up the data in a text editor. However, with ADS’s S-Parameter Checker, designers can now easily view the contents of any S-parameter file without having to setup an S-parameter test bench simulation. This allows them to directly plot the individual relations they wish to see, and shows them the port names against each pin. It also tells designers if the file is passive or reciprocal, as well as the number of data points in the file and the frequency range it covers. Designers can even use S-Parameter Checker to rename, re-order and reduce the number of ports, which enables them to save a new, more usable S-parameter file (Figure 2).



Figure 2. The S-Parameter Checker allows design engineers to easily rename, re-order and reduce the number of ports.


3. ADS provides access to industry-leading channel simulator technology

ADS's channel simulator technology sprung forth in 2009 when transient simulation (SPICE) couldn’t address the measurement of margin-to-mask for really low bit-error-rates (BER), as demanded by high-speed link designs.

Dr. Fangyi Rao's 2006 patent to correct for passivity, while ensuring causality, ensured ADS to be regarded as the msot accurate solution for handling cascades of S-parameter models combined with circuit models in one schematic. The pace of innovation continues today with ADS's Channel Simulator still the industry-standard model. Additionally, the Channel Simulator now supports IBIS package (.pkg) entries directly and more extensively before.


Figure 3. With ADS, designers can mix-and-match models from IBIS, IBIS-AMI, SPICE, and generic built-in models.


4. ADS stays ahead of technology waves (such as PAM-4)

Market pressures on IP routers set an expectation to do more at a lower cost per bit. However, to go faster and provide a single 100-Gbps electrical lane across the distance of a typical backpane is beyond present day technology. 

The solution lies in Pulsed-Amplitude Modulation (PAM) for high speed serial links. PAM represents a revolutionary step in the industry, but comes with its own unique set of challenges as well. For example, we can transmit a PAM-4 symbol at 28 Gbaud and deliver 56 Gbps at the other end, but the IC's use more power and the signal itself has a reduced Signal-to-Noise ratio (SNR). 

Whether you are challenged with managing complexity while reducing production cost, or researching how to go further and faster on low-loss materials and fabrication processes,


 Figure 4. ADS supports PAM-4 simulations, which offers a viable alternative to NRZ. 



5. ADS accelerates DDR4 simulation methodologies

In simulations, how do you check compliance against the mask? Keysight EDA offers a novel DDR Bus simulator specifically designed to accomplish this task. It is a bit-by-bit channel simulator for parallel buses. It characterizes all transmitter paths at once, and calculates the BER contours for each eye at the receive side, together with the measurements for margin to mask. 

The simulator is unique in that it correctly handles the asymmetric rise and falling edges found with single-ended signals.The Tx and Rx models can be used to drive IBIS models, or mixed with SPICE models. The speed of the simulator allows it to be used in place to transient simulation for many pre-layout tasks, where the designer wants to sweep multiple parameters, or investigate performance movements. Together with batch simulation, it is a powerful tool for pre-layout design exploration, as well as post-layout verification for compliance.


Figure 5. Keysight EEsof EDA's DDR Bus simulator is a bit-by-bit channel simulator for parallel buses.


6. ADS puts power in the hands of designers

Power Integrity has become an ever-increasing challenge in modern day high-speed systems, driven by three main forces: higher device integration, lower IC supply voltages, and smaller real estate on the PCB. These modern challenges have forced engineers out of their notebooks and into true PI-DC simulators in order to take into account the real physical layout of the power delivery network (PDN). 

With ADS and the new PIPro suite of EM simulators, designers receive visual feedback in just second on exactly what the voltage distribution looks like for the selected power and ground nets. ADS also allows designers to check the current flow through individual vias and the voltage and current at specific locations like individual pins on the sinks and voltage regulator module (VRM). This information is easily reported in a sortable table. Vias that carry too much current can be highlighted in the layout for easy identification (Figure 6).


Figure 6. Vias carrying too much current can be highlighted in the layout for easy identification.


7. ADS enables flat PDN impedance responses

Once the initial pre-layout design has been created, the first-pass of the PCB layout can be imported into ADS 2016 for analysis using PIPro EM technology. PIPro’s net-driven user interface allows designers to quickly select the power and ground nets for the PDN network they want to simulate, choose simulation models for each of the components (e.g., decaps, EMI filters, inductors, and resistors, etc.), and setup the PI-AC simulator to compute the PDN impedance of the distributed layout with components in place. 

Since the PI-AC simulator has EM technology designed specifically for this purpose, a very accurate result is returned in minutes, not days. Designers can then use ADS 2016’s field visualization, PDN impedance and S-parameter plotting to determine if there are problems with the current PDN design, and to check coupling from one capacitor to the next. With just one click, a schematic representation is generated to transfer the EM-characterized model, together with circuit models of the components.  This back-annotation to an ADS Schematic enables  one smooth cohesive workflow. Designers can then apply their behavioral VRM model, and further tune the decaps for final verification/optimization.


Figure 7. Increasing the decoupling capacitance while increasing ESR improves impedance response flatness.


8. ADS enables electro-thermal simulation

As power delivery networks are forced into tighter PCB real-estate, the power plane becomes far from idealized.  Usually the once perfect plane is perforated heavily with clearance holes from stitching vias, and it can be a struggle for the layout engineer to get the required current up into the package of the device that requires it, without passing through narrow traces of metal.  Calculating an accurate IR-Drop is important for the PI designer, but also knowing the absolute temperature that the PDN traces, vias and chip die will reach, is invaluable information.   High temperatures can cause reliability issues; as the temperature cycles from on/off states can cause the via barrels to weaken and crack over time.

It is not intuitive to the designer whether a via is undersized for the current that is passing through it.  The temperature rise is very dependent on the width of the traces attached to it.  Secondly, resistance of a trace increases with temperature, requiring simulation analyses to determine the final steady state condition.  For every 10 degC change in temperature we see a 4% change in resistance of a trace. These observations point to a need to simulate the PDN design with a DC IR Drop electro-thermal solution.    

ADS provides a fully-automated integrated Electrical-Thermal-Electrical iterative simulation.  Users receive the most accurate representation of DC IR Drop results by taking into account local resistivity changes due to heating. The additional Thermal-only simulation, gives the user the ability to perform thermal floor planning.

With ADS you can easily copy existing DC IR Drop simulation setup to new Electro-Thermal simulation and visualize a list the temperature of planes, pins and vias.


Figure 8. DC IR Drop Electro-Thermal analysis - visualization of temperature.


9. ADS has an interconnect toolbox (Via Designer and CILD)

The signal integrity design challenge is not just to successfully recover the transmitter signal at the receiver, but to understand what is controlling the performance.  What are the significant margin eaters and which ones can I optimize?

Typical connections between a transmitter and a receiver include some section of application specific custom PCB routing.  ADS has a signal integrity tool box to help explore the design trade-offs and deal with the complex interaction between stack-up, transmission line losses, and via topology.

Designing the PCB interconnect starts with some sort of PCB stack-up definition in order to start evaluating the different types of possible transmission line topologies.  Once the transmission lines are optimized for impedance and losses, then one needs to look at via performance to transition between layers. Anyone of these steps has cost and performance trade-offs that can impact the other, resulting in a complex inter-relationship to determine which feature is the real margin eater:  Layer Count, Line Z, Via Backdrills, Material, Layout Density, etc.

ADS provides an Interconnect Tool Box that includes Substrate Editor, Controlled Impedance Line Designer, and Via Designer to simplify the pre-layout PCB interconnect investigation.

Figure 9. This type of pre-layout investigation enables an engineer to understand what is controlling the design margins and make informed cost vs. performance decisions.


10. ADS embodies the Keysight philosophy:

Hardware + Software + People = Insights

With Keysight's greater software-centric solutions focus, Keysight EEsof EDA plays a leading role in virtual compliance testing. Through Compliance Test Benches in ADS, designers can now take ADS simulated waveforms and test them against the same gold suite of compliance tests used on the bench with final verification hardware to attain the utmost confidence in a designs's compliance.

Further bolstering these capabilities in ADS is the support Keysight EDA offers its customers. That support includes a world-wide technical support presence, expert Application Engineers and consultative Field Sales Engineers. This support, together with Keysight’s hardware and software solutions and technical expertise gives customers greater insight and in turn, greater chance of success.



Keysight ADS further cements its leading position in electronic design software with continued advances for circuit simulation, layout and layout verification, silicon RFIC, and just as critically, signal and power integrity.


Phased Array Systems have been around for decades, mostly confined to the aerospace industry; but with 5G development underway, phased arrays are becoming more common and in demand. In order to successfully design and deploy a product the first time, engineers should know how to avoid costly mistakes by using new techniques and simulation methodologies.


Mistake 1: Not predicting the far field spurious emissions in the simulation.

Whether you have an Aerospace/Defense or a commercial communications system, it must pass the test of a spurious emission mask (SEM). The masks are specific to each application, but the requirement remains the same. In the case of phased array, due to the added spatial dimension, the SEM test is more elaborate and is conducted in an anechoic chamber. The SEM test is conducted over the entire sphere (4π solid angle) for all the desired beam directions in both azimuth and elevation.


This very laborious procedure will be repeated if the spurious emissions are found the first time in the chamber and then have to be corrected in the design and brought back to the chamber. Therefore, if one can predict them upfront in the design cycle, the time spent in the anechoic chamber can be greatly reduced.


Figure 1. Predicting the desired beam directions up front in the design cycle, the time spent in the anechoic chamber can be greatly reduced.


This video goes into detail about how these spurious emissions can be predicted.


Mistake 2: Failing to explore the design thoroughly in the simulation phase.

Why would anybody not explore the design and simulation space?  There can be many reasons, but most likely it's due to the simulation speed and the accuracy of the modeling tool. One troubling behavior of phased arrays is coupling between the elements. The cost of a phased array is directly proportional to the size of the array. It is tempting to reduce the inter-element spacing, but unfortunately, that leads to increased coupling between the elements.


The coupling can happen in a few ways. If the lines in the feed network are close, they get coupled. An element not only transmits but can also potentially receive the energy from the adjacent radiating elements. This appears as the reflected energy back into the element’s input.


A third mechanism can also happen; if the elements are realized on the same substrate, higher order surface modes can be excited, propagated, and ultimately radiated. All these effects might cause loss of directivity in certain directions called blind angles. Unless one models the coupling effects and impedance mismatches accurately and explores the design over all the scan angles, these blind spots cannot be uncovered. A typical simulation shows a mild form of loss of directivity shown in the figure below.


Figure 2. Antenna coupling can cause loss of directivity in certain directions, called blind angles.


Mistake 3: Relying on simple spreadsheet calculations.

It is very popular to use spreadsheets to design RF systems. While it is true that they are readily available and quick to simulate, spreadsheets lack the capability to model and simulate. They cannot model multi-ports, RF mismatches, finite isolation, frequency response, accurate non-linearity, collated or uncollated noise, etc.


These common limitations become severe limitations when you start designing phased arrays. You need insights into all the paths, and phased arrays can have up to 400. You need to look into all the 400 paths to understand the behavior; because in a phased array, you cannot simulate one page and scale it up to 400 paths. You need to consider all of them simultaneously to achieve accurate results.


Figure 3. Phased array system design is much more complex than a single path RF system design. Designers cannot scale up the analysis of a single RF path analysis to a full array.


Under certain conditions, the amplifiers in the array are compressed. Due to this compression, the spurious radiation is violating the SEM as shown in the figure below.


Figure 4. SystemVue helps designers catch spurious radiation that violates the spurious emission mask, and can identify which amplifiers are driven into compression or saturation.


That's because some of the amplifiers in some of the chains are being driven into compression or even saturation. So how do you identify these amplifiers? Modern tools, such as SystemVue, make it easy to identify them and understand where the non-linearity is coming from.



Modern design simulation and modeling technologies will make it easy for engineers to avoid these costly mistakes. Watch Keysight’s latest video, How to Avoid Costly Mistakes in Designing Phased Array Systems, to receive greater insights on how to work around these common errors and download the workspace he uses in the video.




 Start your free trial of SystemVue today!






Engineers make simulation reports all the time. However, it is tedious to copy-paste images from ADS to PowerPoint. An easier way to transfer your ADS images to PowerPoint is shown in this short video.


Using the Export_Images add-on, available for download below, ADS users can quickly and easily save images in their schematic, layout, and data display window, and import them into a PowerPoint Presentation. This method is faster, easier, and will provide you with high-quality images for your simulation reports.


Figure 1. The add-on ( can save images from all three window displays above: schematic, layout, and the data display window.


Step 1: Enable the Add-On. Including a custom Add-On is simple and useful in ADS.



Step 2: Initiate the “Export Images” command. From here, ADS downloads all of the images in your workspace at once, so you can save time when making your PowerPoint report.



Step 3: View and place your images. After exporting your images, a folder will appear with all of the images you need to finalize your report.



Step 4: Create your Simulation Report. (And enjoy all the time you saved using the add-on!)


Watch the YouTube video now to get started exporting images for your next simulation report on PowerPoint.


Download the attachment below:

Signal and Power Integrity engineers look to ADS for the correct treatment of high-speed effects like distortion, mismatch, and cross-talk. Building on the strong foundation and loyal users ADS has amassed through the years, ADS 2017 delivers new options and functionality that enable it to be the tool today's designers need to get ahead.


The latest release of ADS is a stronger, faster, and more comprehensive platform for signal and power integrity analysis. Read about the top 10 new features in ADS 2017 for Signal and Power Integrity Engineers or watch the video.


10. Improved substrate editor

The new and improved substrate editor has an efficient edit feature for a larger number of layers. The simplified editor interface reduces simulation setup time and increases productivity.

ads2017 substrate editor

9. Fast Wire labeling

Labeling ports with the correct node names is time consuming, especially when you have many ports. With the new CSV import labeling, naming more than 10 ports is simple. 

ads2017 fast wire labeling


8. Parallel Sweep on windows

In ADS 2017, Batch simulation is able to run in Turbo mode in both Linux and windows. Using the 8-pack Element license and simulation manager, you can unleash the parallel computing power of your workstation PC. Reduce simulation time of large sweeps with simulation manager.

ads2017 parallel sweep


7. Statistical mode PAM -4

To simulate a PAM-4 signal down to 10 ^ -16 BER, a bit-by-bit simulation would take hours. ADS 2017 now supports PAM-4 in statistical mode. You can directly simulate PAM-4 to very low BER in a matter of seconds to minutes.


6. Mixed-mode S-parameter Checker

In the improved S-parameter checker, you can now convert single-ended S-parameters to mixed-mode in a few clicks. Save time and increase your productivity by letting the S-parameter checker show you the mixed-mode response.

ads2017 mixed mode s-param checker


5. S-parameter Spectral Thresholding

Usually, you would expect simulation speed to decrease with higher port count. In ADS 2017, the spectral thresholding algorithm removes weakly coupled ports before simulation. The result is faster simulation speed for a higher port count, without sacrificing accuracy.

ads2017 faster simulation


4. New and improved IBIS Components

Are you looking for specific pins in your IBIS model to interact with? The improved IBIS component interface helps you quickly sort and select desired pins. With built-in smart default settings, the IBIS schematic is cleaner, and setup time is faster.
ibis components


3. 3D Via Designer: Enabling Access to Accurate Via Models

A crucial problem when simulating high-speed signal interconnects is a lack of access to via models that are accurate at high frequencies. To solve this problem, ADS 2017 introduces Via Designer, a tool for creating and modeling PCB vias (single-ended or differential), while giving you full control over the via specifics.
ads2017 3d via designer


2. PIPro Bill of Materials Optimization for Decaps

Decap Optimization in PIPro can take all the decaps as laid out on the board, and search for the optimal solution that meets the desired target impedance profile. The user can define an optimal solution, by specifying weighted criteria such as: number of decaps, unique models, vendors, or cost. PIPro's algorithm intelligently ranks your best candidate solutions so you arrive at the best trade-off between performance and cost.

decap output


1. PIPro DC Electro-Thermal Capability

To find the true IR-drop of your power distribution network, thermal effects need to be considered in your analysis. PIPro performs an automated, iterative electric and thermal solve on each PDN, providing thermal insights to every power integrity engineer. PIPro calculates the temperature distribution of the board, so you can ensure the temperatures of vias, traces, and devices in your design are within the specification.  

ads2017 electro-thermal



These 10 new features are just the beginning of all the new capabilities and usability enhancements in the latest release of Advanced Design System (ADS) 2017. Along with improvements for the Signal and Power Integrity Designers are improvements for RF/MW designers doing RF front-end module and Silicon RFIC design. Check out all the new features on the web page and apply for your free trial of ADS 2017 today.

free trial of ADS 2017

FREE Evaluation of ADS | Keysight EEsof EDA  

A new video by Wolfspeed demonstrates how the Wolfspeed ADS process design kit (PDK) is configured to work with the Keysight ADS electrothermal simulator to co-simulate electrical and thermal performance together.


Figure 1. Wolfspeed’s process design kits work with Keysight Technologies’ ADS electrothermal simulator to co-simulate electrical and thermal performance together.


The electro-thermal simulation capability allows designers can see the impact of thermal effects on circuits while still in the design stage, and account for those effects early on in the design process. This becomes especially helpful when using a high power density technology like SiC or GaN.


Wolfspeed is the largest SiC and GaN wide bandgap Power and RF fabrication facility worldwide. They are the leading supplier of SiC and GaN materials, providing lighter, faster, and more powerful devices to industry experts around the world. Wolfspeed offers non-linear, scalable GaN HEMT models for MMICs, as well as full PDKs for Keysight Technologies’ Advanced Design System (ADS).



Figure 2. Wolfspeed’s video shows allows designers can see the impact of thermal effects on circuits while still in the design stage, and account for those effects early on in the design process.


Because of their dedication to a more energy efficient future, Wolfspeed takes the lead in the innovation of power and wireless systems with wide-band semiconductors. These materials enable devices to function at higher voltages, frequencies, and temperatures, allowing for broader use of alternative energy devices. The electro-thermal simulator accounts for significant thermal effects that often occur with these increasingly popular materials.

You can watch Wolfspeed’s new video below. They walk you through the process of co-simulating electrical and thermal performance using the Wolfspeed PDK.



To learn more about the ADS Electro-Thermal Simulation Element, watch this 30-second video or visit



FREE Evaluation of ADS | Keysight EEsof EDA 

Keysight’s latest release of SystemVue 2017 is the industry’s leading simulation platform for system design and verification, giving designers the earliest possible head start in entering the high-margin 5G market.


With its unique 5G functionality, SystemVue 2017 now makes it possible for 5G cellular system, RF component, and chipset vendors to create pre-5G-compliant reference designs. Designers can start pre-5G now and continue forward into the final 5G New Radio (NR) standard as it becomes available.

 5G verification library

Figure 1. SystemVue 5G Verification library merges Verizon and KT 5G wireless standards with 100GHz mmWave channel model and adaptive beamforming needed for 5G cellular base stations and handsets.


The new software adds functionality not possible with other 5G electronic design automation (EDA) solutions on the market today. Unique features include the ability to incorporate S-parameters of off-the-shelf phase shifters and attenuators, and X- or Sys-parameters of nonlinear amplifiers and mixers.


In addition to its powerful 5G and phased-array functionalities, SystemVue 2017 offers three important updates designed to enable early electronic product designs with high margin and volume potential for emerging standards:


  1. New Automotive Radar library, which features unique pedestrian channel models with micro-Doppler detection of moving pedestrians
  2. NB-IoT or LTE-Advanced Pro, which is an enhancement to the LTE-Advanced baseband verification library for validating Narrow-Band Internet of Things (IoT) product designs
  3. 802.11ax enhancement has also been added to the WLAN baseband verification library for designing even higher speed WiFi networking

 Phased Array Architext

Figure 2. SystemVue 2017 Phase Array Architect allows accurate RF S-, X- and Sys-parameters of amplifiers, phase shifters, attenuators to be used in Phased Array Antenna system design.


5G communications systems architects can quickly iterate and validate their 5G designs, allowing developers to cross traditional Baseband and RF boundaries in order to innovate the physical layer of next-generation communications systems.


For more information on SystemVue 2017, go to




Get your free trial today!



You have a waveform that was generated in MATLAB. How do you use that waveform as the source for a circuit in Genesys?


Keysight’s RF/Microwave Synthesis and Simulation Software, Genesys understands MATLAB. The full-featured MATLAB script debugger in Genesys enables you to develop error-free, fully compatible equations for data processing, simulation, and analysis. Genesys equation pages use MATLAB, so it is very easy to generate MATLAB waveforms in Genesys. You can paste MATLAB code directly onto a Genesys equation page to create any waveform.


Figure 1. You can easily import a MATLAB waveform into Genesys, and use that waveform as a source for a circuit.


Genesys Understands MATLAB

Running the MATLAB code in the equations page allows you to see and verify the waveform. Here, the waveform is stored and plotted in a variable called “PulseTrain”. The user will run the Equations first, and then the variable will be used by the source in the Genesys design.


Figure 2. The waveform is stored and plotted in a variable called “PulseTrain.” (Click image to zoom.)


How to apply the waveform to a circuit

In order to apply the waveform to a circuit, use a Custom Voltage source which allows us to specify a variable, PulseTrain, for the V parameter.


Figure 3. The variable PulseTrain is available for the source to use in the Genesys design.


From here, all that’s needed is to set up the Transient simulation for the desired time step and stop time. Run the simulation, and see the results below.





To use a waveform developed in MATLAB:

  1. Paste the MATLAB code that creates the waveform into an Equation page in Genesys.
  2. Assign the variable containing the waveform to a Custom Voltage source on the schematic.
  3. Run a Transient simulation.
  4. View the results.


Check out the related application note here.





Click here for a free trial of Genesys.

Having trouble getting started with your next circuit design? Keysight EEsof EDA’s YouTube channel is filled with “How To” videos and examples to help you with your complex designs. In each video, Keysight engineers walk you through the steps while also covering the fundamentals of each topic. At the end of each video, you can download the workspace to help get you started on your own projects. These five videos are a must-see for anyone working with Keysight ADS.


1. How to Design an RF Power Amplifier: The Basics

This video shows how power amplifier circuits work. If you are new to high-frequency power amplifier circuit design, this is the place to start. If you are an experienced designer, this video provides unique insights into the fundamentals that you may not have seen before. There is also an entire playlist dedicated to this topic on our YouTube channel.


Questions answered include:

  • What is AC power?
  • How is AC power generated and dissipated?
  • What topologies are convenient to use for power amplifier circuits?
  • What is a loadline and how can this be used to design a power amplifier?



2. How to Design for Power Integrity: Selecting a VRM

This video is one of a three-part series in Power Integrity tutorials. There are many factors to consider when selecting a VRM (Voltage Regulator Module), and this video covers two: Output Impedance and PSRR (Power Supply Rejection Ratio). This video uses measurement-based simulations to show that current mode topology is the best choice for flat impedance VRM.


Questions answered include:

  • What factors should I consider when selecting a VRM?
  • Why is flat impedance the PDN design goal?
  • Why is VRM selection not arbitrary?


3. How to Use Fixture De-embedding to Match Signal Integrity Simulations to Measurements

This video provides a quick 4-step process to show how to de-embed a fixture from a measurement to validate a PCB channel model, and then how to embed the fixture with the model to do a direct compare of simulation to full-path measurement both in the frequency domain and time domain.


Questions answered include:

  • How can I match SI simulations to measurements?
  • How can S-parameters simplify the problem?
  • What is the best process to solve this problem?


4. How to Design Phased Array Systems

This video discusses the most important considerations for phased array system design, especially popular for 5G. It begins with the basics of phased array design, then covers 4 key parameters of phased array architecture. After watching this video, you will be able to download the simulation tool, SystemVue, to perform your own phased array modeling and simulations.


Questions answered include:

  • How does a phased array work?
  • What are the key elements of phased array architecture?
  • What factors influence the far field pattern?




5. How to Understand 5G: Beamforming

This video guides you through what kinds of multi-antenna system architectures are being researched for the next generation 5G standard. It provides examples with end-to-end link level simulation and demonstrates key technical issues of different multi-antenna beamforming system design under mmWave channel environments.


Questions answered include:

  • How does beamforming work?
  • How can I model and simulate for key multi-antenna systems architectures?
  • Is hybrid beamforming too good to be true?
  • What is the 3GPP channel model for mmWave frequency band?




These are just five of the growing library of “How to” videos from Keysight EEsof EDA. Apply for a free trial of ADS or SystemVue to get started on your own designs.




Click here to apply for a free trial of ADS.


Keysight EEsof EDA is introducing a new set of tools for 5G, starting with pre-5G modulation analysis. This new technology is geared toward innovators with 5G testing in mind.  The 89600 VSA software provides comprehensive analysis capabilities for pre-5G signals based on the Verizon 5G open trial specifications.  With the standardized pre-5G technical specifications, engineers are already taking steps toward signal analysis.


vsaFigure 1. 89600 VSA users can observe pre-5G uplink and downlink physics layer measurements based on the Verizon 5G specifications. This example shows a downlink signal with 8 component carriers.


5G networks promise faster speeds, higher data rate, easier connectivity, and better network performance. Pre-5G allows users to experience certain 5G network elements while ensuring compatibility with their current 4G and LTE platforms.


Keysight’s latest 89600 VSA software helps break through the complexity of pre-5G, and will do the same for 3GPP 5G New Radio (NR). 3GPP 5G NR is the emerging global 5G standard. It is expected to be included in Release 15 of the 3GPP standard, which is due out later this year. With Keysight’s new 89600 VSA software release, early adopters can design and verify performance to the draft specification now, before it is published. Its extensive set of tools for demodulation and vector signal analysis enable you to explore virtually every facet of a signal and optimize even the most advanced designs.  


Figure 2. The 89600 VSA software will unify and accelerate the development process by providing
frequency-, time-, and modulation-domain analysis results in a single measurement.


The 89600 VSA software will unify and accelerate the development process by providing frequency-, time-, and modulation-domain analysis results in a single measurement. Users can observe pre-5G uplink and downlink physical layer measurements based on the Verizon 5G specifications. The 89600 VSA software is a vital and effective tool that will help blaze the trail to the 5G frontier.



The latest 89600 VSA software has over 100 recorded demo signals available for trial users. Discover the fundamentals of pre-5G air interface parameters, physical channels and signals.


Read the technical overview for more information on pre-5G signal analysis.


See the vast capabilities of the 89600 VSA Pre-5G Modulation Analysis in this four-minute video tour.



You can now jump start your 5G development for Verizon 5G, and continue for upcoming 3GPP 5G NR with a free trial of the 89600 VSA software.


Demands for faster data speeds and more reliable services are at an all-time high. 5G is predicted to meet these demands, and much more. Although 5G is currently still in the planning stages, researchers are uncovering solutions that were previously thought impossible. Until recently, mm-waves have been viewed as unsuitable for mobile communication. However, new research has shown that propagation issues can be overcome, with help from mm-wave small-circuit designs.


Plextek RFI is a leading company in 5G design, specializing in the design and development of RFICs, MMICs and microwave/mm-wave modules. The designers at Plextek RFI manage their own RF On Wafer (RFOW) test facility, providing several leading foundries highly developed design services. Their designs are used in a wide range of applications from test instrumentation to infrastructure equipment and the latest mm-wave 5G systems.


Plextek RFI also has a growing archive of video tutorials on various design topics in a wide range of applications from test instrumentation to infrastructure equipment and the latest mm-wave 5G systems.

The most recent video tutorial provides a visual demonstration of the design, layout, and performance of a Dual-Band 5G Power Amp using Keysight ADS.


dual band layout

Figure 1. Full layout of a mm-wave 5G dual-band power amplifier.


Dual-band power amps are vastly popular in proposed 5G designs due to the wide range of frequencies used in 5G applications. They perform almost as well as two single-band PAs combined, as they are capable of electronically switching their operating band between the 26GHz and 32GHz 5G bands. They are small, inexpensive, and with ADS, easy to design.


ADS schematic of dual-band PA

Figure 2: ADS schematic of three-stage dual-band power amplifier.


s-parameters pf PHEMT switch transistor

Figure 3: S-parameters vs. frequency of a pHEMT switch transistor, used to alter effects of transmission lines in low and high bands.



Watch the 20-minute tutorial video to dive further into each stage of the power amp design, and to see the effects of the pHEMT switch by simulating the S-parameters at high and low band.


For more information on Plextek RFI, go to here.


See more tutorials by Plextek RFI here.



If you are interested in learning more about 5G design using ADS, an upcoming webcast will cover the “Circuit Design Phase” of a 5G system done all in ADS.

Click here to watch the webcast.


apply for free trial

Apply for a free trial of ADS.

The fundamental goal in cellular and network wireless development is maximizing antenna performance while minimizing antenna size. In order to achieve this, antennas have increased in the number of array elements and in complexity of broadband networks, requiring highly accurate simulation programs for significant designs and tests. With ADS 3D EM simulation software, users can easily design and simulate many different types of antennas. EMPro can simulate the antenna in realistic surroundings, including the phone components, housing and even the human hand and head. Compliance testing can also be performed, such as specific absorption ratio (SAR) and hearing aid compatibility (HAC). Below are two examples of types of antennas you can design and simulate with ADS. Visit Keysight’s EM Applications Page for more examples!


  1. Multi-Band Planar Array Antenna

    Large-array antennas become more challenging when the antenna is used for multiple bands. The field solver required to handle the capacity and speed is a design challenge for many engineers. One approach to this challenge is to divide the EM problem into small “sub-cells” that are integrated individually without carrying out an EM simulation at the full structure level. However, the coupling between the sub-cells will not be taken into account.

    Using Momentum 3D Planar EM Simulator, you can design and simulate an entire multi-band planar array antenna for communication and radar applications with optimum accuracy. The complexity of this design requires a highly accurate simulation software, such as Momentum, to accurately characterize the antenna in terms of radiation and return loss.

    Figure 1: Using Momentum 3D Planar EM Simulator, you can design and simulate an entire multi-band planar array antenna for communication and radar applications.

  2. 8x16 Patch Array Antenna
    In order to create the desired directive radiation patterns, designers arrange multiple antennas so that their coexisting wave patterns add constructively or destructively in a specific formation. The main lobe antenna can be steered by changing the phase of excitations at each array element. Depending on the number of array elements and the complexity of the feeder network, the simulation of a patch array antenna can be quite challenging. Although simulation time and speed are mostly related to the problem size, another effect on simulation time is the frequency bandwidth.
    The EMPro FDTD simulation engine is preferred because it produces a wide band simulation result with a single simulation. No frequency sweeping is necessary. FDTD also uses less memory while speeding up the simulation utilizing GPU acceleration.

    patch array
    Figure 2: The EMPro FDTD simulation engine is preferred because it produces a wide band simulation result with a single simulation. No frequency sweeping is necessary.




These are two of many prevalent applications of ADS and EMPro that can be found on Keysight’s EM Applications Page. Apply for a free trial of EMPro today!

         For engineering students and professionals alike, ADS simulations are a dream come true. A software that does all the calculations for me? Count me in!


         As today’s circuits grow more and more complex, the processes involved in creating, testing, and simulating them tend to follow suit. RF engineers face many challenges in RF design. With vast applications and flourishing technology, engineers need an efficient, easy-to-use workspace to construct their innovative creations.


         In his webcast, RF Simulations Basics, Andy Howard, Senior Applications Engineer and EEsof Applications Expert for 30 years, guides us through the basics of RF Simulation in ADS, showing how it is a valuable tool with multiple applications. For those just getting introduced to RF simulations, this webcast is a great resource for understanding how to perform RF simulations and why. Andy provides six prevalent applications for RF Simulations, two of which I will discuss here, that show us why ADS is the integral part in bringing engineering ideas to life.



Figure 1: ADS helps RF engineers bring their ideas to fruition with its efficient, easy-to-use RF simulation guides.



RF Simulations with ADS

ADS offers a comprehensive set of advanced simulation tools, integrated into a single environment. In the webcast, Andy gives you a feel for what it’s like to run the ADS software. He shows how an ADS user can design a simple block diagram using models. These models represent transmission lines, transistors, capacitors, etc. These are “the building blocks of effective simulations.” Simulating S-Parameters of your RF design is similar to using a network analyzer; however, with ADS you can combine multiple blocks with several different parameters. There is no limit to the number of ports.


The interface allows you to adjust the parameters of each component as you place it in your schematic and set frequency limits. When the design is complete, Andy shows how you can view the Data Display window and tune the component values simultaneously. This provides an excellent visualization of how your design truly depends on the different component values.



Figure 2. With ADS, users can view the Data Display window and tune the component values simultaneously.


What can be achieved with RF Simulation?


1. Better receiver performance for all your communication devices.

The applications of ADS are vast. A simple example Andy gives is an FM Radio Receiver. The simulation provides data at each node of the block diagram, allowing him to determine precisely where the receiver has performance degradation. He also views a spectrum of a particular node, which can indicate spectral content. By doing this example in ADS, the designer can more quickly see which components are causing the degradation.  The engineer can make more accurate predictions about their design without having to do many messy calculations. ADS also allows you to tune the parameters of your devices within the block diagram, allowing you to make adjustments as needed. 



Figure 3: The simulation of an FM Radio Receiver provides data at each node of the block diagram, allowing one to determine the precise location of performance degradation. Simulation done by ADS.




2. Integration of Multiple Technologies

The coupling of multiple technologies is a challenge often faced by RF designers, especially now as multi-tech devices are becoming more common place. Therefore, the need for compatibility between the technologies is imperative. For example, many companies use ADS to design parts such as a Multi-Chip RF Front End Module, as it is popularly used to power smart phones and tablets. ADS allows designers to take a pre-existing module, and virtually mount it on a board. Using multiple technologies can often cause performance degradation and increased simulation times. ADS is unique in its ability to ensure compatibility between different modules and technologies.



Figure 4. ADS allows designers to take a pre-existing module and virtually mount it on a board, allowing RF designers to couple multiple technologies into one simulation. Simulation done by ADS.


         These are only two of many applications of RF Simulations through ADS. Andy provides insight into these as well as four other applications of RF Simulations, including Electro-Thermal Analysis and High Speed Digital Design. He also delves into the different types of simulation engines which allow you to analyze your design’s harmonic balance results and transient simulations.

         Andy has over 15 years of experience designing and simulating circuits. For those looking for an introduction to the fundamentals of RF simulations, Andy provides a well-structured one-hour lecture that describes the multiple uses of RF design software. With these fundamentals, RF students and professionals can easily make their ideas into a reality.