RF Design Tips, Tricks & Tutorials

ADS Users’ RF & Microwave Designs & Applications

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Contours of Constant EVM from a Load Pull Simulation

March 13th, 2013 · Uncategorized

A primary task in amplifier design is determining the best load impedance(s) to present to a device.  Load pull is frequently used for this task, and ADS has many load pull simulation setups and data displays.   This new example shows how to plot contours of constant EVM from a load pull simulation.  

EVM is one method of measuring distortion, and this example enables you to clearly see trade-offs between EVM and output power, and take PAE into consideration also, when choosing the optimal load to present to a device.

This example is explained in a white paper and application note, Running a Load Pull Simulation and Plotting Error Vector Magnitude Contours, by Andy Howard.

You can also download the ADS example from the Agilent EEsof Knowledge Center: http://edocs.soco.agilent.com/display/eesofkcads/Contours+of+EVM+from+a+Load+Pull+Simulation

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References for Power Amplifier (PA) Design

February 25th, 2013 · Uncategorized

ADS Reference Material and Webpages (no login required):

ADS Reference Material and Webpages in the Agilent EEsof EDA Knowledge Center (login required):

A Typical Design Flow in ADS for Power Amplifiers:

ADS 2012 examples specific to PA Design.  Please note that you can browse to the example path shown for each below, and you can click on the hyperlink to see an online overview if you have a Knowledge Center login (since the online documentation resides within this web location).

ADS examples on the Agilent EEsof Knowledge Center (login required) related to power amplifier design

There are more than 80 examples or notes related to power amplifier design.  Do a search for “Power amplifier”.

This page has examples that show envelope tracking simulation: http://edocs.soco.agilent.com/display/eesofkcads/Applying+Envelope+Tracking+to+Improve+Efficiency

This page has an example that shows how to analyze Doherty power amplifiers: http://edocs.soco.agilent.com/display/eesofkcads/Using+ADS+to+Investigate+the+Performance+of+a+Doherty+Power+Amplifier

This is a fairly basic example of a power amplifier using a high-power device: http://edocs.soco.agilent.com/display/eesofkcads/power+amplifier+design+using+Freescale+device

 

This has a good collection of references on amplifier design:

http://edocs.soco.agilent.com/display/eesofkcads/ADS+2012+good+references+to+start+amplifier+design

App Notes and Webcasts (both upcoming and on-demand) about PA Design using ADS (archives include streaming video and slides to download):

Some classic references from Past Workshops & Seminars:

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New Envelope Tracking Examples and more!

February 22nd, 2013 · Uncategorized

ADS applications developer, Andy Howard, has created a new high-power amplifier Envelope Tracking (ET) example that includes a comparison of an X-parameter model and the original transistor-level amplifier with a 64-QAM signal.  With the 64-QAM signal it is easy to change the signal bandwidth and see the impact on the amplifier’s performance with Envelope Tracking:  20130208_Envelope_Tracking_Sim_Ex_3

Also, two existing ADS Envelope Tracking examples have been updated.  

  • The first example, 20130205_Envelope_Tracking_Sim, explains some of the basics of ET and how the bias modulator is implemented using behavioral models.
  • The second example, 20130205_Envelope_Tracking_Sim_Ex_2, shows how to model non-idealities in the bias modulator and includes many more simulation setups and calculations.   

In both of these two examples, many of the data displays have also been updated, making it much easier to make direct comparisons between two different ET simulations. And, they have a corrected method of determining the available source power, which enables the design to better maintain constant gain during envelope tracking. 

To download the full ADS workspace examples, click here and you’ll be taken to the Agilent EEsof EDA Knowledge Center

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Simulating Load Pull with Pulsed Bias and RF Signals

February 21st, 2013 · Uncategorized

Designers of amplifiers for pulsed signals, such as radar systems or defense applications, may need to run load pull simulations using pulsed bias and RF signals.  This ADS example shows how to pulse both the bias voltages and the RF input signal as well as plot contours at a particular time point in the RF pulse.

To view the white paper that describes this application visit Simulating Load Pull with Pulsed Bias and RF

To download the full ADS workspace examples visit the Agilent EEsof EDA Knowledge Center

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ADS Gift to Georgia Institute of Technology

February 4th, 2013 · Uncategorized


Agilent Technologies Commits $90 Million Gift of Software to Georgia Institute of Technology

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Register today for an exciting webcast on GaN PA Design – April 17 – 8am PDT

January 12th, 2013 · Uncategorized

Scintera Networks and Sumitomo Electric, both ADS customers, present results of a linearized and high-power 6GHz GaN power amplifier using RF pre-distortion techniques for microwave P2P applications. Click to register now: http://ow.ly/k1mTL

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ADS Circuit Design “Cookbook” 2.0 Available

January 8th, 2013 · Uncategorized

The 2nd Edition of the ADS Circuit Design Cookbook is available for free. It includes over 300 pages on tutorials, examples and applications of basic and advanced ADS capabilities. The 2nd edition has been updated for ADS 2011 and later release. Order your copy for free by visiting ADS Cookbook 2.0

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Simulating Envelope Tracking

December 12th, 2012 · Uncategorized

Simulating Envelope Tracking with Advanced Design System

This application note shows simulation techniques for envelope tracking of an example amplifier.

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Updates to Load Pull simulation setups and data displays in ADS

November 12th, 2012 · Uncategorized

The Load Pull DesignGuide has been extensively updated for ADS 2011.  Impedance load pull simulation setups have been added.  It is often optimal to sample lower impedances. These additions make it easier to specify the region of the Smith Chart you want to sample.  Also, data display pages have been added that make it easier to make trade-offs between power delivered and PAE, between gain and PAE when delivering a specified output power, or between power delivered and PAE at a specific amount of gain compression. The updated Load Pull DesignGuide may be downloaded from the Agilent EEsof Knowledge Center: http://edocs.soco.agilent.com/display/eesofkcads/Load+Pull+DesignGuide+Enhancements+for+post+ADS+2011_10

This PDF (20121109_Load_Pull_DG_Update_post_ADS_2011_10) describes the improvements and has many screen captures.

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Tell Us & Win: ADS User Survey

October 11th, 2012 · Uncategorized

Do you use ADS? I am interested in your current use of ADS. Please complete this short 6 question survey, and as a thank you, you will be entered into a drawing for a $100 American Express gift card.

ADS User Survey

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