Mixer QuickStart Guide

The Mixer DesignGuide is integrated into the Agilent EEsof Advanced Design System. It contains many analysis schematics and data displays for the design and analysis of RFIC mixers, frequency multipliers and dividers, and the application of discrete mixers in RF systems.

Display Preferences

DesignGuides can be accessed in the Schematic window through either cascading menus or dialog boxes. You can configure your preferred method in the Main, Schematic, or Layout window. Choosing Preferences brings up a dialog box that enables you to:

Note Use the dialog box menu style on Windows systems because resource issues typically make the operating system unstable.

• Disable all DesignGuide menu commands except Preferences in the Main window and remove the DesignGuide menu in the Schematic and Layout windows.
• Select your preferred interface method (cascading menus vs. dialog boxes).
  
  Close and restart the program for your preference changes to take effect.

Accessing Documentation

To access the documentation for the DesignGuide, select either of the following:

• DesignGuide > Mixer > Mixer DesignGuide Documentation (from ADS Schematic window)
• Help > Topics and Index > DesignGuides > Mixer (from any ADS window)

Mixer DesignGuide Features

• Passive and active mixer library
• Single-ended and differential Input/Output simulation schematics
• Up or Down conversion
• Sweeps of local oscillator and RF power, LO and RF frequencies, and user-defined parameters
• Analysis templates for:
  • DC Biasing
  • Output spectrum, conversion gain, port impedances, and isolation simulations
  • Gain compression
  • Intermodulation distortion and intercepts
  • Noise figure
  • Dynamic Range
  • Adjacent channel power with digital modulation
• Frequency multipliers and dividers:
  • Static frequency dividers
  • Injection locked frequency dividers
  • Passive and active frequency doublers
• Impedance matching networks

Note The DesignGuide is not a complete solution for mixer and RF system designers, but will provide you with some useful tools. It is intended to save you time in setting up schematics and displays.

Mixer DesignGuide Contents

The Mixer DesignGuide is made up of simulation files and utilities to facilitate your design and analysis of mixers. From an ADS Schematic or Layout window, choose DesignGuide > Mixer DesignGuide to display the schematics and tools organized in the following categories.<div align="left">

Category	Description
Device Characterization	Curve-tracer schematics for BJTs, NMOS, and PMOS. The schematics for DC bias point evaluation of active mixer circuits can be used to determine the proper DC bias conditions and device widths to be used in a mixer. Also includes two sample MOSFET BSIM3 device model parameter sets.
Example Mixers	Liibrary of mixer examples that can be used as a starting point for your own design.
Differential and Single-Ended Mixer Characterization	Characterizations for Differential and Single-Ended mixers can be selected with no swept parameters, with swept LO power, swept input frequency, or a user-defined arbitrary swept parameter. These options are useful for finding the optimum LO power, bandwidth, and parameters such as device widths or component values respectively.
Mixer Examples with Modulated Signals	Schematics for simulation of mixers driven by digital modulation types such as GSM or CDMA.
Matching Networks	Lumped 2 element and multi-element matching network schematic templates to design a matching network to interface between stages or to the off-chip (usually 50 ohm) environment using known input and output impedances or admittances. The S-parameters determined by the schematic called Mixer Characterization > IF Spect, Isolation, Conv. Gain, Port Impedances can be used in conjunction with these network design tools to match to a known source or load impedance.
Transistor Bias Utility	The Transistor Bias Utility provides SmartComponents and automated-assistants for the design and simulation of common resistive and active transistor bias networks. The automated capabilities can determine the transistor DC parameters, design an appropriate network to achieve a given bias point, and simulate and display the achieved performance. All SmartComponents can be modified when selected. You simply select a SmartComponent and with little effort redesign or verify their performance.
Smith Chart Utility	The Smith Chart Utility provides full smith chart capabilities, synthesis of matching networks, allowing impedance matching and plotting of constant Gain/Q/VSWR/Noise circles.
Impedance Matching Utility	The Impedance Matching Utility performs the synthesis of lumped and distributed impedance matching networks based on provided specifications. The Utility features automatic simulation, sensitivity analysis, and display setup to enable simple and efficient component verification.
Frequency Multipliers and Dividers	From an ADS Schematic or Layout window, choose DesignGuide > Freq Multipliers and Dividers to view the example subnetworks, design simulation, and displays for the following types of frequency translation devices. Static frequency dividers Injection locked frequency dividers Frequency doublers

Using Mixer Characterizations

The characterization items have identical options, which can be used to select the type of analysis. When this final selection is made, a schematic with a sample mixer will be copied into your project. Previously simulated results, using the sample mixer, are displayed by the associated data display file that is opened automatically.
To use this as a template for your own designs, substitute your own mixer schematic in the mixer subnetwork. Push into the subnetwork, delete the existing mixer (but keep the ports), and replace it with your own design. Return to the top-level schematic, set the simulation parameters, and run a simulation. If you keep the top-level schematic name, the corresponding data display will be updated automatically. Also, note that you must provide your own verified nonlinear device models to get accurate simulation results.

• Simulation control parameters that need to be set are enclosed in red boxes on the schematics, as follows.
  
• Data displays that use many equations have the equations on a separate page. See the Page menu.
• Some data displays have more than one page of output. Again, see the Page menu.
• In all mixer characterization schematics, RFfreq is the variable defining the input signal frequency and IFfreq is the variable defining the output frequency. If RFfreq is higher than IFfreq, the simulation is set up for down-conversion. If you want to simulate up-conversion, define RFfreq and IFfreq such that IFfreq > RFfreq.