Introduction to advanced design system (ads) 2009 RF simulation

One 、 introduction
ADS As Agilent A powerful EDA Software , Integrated from IC Level to circuit level to system level simulation module , Can deal with simple components to complex system simulation , It can span time domain and frequency domain , Can cover analog and digital , Whether quadratic or cubic ,ADS It's easy to handle .
At present, the mainstream electromagnetic simulation software is mainly based on the following methods ：
The method of moments （MoM）：ADS、Ansoft Designer、Microwave Office etc.
The finite element method （FEM）：Ansoft HFSS、ANSYS、EMDS
Finite difference time domain method （FDTD）：EMPIRE、CST Microwave、XFDTD
Each software is limited by its own algorithm , Both have their own advantages and disadvantages , In the electromagnetic simulation of high-frequency structures ,HFSS With high accuracy 、 Mature adaptive mesh generation technology 、 The convenience and ease of use of the operation interface has been widely respected in the industry ,ADS Compared with other simulation software , There are also certain advantages . Such as Agilent The company cooperates with other major component manufacturers and provides the latest Design Kit For users , Let users get the latest design resources at the first time ,Agilent The company has a deep accumulation of instrument testing technology , This is an advantage that other software companies cannot compare ,Agilent The company and other famous EDA Design software such as Cadence、Matlab And so on .
ADS Provide some examples for learning reference , At the same time, the help files provided are meticulous , These two contents are learning ADS A very beneficial tool , meanwhile Agilent The company also has some application notes on its official website that can be downloaded for learning .
Two 、 Install device library
Such as using Murata warehouse , You can download it from Murata's official website and install it to ADS Inside .
1、 stay ADS Start after the software installation , Enter menu DesignKit->Install Design Kits,

Chart 1 DesignKit install
2、 eject install ADS Design Kit The window of , Hit in the window Unzip Design Kit Now, stay UnZip File Select Murata yuanpianku , After confirmation, you can see that Murata components have been decompressed to ADS in , Installation level selection user level that will do , Click on OK After that, I successfully joined Murata component library .

3、 After successful installation , Corresponding components can be added to the schematic diagram for design simulation , Need to pay attention to when , When using Murata components for simulation , You need to add Murata simulation control to the schematic .

Chart 3 Murata controls and components
After adding Murata devices to the schematic , It can be done by Parameter entry Mode Select the specific Murata device model , After setting the components , The value of this element cannot be tuned 、 Optimization and other methods , Can only pass again in Parameter entry Mode Make changes .

Chart 4 Modify the value of Murata component
3、 ... and 、 Component panel
New project , establish Design after , The component panel will appear .

Chart 10 Component panel
Lumped-Components： Lumped parameter component panel , Including resistance 、 Capacitance, inductance, etc
Sources-Freq Domain： Frequency domain source panel , Including various source models in the frequency domain , Such as frequency domain voltage source
Sources-Modulated： Modulation source panel , Including various modulation signal source models , Produce as GSM、CDMA And other modulated signals
Sources-Noise： Noise source panel , Including various noise models , Such as noise voltage source
Sources-Time Domain： Time domain source panel , Including various time-domain signal source models , Such as time domain voltage source
Simulation-DC： DC simulation panel , Contains various controls required for DC simulation
Simulation-AC： AC simulation panel , Contains various controls required for AC simulation
Simulation-S_Param：S Parameter simulation panel , contain S Various controls of parameter simulation
Simulation-HB： Harmonic balance simulation panel , Contains various controls for harmonic balance simulation
Simulation-LSSP： Big signal S Parameter simulation panel , Including big signal S Various controls of parameter simulation
Simulation-XDB： Gain compression simulation panel , Contains various controls for gain compression simulation
Simulation-Transient： Transient simulation panel , Contains various controls required for transient simulation
Optim/Stat/Yield/DOE： Optimize / Statistics / The yield / Dedicated device control panel , Contains various optimizations 、 Statistics 、 The yield 、 Special equipment and other controls , The design can be optimized .
Probe Components： Display component panel , Models containing various display devices , Such as voltmeter 、 Galvanometer, etc .
Data Items： Data management panel , The main function is to ADS Manage data entries in
TLines-Ideal： Ideal transmission line panel , Ideal model including coaxial line and other transmission lines
TLines-Microstrip： Microstrip transmission line panel , Microstrip line models with various shapes and characteristics
TLines-Printed Circuit Board： PCB transmission line panel , Containing various shapes and characteristics PCB Transmission line
TLines-WaveGuide： Waveguide transmission line panel , Including various waveguide devices .
Device-BJT： Crystal triode component panel , Provide various crystal triode models
Smith Chart Matching：Smith Circle chart matching panel , Provide a for matching circuit design smith Circular graph , It can be used for matching design and analysis
Transistor Bias： Transistor bias circuit panel , The panel contains various transistor bias circuits , It is very convenient to use when designing transistor circuits .
Impedance Match： Impedance matching component panel , It contains various circuit forms for matching .
Four 、 Data display window
When the simulation runs correctly , Through the data display window , Further analyze the simulation data ,ADS The data display and analysis method of is flexible , In the data window, you can complete a variety of chart formats to display simulation data 、 You can mark and read the data of any point on the simulation curve 、 Data can be processed and displayed with equations .

In the data display window Palette The display mode of simulation data can be added in the panel , If displayed in rectangular coordinates 、 Polar graphic display 、smith Graphic display, etc ;
5、 ... and 、 Introduction to main simulators
5.1 DC simulator
stay Simulation-DC The DC simulator can be called under the panel , It is an important tool for DC simulation such as transistors , Usually, you only need to set the scanned variables 、 Start and end values of scanning variables 、 Scanning step can be simulated , For some complex applications , Other controls in the DC simulation panel are required to participate in the completion .

Double click the DC simulation control , Pop up the configuration window of DC simulation control , stay sweep The tab includes the DC scanning variables 、 Scan type 、 Start and end of scanning, step and setting of user-defined scanning plan , stay parameters On the tab , Set the status level, etc , At the same time, it can be in display Configure the information that the DC simulator needs to display in the schematic diagram in the tab .
Under DC simulation panel sweep plan and prm swp Control can be used for user-defined scanning plan and parameter scanning , At the same time, you can also go through disp temp Control to load ADS To view the simulation results , The display template can be self-contained or self edited .Meas eqn Control for formula editing , The formula can call all parameters and simulation results in the schematic , The results can be displayed in the data display window .
5.2 AC simulator
AC The simulation control is Simulation-AC Under the panel, you can find , Its function is to scan the small signal transmission parameters at each frequency point , Its setting is similar to S The simulation control of parameters is similar , No more details here .
5.3 S Parameter emulation control
S Parameter is RF The more important analysis method of circuit ,S Parameter simulation is right RF Design is a very important way , Its function is to simulate the scattering parameters at a frequency .
Yes S The setting of parameter simulation control is frequency The tab sets the scanning frequency range and step 、 Scanning mode, etc , stay parameters The tab sets the S Parameters 、Y Parameters 、 Group delay, etc , If it is necessary to calculate the system noise figure , Need to be in noise The tab will calculate noise Choose .
S The parameter simulation panel also provides many commonly used calculation controls , You can directly calculate S Parameter simulation is the result that needs to be viewed , Such as more commonly used stabfct Control is used to calculate Rollett Stability factor K,K>1 The circuit is absolutely stable ,stabms The control is to calculate the circuit stability coefficient b, Function and stabfct equally , But the definition is different .
5.4 Harmonic balance simulation control
Harmonic balance is a frequency domain analysis technique that simulates a nonlinear circuit and system , It can directly obtain the voltage and current in the frequency domain and directly calculate the frequency spectrum of the steady state , Widely used in RF And frequency domain characteristic simulation of microwave circuit , Such as calculating spectrum 、 Third order intermodulation point 、 Intermodulation distortion .
5.5 Gain compression simulation controller
The gain compression simulation controller is used to find custom gain compression points , It compares the deviation point of the ideal linear power curve with the actual calculated power curve . Gain compression control can easily find 1dB Compression point .

Chart 13 Gain compression controller
5.6 transient / Convolution simulation controller
Transient simulation is SPICE The most basic method of , It is often used to simulate digital or analog circuits , It is to calculate the time dependence of a group of voltage or current .

As for the specific simulation methods, see my other blogs .