Radar Applications Guide
The Radar Applications Guide is available from the ADS installation CD under the Application Guide category. Once installed, it is accessed from the schematic window under the "DesignGuide" menu.
The objective of the Radar Applications guide is to demonstrate the capability of Advanced Design System to simulate Pulse compression simulation in a radarsystem and to demonstrate IFM receiver simulation for EW application.
- "FM-CW Radar Simulation" demonstrates a simple Doppler radar simulationusing envelope simulator. A user defined target model is implemented. The echosignal is a function of target range, velocity, and cross-section. The Dopplershift in frequency is plotted.
LFM Radar Component and Simulation Setup
Figure 2: LFM Radar Component and Simulation.
- "LFM Waveform Generation" demonstrates generation of linear frequencymodulated signal using numerical signal processing components. The generation ofchirp signal for different compression ratio is also demonstrated.
- "LFM Using Direct Digital Synthesis" demonstrates direct digital synthesisof a Linear Frequency modulated signal. Numeric synthesizable DSP components areused for direct digital synthesis, and output waveform is plotted for 4, 8, and 32bit resolution.
- "LFM Chirped Transmitter and Receive Simulation" demonstrates LFM pulsecompression implementation a using pattern match component at the receiver. Theplot shows the transmitted waveform and compressed pulse signal at thereceiver.
- "LFM Two Target Modeling and Detection" demonstrates the detection of twotargets using a single pulse.
- "LFM with RF Transmitter" demonstrates co-simulation of DSP and RFComponents. The upconverter is designed using RF system components andco-simulation between Agilent Ptolemy and Envelope simulator is demonstrated. TheRF signal is down converted and the pulse is compressed using pattern matchcomponent.
- "LFM with RF Transmitter and Receiver" demonstrates cosimulation of RF withDSP. This system includes an RF transmitter and receiver. Sensitivity timecontrol, automatic gain control, and channel modeling are included in thesimulation. The simulation is performed only for a single pulse period.
- "LFM Radar Receiver Simulation" demonstrates LFM pulse compression using analternative implementation of Chirp signal generation and Compression Filter. Aparametric model of LFM Signal Generator and Channel model is implemented withthis simulation.
Antenna Components and Simulations
"MOM2ADS Antenna Radiation Pattern Translation Utility" can be used totranslate the 3-D radiation pattern of an antenna designed using Momentum forsimulation in ADS. Once the planar antenna is analyzed using Momentum, the 3-Dradiation pattern can be calculated using Momentum Visualization. The normalizedelectric far-field components for the complete hemisphere will be saved in ASCIIformat in the file "proj.fff" in the <project_dir>/mom_dsn/<design_name>directory. Select proj.fff using the file browser in the MOM2ADS Antenna radiationPattern Translation Utility. The translation utility will calculate the totalelectric field as a function of theta and phi and change file format so that itcan be accessed using the DAC component in ADS. This new file "proj.ads" will beadded to the same directory as the original "proj.fff" file.
Figure 3: Data Based Antenna Model Simulation.
- "Data Based Antenna Model Simulation" demonstrates the simulation of a 3-Ddata based antenna model. The simulation accepts the 3-D radiation pattern file"proj.ads" generated by the MOM2ADS File Translation Utility. The radiationpattern can be simulated as a function of theta, phi, and Antenna RotationAngle.
- "2-D Antenna Radiation Pattern Implementation Using Data Display"demonstrates the Sin(X)/X implementation of a 2-D Antenna radiation pattern. Themarker can be scrolled to change the antenna direction. The data display is usedfor antenna radiation pattern verification before an equation can be implemented as a behavioral model using the S2P equation based component.
- "2-D Antenna Radiation Pattern Simulation" demonstrates the simulation of a2-D user-defined Antenna behavioral model for various Antenna Rotation Angle.Sin(X)/X radiation pattern equations are implemented using the S2P_Equation basedmodel to generate radiation pattern. The model provides ideal isolation in thereverse direction (S[1,2]=0), and can be modified as desired.
Monopulse Radar Components and Simulations
Figure 4: Monopulse RF System Simulation.
- "Monopulse Antenna Feed Simulation for Sum and Difference Channel"demonstrates the simulation of a Target and Monopulse Radar feed model integratedwith a 2-D radiation pattern. +25 degrees Antenna Rotation Angle for the pairs ofvertical antenna are defined. The simulation is performed as a function of azimuthangle theta keeping the target position fixed. The Sum and Difference channeloutput is plotted.
- "RF Front End Simulation for Pulse Modulated Signal" demonstrates envelopesimulation for an RF subsystem. The data display shows the pulse parameter derivedfrom measurement. The subsystem shows SPST switch modeling.
- "Monopulse RF System Simulation" demonstrates the RF simulation of a threechannel Monopulse system with double down conversion. The sum channel, azimuth,and elevation channel response is plotted. Target model can be modified to includeDoppler frequency effects.
- "Target Azimuth Angle Tracking" demonstrates a three channel MonopulseRadar Receiver integrated with a 2-D Antenna Radiation Pattern behavioral model tocalculate target Azimuth Angle. The simulation is performed as a function oftarget azimuth position and the target azimuth angle is calculated and plotted asa function of target position.
- "Pulse Compression Using Barker Code" demonstrates the pulse compressionsimulation using Barker Sequence. The data display shows the transmitted phasemodulated signal and the received pulse compressed waveform.
- "Three Channel Monopulse Radar Simulation" demonstrates a Barker sequencepulse compression implementation in a three channel Monopulse radar receiver. Thecompressed pulse is shown for sum, azimuth, and elevation channel.
IFM Receiver Components and Simulations
Figure 5: Eight Channel Digital IFM Simulation.
- "IFM Correlator Simulation" demonstrates cosimulation of a single channelIFM receiver. Output angle is plotted and instantaneous frequency iscalculated.
- "Single Channel simulation of IFM" demonstrates envelope simulation for anRF subsystem. The data display shows the pulse parameter derived from measurement.The subsystem shows SPST switch modeling.
- "Two Tone Simulation of IFM" demonstrates an IFM single channel cosimulationin the presence of two input independent frequencies. The power level of onesignal tone is kept fixed while the power level of the other signal tone is variedfrom minimum value to maximum value. The data display shows IFM always respond tothe highest power level signal, and when two-power levels are nearly equal, theoutput of IFM shows uncertainty in angle measurement.
- "Four Channel Simulation of IFM" demonstrates a four-channel simulation ofan IFM system. A DSP algorithm can be implemented to resolve ambiguity infrequency measurement over a wide frequency bandwidth.
- "Eight Channel Digital IFM System Simulation" demonstrates the AgilentPtolemy implementation of an eight channel IFM system. The instantaneous outputfrequency as a function of input RF frequency is plotted.