Radar

Radar and sensor design for aerospace, defense, and commercial applications continues to evolve based on advances in antenna-array and semiconductor technologies. These applications are driving the need for smaller, cost-effective systems with the reliability and resolution to accurately track the speed, distance, and direction of movement of multiple targets. The Cadence^® AWR^® software platform provides the design automation and simulation/model technology to accurately represent signal generation, transmission, phased arrays, T/R switching, clutter, noise, jamming, and signal processing, enabling users to tackle the design challenges and analysis requirements for modern radar systems.

Conceptualize

An integrated RF system design platform enables radar developers to explore various architectural options, signal processing algorithms, RF component requirements, and target/environment factors. Using high-level behavioral RF/digital signal processing models, designers can quickly implement a virtual radar system to investigate tradeoffs between choice of waveform, RF-component selection, and antenna details. Developing phased array antennas for radars utilizing MIMO and beam steering technology requires special design tools to design the array configuration, antenna elements, and feed network, along with a platform that can incorporate this simulation data into the larger radar simulation. As the desired simulated radar performance is achieved, the platform should support co-simulation with circuit and antenna electromagnetic (EM) analysis to transition from conceptual design to physical realization.

Simulation

Maximizing radar performance requires thorough analysis and optimization of each subassembly and component in the system. Designers require specific simulation technologies to capture and analyze time-domain, pulsed and modulated frequency responses, link budget (power, noise), and spurious signals in order to predict the overall radar performance, inclusive of device nonlinearities and chain impairments. Simulation must incorporate signal generation, transmission, antenna, T/R switching, clutter, noise, jamming, receiving, signal processing for moving target-indication (MTI) and moving-target detection (MTD), constant false-alarm rate (CFAR), and channel propagation.

Model Support

Commercial and defense radar systems operating in the millimeter-wave (mmWave) spectrum and utilizing advanced semiconductor and integration technologies are being driven by new size and performance requirements. System designers require a comprehensive system model library that includes RF behavioral, file, and circuit-based models and DSP components for simulating different fixed-point formats, as well as antenna, radar-cross-section (RCS) target and propagation models for multi-path fading, Doppler shift, RF clutter, jamming, and more.

Testbenches

Designers often rely on existing architectures, waveforms, and known component specs to define their initial system and simulation setup in order to expedite radar system development and perform critical measurements. Depending upon the application, developers may choose a continuous wave (CW) radar for a radio altimeter or proximity sensor, a frequency-modulated CW (FMCW) radar for automotive, or pulsed radar for synthetic aperture and weather tracking. Pre-configured simulation radar examples allow developers to adopt existing systems and modify them to a particular application and testbenches enable them to perform parametric tests on individual circuit modules, including benchmarks such as noise figure (NF), gain, voltage standing-wave ratio (VSWR), intermodulation distortion, and more. In addition, functional performance simulation examples guide developers conducting more rigorous end-to-end system evaluation, enabling them to understand the response to factors such as multiple targets, clutter, jamming, and noise.

Antenna Design

The benefits of MIMO and beam steering phased array systems over omni-directional antennas include higher directivity, fast electronic steering (beams that can be re-directed in milliseconds), and the ability to emit multiple beams simultaneously for multi-functional operations. Simulation tools need to support these antenna designs and array configurations, allowing interactive specification of the layout, feed network details, RF-link settings, gain tapers, and element failures. With hierarchical EM analysis that ensures the proper design and placement of antennas and mounting structures, in-situ circuit co-simulation enables radar designers to study the interactions between antenna arrays and the RF front-end circuitry.

FMCW Radar

AWR software was used to re-design an FMCW radar for educational purposes using smaller, less expensive surface-mount technology (SMT) components, including a voltage-controlled oscillator (VCO), attenuator, power amplifier (PA), 3dB coupler, low-noise amplifier (LNA), and mixer. This homodyne system self-mixed for its downconversion so that the IF spectrum could be sampled by the PC.

Automotive Radar

Advance driver-assist system (ADAS) technology based on 77GHz radar utilizes smaller antennas (one-third of the size of the current 24GHz ones), higher permitted transmit power, and, most importantly, wider available bandwidth, to enable higher object resolution. AWR software provides RF-aware system design software that supports radar simulations with detailed analysis of RF front-end components, including nonlinear RF chains, advanced antenna design, and channel modeling. Co-simulation with circuit and EM analysis provides accurate simulation of system performance prior to building and testing.

SAR

SAMPL Lab students built an efficient, easy-to-use Synthetic Aperture Radar (SAR) simulator that connects to MATLAB for signal processing. SAR is a type of radar used to create 2D and 3D representations of an object and uses the motion of the radar antenna over a targeted region to provide finer spatial resolution than is possible with conventional beam-scanning radars. The SAMPL Lab design focuses on avsub-Nyquist sampling of the received signal and full reconstruction of the image.

Smart (CW) Radar

Respiratory gating and tumor tracking are two promising motion-adaptive lung cancer treatments that minimize the incidence and severity of normal tissues and precisely deliver a radiation dose to the tumor. However, conventional gating techniques are either invasive to the body or bring insufficient accuracy and discomfort to the patients. Graduate students at Texas Tech University, in partnership with the National Science Foundation (NSF) and Cancer Prevention and Research Institute of Texas (CPRIT), used AWR design software to develop a smart DC-coupled radar sensor to track the tumor location and thus control the radiation beam.

Phased Array Antenna

Massive MIMO and beamforming signal processing enabled by phased array antenna systems are expected to play a critical role in 5G as both greatly enhance coverage and the user experience. New phased array modeling capabilities in the Cadence AWR Design Environment^® platform provide ease of configuration, reduced overhead, and shorter design and simulation times by enabling designers to configure the array’s geometry using either a standard or custom layout pattern.

Options

The radar, testbench, and phased array library module provides radar signal generation, radar-specific target and propagation modeling, and radar signal processing capabilities. The library is tailored to give easy access to all the needed capabilities for simulations such as RF interference, antenna arrays, and multipath channels. The types of radars supported span military, medical, weather, automotive, and more.

The phased array antenna generation wizard allows designers to rapidly configure a physical array, assign antenna radiation patterns derived from AWR AXIEM or Analyst EM analysis for the individual antenna elements, and model mutual coupling and edge/corner behavior. The wizard also allows designers to specify link and feed performance, incorporate gain tapering to reduce antenna side lobes, and investigate the impact of element failures on the overall array performance, providing real-time visualization of far-field radiation patterns from all these user-specified parameters and then automatically generates either a system or circuit-based network.