For IMS2016 - The Latest Design Software from National Instruments

May 3, 2016 | Posted by: David Vye

Performance of high-frequency electronics is continually advancing to meet increasing global demands for information. And while the cell phone has been around for over 40 years and the smart phone for over a decade, wireless communication systems are still evolving to address new applications and to handle more data throughput in the age of big data. Emerging technologies for future communication networks are hot topics among the talks and special sessions being discussed at this year’s International Microwave Symposium in San Francisco.

Looking beyond cellular is the central theme of the keynote talk by the father of the cell phone, Dr. Martin Cooper. Discussions of other forward looking networks range from UC Berkeley’s Prof. Jan M. Rabaey - “The Human Intranet- Where Swarms and Humans Meet" which envisions a combination of IoT and wearable devices to form “an open scalable platform that seamlessly integrates an ever-increasing number of sensor, actuation, computation, storage, communication and energy nodes located on, in, or around the human body” to the rump session - “The Internet of Space – Technological and Economic Challenges for the Future Space-based Internet” which examines how emerging micro-satellite communications will help serve approximately 60% (4.5B) of the world’s population which cannot currently access the internet.

From the inner body to outer space, how will the hardware that connects more people and things to data with greater speed and capacity continue to advance? Through collaborative innovation and continued advances in engineering tools. An overview on how software tools are enabling engineering creativity will be presented by NI President, CEO and co-founder, Dr. James Truchard discussing “Software’s Role in Next-Generation 5G RF and Microwave Systems.” More detail on the state of smart RF/microwave design and test solutions from National Instruments will be presented in the MicroApp presentations and product demonstrations available in booth  #1529. 

MicroApp presentations focusing on the latest RF design solutions offered by NI parallel the technology trends enabling next-generation communications development. Since the NI AWR Design Environment v12 was announced at IMS2015 in Phoenix, NI has introduced the first commercially-available, cloud-based, antenna synthesis software (AntSyn), the first bi-directional link between Microwave Office and ANSYS HFSS (AWR Connected for HFSS), along with application projects developed using new load-pull and phased-array capabilities introduced in v12.

The NI AWR Design Environment platform continues to enhance capabilities to meet the challenges presented by systems such as 5G and IoT, employing new technologies that include a move toward mm-wave bands, high-linearity/efficiency PAs, electronic beam-steering, tunable/reconfigurable front-ends, multi-band filtering, use of new semiconductor and meta-materials, as well as the advanced packaging and interconnect technology used in heterogeneous multi-chip modules. Much of the materials prepared by NI experts for IMS2016, address these challenges.

Designing better PAs … better.

If your focus is on designing RF power amplifiers with higher linearity and power added efficiency (PAE), the latest load-pull capabilities in NI AWR Design Environment offer an unprecedented level of support and data management. Today’s PAs must achieve multiple performance metrics that are difficult to achieve simultaneously. In addition, higher PAE levels can often only be achieved through harmonically tuned devices often employing output waveform shaping techniques. Combined, these requirements force many designers not using the NI AWR Design Environment to iterate their optimization efforts between different impedance matching scenarios until a reasonable trade-off is achieved. Optimum PA performance is extremely difficult and time consuming with this back and forth approach.

With the load-pull capabilities within NI AWR Design Environment, engineers can dynamically explore the impact of fundamental and harmonic terminations and directly observe the impact (simultaneously) on any number of PA responses including gain compression vs power, PAE, EVM/ACPR, etc. A comprehensive tutorial / demo based on a Qorvo 10W (P3dB),  discrete GaN on SiC HEMT device biased for class B operations has been developed. The related Modelithics device model lets designers accurately simulate responses (IV waveforms) at the devices current generator plane, create large simulated data sets that can be used for harmonic load pull analysis and matching network development. An overview presentation of this work will be offered in the MicroApps sessions on the exhibition floor and through live demos in the NI booth.

Integration made possible through EM analysis

Many of today’s PAs are integrated into radio front-end modules that contain the filtering and switching necessary for multi-mode, multi-band mobile devices. Such modules include high density components, embedded passives and complex interconnects that require planar and/or 3D electromagnetic characterization. The latest chip-package-board design and validation solutions from NI are based on the powerful integration of AXIEM (3D planar) and Analyst (arbitrary 3D finite element) EM solvers within NI AWR Design Environment.

Complementing these EM modeling tools, NI has developed bi-directional interoperability between Microwave Office circuit simulator and 3rd party EM simulators such as ANSYS HFSS. This integration supports unrestricted planar structures as well as commonly used 3D circuit interconnect structures such as wire bonds and ball grid arrays. Structures defined in NI AWR Design Environment are then automatically solved by HFSS during the overall network analysis with the results embedded directly into the circuit hierarchy without leaving the circuit design environment or requiring manual steps on the part of the designer. The design environment manages the flow of data between Microwave Office and HFSS, providing greater accuracy as needed to ensure first pass success.

EM analysis is also critical for antenna designers and antenna system integrators concerned with overall performance related to antenna/front-end interactions. As next generation communication and radar systems adopt phased array antennas for electronic beam-steering, the varying impedance load observed by the PA output as a function of cell location in the array and beam direction will impact its performance. As a result, in-situ antenna simulation within the circuit analysis is of growing interest. NI AWR software experts will demonstrate how to simulate the interaction between the array and the RF circuit controlling the amplitude and phase of the signal feeding individual antenna elements. Several antenna types will be characterized using both AXIEM and Analyst, demonstrating how to model scan blindness, power radiated over scan angle, PA nonlinear behavior through harmonic balance simulation and how to identify resonances between the antenna and the feed network.

A new starting point for antenna design

EM simulation and EM optimization have been the tools of choice for modern antenna design, with designers modifying the physical dimensions of antenna structures they already know or can find in reference materials. While tweaking physical dimensions will allow designers to shift antenna behavior to operate in the band of interest, there is no guarantee that the optimum performance has been achieved. To address the challenge of finding the optimum antenna structure and dimensions for a desired set of electrical characteristics, AntSyn was recently announced as part of the NI AWR software portfolio.   

Based on evolutionary algorithms (EA), a programmatic method to explore the design space and automatically locate novel antenna designs combined with EM simulation, AntSyn is proving to be more effective at generating antenna structures with greater performance than would otherwise be developed by traditional methods. AntSyn will make its North American debut at this year’s IMS.

A design flow for high Q filters

Dan Swanson of SW Filter will join NI to present a design flow for developing narrow band, high Q cavity comb-line filters based on Microwave Office and Analyst. This universal procedure based on the Dishal’s method with powerful extensions that include the port tuning concept, equal ripple optimization techniques, and efficient EM simulation can be applied to virtually any filter technology or topology in order to achieve the desired response and avoid unexpected spurious couplings.

Join us at the IMS 2016 MicroApps theater for these technology talks and/or stop by NI booth #1529 for more in-depth demonstrations and discussions with NI AWR software experts.