Infinite Synthesized Networks (ISN®)

How we do it

Proprietary design tools (ISN®):

Infinite Synthesized Networks® (ISN®) is a suite of proprietary mathematical methods, software design tools, and network synthesis techniques for RF filter design that enables the Resonant team to explore a much larger set of possible design solutions than manual design processes that are common in the industry.

The ISN®-developed filters still use surface acoustic wave (SAW) or temperature-compensated surface acoustic wave (TC-SAW) manufacturing methods and perform as well as those using higher cost manufacturing methods such as bulk acoustic wave (BAW). In exploring the use of ISN® for BAW, Resonant developed a brand-new BAW resonating structure called XBAR®. XBAR® technology is ideal for emerging 5G mobile devices that need higher bandwidth at higher frequency, and XBAR® filters can be manufactured using existing fabrication processes for fast production.

While most of the industry designs SAW filters using a coupling-of-modes (COM) model, Resonant uses circuit and physical models. Circuit models are computationally much faster, and physical models are highly accurate, based entirely on fundamental material properties and dimensions. Resonant’s method delivers excellent predictability, enabling achievement of the desired product performance in fewer turns through the foundry.

Single-Band Designs

Some of the single-band filter designs are for duplexers that have historically been TC-SAWs or BAWs while others are for discrete SAW filters that may need improvements in performance, size, or cost. The single-band designs include “Wi-Fi co-existence” filters, which pass desired wireless frequencies while protecting Wi-Fi from interference, and designs for module applications that require wafer-level (WL) packaging and modeling of the module board. Using the ISN platform, combined with Resonant’s experience and know-how, the company can design innovative SAW filters that meet the performance requirements for many of these bands but at significantly less cost, with faster time-to-market than that of BAW filters or even TC-SAW filters they would replace.

Multiplexer Designs

Wireless carriers worldwide are experiencing increasing demand for higher data speeds. Carrier aggregation (CA) allows multiple data streams from different frequencies to be added together to provide increased data rate for mobile device users. However, CA further complicates the required filter characteristics. Quadplexers (which multiplex four RF paths) enable CA on both receive and transmit paths and reduce the RF front-end complexity by removing switches. But complexity of the filter functionality increases dramatically. Resonant’s ISN® design platform is ideally suited to solve these difficult filter design problems that cover a wide frequency range and have much more demanding performance requirements.

5G Filter Designs

The ISN® design software platform enables Resonant to design novel filters that are more than simple replacements; rather, ISN® can enable an architecture change and provide a step function improvement in filter performance, size, and cost to a device manufacturer.

XBAR® is Resonant’s high performance resonator technology developed using ISN® for filters for 5G New Radio (NR) devices, Wi-Fi systems, and millimeter wave systems. See more information on XBAR® here.

Resonant delivers designs to the foundry in a language they understand:

Resonant’s models are fundamental, easing integration with foundry partners because Resonant’s models speak the “foundry language” of basic material properties and dimensions. In addition, through its ISN® Foundry Program, Resonant has pre-qualified a number of foundry, back-end, and packaging partners for faster production times.

Legacy COM filter designs are delivered to the foundry and require the foundry to figure out how to produce the filter. Resonant delivers the complete recipe to produce its filter designs, including basic material properties, density, and dimensions.