New-Tech Europe Magazine | Q3 2020

5G networks [6]. As such, in November 2019, the World Radio Communication Conference (WRC- 19), concluded that 5G should be allocated, on a global basis access to certain sections of these mmW bands [7]. Applications that are part of the IoT ecosystem will also drive high-volume utilization of mmW frequencies. The benefits of broadband and mmW will be a boon to a number of industries. Commercialization and strong demand, however, in no way lessen the performance requirements or the challenges of meeting them. To the contrary, the former depends entirely on the latter. The challenges of atmospheric attenuation, scattering (e.g. urban canyons), and poor penetration all necessitate high- density point-to-point deployments to reduce the impacts noted. At the core of these systems are high- performance nanometer silicon, GaAs and GaN electronics that need to deliver leading edge capabilities at a cost-effective price point, “cost- effective” being the operative word. The increased demand for high- performance, broadband mmW systems will not be serviceable/ scalable if the supporting solutions can not meet the cost structure needed. Searching for a Solution to the Cost-Performance Dichotomy Two years ago, Mini-Circuits foresaw the demand curve and the simultaneous need for high- performance and cost-competitive mmW solutions, and launched an internal research and development effort to solve the challenge. The two-year effort was a substantial investment in time, resources and opportunity cost, and one could

the problem of mmW performance. Initial analysis identified three areas beyond the circuit design itself that could contribute meaningful improvements to extending the frequency range of QFN packaged components. These include simulation enhancements, package components and manufacturing techniques. Simulation Enhancements Traditionally, MMIC products are designed with most of the focus on the electrical simulation at the IC level, with simple models to represent the package interconnects and grounding of traditional plastic, over-molded packaging. At frequencies below 10 GHz, this approach arrives in the ballpark of actual performance with minimal simulation spins to account for the package. Above 10 GHz, the electrical-only simulation approach becomes inaccurate, and around 50 GHz, this approach won’t even yield a close approximation to real world behavior. To accurately predict IC operation at mmW frequencies, 2.5D or 3D electromagnetic (EM) simulations are essential. These tool suites are now widely available and can greatly increase modelling accuracy. They do, however, trade modelling accuracy for longer development time, so they must be applied judiciously. The process of IC simulations followed by EM simulations of the complete packaged solution, if applied by brute force, is slow and inefficient. At Mini-Circuits, we’ve looked at the entire design process, and optimized the application of these tools to the tasks where they are best suited. Our unique multiphysics simulation approach speeds the entire design process while ensuring close agreement

argue that there are less expensive paths to follow. Historically, it was normal practice for mmWcomponent vendors to deliver their solutions only in die form, eliminating the package entirely. While some legacy applications can afford this manually intensive approach, most customers working in these higher frequency ranges have neither the capability nor the desire to deal with bare die and chip and wire assemblies. With shorter time to market, smaller engineering teams, and greater cost pressures, customers have realized that the performance benefits don’t outweigh the higher total cost of ownership of bare die solutions. Another often-used approach is the aforementioned open cavity package form factor. HTCC solutions have been around for decades and are widely accepted in the industry. However, the more expensive assembly process results in higher component costs which again make it difficult, if not impossible to meet the cost targets for today’s high volume mmW applications. Die on carrier (ceramic, alumina or other high-end substrate) is a hybrid method between bare die and air cavity packaging, but this method offers little physical protection for the active components. These carriers often need to be assembled into expensive hermetic enclosures or protected via conformal coating which carries a higher initial and/or rework cost (e.g. applying, removing and reapplying conformal coating). After evaluating many of these options, Mini-Circuits decided to look internally and leverage in- house capabilities to deliver the high-performance packaging we needed. Working with our integrated circuit (IC) designers and package development team in Malaysia, Mini-Circuits researched new ways to apply our packaging capability to

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