A Primer on RF Semiconductors (MMICs) Radhakrishna Setty, Technical Advisor Introduction Semiconductors are ubiquitous in modern society. In addition to microprocessors for computing technologies, they are used in practically every active wireless communications system including cell phone towers, cell phones, radars and satellites to name a few. Mini-Circuits designs and produces several semiconductor-based (MMIC) components […]
High-performance, millimeter-wave (mmW) Monolithic Microwave Integrated Circuit (MMIC) products and cost-effective surface mount lead-frame-based packaging typically don’t come up in the same conversation, and for good reason. Just two to three years ago, it was difficult to conceive of operating at frequencies above 20 GHz without considering an expensive, open cavity, High Temperature Co-fired Ceramic (HTCC) package or resorting to more bespoke chip and wire assemblies.
Microwave hybrid circuitry is generally built by integrating several discrete dice via wire bonding. Circuit designers are faced with the task of predicting the performance of hybrids, which comes with some specific challenges.
A Practical Approach to the Design and Implementation of Scalable, High-Performance, Custom SMT Packages for mmWave Applications
After many years of research and development, electrical engineers, physicists, mathematicians and scientists have come to realize the benefits of operating communications systems at higher frequencies. Some of the most notable advances stemming from this research include: smaller circuit implementations for the same functionality; improved antenna gain for a given antenna size; and dramatic increases in data-carrying capacity. However, numerous challenges remain in implementing high-frequency circuits under real-world constraints. Among the non-trivial problems, packaging stands out.
Since the advent of Network Synthesis Theory at the turn of the last century, filter designers have been developing ever more sophisticated solutions to translate polynomial transfer functions into working, physical components.
Fixed attenuators are invaluable problem-solvers for circuit-level and system-level designers. In addition to controlling amplitude levels, fixed attenuators can improve the impedance match between impedance-sensitive devices such as amplifiers and filters, and provide the isolation needed to stabilize oscillators.
מנחתים קבועים הם התקנים יקרי ערך שפותרים בעיות למתכננים ברמת המעגל ולמתכננים ברמת המערכת. בנוסף לשליטה על רמות המשרעת (אמפליטודה), מנחתים קבועים יכולים לשפר את תיאום העכבות בין התקנים שיש להם רגישות לעכבה (אימפדאנס), כגון מגברים ומסננים ולספק את הבידוד הנדרש לייצוב מתנדים.
Modelithics and Mini-Circuits have collaborated to create Microwave Global Models™ for Mini-Circuits’ YAT and RCAT broadband surface mount attenuator families. These attenuators can be used to reduce signal levels, increase isolation, or improve impedance-match and retur-loss performance. Both the plastic QFN package style YAT Series and the hermetic, ceramic cavity RCAT Series are available in a tiny 2mm x 2mm footprint. The key to Mini-Circuits’ YAT and RCAT attenuators’ small size, excellent uniformity, and 2W power rating is the GaAs semiconductor fabrication process having through-wafer Cu metallization vias to realize low thermal resistance and wideband operation. Available values range from 0 to 30 dB and these components are well matched to 50 ohms over the entire DC to 18/20 GHz specification range.