White Paper

w w w. t m s . m r c y. c o m WHITE PAPER A Modular Framework from the Ground Up As new applications require smaller and smaller electronics, it becomes increasingly difficult to maintain a modular design. However, this modular approach is key to reducing development time through technology re-use and ensuring a future-proof system through easy upgrades. For example, a modular product can quickly be redesigned to accommodate a different frequency band or use an improved component by making changes to a limited number of design elements. This approach enables the most cutting edge products since it becomes possible to incorporate the rapid technology growth described by Moore's Law. To achieve this modular design framework, the Spec- trumSeries Compact Multi-Band Platform contains mul- tiple, small layers that are individually manufactured and tested, then easily combined with solderless contacts. By formalizing the interconnection between layers, the designer can use a variety of technologies. Sensitive RF chip-and-wire components are placed in hermetic packages—a technology that is proven on multiple programs and small enough to fit on a single layer. This high-performance, low-loss approach incorporates bare die and wire bonds. Vias and hermetic feed-throughs on the bottom of the package provide the high-frequency connections to the rest of the module and outside world. Control and bias components are placed on SMT boards that utilize standard, automated assembly to reduce costs. For advanced applications, multilayer boards allow the complex signal routing required by densely integrated digital devices. In addition to standard SMT components, these types of boards can include printed patch antennas or complex ball-grid array (BGA) devices. Figure 3. BuiltSECURE™ BGA-packaged, SiP Component 2 In order to conserve limited volume, we are developing this platform with the capability to support custom system-in-package (SiP) components. For maximum space savings, multiple digital die are integrated in a single BGA package. Our SiP technology is qualified on multiple high- reliability platforms and supports a variety of devices such as processors, memory, passive components and power circuitry. Using this technology, advanced digital processing circuity is integrated on a single ruggedized layer. Figure 4. Orthogonal RF board-to-board connection Critical to successfully implementing this technology are the board-to- board interconnects. DC and digital contacts are made through a flex harness and DC pins around the circumference of the module. This nail- and-socket approach enables a high pin-count while also contributing to easy assembly. SMP-style RF connectors support high-frequency operation for both board-to-board and external connections. Additionally, Mercury's patented coaxial-to-microstrip transition technology enables high-frequency orthogonal connections in an extremely compact space. Through the use of this modular, technology-agnostic framework, the design engineer has a starting point for any new design. As the library grows, the design process is simplified by combining pre-existing layers with custom layers. This reduces development time, lowers cost and enables easy product modifications. An Ultra-Compact Transceiver While multiple types of products are possible with this platform, one common example is an integrated RF/digital transceiver. Instead of separate assemblies for the RF front-end and digital processing, this platform combines them into a single, compact module. Depending on the customer's specifications, the transmit and receive blocks can be integrated into a single layer or separated in two hermetically enclosed layers. Applying our experience with high-frequency microwave assemblies, these broadband modules can be designed to operate at frequencies beyond Ka-band.

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