Real-time concurrent design of adaptive high-frequency circuits

Adaptive circuitry is a popular avenue for extending the reliability, longevity, or parametric performance of many mission-critical systems.' The design of today's adaptive circuits, when at high frequency and digitally controlled, requires consideration of design domains whose tools and methodologies have traditionally been partitioned, separate, and distinct throughout the design process, and have only been integrated at the final phases of development. This paper presents and discusses a new. fully integrated, concurrent design approach for adaptive circuits in communication systems. Using a simple digital attenuator and amplifier in a complex-modulated system as motivation, the design flow concurrently brings together and enables real-time trade-offs among system, circuit, physical (layout), and software issues. The results show that desired performance can be achieved more quickly and easily by simultaneously considering the disparate domains as opposed to the time-consuming traditional incremental methodology.