Author: Ahmed HelmyPublisher:
ISBN:
Category : Radio frequency integrated circuits
Languages : en
Pages :
Book Description
Abstract: Substrate noise coupling in integrated circuits is the process by which interference signals generated by high speed digital blocks cause parasitic currents to flow in the silicon substrate and couple devices in various parts of the circuits on this common substrate. In RFIC the switching noise couples to the sensitive analog circuits through the substrate causing degradation in performance and yield hit. Overcoming substrate coupling is a key issue in successful "system on chip" integration. In this thesis a substrate aware design flow is built, calibrated to silicon and used as part of the design flow to uncover substrate coupling problems in RFICs in the design phase. The flow is used to develop the first comprehensive RF substrate noise isolation design guide to be used by RF designers during the design phase. This will allow designers to optimize the design to maximize noise isolation and protect sensitive blocks from being degraded by substrate noise coupling. Several effects of substrate coupling on circuit performance will be identified and remedies will be given based on the design guide. Three case studies are designed to analyze the substrate coupling problem in RFICs. The case studies are designed to attack the problem from the device, circuit and system levels. On the device level a special emphasis is given to designing on chip inductors as an important device in RFIC. An accurate model is developed for a broadband fit of the inductor scattering parameters. This model is shown to be scalable and is proven to be accurate across various frequency bands and geometries. A special emphasis is put on the design for manufacturing effects that affect the design robustness. A circuit level case study is developed and results are compared to simulations and measurements to highlight the need for such a flow before tapping out to ensure a yielding part. The system level problem studied is a GSM receiver where the research results are directly applied to it as a demonstration vehicle to debug and resolve a system level substrate noise coupling problem that otherwise caused a product to be on the edge of malfunction.