Improved Complex Receiver System Design Strategies to Overcome EMI/EMC Challenges

This article analyzes various strategies and implementation techniques in detail for complex receiver system design to qualify Environmental Stress Screening (ESS) especially EMI/EMC tests for airborne system applications. Isolation of leakage energy between various RF/DC-DC converters/regulators/pulsing blocks are the key target of this design to keep conductive and radiative emission to a minimum. Hence, complex receiver design has been segregated into various modules. Then they are stacked together very tactfully within the specified area without compromising inter-channel/module interference between them and the form factor, respectively. The super compact stacks are further channelized for RF, DC supply, controls etc. and protected from any kind of interference. Low cost flexi interconnects are made to interface various stacks to arrest unwanted high/low frequency leakages. Proper layout, component placement, layer specific signal routing, and wire shielding have been used to protect low/high frequency reference clock, control signals, switching pulses, etc. from mixing. Processor boards with a DC supply unit are also integrated into the receiver as another stack and have been isolated from each other to qualify emission tests. Finally, four modules are developed and tested over temperatures of -40°C to +71°C (ESS) and EMI/EMC successfully to establish the methodology for mass production.