Maximizing Channel-to-Channel Isolation on PCBs for Multichannel Beamformers (Download)
Good channel-to-channel isolation is critical for maintaining performance in beamformer integrated circuits (BFICs). Channel-to-channel gain settings in phased-array applications can vary significantly to achieve the desired element tapering for sidelobe reduction and muting (a 30-dB difference isn’t unusual).
Modern BFICs typically have multiple parallel RF paths on the chip that are routed to pins located either on the same edge and/or same corner of the IC package, often with all inputs (or outputs) also on the same edge. As a result, the challenge is in routing the multiple RF lines to and from these closely spaced pins on printed circuit boards (PCBs) while maintaining sufficient isolation between the lines.