Embedded RF Filters for WLAN and Bluetooth Applications

This paper discusses the design and integration of RF filters in multilayer organic substrate. Using a methodic approach, several low-pass and band-pass filters have been designed, fabricated and fully characterized. The electrical analysis clearly indicates, which of the low-pass filters is less susceptible to process variations and therefore more appropriate for high volume manufacturing. It is shown that these filters provide electrical performance similar to their commercially available ceramic counterparts while using relatively smaller real estate. All filters are fabricated in the innermost layers of a multilayer organic package substrate with embedded passives capability.