Design consideration for system-in-a-package with embedded passive circuits

Novel compact embedded super-diplexer for quadband GSM RF system is proposed. The design of super-diplexer is based on the performance of cascaded diplexer and low/high lowpass filters. At the same time, low cost compact embedded Tx GSM lowpass filter and diplexer on low cost laminate are designed to replace discrete LTCC lowpass filter and diplexer. The embedded lowpass filters, diplexer and super-diplexer are built and measured results show good agreement with the simulated data. The measured result of super-diplexer is well matched to the cascaded performance of diplexer and lowpass filter. The compactness of the newly developed super-diplexer makes the design and integration of quadband GSM RF systems attractive for further development and applications in SOC and/or SIP.