Highly Compact Embedded Duplexer Implementation for WiMAX Dual-band Front-end Module with Organic Package Substrate

In this paper, low cost and high performance duplexers are investigated for WiMAX front-end module with multi-layered organic package substrate. This dual band FEM includes a 2.5GHz power amplifier die with switch and has tiny PKG form factor. In addition to module size limitation, FEM requires higher gain and stringent attenuation characteristics specification. The embedded BPFs and duplexer were designed on 8 layer organic substrates by using ADS and HFSS for finding out efficient structure and verifying FEM specifications. The dual-band FEM with embedded passive components incorporates duplexer including 2GHz and 5 GHz BPFs. BPFs and duplexer have size of 1.65 × 1.8 × 0.12mm, 1.32 × 1.2 × 0.12mm and 2× 2× 0.6mm respectively. Integrated dual-band BPFs show an insertion loss of < −1.8 dB in path band and 22∼40 dB attenuation performance in rejection band. The measured results of BPFs and duplexer show good electrical performance with low insertion loss, high attenuation. Embedded passive Packaging technology has many advantages such as improving packaging efficiency and better electrical performances for low cost and highly compact RF SOP (System on Package) applications.