Low Cost Embedded Duplexer Implementation for WiMAX Front-end Module with Multi-layer Organic Substrate

In this paper, low cost and highly compact band pass filters and duplexers are investigated for Dual-band WiMAX FEM (front-end module) with multi-layered organic package substrate. This dual band FEM includes a 2,5 GHz power amplifier die with switch and should have tiny PKG form factor for small mobile applications. In addition to module size limitation, FEM requires higher gain and stringent attenuation specification for achieving better sensitivity. To implement low cost and highly compact FEM, an effective solution is to embed passive components inside PCB. The embedded BPFs and duplexer were designed on 8 layer organic substrates for finding out efficient structure and verifying FEM specifications. This components design implemented by using ADS and HFSS The dual-band FEM with embedded passive components incorporates duplexer including 2 GHz, 5 GHz BPFs. BPFs and duplexer have size of 1.65 times 1.8 times 0.12 mm, 1.32 times 1.2 times 0.12 mm, 2 times 2 times 0.6 mm respectively. Integrated dual-band BPFs show an insertion loss of Lt-1.8dB in path band and 22~40dB 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.