A miniaturized LTCC multi-layered front-end module for dual band WLAN (802.11 a/b/g) applications

In this paper, dual-band LTCC RF front-end module (FEM) and PCB printed antenna are designed, fabricated, and characterized for IEEE 802.11 a/b/g wireless LAN Applications. The proposed LTCC RF FEM includes a diplexer and two band pass filters as a solution to 802.11 a/b/g system-on-package (SOP). A LTCC balun and dual-band antenna are also proposed to be integrated with the proposed RF FEM. The fabricated dual-band WLAN FEM has insertion loss of -2.8 dB and -3.5 dB in 2.4∼2.5 GHz band and 5.725∼5.825 GHz band, respectively. The isolation characteristic is Min. -48 dB in other operating frequency bands. The fabricated balun has the insertion loss of -0.7 dB, magnitude difference of 0.2 dB, and phase difference of 176∼177 degree at operating frequency of 2.4∼2.5 GHz. The PCB printed antenna has max. 2.4 dBi gain in omni-directional radiation pattern at 2.45 GHz and 5.0 dBi gain in directional radiation pattern at 5.8 GHz, respectively.