A compact 802.11b/g WLAN front-end module with integrated passive devices on modified ceramic substrate

We present a thin film on modified ceramic (TFoMC) technique in this work to achieve high-accuracy and high-uniformity design. The integrated passive devices (IPDs), including capacitors, inductors, band-pass filters and Baluns, are realized based on the proposed TFoMC technology. The IPD characterization results are close to the HFSS simulation, and reveal good in-substrate uniformity at the same time. To evaluate the TFoMC substrate performance, a WLAN front-end module (FEM) is designed and fabricated by integrating the IPDs, power amplifier (PA) die and switch die on the modified ceramic substrate. The FEM exhibits a 31-dB large signal gain with the power add efficiency over 10% in the pass band, and passes the spectrum mask specifications under 802.11b/g modulations. The error vector magnitudes of the FEM are 1.0 and 2.9%rms for 802.11b and 802.11g modulations, respectively. The IPD and FEM characterization results meet all the design requirements, indicating the excellent performance of the TFoMC substrate and making it as a promising candidate for the wireless-related applications.