Embedded passives on multi-layer printed wiring board (PWB) for 5GHz front-end module

As wireless communication devices become smaller and lighter, less space is allowed for the placement of the RF components. Area reduction of circuit design is becoming more and more notable. This paper introduces the design and model for the basic embedded passives, and methods of circuits design with embedded elements for 5 GHz RF front-end module for IEEE 802.11a on PWB lamination process. The developed front-end module includes PA (power amplifier) and SPDT (single pole, double throw) switch. The power amplifier exhibits 25.5 dB of gain, 26 dBm of output P1dB, and output IP3 of 37.6 dBm. The SPDT switch shows 2 dB of insertion loss and 18dB of port return loss. Six layer stacks and three kinds of materials, such as Hi-DK material, low-loss material and commercial organic material were applied in this design. In this substrate, we use special high dielectric constant (DK >60 @ 1MHz) material to design embedded capacitors and use the embedded resistors (1k ohm/per square) for whole SiP module. The simulation and measured results have demonstrated a successful circuit's design of RF front-end module for 802.11a WLAN.