Embedded capacitors technology in 2.4 GHz power amplifier with multi-layer printed wiring board (PWB) process

In addition to the technology of system on a chip (SOC), the board level, system in a package (SIP) technology, will be another trend concordant with SOC technology to meet the requirements of future high frequency products. Therefore, the Embedded Passives technology becomes an important subject for both SOC and SIP technology to implement and extend their application field. For SIP technology, the integral substrate technology is a solution to realize embedded passives. The integral substrate technology is a noble design and manufacturing methodology which uses special materials to achieve specific circuit functions, and combines fine processes such as high density interconnection (HDI) technology. In this paper, a newly achieved high dielectric constant (Hi-DK) material, which is suitable for the Multi-Layer Printed Wiring Board (PWB) lamination process, is used to implement embedded capacitors. The electrical parameters such as dielectric constant and loss tangent versus frequency of the Hi-DK material were extracted from circuit characteristics. Many different types and sizes of embedded capacitors were designed and had been fitted by some circuit equivalent models; then we constructed a library of these elements. Furthermore, we verified these embedded capacitors by a 2.4 GHz power amplifier on a 6-layer, built-up process PWB, for wireless LAN application. The performance of the power amplifier designed by embedded capacitors was as good as the one designed by surface mount capacitors.