Overview of Front-End RF Passive Integration into SoCs
Whereas integration of digital baseband and radio seemed impossible less than 10 years ago, today large systems-on-a-chip (SoCs) with the radio-frequency (RF), mixed signal, and digital blocks integrated on the same die are almost inevitable. The volume of investment and economies of scale make the standard CMOS process the perpetual cost leader. With more than 1 billion units produced each year, the cell phone market is the largest and most competitive that the semiconductor industry has to address, and as such, CMOS systems-on-a-chip with a large level of integration provide the lowest-cost path to products, assuming that the technical hurdles of implementation can be crossed. Despite the low-cost CMOS advantages and RF and digital integration, in all cellular applications where very aggressive filtering is required, external SAW filters are still very common. In addition to the extra cost and physical printed-circuit board (PCB) space imposed by these components, they introduce significant challenges in RF IC, package, and board design in multi-mode and multi-band systems, which are quite typical in cellular applications.
Considering all these concerns, given the advances on technology, and with the innovations on circuit and system design happening continuously, integrating these components on the SoC seems inevitable, and imminent. In this ...