3G/4G Multimode Cellular Front-end
In of our series we looked at the challenges and factors of the front end for 3G multimode handsets that were mostly externally driven. Our focus was on regulatory issues concerning frequency spectrum and market drivers that impacted future front end requirements. In this second installment, we'll examine the multiple architectures available to accomplish multimode front ends, and we will summarize the trade-offs of each individual approach.
In this section our goal is to examine the different front end architecture options and discuss the pros and cons of each approach. To do so will draw upon the Part 1 white paper that looked at the number of band combinations and how that impacts the front end architecture.
Recall in Part 1 that we explored what a typical multi-band handset may look like. Our market analysis and feedback indicate that phones and data cards will be capable of handling between two and five UMTS bands as well as being backward-compatible to 2G systems. One view of what that might look like conceptually can be seen in the drawing below (Figure 1). These band combinations will change depending on the carrier, roaming agreements in place, and region of the world.