What’s In Front Of The Baseband?

When describing the hardware of current smartphones, particular emphasis is usually put on the fact that there are there are two main processor blocks in the device. On the one hand there is the application processor, usually with several CPU cores today, that runs Android or another operating system. On the other hand, there's the baseband processor, sometimes also referred to as 'the modem' that handles communication with cellular networks such as GSM, UMTS and LTE. In many phones, both functionalities are integrated in the same chip. The modem, however requires a couple of functionalities between itself and the antennas such as transcievers that are separating the uplink and the downlink, frequency filters, power amplifiers, band switches, etc, commonly referred to as 'the front-end'. Quite some time ago, I saw this post on AnandTech that describes the latest state of the art and challenges in that area. Well worth a read!