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| Analog Devices' RF Transceivers for Mobile WiMAX Applications Analog Devices has introduced RF-to-digital baseband transceivers designed to enable broadband connectivity in mobile communications terminals, such as cell phones, personal digital assistants, and handheld multimedia devices, using WiMAX. As WiMAX evolves from a fixed-line protocol to one that increasingly serves portable communications applications, device manufacturers are requiring smaller, more energy-efficient solutions that deliver IEEE 802.16d/e mobile WiMAX standard compatibility within the cost, space, and power budgets of mobile communications terminals. According to research firm, In-Stat, the global market for WiMAX chipsets is expected to increase to 21 million units in 2011, up from three million in 2006 — with much of that coming from growth in the Mobile WiMAX sector. Already, wireless service carriers, including Sprint Nextel and Clearwire, are planning Mobile WiMAX deployment in the U.S. in conjunction with device manufacturers such as Motorola, Nokia, and Samsung. Plans for worldwide networks in Europe, Africa and Asia-Pacific are similarly spurring demand for RF transceivers capable of supporting the 2.3- to 2.7-GHz and 3.3- to 3.8-GHz Mobile WiMAX spectrum. Building on ADI's AD9352 and AD9353 family of integrated WiMAX transceiver components introduced in 2006, the AD9354 and AD9355 components consume less power than other transceivers in their class and are available in a 20 percent smaller package, while adding an additional receiver path for multiple-input multiple-output support. The power and space savings of the AD9354 and AD9355 components enable manufacturers to incorporate WiMAX functionality into handsets, thumb drives or PCMCIA cards. By integrating ADCs, DACs and real-time control and calibration loops, the transceiver components repartition the signal chain, combining all analog and RF functionality on the AD9354 or AD9355 components. This frees providers of the communications and applications processors to manufacture their digital products in the most cost-effective digital CMOS process technologies, reducing power, package size and system design complexity. The AD9354 and AD9355 transceivers integrate two direct-conversion receivers that provide support for MIMO technology, which ensures mobile devices achieve uninterrupted WiMAX service. The direct-conversion transmitter architecture achieves state-of-the-art error vector magnitude, maximizing network throughput. The transceivers communicate with a WiMAX terminal's baseband ASIC or FPGA using the industry standard JESD207 digital interface that Analog Devices helped to define. The data bus requires 13 pins, which is comparable to competitive products employing analog interfaces. The AD9354 and AD9355 operate in the 2.3- to 2.7-GHz and the 3.3- to 3.7-GHz ranges and support channel bandwidths of 3.5, 4.375, 5, 7, 8.75 and 10 MHz. The devices have an excellent 3.25 dB noise figure and best-in-class linearity, both of which enable optimum real-world performance as WiMAX network traffic increases. The smart partitioning architecture enables autonomous automatic-gain control, transmit-power control, and calibration routines that dramatically reduce the RF driver development effort. Additionally, the highly accurate closed-loop power control enables 1-point factory calibration of transmit power. In contrast, other transceivers require 8 to 10 calibration points, which increase final test costs and extended development times. write your comments about the article :: © 2007 Networking News :: home page |