Analog Devices has introduced RF-to-digital baseband transceivers designed to enable the IEEE 802.16d/e mobile WiMAX (Worldwide Interoperability for Microwave Access) standard for mobile communications devices, such as cell phones, personal digital assistants (PDAs), and handheld multimedia devices.
The AD9354 and AD9355 offer low power consumption and are available in a small package, while adding an additional receiver path for multiple-input multiple-output (MIMO) support. The power and space savings of the AD9354 and AD9355 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 transceivers enable designers to eliminate all analogue and RF functionality from their baseband processors.
With separate digital and analogue blocks, the communications and applications processors can be manufactured in 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 tight error vector magnitude (EVM), maximising network throughput. The transceivers communicate with a WiMAX terminal's baseband ASIC or FPGA using the industry standard JESD207 digital interface. The data bus requires 13 pins.
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 a good 3.25 dB noise figure (NF) and high linearity, both of which enable optimum real-world performance as WiMAX network traffic increases. The smart partitioning architecture enables autonomous AGC (automatic-gain control), transmit-power control (TPC), 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.
The AD9354 and AD9355 mobile WiMAX transceivers are sampling now.
