The AD9356 is a fully integrated dual receiver, dual transmitter for WiMAX /BWA/WiBRO basestations and fixed CPEs. The RF MxFE combines the RF front-end with mixed-signal baseband data converters and filtering enabling an easy-to-use a JESD-207 or ADI/Q(R) digital interface to the Baseband Processor (BBP) ASIC or FPGA. The AD9356 operates in the 2.3 to 2.7 GHz range covering most of the licensed and unlicensed bands and supports channel bandwidths of 3.5, 4.375, 5, 7, 8.75, and 10 MHz.
The direct-conversion receivers have state-of-the-art noise figure and linearity and require no external components with the exception of baluns. The complete RF sub-system integrates autonomous AGC loops, DC offset corrections, and quadrature calibrations, thus eliminating the need for high-speed interaction with the BBP processor.
Two high dynamic range ADCs digitize the received signal. Decimation and channel filters produce a 12-bit output signal at a sample rate determined by the bandwidth mode. The transmit path takes 12-bit input data and interpolates before converting to the analog domain and upconverting to the carrier frequency. The highly linear transmit path has excellent spectral purity with side-band noise less than -130 dBc/Hz at 8 MHz offset and offers EVM of -38 dB at 0 dBm output power. The transmit power is detected by an accurate power detector with a range of more than 50 dB in 0.25 dB steps. A single factory measurement calibrates the detector.
The reference frequency may be provided by an external reference or via an internal digitally controlled crystal oscillator (DCXO) with a resolution of 0.012 ppm. Using the built-in state machine to control the device, the AD9356 may be easily controlled in TDD, HFDD, or, if two devices are used, FDD modes. One three-input internal auxiliary ADC and two auxiliary DACs are available for system monitoring and control. Four general purpose I/Os are also included and can be register programmed or automatically sequenced by a user-defined state machine. Mode control is via a 4-wire serial port and two control signals. A single 3.3V supply powers the AD9356 with on-chip LDOs providing all other required supplies. The AD9356 package is a 10 x 10 mm, 144-ball BGA.