TO MAKE IT EASIER to build in mobile-WiMAX support, a single-chip, 2.3-to-2.7-GHz, multiple-inputmultiple- output (MIMO) RF transceiver has emerged. By using a dual-receiver architecture to mitigate RF channel fading, the MAX2839 is vowing to improve receiver signal-to-noise ratio (SNR) by 10 dB compared to a single-receiver architecture. The transceiver's two receivers feature a low noise figure at 2.3 dB and 81-dBm sensitivity for a 64-quadrature-amplitude-modulation (QAM) signal at 5-MHz channel bandwidth. In addition, their 95-dB gain control range is digitally controlled in 1-dB steps. The receivers are factory calibrated to achieve better than 35 dB error vector magnitude (EVM), 45 dBc of sideband suppression, and carrier leakage of 40 dBc without DC-offset correction. On the transmitter, the MAX2839 features a 62-dB gain control range that is digitally controlled in 1-dB steps. It delivers a 0 dBm linear output with a 64-QAM signal, greater than 45 dBc of sideband suppression, and EVM of more than 36 dB. At the same time, the transmitter meets a 70-dBr spectral mask. The MAX2839 operates from a 2.7-to-3.6-V supply. To save power in systemsleep/ standby mode, a low-power shutdown mode reduces current consumption to 10 mA. The transceiver is available in a small, 8-x-8-mm, leadless, 56-pin TQFN package. P&A: $9.31 (1000-up, FOB USA), stock.
Maxim Integrated Products, 120 San Gabriel Dr., Sunnyvale, CA 94086; (408) 737-7600, FAX: (408) 737-7194, Internet: www.maxim-ic.com.
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