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802.11A and 802.11A/G RF Transceivers Support Pre-802.11N MIMO and Smart-Antenna Radio Systems

SUNNYVALE, CA-December 1, 2004-Maxim Integrated Products (NASDAQ: MXIM) announces the release of two single-chip RF transceivers designed for single-band 802.11a and dual-band 802.11a/g WLAN applications. The MAX2828 covers the world-band frequency spectrum from 4.9GHz to 5.9GHz, while the MAX2829 covers both 2.4GHz to 2.5GHz and 4.9GHz to 5.9GHz bands. The ICs feature a MIMO (Multiple-Input-Multiple-Output) mode in which the phase angle of the local oscillator is held constant during transmit/receive operation, allowing multiple transceivers to be synchronized to the system reference oscillator. This feature is critical for 802.11n NxN MIMO radio and smart-antenna-based WLAN applications.

The MAX2828/MAX2829 transceivers are manufactured using Maxim's in-house, high-performance SiGe BiCMOS process. Compared to CMOS-only designs, this process results in as much as 4dB better receiver sensitivity performance in both 11a and 11g 54Mbps mode. This performance improvement translates to 58% longer range for line-of-sight WLAN applications and 36% longer range for indoor applications.

The transceivers derive their superior receiver sensitivity from a combination of an RF-optimized IC process technology and innovative circuit design. The result is a low receiver noise figure of 3.5 dB, low oscillator phase noise of -99dBc/Hz at 100kHz, only 35ns group-delay variation in the channel filter passband, and high-I/Q quadrature sideband suppression of 40dBc. A fast, digital AGC and DC-offset cancellation scheme allows antenna diversity selection within a packet header, thereby further improving range. The transceivers are also designed with -10dBm receiver input IP3 at max gain, and 80dB filter channel selectivity, resulting in excellent immunity to 802.11a/g OFDM and 802.11b CCK jammers. On the transmitter side, the Tx output is highly linear, delivering -2.5dBm for 802.11g and -5dBm for 802.11a at <2% EVM. This allows the external PA to deliver its maximum power without added distortion from the transceiver, directly improving transmitter range.

The MAX2828/MAX2829 transceivers significantly reduce the radio BOM cost and implementation size by integrating all RF transceiver function blocks between the RF switch and baseband processor I/Os. No external SAW filter is required. The transceivers integrate the full transmit path (from baseband IQ input to RF output) and full receive path (from LNA input to baseband IQ output), a low-noise VCO, a fractional-N PLL synthesizer, and baseband/control interface. The transceivers operate from a +2.7V to +3.6V supply. A 1µA low-power shutdown mode saves power during the system sleep mode.

The ICs are available in a small 8mm x 8mm, 56-pin, leadless QFN. Prices start at $7.11 (1000-up, FOB USA). An evaluation kit is available to speed designs. Please contact the factory for a complete RF and baseband/MAC reference design. Visit www.maxim-ic.com/MAX2828 for the complete data sheet and further information on Maxim's full line of WLAN RF IC products.