The MAX2837 direct-conversion zero-IF RF transceiver is designed specifically for 2.3GHz to 2.7GHz wireless broadband systems. The MAX2837 completely integrates all circuitry required to implement the RF transceiver function, providing RF-to-baseband receive path; and baseband-to-RF transmit path, VCO, frequency synthesizer, crystal oscillator, and baseband/control interface. The device includes a fast-settling sigma-delta RF synthesizer with smaller than 20Hz frequency steps and a crystal oscillator, which allows the use of a low-cost crystal in place of a TCXO. The transceiver IC also integrates circuits for on-chip DC offset cancellation, I/Q error, and carrier-leakage detection circuits. Only an RF bandpass filter (BPF), crystal, RF switch, PA, and a small number of passive components are needed to form a complete wireless broadband RF radio solution.

The MAX2837 completely eliminates the need for an external SAW filter by implementing on-chip monolithic filters for both the receiver and transmitter. The baseband filters along with the Rx and Tx signal paths are optimized to meet stringent noise figure and linearity specifications. The device supports up to 2048 FFT OFDM and implements programmable channel filters for 1.75MHz to 28MHz RF channel bandwidths. The transceiver requires only 2μs Tx-Rx switching time, which includes frequency transient settling. The IC is available in a small, 48-pin thin QFN package measuring only 6mm x 6mm x 0.8mm.

MAX2837直接變頻、零IF RF收發(fā)器設(shè)計(jì)用于2.3GHz至2.7GHz無(wú)線寬帶系統(tǒng)。MAX2837完全集成了實(shí)現(xiàn)RF發(fā)送器功能所需的全部電路，提供RF至基帶接收通道、基帶至RF發(fā)送通道、VCO、頻率合成器、晶體振蕩器和基帶/控制接口。器件包含具有快速建立時(shí)間的Σ-Δ RF合成器，具有小于20Hz的頻率步長(zhǎng)和晶體振蕩器，允許使用低成本的TCXO晶體。該收發(fā)器IC還集成了片上DC偏移消除和I/Q誤碼以及載波泄漏檢測(cè)電路。僅需RF帶通濾波器(BPF)、晶體、RF開(kāi)關(guān)和一對(duì)非平衡變壓器以及少量的無(wú)源器件即可構(gòu)建完整的無(wú)線寬帶RF雷達(dá)解決方案。

MAX2837為接收器和發(fā)送器集成了完整的片上濾波器，完全無(wú)需外部SAW濾波器?；鶐V波器以及Rx和Tx信號(hào)通道經(jīng)過(guò)優(yōu)化，滿(mǎn)足嚴(yán)格的噪聲系數(shù)和線性度指標(biāo)。該器件支持高達(dá)2048 FFT的OFDM，并為1.75MHz至28MHz RF通道帶寬實(shí)現(xiàn)可編程通道濾波器。收發(fā)器僅需2μs Tx-Rx切換時(shí)間，包括頻率瞬態(tài)建立時(shí)間。該IC提供小型、48引腳薄型QFN封裝，尺寸僅為6mm x 6mm x 0.8mm。