Maxim MAX19997A下变换双路混频方案

Maxim公司的MAX19997A是双路下变换混频器,能为1800MHz 到2900MHz频段的基带应用提供高线性和低噪音,支持低边和高边LO注入架构,低边配置提供8.7dB增益, +24dBm 输入IP3和10.3dB NF;高边配置时提供8.7dB增益, +24dBm 输入IP3和10.4dB NF.MAX19997A可应用在2.3GHz WCS 基站,2.5GHz WiMAX和LTE 基站,2.7GHz MMDS 基站以及UMTS/WCDMA 和dma2000® 3G,PCS1900 与EDGE,PHS/PAS等基站,固定宽带无线接入,无线本地网络,私人无线电台和军事系统.本文介绍了MAX19997A的主要特性,方框图和应用电路图以及2400MHz到2900MHz与1950MHz标准RF频段应用电路元件表.


The MAX19997A dual downconversion mixer is a versatile, highly integrated diversity downconverter that provides high linearity and low noise figure for a multitude of 1800MHz to 2900MHz base-station applications. The MAX19997A fully supports both low- and high-side LO injection architectures for the 2300MHz to 2900MHz WiMAX™, LTE, WCS, and MMDS bands, providing 8.7dB gain, +24dBm input IP3, and 10.3dB NF in the low-side configuration, and 8.7dB gain, +24dBm input IP3, and 10.4dB NF in the high-side configuration. Highside LO injection architectures can be further extended down to 1800MHz with the addition of one tuning element (a shunt inductor) on each RF port.
The device integrates baluns in the RF and LO ports, an LO buffer, two double-balanced mixers, and a pair of differential IF output amplifiers. The MAX19997A requires a typical LO drive of 0dBm and a supply current guaranteed below 420mA to achieve the targeted linearity performance.

The MAX19997A is available in a compact 6mm x 6mm, 36-pin thin QFN lead-free package with an exposedpad. Electrical performance is guaranteed over the extended temperature range, from TC = -40°C to +85°C.

MAX19997A应用:

2.3GHz WCS Base Stations
2.5GHz WiMAX and LTE Base Stations
2.7GHz MMDS Base Stations
UMTS/WCDMA and cdma2000® 3G Base Stations
PCS1900 and EDGE Base Stations
PHS/PAS Base Stations
Fixed Broadband Wireless Access
Wireless Local Loop
Private Mobile Radios
Military Systems

MAX19997A主要特性:
1800MHz to 2900MHz RF Frequency Range
1950MHz to 3400MHz LO Frequency Range
50MHz to 500MHz IF Frequency Range
Supports Both Low-Side and High-Side LO Injection
8.7dB Conversion Gain
+24dBm Input IP3
10.3dB Noise Figure
+11.3dBm Input 1dB Compression Point
70dBc Typical 2 x 2 Spurious Rejection at PRF = -10dBm
Dual Channels Ideal for Diversity Receiver Applications
Integrated LO Buffer
Integrated LO and RF Baluns for Single-Ended Inputs
Low -3dBm to +3dBm LO Drive
Pin Compatible with the MAX19999 3000MHz to 4000MHz Mixer
Pin Similar to the MAX9995/MAX9995A and MAX19995/MAX19995A 1700MHz to 2200MHz
Mixers and the MAX9985/MAX9985A and MAX19985/MAX19985A 700MHz to 1000MHz Mixers
42dB Channel-to-Channel Isolation
Single +5.0V or +3.3V Supply
External Current-Setting Resistors Provide Option for Operating Device in Reduced-Power/Reduced-Performance Mode



图1.MAX19997A典型应用电路图
表1.标准RF频段应用电路元件表(最佳频率范围2400MHz到2900MHz)
Table 1. Standard RF Band Application Circuit Component Values (Optimized for
Frequencies Ranging from 2400MHz to 2900MHz)



表2.标准RF频段应用电路元件表(最佳频率1950MHz)
Table 2. Extended RF Band Application Circuit Component Values (Optimized for 1950MHz Operation)