AD831 高性能、低失真500 MHz混频器

AD831: 高性能、低失真500 MHz混频器

AD831是一款低失真、宽动态范围、单芯片混频器，适合诸如HF和VHF接收机中的射频（RF）至中频（IF）下变频、DMR基站中的第二混频器、直接至基带变频、正交调制与解调以及超声成像中的多普勒频移检测等应用。该混频器内置一个LO驱动器和一个低噪声输出放大器，并且提供用户可编程功耗与三阶交调截点。

AD831提供+24 dBm三阶交调截点，可实现-10 dBm LO功耗，无需高功耗LO驱动器，也不存在相应的屏蔽和隔离问题，因而与无源混频器相比，能够改善系统性能、降低系统成本。该混频器采用±5 V电源供电时，RF、IF和LO端口可以为直流耦合或交流耦合；采用最小的9 V单电源供电时，这些端口可以为交流耦合。混频器采用RF与LO输入的工作频率可以高达500 MHz。该混频器的IF输出可以用作差分电流输出或单端电压输出。差分输出来自一对开集，并且可以通过一个变压器或电容进行交流耦合，以提供250 MHz输出带宽。在下变频应用中，可以将单个电容跨接在这些输出上来实现低通滤波器，以便直接在混频器内核处减小谐波，简化输出滤波。构建正交振幅调制器或镜像抑制混频器时，将两个AD831相连可以对其差分电流输出求和。

积分低噪声放大器提供一个单端电压输出，并且可以驱动滤波器、50 W放大器输入和模数转换器等低阻抗负载。其小信号带宽可超过200 MHz。连接在引脚OUT与FB之间的单个电阻用来设置增益。该放大器具有低直流失调特性，因而可以用于直接至基带变频和正交振幅解调等直接耦合应用。使用其输出放大器和最优源阻抗时，该混频器的SSB噪声系数在70 MHz时为10.3 dB。与无源混频器不同，AD831没有插入损耗，不需要外部双工器或无源端接。利用可编程偏置特性，用户可通过降低1 dB压缩点和三阶交调截点来降低功耗，从而可以在动态范围与功耗之间进行权衡考虑。例如，在蜂窝和双向无线电基站中，AD831可以用作低功耗第二混频器，同时仍然能提供远优于无源解决方案的性能。

The AD831 is a low distortion, wide dynamic range, monolithic mixer for use in such applications as RF to IF down conversion in HF and VHF receivers, the second mixer in DMR base stations, direct-to-baseband conversion, quadrature modulation and demodulation, and doppler-shift detection in ultrasound imaging applications. The mixer includes an LO driver and a low-noise output amplifier and provides both user-programmable power consumption and 3rd-order intercept point.The AD831 provides a +24 dBm third-order intercept point for -10 dBm LO power, thus improving system performance and reducing system cost compared to passive mixers, by eliminating the need for a high power LO driver and its attendant shielding and isolation problems.The RF, IF, and LO ports may be dc or ac coupled when the mixer is operating from ±5 V supplies or ac coupled when operating from a single supply of 9 V minimum. The mixer operates with RF and LO inputs as high as 500 MHz.

The mixer's IF output is available as either a differential current output or a single-ended voltage output. The differential output is from a pair of open collectors and may be ac coupled via a transformer or capacitor to provide a 250 MHz output bandwidth. In down-conversion applications, a single capacitor connected across these outputs implements a low-pass filter to reduce harmonics directly at the mixer core, simplifying output filtering. When building a quadrature-amplitude modulator or image reject mixer, the differential current outputs of two AD831s may be summed by connecting them together.

An integral low noise amplifier provides a single-ended voltage output and can drive such low impedance loads as filters, 50 W amplifier inputs, and A/D converters. Its small signal bandwidth exceeds 200 MHz. A single resistor connected between pins OUT and FB sets its gain. The amplifier's low dc offset allows its use in such direct-coupled applications as direct-to-baseband conversion and quadrature-amplitude demodulation.The mixer's SSB noise figure is 10.3 dB at 70 MHz using its output amplifier and optimum source impedance. Unlike passive mixers, the AD831 has no insertion loss and does not require an external diplexer or passive termination.A programmable-bias feature allows the user to reduce power consumption, with a reduction in the 1 dB compression point and third-order intercept. This permits a tradeoff between dynamic range and power consumption. For example, the AD831 may be used as a second mixer in cellular and two-way radio base stations at reduced power while still providing a substantial performance improvement over passive solutions.

技术特性

双重平衡混频器
低失真
三阶交调截点(IP3)：+24 dBm
1 dB压缩点：+10 dBm
带宽
RF和LO输入带宽：500 MHz
差分电流IF输出：250 MHz
单端电压IF输出：DC至200 MHz以上
只需很低的LO驱动：–10 dBm
单电源或双电源供电
使用双电源时为直流耦合
所有端口均可直流耦合
无低频下限，工作频率低至DC
用户可编程功耗

Doubly Balanced Mixer
Low Distortion +24 dBm Third Order Intercept (IP3) +10 dBm 1 dB Compression Point
Bandwidth 500 MHz RF and LO Input Bandwidths 250 MHz Differential Current IF Output DC to >200 MHz Single-Ended Voltage IF Output
Low LO Drive Required: –10 dBm
Single- or Dual-Supply Operation
DC Coupled Using Dual Supplies All Ports May Be DC Coupled No Lower Frequency Limit-Operation to DC
User-Programmable Power Consumption

技术指标

RF Frequency (MHZ): 400
IF Frequency (MHz): 200
LO Frequency (MHz): 400
LO Drive (dBm): 0
Conversion Gain (dB): 0
IP3 (dBm): 24
P1dB (dBm): 10
NF (dB): 14dB

功能框图

订购指南

产品型号	封装	引脚	温度范围	包装和数量	报价*(100-499)	报价*1000 pcs	RoHS
AD831AP 产品状态: 量产	20 ld PLCC	20	工业	Tube, 49	$ 9.47	$ 7.90	N 材料信息
AD831AP-REEL 产品状态: 量产	20 ld PLCC	20	工业	Reel, 1000	$ 0.00	$ 6.83	N 材料信息
AD831AP-REEL7 产品状态: 量产	20 ld PLCC	20	工业	Reel, 250	$ 0.00	$ 7.90	N 材料信息
AD831APZ 产品状态: 量产	20 ld PLCC	20	工业	Tube, 49	$ 8.20	$ 6.83	Y 材料信息
AD831APZ-REEL 产品状态: 量产	20 ld PLCC	20	工业	Reel, 1000	-	$ 6.83	Y 材料信息
AD831APZ-REEL7 产品状态: 量产	20 ld PLCC	20	工业	Reel, 250	-	$ 6.83	Y 材料信息

开发工具

产品型号	描述	报价	RoHS
EVAL-AD831EBZ 产品状态: 量产	Evaluation Board	$ 101.15	是