Linear 公司的LTC5598是5-1600MHz高线性正交I/Q调制器,允许采用差分基带I和Q信号的RF信号进行直接调制. LTC5598支持点对点微波连接, GSM, EDGE, CDMA, 700MHz 波段LTE,CDMA2000, CATV应用和其它系统应用,140MHz的IP3为+27.7dBm, 900MHz的IP3为+22.9dBm.本文介绍了LTC5598的主要特性,方框图,典型应用电路和评估板电路.
The LTC5598 is a direct I/Q modulator designed for high performance wireless applications, including wireless infrastructure. It allows direct modulation of an RF signal
using differential baseband I and Q signals. It supports point-to-point microwave link, GSM, EDGE, CDMA, 700MHz band LTE, CDMA2000, CATV applications and other systems. It may also be confi gured as an image reject upconverting mixer, by applying 90°phase-shifted signals to the I and Q inputs.
The I/Q baseband inputs consist of voltage-to-current converters that in turn drive double-balanced mixers. The outputs of these mixers are summed and applied to a buffer, which converts the differential mixer signals to a 50Ω single-ended buffered RF output. The four balanced I and Q baseband input ports are intended for DC coupling from a source with a common-mode voltage level of about 0.5V. The LO path consists of an LO buffer with single-ended or differential inputs, and precision quadrature generators that produce the LO drive for the mixers. The supply voltage range is 4.5V to 5.25V, with about 168mA current.
主要特性:
Frequency Range: 5MHz to 1600MHz
High Output IP3: +27.7dBm at 140MHz +22.9dBm at 900MHz
Low Output Noise Floor at 6MHz Offset: No Baseband AC Input: –161.2dBm/Hz
POUT = 5.5dBm: –160dBm/Hz
Low LO Feedthrough:–55dBm at 140MHz
High Image Rejection:–50.4dBc at 140MHz
Integrated LO Buffer and LO Quadrature Phase Generator
50Ω Single-Ended LO and RF Ports
>400MHz Baseband Bandwidth
24-Lead QFN 4mm.4mm Package
Pin-Compatible with Industry Standard Pin-Out
Shut-down Mode
主要应用 :
Point-to-Point Microwave Link
Military Radio
Basestation Transmitter GSM/EDGE/CDMA2K
700MHz LTE Basestation Transmitter
Satellite Communication
CATV/Cable Broadband Modulators
13.56MHz/UHF RFID Modulator
图1.LTC5598方框图
图2. LTC5598典型应用电路
图3. LTC5598评估板电路图
