This document introduces the function and characteristics of LT5572 I/Q modulator, including supported modulation formats, input and output interfaces, and application scenarios.
This document provides a quick start guide for the DC945 demonstration circuit, which features the LT5572 high linearity direct quadrature modulator. The circuit is designed for wireless infrastructure applications and supports various modulation formats including GSM, EDGE, and CDMA. It operates as an I/Q modulator with an RF frequency range of 1.5GHz to 2.5GHz.
The guide details the typical performance summary and application notes regarding RF frequency range, baseband frequency range, and leakage performance. It also outlines a specific quick start procedure for setting up test equipment, including signal generators, a combiner, and a spectrum analyzer, to evaluate the modulator's performance metrics such as conversion gain and distortion intercept points.
| RF Frequency Range | 1.5 to 2.5 GHz |
|---|---|
| Baseband Frequency Range | DC to 460 MHz |
| Supply Voltage | 4.5V to 5.25V |
| Supply Current | 120 mA |
| Maximum Shutdown Current | 230 pA |
| Output 1dB Compression | +9.3 dBm |
| LO leakage | -39.4 dBm |
The RF frequency range extends from 1.5 GHz to 2.5 GHz.
The baseband frequency range extends from DC to 460 MHz (3dB bandwidth).
The LT5572 offers excellent LO to RF leakage performance, typically -39.4 dBm.
The HP3326A is given as an example of a signal generator with dual outputs and adjustable phase.