A very high linearity and low noise I/Q demodulator from Linear Technology provides the performance needed for direct conversion and IF conversion of radio signals to baseband for high performance receivers. The LT5517 has an IIP3 of 23.5 dBm and a noise figure of 9.5 dB at 200 MHz, allowing the detection of weak signals, even in the presence of high level interference. This performance results in a Spurious Free Dynamic Range (SFDR) exceeding 80 dB. The LT5517 integrates a precision 0° and 90° phase splitter, providing accurate I (In phase) and Q (Quadrature phase) demodulation of RF signals, ranging from 40 MHz to 900 MHz, directly to baseband in a compact solution. Other applications include micro-base stations, repeater cells, RFID readers, and broadband fixed wireless access. The LT5517 incorporates a pair of matched high linearity mixers, with an on-chip quadrature phase generator and splitter. The I and Q signal paths are internally gain matched to 0.03 dB typical, with a typical phase mismatch of 0.7°, resulting in highly accurate I and Q demodulation. The differential I and Q outputs have low DC offset, typically 0.5 mV, and built-in 130 MHz low-pass filters to remove out-of-band noise. The LT5517 provides a compact and robust receiver solution.
Linear Technology Corporation