Microwave Journal

Linear Technology's 92mW direct conversion I/Q modulator

August 13, 2014

A new low power I/Q modulator from Linear Technology enables battery-powered transmitters operating in the 30MHz to 1.3GHz frequency bands, breaking new ground in power consumption, sideband suppression, carrier leakage and dynamic range performance. The LTC5599 modulator, powered from a single 2.7V to 3.6V supply, draws only 28mA current, less than 60% that of alternative solutions-with no performance sacrifice. The LTC5599 delivers outstanding native -52.6dBc sideband suppression and -51.5dBm carrier leakage without calibration. With on-chip calibration resources, performance can be further improved to
-60dBc and -65dBm, respectively. Moreover the device output achieves an excellent noise floor of -156dBm/Hz with an OIP3 of 20.8dBm, delivering superior transmitter performance.

The LTC5599 combines low power consumption and robust performance to suit a wide range of demanding battery-powered radios and wireless communications applications that are exposed to strong radio interference. These include wireless professional microphones, frequency hopping narrowband and broadband portable field radios, public safety radios, train communications, as well as broadband VHF/UHF white space modems, software-defined radios, portable RF test equipment, picocell base stations, low-power microwave backhaul, small wireless repeaters and satellite modems.

 The LTC5599 is available in a 4mm x 4mm QFN package, providing a compact footprint. The product is specified for case operating temperature from -40°C to 105°C, supporting reliable operation in extended temperature environments. The device can be conveniently shut down with an enable control pin. When disabled, the device conserves power by drawing a typical of 0.7µA standby current. The LTC5599, priced starting at $4.45 each in 1,000-pieces quantities, is available immediately in production quantities. For more information, visit www.linear.com/product/LTC5599