6GHz low power direct conversion I/Q modulator

May 30, 2016 // By Graham Prophet
LTC5589 is a low power I/Q modulator that simplifies sideband and carrier suppression calibration, and which enables battery-powered, high performance broadband transmitters operating in the range from 700MHz to 6GHz.

Powered by a single 2.7V to 3.6V supply, the LTC5589 modulator draws 29.5 mA current, 50% lower power consumption than other solutions. The new modulator exhibits sideband suppression performance of -50 dBc and carrier leakage of -43 dBm typical without calibration. Sideband and carrier suppression can be further improved by using the on-chip tuning capabilities via the SPI bus, to better than -60 dBc and -60 dBm, respectively. It has a very low output noise floor of -158.8 dBm/Hz, combined with OIP3 of 19 dBm, resulting in superior transmitter performance.


The LTC5589 supports narrowband as well as wideband transmitters. Its baseband bandwidth extends to 92 MHz with ±1 dB gain flatness, providing 184 MHz RF bandwidth at 1.8 GHz.