I/Q Modulator Covers 200 MHz To 6 GHz

Oct. 14, 2010

2 min read

IN ADDITION TO SPANNING an impressive 200 MHz to 6 GHz, the LTC5588-1 ultrahigh- linearity, direct-conversion, in-phase/quadrature (I/Q) modulator provides an output third-order intercept point of +30.9 dBm at 2.14 GHzwithout calibration. The device also offers simple calibration by a single-pin adjustment with a DC input voltage. This feature further optimizes its output third-order intercept point to +35.1 dBm. The LTC5588-1 boasts a noise floor of -160.6 dBm/Hz at 6 MHz offset from the carrier. It offers image suppression of -56.6 dBc at 2.14 GHz. In addition, the modulator's carrier leakage is -39.6 dBm while delivering +5-dBm signal power to its output without calibration. The device delivers stable performance from -40 to +85C (varying about 3 dB). The LTC5588-1's I and Q inputs are biased to a 0.5- VDC common-mode voltage that is directly compatible with commercially available digital-to-analog converters, which have similar DC common-mode voltage. Those inputs support signal bandwidth greater than 400 MHz. The I/Q modulator is powered from a single +3.3-VDC supply with an operating current of 300 mA. The I/Q modulator has fast turn-on and turn-off time, at 15 and 5 ns, respectively, supporting timedivision- duplexing (TDD) operation. P&A: stock; starting at $5.70 for 1000Q.

Linear Technology Corp., 1630 McCarthy Blvd., Milpitas, CA 95035-7417; (408) 432-1900, Internet: www.linear.com.

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About the Author

Nancy Friedrich

RF Product Marketing Manager for Aerospace Defense, Keysight Technologies

Nancy Friedrich is RF Product Marketing Manager for Aerospace Defense at Keysight Technologies. Nancy Friedrich started a career in engineering media about two decades ago with a stint editing copy and writing news for Electronic Design. A few years later, she began writing full time as technology editor at Wireless Systems Design. In 2005, Nancy was named editor-in-chief of Microwaves & RF, a position she held (along with other positions as group content head) until 2018. Nancy then moved to a position at UBM, where she was editor-in-chief of Design News and content director for tradeshows including DesignCon, ESC, and the Smart Manufacturing shows.