Microwave Journal
www.microwavejournal.com/articles/7162-analog-devices-introduces-broadband-quadrature-modulator

Analog Devices Introduces Broadband Quadrature Modulator

October 31, 2008

Analog Devices Inc., a leader in semiconductors for signal processing applications, introduced the industry’s first high-performance broadband I/Q quadrature modulator to integrate automatic gain control (AGC) circuitry within a compact 6×6 mm LFCSP (lead-frame chip-scale package). ADI’s ADL5386 provides a unique combination of performance and unmatched integration levels for low intermediate frequency (IF) and radio frequency (RF) transmitters within broadband wireless access systems, microwave radio links, cable modem termination systems and cellular infrastructure equipment.


Operating over a 50 MHz to 2200 MHz frequency range, the ADL5386 supports high-data-rate complex modulation for next-generation communication infrastructure equipment. Functionally complete, the ADL5386 integrates a 25 dB dynamic range output power detector and a VVA (voltage variable attenuator). Together, they form a closed-loop automatic level control (ALC) or AGC, enabling the ADL5386 to accurately set the output power to a user determined level. The ADL5386 provides a complete subsystem within a small footprint, saving considerable board space, component cost and circuit complexity over discrete implementations.

The ADL5386 provides exceptional output dynamic range due to its high output power capability (+10 dBm P1dB), high single-ended output linearity (+24 dBm IP3) and low noise floor (–160 dBm/Hz). The –38 dBm carrier feedthrough and –46 dBc sideband suppression at 350 MHz minimizes the need for calibration and nulling in complex high-order modulation applications such as 64 QAM (quadrature amplitude modulation) and greater.

The ADL5386 wideband inputs (DC to 700 MHz) are compatible with the output levels of ADI’s AD977x family of TxDAC+® (transmit digital-to-analog converter) devices. The –7 dBm local oscillator (LO) drive requirement is compatible with ADI’s ADF4360 series of integrated PLL (phase-locked loop) synthesizers. The 2× LO input frequency of the ADL5386 helps to minimize LO pulling in applications where LO isolation and board density are critical.