The AD8340 vector modulator performs arbitrary amplitude and phase modulation of an RF signal. Because the RF signal path is linear, the original modulation is preserved. This part can be used as a general-purpose RF modulator, a variable attenuator/phase shifter or a re-modulator. The amplitude can be controlled from a maximum of ?2dB to less than -32dB and the phase can be shifted continuously over the entire 360degree range. For maximum gain, the AD8340 delivers an OP1dB of 11dBm, an OIP3 of 24dBm and an output noise floor of -149dBm/Hz, independent of phase. It operates over a frequency range of 700MHz to 1.0GHz.

The baseband inputs in Cartesian I and Q format control the amplitude and phase modulation imposed on the RF input signal. Both I and Q inputs are dc-coupled with a +-500mV differential full-scale range. The maximum modulation band- width is 230MHz, which can be reduced by adding external capacitors to limit the noise bandwidth on the control lines.

The AD8340 is fabricated using the Analog Devices, Inc. proprietary, high performance 25GHz SOI complementary bipolar IC process. It is available in a 24-lead RoHS-compliant LFCSP package and operates over a -40°C to +85°C temperature range. Evaluation boards are available.