The ADL5390 vector multiplier consists of a matched pair of broadband variable gain amplifiers whose outputs are summed. The separate gain controls for each amplifier are linear-in-magnitude. If the two input RF signals are in quadrature, the vector multiplier can be configured as a vector modulator or as a variable attenuator/phase shifter by using the gain control pins as Cartesian variables. In this case, the output amplitude can be controlled from a maximum of +5 dB to less than –30 dB, and the phase can be shifted continuously over the entire 360° range. Since the signal paths are linear, the original modulation on the inputs is preserved. If the two signals are independent, then the vector multiplier can function as a 2:1 multiplexer or can provide fading from one channel to another.
The ADL5390 operates over a wide frequency range of 20 MHz to 2400 MHz. For a maximum gain setting on one channel at 380 MHz, the ADL5390 delivers an OP1dB of 11 dBm, an OIP3 of 24 dBm, and an output noise floor of ?148 dBm/Hz. The gain and phase matching between the two VGAs is better than 0.5 dB and 1°, respectively, over most of the operating range.