Description
Demonstration circuit 2091A is optimized for evaluation
of the LTC®5599 low power direct quadrature modulator.
The balanced I and Q baseband input ports can be either
AC- or DC-coupled to a source with a common mode voltage
level of about 1.4V. Fixed LC networks on the LO and
RF ports cover a continuous 90MHz to 1300MHz range.
The SPI interface controls the supply current, modulator
gain, and allows optimization of the LO carrier feedthrough
and side-band suppression.