In-phase quadrature modulation, or IQ modulation, is by far the dominant modulation scheme in communication applications for transmitting and receiving data. Its popularity is due to its efficient use of bandwidth, which continues to be a critical bottleneck in our data-hungry world. Because IQ modulation designers face a continual bandwidth crunch in a spectrum that is filled with interference, test via signal simulation is critical. This paper will look at how you can use the 33500B Series waveform generators with the IQ Signal Player option for generating ideal as well as non-ideal IQ signals.