Millimeter-wave frequency FDTD simulation for error vector magnitude of modulated signals

At millimeter-wave frequencies, a simulation of propagating complex modulated signals through an environmental channel can be computationally prohibitive using the finite difference time domain (FDTD) method. The “grid impulse response” method uses a delta-function as a source signal to solve for the transfer function of the finite difference time domain grid. Once the transfer function of the channel is known, any number of source signals of differing lengths, such as those involving M-ary quadrature amplitude modulation may be used to estimate the propagation of a complex modulated signal through the environmental channel. Numerical investigations show that the maximum error between the two approaches can be very small. Simple environmental channels are used to present the error vector magnitude at mmWave frequencies obtained from the grid impulse response method.