Millimeter wave (mmWave) frequencies are gaining significant attention in 5G communications due to their wide bandwidth compared to lower frequency cellular bands. This wider bandwidth helps meet the significant increase in data demand. However, there is a drawback of significant path losses. A 5G network was modeled using the SIMU5G framework within the OMNeT++ simulator to show carrier aggregation (CA) behavior and mmWave technology on network capacity. There were clear improvements in overall throughput with 10 carriers compared to a single-carrier configuration. There was also an increase in capacity with larger resource blocks (RBs). However, this increased computational complexity due to subcarrier spacing and greater transmission power requirements at the gNB (i.e. response for connecting user equipment like smart phones and other devices to the 5 G network). Negative impacts on system capacity included Doppler shift (as low as 3%), reduced bandwidth allocated to each user in the network given the higher number of users, and user distance from the base station. The findings provided valuable insight into the positive and negative effects of mmWave carrier aggregation on cellular network performance.