Frequency conversion is a research area focused on converting the frequency of electromagnetic signals from one frequency to another. This process is commonly used in communication systems, radar systems, and other electronic devices. Frequency conversion can involve both up-conversion (increasing the frequency) and down-conversion (decreasing the frequency) of signals. This research area often involves the study of various techniques and devices, such as mixers, frequency multipliers, and frequency synthesizers, to achieve the desired frequency conversion.