 IF gain amplifier generates second- and third-order har- monic distortion (HD2 and HD3) products from the strong interferer, which can fall in the signal band of interest. These low-order harmonics are typically either frequency controlled by choosing an appropriate IF frequency or attenuated by the following BPF. Several impairments originate from the data converter. Similar to the IF amplifier, the ADC generates strong low-order harmonic distortions (HD2 and HD3) from the blocker. The IF frequency can be chosen such that these harmonics are located out-of-band for an in-band blocker. For an OOB blocker, adequate external filtering should be provided. High-order harmonics set a spur floor that cannot be controlled and needs to be taken into consider- ation. The phase noise of the sampling clock (jitter) also mixes with the interferer. It scales with 20 log (fs/fin), SO the higher the input frequency range (IF) with a fixed ADC sampling rate, the larger its impact on the overall system noise. The RF-sampling ADC may achieve its fast clock rate using interleaving techniques. In this case, the interleaving spurs need to be considered not only for the noise analysis with in-band blockers but also for the filter design for out-of-band interferers. 5.6 Considerations for Implementation and Operation in mmWave Bands 5.6.1 Semiconductor Technologies for mmWave Operation The mmWave RF analog implementations have been historically dominated by III - V 14 mono- lithic microwave integrated circuit (MMIC)¹5 semiconductor technologies which primarily use A substance that can act as an electrical conductor or insulator depending on chemical alterations or external conditions. Examples include silicon, germanium, and gallium arsenide. It is called III-V materials since semiconductor elements are in groups III and V of the periodic table of chemical elements. An MMIC is a type of integrated circuit device that operates in microwave frequencies. These devices typi- cally perform functions such as mixing, power amplification, low