nt effectively gets counted double towards the EIRP. EIRP obviously impacts EVM. Target EVM numbers are dictated by 3GPP and need to be met by the RF subsystem. Scan range indicates the "reach" of the beamformer both in horizontal (azimuth) and vertical (elevation) directions. A 90-degree (-45.. .45) range implies that 4 RF subsystems need to be connected to support a full 360-degree range. Frequency band/range. Obviously, the target frequency band and range need to be wide enough to cover the application requirements. To our knowledge, there are no single RF solutions (yet) in the market that cover the complete set of options between 24 and 39 GHz as required by 5G/NR release 15. Power consumption/power efficiency. These are the key metrics for mmWave RF subsystems. mmWave PAs are inefficient due to the complexity of the technology. In addition, the analog nature of the beamformer (with some exemptions) means that a feedback based DPD algorithm can't be implemented, further reducing beamforming gains. mmWave RF subsystems require high EIRP to achieve coverage. Beamforming precision defines the minimum width and resolution of control of the radiated beam. mmWave Link Budget Example An example link budget to provide insight into mmWave RF Subsystem dimensioning is given here: We consider a gNB (base station) and UE (client) system with the following characteristics: Chapter 4 Hardware architecture choices 169 PA/LNA Baseband SoC Antenna Element Baseband Tx Chain + 0° 90° PA/LNA Baseband Rx Chain + Antenna Element RFIC Control FIGURE 4-25 mmWave radio frequency (RF) system. RF Bandwidth = 400 MHz Receiver Noise Figure (gNB and UE) = 5 dB Number of gNB antennas is 256, antenna gain/element of 5 dB Number of gNB antennas is 32, antenna gain/element of 5 dB Transmit power/PA (P01dB) of 15 dBm (low end CMOS up to SiGe) Assume PAPR of 11 dB (moderate to no CFR applied) Assume no losses due to T/R switches, cable/connector, etc.-these can be added by the reader in a true system analysis 3GPP 38.803 11 defined path loss (