High-Power V-Band-to-G-Band Photonically Driven Electromagnetic Emitters

High-power V -band-to- G -band (50-220 GHz) photonically driven electromagnetic emitters, composed of frequency-independent (FI) antennas and charge-compensated modified unitraveling carrier photodiodes (CC-MUTC PDs), are demonstrated in this article. The designed and fabricated PDs achieve a responsivity of 0.2 A/W and are able to provide up to 12-dBm output power. The impedances of the PD and the FI antennas (the sinuous antenna, the spiral antenna, and the log-periodic antenna) are characterized, showing that different antennas could be selected to provide either highest radiated power or widest bandwidth depending on applications. The measurement results indicate that the integrated emitter with the sinuous antenna and the 8- \mu \mathrm {m} PD achieves a record-high broadside effective isotropic radiated power (EIRP) of 20 dBm with an optical-to-terahertz (THz) power conversion efficiency of 15.7% while maintaining EIRP greater than 0 dBm up through 115 GHz of bandwidth (50-165 GHz). The emitter with the spiral antenna and the 5- \mu \mathrm {m} PD provides a wide 3-dB bandwidth of 34 GHz with a maximum EIRP of 8.8 dBm. These high-power wideband emitters can be used for wireless communications, millimeter-wave (mm-wave) and sub-THz imaging, and radar systems.