15 to 72 GHz Closed-Loop Impairment Corrected mm-Wave Delay-Locked IQ Modulator for 5G Applications

A mmWave Delay-Locked IQ Modulator with operational-amplifier based feedback loops working as closed-loop impairment correcting circuits is presented. The circuit makes uses of higher levels of integration and low-parasitic environment available in Keysight's proprietary InP HBT technology. The results suggest that higher levels of integration in IQ modulators along with inclusion of active feedback loops provide better levels of performance and stability than those achieved with typical open-loop (i.e. manual) adjustment approach.