Design and characterise radio-frequency circuits, antennas, and wireless systems operating from sub-1 GHz to mm-wave (77 GHz and beyond) — covering 5G NR, Wi-Fi 6E, radar, satellite, and defence-comms bands. Day-to-day spans LNA / PA / mixer / VCO / PLL circuit design in ADS or Cadence RF, antenna synthesis and simulation in HFSS / CST, S-parameter and noise-figure measurement on a VNA, link-budget analysis, EMC/EMI pre-compliance on a spectrum analyser, and RFIC bring-up on characterisation benches. In India the role concentrates at semiconductor GCCs (Qualcomm India, MediaTek India), telecom equipment OEMs (Nokia, Ericsson), ISRO and DRDO labs, defence PSUs (BEL, ECIL, NPOL), and private defence-electronics integrators (Tata Advanced Systems, Bharat Forge Defence, Astra Microwave Products, Alpha Design Technologies). The RF domain is one of the most physics-heavy roles in electronics, combining electromagnetics, circuit theory, and system-level thinking in equal measure.