  Advanced microwave technologies constitute the foundation of a wide range of
modern sciences, including quantum computing, microwave photonics, spintronics,
etc. To facilitate the design of chip-based microwave devices, there is an
increasing demand for state-of-the-art microscopic techniques capable of
characterizing the near-field microwave distribution and performance. In this
work, we integrate Josephson junctions onto a nano-sized quartz tip, forming a
highly sensitive microwave mixer on-tip. This allows us to conduct
spectroscopic imaging of near-field microwave distributions with high spatial
resolution. Leveraging its microwave-sensitive characteristics, our Josephson
microscope achieves a broad detecting bandwidth of up to 200 GHz with
remarkable frequency and intensity sensitivities. Our work emphasizes the
benefits of utilizing the Josephson microscope as a real-time, non-destructive
technique to advance integrated microwave electronics.
