An Integrated Signal Injection and Detection Broadband Near-Field Probe for Circuit Characterization

In this letter, a probe with integrated signal injection and detection is designed. By actively injecting signals into the circuit, the probe enables the identification of characteristics at different locations of the circuit. The probe features a minimum width of 4 mm, and a length of 59.32 mm. By using L-shaped structures and impedance matching techniques, the probe achieves a frequency range of 40 GHz. In addition, the design incorporates a ground–signal–ground–signal–ground structure to ensure high isolation between the injection and detection components. Near-field scanning of the microstrip line enables the realization of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">S</i>-parameter and phase distributions at various frequencies, facilitating the extraction of circuit characteristics at different spatial locations.