A New Differential Composite Probe With Parasitic Series Loops and High Sensitivity

In this work, a new differential composite probe with parasitic series loops is developed. The proposed probe consists of a U-shaped loop as the driving element, a pair of series dual loops as parasitic loops, and two striplines with two output sub-miniature-As (SMAs). First, a traditional U-shaped loop probe is utilized to test the electromagnetic fields (E and H) at the same time. Second, a pair of series dual loops as parasitic elements is inserted on both sides of the U-shaped loop to improve the detection sensitivity. The reason is that additional parasitic loops can receive more electromagnetic field components, which can increase the detection sensitivity. It is noticed that a pair of special connected via is used to connect the end of series dual loops with the middle U-shaped loop in a mirrored manner. To prevent unwanted electromagnetic modes, two rows of via fences next to these detection loops are introduced into the proposed probe. In addition, to demonstrate the unique features of the presented probe, the probe’s simulation model is simulated, fabricated, and measured based on a standard $50~\Omega $ microstrip line. Measured results reveal that the presented differential composite probe can not only test the electromagnetic fields (E and H) at the same time but also have high detection sensitivity and low profile.