Contactless Vector Network Analysis With Printed Loop Couplers

In this paper, an introduction to contactless vector network analysis is given. Furthermore, the implementation of a contactless measurement setup is presented using different printed coupling structures. The coupling structures are connected to a vector network analyzer (VNA) by means of conventional on-wafer probes, as well as planar-coaxial transitions. For the contactless method, conventional calibration algorithms are used to determine the scattering parameters of a device within a complex planar circuit. The contactless measured results are compared to results received with a conventional VNA and to simulation results obtained with a 3-D field simulator. These comparisons show that, especially for small coupling structures of approximately 1 mm, the results correspond well up to 20 GHz.