An apparatus for probing high frequency electronic devices in wafer form includes a high frequency wafer probe (16, 56) having a conductor (36, 61), a dielectric layer (37, 71, 72), a grounding layer (38, 81, 82, 91), a signal probe needle (39,86), and a pair of ground needles (43, 72, 76) coupled to...http://www.google.de/patents/US5486770?utm_source=gb-gplus-sharePatent US5486770 - High frequency wafer probe apparatus and method
