Apparatus, system and method for improved calibration and measurement of differential devices
View Patent ↗An apparatus, system and method for facilitating the calibration and measurement of differential devices by a variety of laboratory fixtures. An adapter is used to transition the connection of standard coaxial interfaces to a hermaphroditic differential interface while compensating for discontinuities on impedance at the connection. The adapter includes a transition region with conductors and shield dimensions that compensate for the discontinuity in impedance. The adapter has pin and socket inputs so that a mated pair of the adapters provides an insertable device for test and measurement on a four port vector network analyzer.
1. An insertable test device, comprising:
a first adapter having a first differential interface; and
a second adapter having a second differential interface, wherein each of the first adapter and second adapter includes at least two coaxial interfaces for coupling to a coaxial device, a first signal conductor for transmitting signals through the adapter, a second signal conductor for transmitting signals through the adapter, a shield conductor, and a transition region for providing a transition between coaxial and differential transmission environments and maintaining a uniform differential impedance through the transition; and the first adapter and the second adapter are mated at the first differential interface and the second differential interface, wherein the mated first adapter and second adapter provides less than −20 dB of differential return loss through 18 gigahertz.
2. The insertable test device of claim 1 , wherein the mated first adapter and second adapter provides less than −25 dB of common mode conversion by reflection through 18 gigahertz at the at least two coaxial interfaces of each of the first adapter and the second adapter.
3. The insertable test device of claim 1 , wherein less than −30 dB of mode conversion occurs during transmission through the mated first adapter and second adapter.