Switching coaxial PCB testpoint
Original Publication Date: 2001-Oct-01
Included in the Prior Art Database: 2003-Jul-23
In radio-based electronic products without an external RF (radio frequency) connector (an external connec- tor is used for connecting accessories or an antenna and is typically used for production tests as well) the need for a RF connection in for instance production- testers often stipulates a 50 ohms coaxial PCB (printed circuit board) testpoint for a likewise coaxial 50 ohms testneedle in the test equipment. The method proposed here gives a new scope for development in the design of such a RF coaxial testpoint. A testpoint which is required to be 50 ohms can load the RF signal paths quite heavily, especially if they are far from 50 ohms. The problem is that the testpoint will keep loading the RF circuits also after production. The idea is that the outer RF signal ground ring is divided into two or three equal size arcs (circular elements) of which only one is the original RF signal ground (see fig. 1). The remaining one or two arcs will now be floating unless a coaxial testneedle is connected to the PCB, in which case they are grounded. The reason for two or three segments is that these geometric constructions ensures that the testneedle will connect to all pads.