Microstrip flexible printed wiring board interconnect line

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT The invention is a class of RF flexible PWB transmission lines used to connect strip transmission line microwave PWB assemblies without the use of coax connectors and coaxial cables.
The invention can interconnect strip transmission line microwave PWB assemblies with fewer RF connector components and in less RF connector volume than that occupied by conventional connector apparatus.
The invention uses flex PWB line fabrication technology to create a flexible microstripline interconnection circuit.
This flexible line is designed to operate at microwave frequencies with little or no RF distortion as a function of flex or twist.
Little or no radiation leakage has been detected from the line up to 8 inches in length.
An exemplary embodiment is shown in FIG.
1.
First and second stripline circuit boards 10 and 20 each have formed on respective upper surfaces 12 and 22 microwave stripline transmission lines (not shown in FIG.
1) in a conventional manner.
It is desired to provide a flexible RF interconnection between the respective stripline transmission lines.
Such an interconnection is provided by flexible microstrip interconnection line 50.
Circuit 50 may provide, by way of example, a connection between a T/R module 24 on board 20 and an RF stripline feed on board 10 in an active array antenna assembly.
The flexible line 50 comprises a flexible dielectric circuit board 52 having formed on one surface 60 a conductive ground plane layer 54.
A microstrip top conductor trace 56 is formed on the opposed surface 58 of the dielectric circuit board 52.
The flexible line 50 is in this exemplary embodiment arranged in a loop 62, so that the line provides physical tolerance relief as well as an RF connection between the microwave stripline circuit board assemblies 10 and 20.
The line 50 operates at microwave frequencies even when the line is bent and twisted.
In this embodiment, the dielectric circuit board 52 is a thin layer of dielectric material such as 5880 RT/Duroid (TM) and Kapton (TM) having a thickness of 0