A VARIABLE DIFFERENTIAL PHASE SHIFTER

摘要

A variable differential phase shifter is provided. The device provides a continuous variation in phase between two outputs derived from a single output. The device is suitable for application at signal frequencies around 900 MHz, and is constructed in the form of an inner (38) and outer (37) sleeve capacitively coupled to an inner conductive rod (24) and outer conductive tube (26) respectively, wherein the inner (38), and outer (37) sleeves are connected to an input and can be moved in fixed relative relation thereby varying the phase relationship between the two outputs which are connected to the inner rod (24) and outer tube (26). A dielectric layer (25 and 27) may be provided around the inner rod (24) and outer tube (26). An unequal power division version of the device is provided for by the inclusion of a dielectric tube surrounding a portion of the inner rod.