Compact delay lines and associated circuitry useful for wideband phased-array system

Abstract

A phased array system includes tunable delay elements having active delay element(s) and passive delay element(s). A second resolution by the passive delay element is smaller than a first resolution by the active delay element, and the resolution corresponds to delay applied to an input signal and has discrete steps for phase over which the delay element can be operated. For multiple sets of tunable delay elements, a calibration process sets, for one set of the delay elements, all but an n-th active delay element and the passive delay element to a first phase, and the n-th active delay element to a second phase. In a second set of the delay elements, all of the active delay elements are set to the first phase and the passive delay element is set to the second phase. A phase difference is detected and adjusted to meet a criterion between the two sets.