Performance assurance apparatus for phased antenna array drives

Claim 1

In an r.f. phase shift system including a plurality of diodes, digital phase shift specifying means for supplying a binary signal specifying bias states for said diodes, and means for selectively biasing said diodes to operate in one of a conducting and a nonconducting state to bring about a predetermined r.f. phase shift in response to the phase shift dictated by said phase shift specifying means, each of said diodes exhibiting characteristic first and second potentials when biased to said conducting and nonconducting states, a monitoring circuit for determining whether said diodes are properly biased to bring about said predetermined phase shift, said monitoring circuit comprising means coupled to each of said diodes for sensing the bias state indicating characteristic potential there across, means coupled to said sensing means for producing a diode bias state indicating first additional binary signal corresponding to said obtaining characteristic potential, means coupled to said first additional binary signal producing means and to said phase shift specifying means for comparing said first additional binary signal with said binary signal corresponding to the desired bias condition at said diodes to achieve a predetermined phase shift, and indicating means connected to said comparing means to provide a warning indication upon the sensing of a lack of correspondence between said binary signal and said first additional binary signal.