Patent ID: 6928281

Claim:
An active antenna power interface circuit for coupling a supply voltage from a radio receiver to an antenna feed, comprising: a DC power input; a power switching element connected in series between said DC power input and said antenna feed, said power switching element having a control input for selecting a conducting state or a nonconducting state of said power switching element; a high side voltage sensor sensing a first voltage proportional to a voltage at said DC power input; a low side voltage sensor sensing a second voltage proportional to a voltage at said antenna feed; and a controller coupled to said control input and to said voltage sensors, said controller placing said power switching element into said conducting state, sampling said first and second voltages, calculating a voltage difference in response to said first and second voltages, comparing said voltage difference to an upper limit and a lower limit, if said voltage difference is greater than said upper limit then signaling a short-circuit fault, and if said voltage difference is less than said lower limit then signaling an open-circuit fault.