Abstract: A testing apparatus that comprises an electrical device. A first circuit is in electrical communication with the electrical device. The first circuit including an amplifier. First and second couplers are electrically connected to the first circuit and arranged in series with the amplifier. The amplifier is positioned between the first and second couplers. A second circuit has a first end in electrical communication with the first coupler and a second end in electrical communication with the second coupler. The total gain of the first coupler, the second coupler, the portion of the first circuit between the first and second couplers, and the second circuit is approximately zero.

Abstract: A redundant balanced amplifying apparatus. The apparatus comprises a signal path. A portion of the signal path is split into a first and second sets of signal branches. The first and second sets of signal branches are parallel. A plurality of amplifiers are arranged so that each signal branch within the first and second sets of signal branches flows through at least one amplifier. A first set of switches are arranged to selectively shunt signal branches within the first set of signal branches. The first set of switches have at least one switch. A second set of switches are arranged to selectively shunt signal branches within the second set of signal branches. The second set of switches have at least one switch.