Abstract: A self-monitoring satellite system is disclosed to more quickly and accurately convey satellite signal information and verification of its reliability to users of the signal. In a first aspect, the satellite includes one or more receivers on the satellite to monitor the reliability of signals transmitted from the satellite. In a second aspect, a warning signal is generated and transmitted substantially simultaneous with an unreliable satellite signal and at the same frequency as the satellite signal. Exemplary embodiments to implement the various aspects of the self-monitoring satellite system invention are configured as global positioning system (GPS) satellites, signals, and receivers.

Abstract: A high performance diplexer is disclosed having a common conductor which branches into two resonators in distributive form. The diplexer may be used reciprocally, has low insertion loss, is tuneable, has high signal isolation and impedance matching, and may be readily produced to meet the space requirements relating to size, temperature, radiation and performance. A method of tuning the resonators of the diplexer is also disclosed. Specific applications for the diplexer are also disclosed and include use in a GPS transmitter, GPS receiver and as part of an electronic scan array (ESA) antenna. The diplexer's small size and weight, and its resistance to the conditions of space make it ideal for use in satellite applications.