Abstract: Methods for increasing the efficiency of satellite constellation operations are disclosed. The steps of the present invention comprise calculating the maximum number of communications signals that each satellite in the satellite constellation can generate, determining an operational constraint on each satellite, the operational constraint limiting the number of communications signals that each satellite can radiate substantially simultaneously, determining an operational space for each satellite wherein the operational space is defined using the operational constraint and the calculated number of signals, and using the operational space for each satellite in the constellation to determine the operational point for the constellation.

Abstract: A direct conversion receiver comprising a preprocessor coupled to a frequency translator which, in one implementation, is a modified Gilbert mixer. In one embodiment, the preprocessor imparts desired characteristics to split-phase signals received from a local oscillator, including transition points which are determined by crossings through a DC offset, substantial symmetry about a DC offset, and steep transitions about the transition points. In one embodiment, the period of the signals from the local oscillator is divided into portions, and only one of the output signals from the preprocessor is asserted in a predefined state at a time, the predefined state determined effective to reverse polarity of the mixer, signals and a related frequency translator which is responsive to the signals. The frequency translator has a first input at a first input frequency, and at least one second input at a second frequency.

Abstract: A linear power amplifier amplifies a linear baseband signal having I and Q components. An up-converting mixer uses optically activated switches to mix the amplified baseband signal with a local oscillator signal at specified carrier frequency. The optically activated switches are activated according to a switching sequence that produces a constant impedance over each carrier frequency cycle. In this way, the optically activated switches prevents introduction of non-linearities during the up-conversion process.