Abstract: Due to the large up front cost in fielding a full capacity satellite constellation (100), it is desirable to have the ability to modify the constellation after deployment to add more capacity in a fashion that does not interrupt service, in order to satisfy a variable or growing market demand. In a satellite constellation including a plurality of orbital planes, each of the orbital planes precesses at a known rate. This invention employs deliberate dynamic manipulation of the orbital precession rates for different satellite planes to increase the separation distance between two adjacent planes. A new plane is then inserted between the two adjacent planes to increase the number of planes and increase the capacity. By continuing a gradual variation, a new orbital plane can be added periodically, e.g. once a year, and the variation can be stopped when no additional orbital planes are desired.

Abstract: A mechanical scanning and digital beamforming antenna (20, FIG. 2) uses a receive and transmit digital beamforming network (FIG. 3, 410, 320) to provide communications beam scanning in a first plane. In a second plane, a reflective surface (FIG. 2, 240) is used to focus and scan the communications beam. Through proper orientation of the reflective surface (240), a communications satellite (FIG. 1, 10) can be tracked by way of electronic scanning by way of the transmit or receive digital beamforming network (FIG. 3, 320, 410). Thus, the complexity of the digital beamforming network is reduced as is the wear on the mechanical components of the antenna. The mechanical scanning and digital beamforming antenna (20, FIG. 20) makes use of a second digital beamforming network (FIG. 3, 415, 325) and reflective surface (FIG. 3, 250) to ensure that two communications satellites can be simultaneously tracked.

Abstract: A user terminal (110) includes a rotating electronically steerable antenna system (210) which combines coarse mechanical beam steering with fine electronic beam steering to provide full hemispherical coverage and enable hand-offs in a satellite communication system. The antenna system (210) comprises at least one antenna unit (and preferably two antenna units) including a mechanically rotatable base (330), an antenna holder (320) coupled to the mechanically rotatable base, and two electronically steerable antenna subunit (310) mounted on the antenna holder. Antenna system (210) also includes an antenna unit controller (260) adapted to control rotation of the mechanically rotatable base (330).

Abstract: A space-based communication system (30), includes a transmission terminal having a transmission antenna (42) and a power amplifier (40) to power the transmission antenna, the power amplifier to generate a power output sufficient to generate an RF signal through the transmission antenna (42), a receive terminal including a receive antenna (45) to receive the RF signal from the transmission terminal and a low noise amplifier (43) to amplify the RF signal channeled through the receive antenna, and a thermoelectric cooler (62) for cooling the low noise amplifier (43) to a predetermined temperature for increasing the sensitivity of the low noise amplifier to minimize the power output generated by the power amplifier required to generate the RF signal thereby minimizing the overall power requirements of the spaced-based communication system (30).

Abstract: A radio-frequency circuit (20) includes a hybrid integrated circuit (24) having a passive circuit element (38) and a d-c biasing circuit element (54) embedded within a first substrate (32) of a low cost and rugged first semiconducting material, and first and second active circuit elements (36, 40) embedded within second and third substrates (44, 46), respectively, of a second semiconductor material having the characterisitics of greater frangibility but higher gain than the first semiconductor material. The first and second activ circuit elements (36, 40) are substantially first and second single components (36, 40), and are each electrically coupled to the passive circuit element (38). The d-c biasing circuit element (54) is electrically coupled to the first and second active circuit elements (36, 40). The second and third substrates (44, 46) are physically coupled to the first substrate (32), which is thicker than either the second or third substrate (44, 46).