1. A communications system comprising:
a space-based network (SBN) comprising at least one satellite that generates a plurality of spot beams using a first set of frequencies; and
an ancillary terrestrial network (ATN) using a second set of radio frequencies,
wherein, in a coverage zone of a given spot beam wherein the SBN and the ATN use at least one frequency from the first and second sets of frequencies in common the SBN uses a narrower bandwidth than the ATN on both forward and return links, the ATN employs frequency spreading on at least its return link communications, the SBN employs spatial beam nulling directed toward at least one ancillary terrestrial component (ATC) of the ATN, the SBN employs forward link margin control, the ATN employs return link power control, the SBN employs return link power control and base stations of the ATN provide isolation in the direction of at least one satellite of the SBN.
2. The system of claim 1, wherein the SBN employs fixed andor adaptive return link spatial beam nulling.
3. The system of claim 2, wherein the SBN employs waveform-blind andor waveform-aware return link spatial beam nulling.
4. The system of claim 3, wherein the SBN employs return link beamforming based on a linear constrained mean variance (LCMV) algorithm.
5. The system of claim 1, wherein base stations of the ATN employ spectral nulling at frequencies from the first set of radio frequencies.
6. The system of claim 1, wherein the SBN employs forward link spatial beam nulling toward at least one ATC of the ATN.
7. The system of claim 1, wherein the forward link margin control employed by the SBN is configured to provide a terminal communicating with the SBN increased link margin to override interference from a proximate ATN base station.
8. The system of claim 7, wherein the forward link margin control employed by the SBN is configured to provide a terminal communicating with the SBN increased link margin to override interference from a proximate ATN base station until the terminal is in a nominal coverage zone of the proximate ATN base station.
9. The system of claim 1, wherein the forward link margin control employed by the SBN comprises adaptive power control andor adaptive information rate control.
10. The system of claim 1, further comprising a mobility manager configured to support transfer of communications of a terminal between the SBN and the ATN based on proximity to a base station of the ATN.
11. The system of claim 10, wherein the mobility manager supports idle roaming andor in-call handover.
12. The system of claim 10, wherein the mobility manager is configured to support transfer of terminal communications between the SBN and the ATN using location information from a location information source other than the SBN or the ATN.
13. The system of claim 12, wherein the location information source other than the SBN or the ATN comprises GPS.
14. The system of claim 1, wherein the base stations provide isolation with respect to satellites of the SBN in a range from around 10 dB to around 15 dB.
15. The system of claim 1, wherein the ATN and the SBN are configured to support completely or partially overlapping use of the first and second sets of radio frequencies.
16. A method of operating a communications system comprising an SBN comprising a plurality of spotbeams using a first set of frequencies and an ATN using a second set of radio frequencies, the method comprising:
operating the SBN and the ATN such that, in a given coverage zone of a given spot beam the SBN and the ATN use at least one frequency from the first and second sets of frequencies in common and, in the given coverage zone:
the SBN using a narrower bandwidth than the ATN on both forward and return links;
the ATN employing frequency spreading on at least its return link communications;
the SBN employing spatial beam nulling directed toward at least one ATC of the ATN;
the SBN employing forward link margin control;
the ATN employing return link power control;
the SBN employing return link power control; and
base stations of the ATN providing isolation in the direction of at least one satellite of the SBN.
17. The method of claim 16, wherein the spatial beam nulling comprises fixed andor adaptive return link spatial beam nulling.
18. The method of claim 17, wherein the adaptive return link spatial beam nulling comprises waveform-blind andor waveform-aware return link spatial beam nulling.
19. The method of claim 18, wherein the adaptive return link spatial beam nulling comprise return link spatial beamforming based on a linear constrained mean variance (LCMV) algorithm.
20. The method of claim 16, further comprising base stations of the ATN employing spectral nulling at frequencies from the first set of radio frequencies.
21. The method of claim 16, further comprising the SBN employing forward link spatial beam nulling toward at least one ATC of the ATN.
22. The method of claim 16, wherein the forward link margin control employed by the SBN is configured to provide a terminal communicating with the SBN increased link margin to override interference from a proximate ATN base station.
23. The method of claim 22, wherein the forward link margin control employed by the SBN is configured to provide a terminal communicating with the SBN increased link margin to override interference from a proximate ATN base station until the terminal is in a nominal coverage zone of the proximate ATN base station.
24. The method of claim 16, wherein the forward link margin control employed by the SBN comprises adaptive power control andor adaptive information rate control.
25. The method of claim 16, further comprising managing terminal mobility to support transfer of communications of a terminal between the SBN and the ATN based on proximity to a base station of the ATN.
26. The method of claim 25, wherein managing terminal mobility comprises supporting idle roaming andor in-call handover.
27. The method of claim 25, wherein managing terminal mobility comprises supporting transfer of terminal communications between the SBN and the ATN using location information from a location information source other than the SBN or the ATN.
28. The method of claim 26, wherein the location information source other than the SBN or the ATN comprises GPS.
29. The method of claim 16, further comprising the base stations of the ATN providing isolation with respect to satellites of the SBN in a range from around 10 dB to around 15 dB.
30. The method of claim 16, comprising the ATN and the SBN supporting completely or partially overlapping use of the first and second sets of radio frequencies.
31. A communication system comprising:
an SBN comprising at least one satellite that generates a plurality of spot beams using a set of frequencies and configured, in a coverage zone of a given spot beam wherein the SBN and an ATN use at least one frequency in common, to use a narrower bandwidth than the ATN on both forward and return links, to employ spatial beam nulling directed toward at least one ancillary terrestrial component (ATC) of the ATN, to employ return link power control and to employ forward link margin control.
32. The system of claim 31, wherein the SBN is configured employ fixed andor adaptive return link spatial beam nulling.
33. The system of claim 31, wherein the SBN is configured to employ forward link spatial beam nulling toward at least one ATC of the ATN.
34. The system of claim 31, wherein the forward link margin control employed by the SBN is configured to provide a terminal communicating with the SBN increased link margin to override interference from a proximate ATN base station.
35. The system of claim 31, wherein the forward link margin control employed by the SBN comprises adaptive power control andor adaptive information rate control.
36. The system of claim 31, further comprising a mobility manager configured to support transfer of communications of a terminal between the SBN and the ATN based on proximity to a base station of the ATN.
37. The system of claim 36, wherein the mobility manager supports idle roaming andor in-call handover.
38. A communications system comprising:
an ATN comprising a plurality of ATCs, each comprising at least one base station, the ATN configured, in a coverage zone of a given spot beam wherein an SBN and the ATN use at least one frequency in common, to use a bandwidth broader than the SBN on both forward and return links, to employ frequency spreading on at least its return link communications, to employ return link power control and to provide isolation of ATN base stations in the direction of at least one satellite of the SBN.
39. The system of claim 38, wherein base stations of the ATN employ spectral nulling at frequencies used by the SBN.
40. The system of claim 38, further comprising a mobility manager configured to support transfer of communications of a terminal between the SBN and the ATN based on proximity to a base station of the ATN.
41. The system of claim 40, wherein the mobility manager supports idle roaming andor in-call handover.
42. The system of claim 38, wherein the base stations provide isolation with respect to satellites of the SBN in a range from around 10 dB to around 15 dB.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A manufacturing method of a thin film transistor comprising the steps of:
forming a first conductive film;
forming an insulating film over the first conductive film;
forming a semiconductor film over the insulating film;
forming an impurity semiconductor film over the semiconductor film;
forming a second conductive film over the impurity semiconductor film;
forming a first resist mask over the second conductive film, the first resist mask including a first region, a second region whose thickness is larger than the thickness of the first region, and a third region whose thickness is larger than the thickness of the second region;
performing first etching on the insulating film, the semiconductor film, the impurity semiconductor film, and the second conductive film using the first resist mask to expose at least a surface of the first conductive film;
performing second etching in which side-etching is performed on a part of the first conductive film to form a gate electrode layer;
forming a second resist mask by recessing the first resist mask to expose the second conductive film;
performing third etching on the insulating film, the semiconductor film, the impurity semiconductor film, and the second conductive film using the second resist mask to remove the insulating film, the semiconductor film, the impurity semiconductor film, and the second conductive film;
forming a third resist mask by recessing the second resist mask to expose the second conductive film; and
performing fourth etching on a part of the semiconductor film, the impurity semiconductor film, and the second conductive film using the third resist mask to remove the part of the semiconductor film, the impurity semiconductor film, and the second conductive film, and to form a source electrode layer, a drain electrode layer, a source region and a drain region.
2. The manufacturing method of a thin film transistor according to claim 1, wherein the first resist mask is formed using a four-tone photomask.
3. The manufacturing method of a thin film transistor according to claim 1, wherein the first resist mask is formed using a three-tone photomask and a laser.
4. The manufacturing method of a thin film transistor according to claim 1, wherein dry etching is employed for the first etching, the third etching, and the fourth etching, and wet etching is employed for the second etching.
5. The manufacturing method of a thin film transistor according to claim 1,
wherein an element region is formed by the first etching, and
wherein a side surface of the gate electrode layer is formed to be more on the inside than a side surface of the element region by an almost uniform distance by the second etching.
6. A manufacturing method of a display device, wherein a pixel electrode is selectively formed connecting to the source electrode layer and the drain electrode layer of a thin film transistor manufactured by the method according to claim 1.
7. A manufacturing method of a display device comprising the steps of:
forming a first conductive film;
forming a first insulating film over the first conductive film;
forming a semiconductor film over the first insulating film;
forming an impurity semiconductor film over the semiconductor film;
forming a second conductive film over the impurity semiconductor film;
forming a first resist mask over the second conductive film, the first resist mask including a first region, a second region whose thickness is larger than the thickness of the first region, and a third region whose thickness is larger than the thickness of the second region;
performing first etching on the first insulating film, the semiconductor film, the impurity semiconductor film, and the second conductive film using the first resist mask to expose at least a surface of the first conductive film;
performing second etching in which side-etching is performed on a part of the first conductive film to form a gate electrode layer;
forming a second resist mask by recessing the first resist mask to expose the second conductive film;
performing third etching on the first insulating film, the semiconductor film, the impurity semiconductor film, and the second conductive film using the second resist mask to remove the first insulating film, the semiconductor film, the impurity semiconductor film, and the second conductive film;
forming a third resist mask by recessing the second resist mask to expose the second conductive film;
performing fourth etching on a part of the semiconductor film, the impurity semiconductor film, and the second conductive film using the third resist mask to remove the part of the semiconductor film, the impurity semiconductor film, and the second conductive film, and to form a source electrode layer, a drain electrode layer, a source region and a drain region, and to form a thin film transistor;
removing the third resist mask;
forming a second insulating film covering the thin film transistor;
forming an opening portion in the second insulating film to expose a part of the source electrode layer and a part of the drain electrode layer; and
selectively forming a pixel electrode over the opening portion and the second insulating film.
8. The manufacturing method of a display device according to claim 7, wherein the first resist mask is formed using a four-tone photomask.
9. The manufacturing method of a display device according to claim 7, wherein the first resist mask is formed using a three-tone photomask and a laser.
10. The manufacturing method of a display device according to claim 7, wherein dry etching is employed for the first etching, the third etching, and the fourth etching, and wet etching is employed for the second etching.
11. The manufacturing method of a display device according to claim 7,
wherein an element region is formed by the first etching, and
wherein a side surface of the gate electrode layer is formed to be more on the inside than a side surface of the element region by an almost uniform distance by the second etching.
12. The manufacturing method of a display device according to claim 7, wherein the second insulating film is formed by stacking an insulating film formed by a CVD method or a sputtering method and an insulating film formed by a spin coating method.
13. The manufacturing method of a display device according to claim 7, wherein the pixel electrode is formed by photolithography.
14. A manufacturing method of an electronic device comprising the steps of:
forming a first conductive film;
forming a first insulating film over the first conductive film;
forming a semiconductor film over the first insulating film;
forming a second conductive film;
forming a first resist mask over the second conductive film, the first resist mask including a first region, a second region whose thickness is larger than the thickness of the first region, and a third region whose thickness is larger than the thickness of the second region;
performing first etching on the first insulating film, the semiconductor film, and the second conductive film using the first resist mask to expose at least a surface of the first conductive film;
performing second etching in which side-etching is performed on a part of the first conductive film to form a gate electrode layer;
forming a second resist mask by recessing the first resist mask to expose the second conductive film;
performing third etching on the first insulating film, the semiconductor film, and the second conductive film using the second resist mask to remove the first insulating film, the semiconductor film, and the second conductive film;
forming a third resist mask by recessing the second resist mask to expose the second conductive film; and
performing fourth etching on a part of the semiconductor film, and the second conductive film using the third resist mask to form a source electrode layer and a drain electrode layer.
15. The manufacturing method of an electronic device according to claim 14, wherein the first resist mask is formed using a four-tone photomask.
16. The manufacturing method of an electronic device according to claim 14, wherein the first resist mask is formed using a three-tone photomask and a laser.
17. The manufacturing method of an electronic device according to claim 14, wherein dry etching is employed for the first etching, the third etching, and the fourth etching, and wet etching is employed for the second etching.
18. The manufacturing method of an electronic device according to claim 14,
wherein an element region is formed by the first etching, and
wherein a side surface of the gate electrode layer is formed to be more on the inside than a side surface of the element region by an almost uniform distance by the second etching.
19. A manufacturing method of an electronic device according to claim 14, wherein a pixel electrode is selectively formed connecting to the source electrode layer and the drain electrode layer.