CN111211827A

CN111211827A - Tile-based satellite payload system and associated methods

Info

Publication number: CN111211827A
Application number: CN201911148270.6A
Authority: CN
Inventors: 克里斯多佛·麦克莱恩
Original assignee: Panasonic Avionics Corp
Current assignee: Panasonic Avionics Corp
Priority date: 2018-11-21
Filing date: 2019-11-21
Publication date: 2020-05-29
Anticipated expiration: 2039-11-21
Also published as: CN111211827B; CN116667909A

Abstract

To tile satellite payload systems and related methods. Methods and systems for satellite payloads are provided. The first system is based on using focal plane array tiles with reflectors. The second system uses active lens tiles, focal plane array tiles, and reflectors. The third system includes an active reflector tile, a focal plane array tile, and a reflector. Yet another system achieves beam power sharing by selectively providing power to solid state power amplifiers used in satellite payloads. Another system uses multiple microsatellites to provide satellite coverage for an area.

Description

Tile-based satellite payload system and associated methods

Cross Reference to Related Applications

In accordance with 35USC 119(e), the present patent application claims priority from U.S. provisional patent application Serial No. 62/770485 entitled "Tile Based software Communications Payloads and software dynamic Power Sharing Using SSPAs" filed on 11.21.2018 and U.S. provisional patent application Serial No. 62/778199 entitled "A System of Micro High Throughput computers for mobility Services" filed on 11.12.2018, the disclosures of which are incorporated herein by reference in their entirety.

Technical Field

The present disclosure relates to satellite payloads, and more particularly, to modular satellite payload systems and related methods.

Background

Satellite communications are commonly used by transportation vehicles, including aircraft, to transmit and receive information. Satellites typically use a communication "payload" that transmits and receives signals.

Current technologies, especially for streaming audio/video, require high bandwidth for satellite payloads. High Throughput Satellites (HTS) are used to meet the higher bandwidth requirements. HTS-based systems use multiple spot beams to cover a geographic area. Spot beams enable the spectrum allocated to satellite communications to be reused multiple times by the same payload. Smaller spot beams enable concentration of satellite power and enable individual transponders on the payload to support more bandwidth.

A typical HTS system may use 40 to 80 spot beams and about 80 to 100 transponders. A transponder is the basic unit of satellite payload. The transponder includes various components for receiving and transmitting beams. The cost of building a transponder chain for a payload can be millions of dollars. One reason for the high cost of transponders is that the payload is complex, unique and often hand-made. For example, the HTS payload internal waveguide layout of KaSat may have multiple (e.g., 2500) customized waveguide sections connecting various spot beams (e.g., 80) and multiple (e.g., 65) Traveling Wave Tube Amplifiers (TWTAs). TWTAs are used to support high Radio Frequency (RF) power (e.g., greater than 100W). Typically, each waveguide section is custom made and placed manually within the payload. TWTAs use high power vacuum tubes that require special manufacturing techniques and equipment. Other components, such as a cavity filter for channel filtering, may also be manually adjusted by manually adjusting screws in the sides of the cavity. Therefore, building a conventional HTS payload is time consuming and cost prohibitive. In addition, conventional HTS components are large and heavy, which presents design challenges in meeting the demand for increased bandwidth. Therefore, HTS systems require better architectural solutions.

In conventional satellite systems, power sharing between satellite beams is achieved through TWTAs, cavity filter Output Multiplexers (OMUX) and multiport amplifiers (Multi-Port amplifiers, "MPAs"). These components are complex and heavy and allow power sharing only between a limited number of beams.

The distribution of user traffic may change over time at the surface of the earth. This may happen for fixed applications, because different time zones have different day and night, and for mobile applications, the user terminal moves during the day. The variation of user traffic distribution over time is particularly evident in airline traffic patterns, where the fleet of aircraft moves from one region (e.g., north america) to another region (e.g., europe) and then back again within twenty-four hours. If the entire area is covered by a single wide beam, traffic movement within the area is not a problem. However, conventional HTS divides the region into smaller spot beams in an attempt to improve the performance and economy of the satellite. Differentiating into smaller beams results in a situation where the mobile traffic creates separate peaks in time for each beam. Providing peak capacity in each beam can result in wasted capacity during the day. A better solution is needed for power sharing between satellite beams.

HTS systems using multiple beams have steadily replaced wide beam satellites for mobile services. Typically, HTS-based payloads use multiple spot beams to increase the capacity obtained from the same rail (orbital slot) as described above. Drawbacks of HTS payloads are their size, complexity, time to market, cost, and lack of flexibility. For example, typical HTS systems have a mass ranging from 3000 kg to 6000 kg, with thousands of hand-made components. HTS systems typically take 3 to 4 years to build and deploy. In addition, most HTS systems are custom-made and tailored to specific rail positions, coverage areas, and ground stations. Typical conventional HTS systems can cost between 3 to 6 billion dollars, which makes them known as risk and expensive investment. There is a need for a better solution for conventional HTS systems that can efficiently use spot beams.

Disclosure of Invention

Methods and systems for satellite payloads are provided. In one aspect, a payload system is provided that includes a plurality of focal plane array tiles (tiles) arranged in an array, the focal plane array tiles interfaced with a reflector for receiving and transmitting signals. A focal plane array tile of the plurality of focal plane array tiles includes a receiving portion, a transmitting portion, and a switching module. The receiving section includes: a first filter that isolates a reception signal from a transmission signal; a low noise amplifier that amplifies a reception signal; and a first frequency conversion module that converts a frequency of the received signal into an intermediate frequency. The transmitting part includes a second frequency conversion module that converts the frequency of the transmission signal into a radio frequency. The switching module receives the output from the receiving portion and switches the output to another focal plane array tile.

In another aspect, a satellite payload system includes a plurality of active lens tiles interfaced with a plurality of focal plane tiles interfaced with a reflector for receiving and transmitting signals. An active lens tile of the plurality of active lens tiles includes a receiving portion and a transmitting portion. The receiving portion of the active lens tile includes: a first filter that isolates a transmission signal at the transmission section from a reception signal; and a low noise amplifier which amplifies the reception signal. The transmitting portion of the active lens tile includes a high power amplifier that amplifies the output of a phase shifter that receives the transmit signal.

A focal plane tile of the plurality of focal plane tiles includes a receiving portion, a transmitting portion, and a switching module. The receiving portion of the focal plane tile includes a first frequency conversion module to convert the frequency of the received signal to an intermediate frequency. The transmitting portion of the focal plane tile includes a second frequency conversion module to convert the frequency of the transmit signal to a radio frequency. The switching module receives an output from the receiving portion of the focal plane tile and switches the output to another focal plane tile.

In yet another aspect, a satellite payload system includes a plurality of active reflector tiles that interface with a plurality of focal plane tiles that interface with a reflector for receiving and transmitting signals. An active reflector tile of the plurality of active lens tiles includes a receiving portion and a transmitting portion. The receiving portion of the active lens tile includes: a first circulator for isolating a transmission signal from a reception signal in the transmission unit; and a low noise amplifier which amplifies the reception signal. The transmitting portion of the active reflector tile includes: a second circulator isolating a transmission signal from a reception signal; and a high power amplifier which amplifies an output of the phase shifter receiving the transmission signal.

Drawings

Various features of the present disclosure will now be described with reference to the drawings of the various aspects disclosed herein. In the drawings, like parts may have like reference numerals. The illustrated aspects are intended to illustrate, but not to limit, the present disclosure. The drawings include the following figures:

fig. 1A illustrates an example of a plurality of satellite payload systems in accordance with an aspect of the present disclosure;

FIG. 1B illustrates an example of a focal plane array tile in accordance with an aspect of the present disclosure;

FIG. 1C illustrates another example of a focal plane array tile in accordance with an aspect of the present disclosure;

fig. 1D illustrates an example of an active lens tile and a focal plane tile in accordance with an aspect of the present disclosure;

FIG. 1E illustrates an arrangement for using the active lens tiles and focal plane tiles of FIG. 1D in accordance with an aspect of the present disclosure;

fig. 1F illustrates an example of a system having active reflector tiles and focal plane tiles in accordance with an aspect of the present disclosure;

fig. 1G illustrates an example of an active reflector tile and focal plane tile with a circulator in accordance with an aspect of the present disclosure;

fig. 1H illustrates an example of an active reflector tile and a focal plane tile with a frequency converter in accordance with an aspect of the present disclosure;

fig. 1I illustrates an example of active reflector tiles and focal plane tiles using cross polarization for signal isolation in accordance with an aspect of the present disclosure;

fig. 2 illustrates an example of arranging payload tiles into an array in accordance with an aspect of the present disclosure;

FIG. 3A illustrates an example of power sharing for satellite beams;

FIG. 3B illustrates an example of a conventional system for power sharing in satellite beams;

FIG. 3C illustrates another example of a conventional system for power sharing in satellite beams;

fig. 3D illustrates an example of using a Solid State Power Amplifier (SSPA) in a satellite payload in accordance with an aspect of the disclosure;

fig. 3E illustrates one example of selectively powering an SSPA for satellite payloads in accordance with an aspect of the present disclosure;

FIG. 3F illustrates a process for selectively powering an SSPA in accordance with an aspect of the present disclosure;

fig. 3G illustrates an example of using SSPA for optimal feed device size in accordance with an aspect of the present disclosure;

FIG. 4A shows an example of satellite coverage using multi-spot beams;

FIG. 4B illustrates the use of multi-spot beams using micro-satellites in accordance with an aspect of the present disclosure; and

fig. 4C illustrates a process for using multiple microsatellites according to an aspect of the present disclosure.

Detailed Description

As a preliminary matter, the terms "component," "module," "system," and the like, as used herein are intended to refer to a computer-related entity, either a software-executing general-purpose processor, hardware, firmware, or a combination thereof. For example, a component may be, but is not limited to being, a process running on a hardware processor, an object, an executable, a thread of execution, a program, and/or a computer.

In accordance with the claimed subject matter, the computer-executable components may be stored, for example, on non-transitory computer/machine-readable media including, but not limited to, ASICs (application specific integrated circuits), CDs (compact discs), DVDs (digital video discs), ROMs (read only memories), hard disks, EEPROMs (electrically erasable programmable read only memories), solid state memory devices, or any other storage devices. Conditional processing/routines may be expressed by qualifiers that are used interchangeably herein and are intended to have the same meaning, if any, or when such qualifiers are present.

In one aspect, the techniques disclosed herein provide a cost-effective solution for HTS ("high throughput satellite") payloads. Novel payload architectures/configurations are disclosed that use mass-produced Integrated Circuit (IC) modules and are tiled (tiled) together to form a payload. The payload systems disclosed herein are lighter, less expensive, and easier to assemble than conventional systems. In addition to standard transponder functionality, the described architecture also supports frame switching functionality to support beam hopping (also known as satellite switched Time Division Multiple Access (TDMA)).

In one aspect, payload tiles (payload tiles) are disclosed that use similar techniques with similar transmit and receive functionality. These tiles are used to feed deployable or openable reflectors (e.g., hundreds or thousands) supporting a large number of spot beams and providing gain to support high bandwidth with lower power usage, as compared to conventional, expensive, heavy, and difficult to manufacture HTS systems. In some cases, the payload tiles may be used as direct radiating antennas, eliminating the need for reflectors, as described in detail below.

Payload system: fig. 1A illustrates an example of three different payload systems (or configurations/architectures, used interchangeably throughout the specification) using tiled payload technology in accordance with an aspect of the present disclosure. In one aspect, a focal plane array system 102 (which may also be referred to as system 102 or configuration 102) is provided. System 102 includes a plurality of focal plane tiles 104, the plurality of focal plane tiles 104 receiving a beam from passive reflector 106 and transmitting the beam to passive reflector 106. Details regarding the system 102 and the focal plane tile 104 are provided below.

In another aspect of the present disclosure, an active lens system 112 (which may also be referred to as system 112 or configuration 112) is provided with a plurality of focal plane tiles 108 and a plurality of active lens tiles 110. Details regarding system 112 and

tiles

108 and 110 are provided below.

In yet another aspect of the present disclosure, an active reflector system 114 (which may also be referred to as system 114 or configuration 114) is provided with a plurality of active reflector tiles 116 and a plurality of focal plane tiles 118. Details regarding system 114 and tiles 116 and 118 are provided below.

The differences between the various configurations of fig. 1A depend on the relationship of the tiles with respect to the reflector 106, and how the transponder and switching functions are split between the focal plane and the active lens/reflector tiles, as described in detail below.

In one aspect, although systems 102, 112, and 114 are shown using passive reflector 106, the adaptive aspects of the present disclosure are not limited to passive reflector 106. Active lens system 112 and active reflector system 114 may be configured to operate in a direct radiation mode without passive reflector 106. Furthermore, although fig. 1A shows a coaxial configuration for simplicity, other arrangements such as offset feeds (offset feeds), Gregorian (Gregorian), or Cassegrain (Cassegrain) configurations may also be used with the novel tiled payloads (tile based payloads) of the present disclosure.

Focal plane array tile: fig. 1B illustrates a block diagram of a focal plane array tile 120 (which may be referred to as tile 120) of the focal plane array tile 104 of the system 102 in accordance with an aspect of the present disclosure. A plurality of focal plane array tiles are arranged in an array for use as satellite payloads. The various components of the focal plane array tile 120 can be fabricated with integrated circuit components using standard fabrication techniques.

On the one hand, the tile 120 includes a reception (Rx) section 120A processing a reception signal and a transmission (Tx) section 120B processing a transmission signal with interleaved Rx elements 122 and Tx elements 154. In one aspect, the Rx element 122 is configured to receive an input signal. The Rx elements 122 may be grouped together with other Rx elements to form an Rx chain. The input signal passes through a reject filter (reject filter)124, and the reject filter 124 isolates the received signal from noise in the transmission section 120B. In one aspect, orthogonal polarizations may be used to isolate the received signal from the transmit section noise.

The output from the filter 124 is amplified to an operating level by a Low Noise Amplifier (LNA) 126. The output from LNA 126 is provided to a "down-conversion" module (shown as "down-conversion to IF (n) (used interchangeably throughout the specification)) 128 (which may be referred to as" module 128 ") that converts the frequency of the output from LNA 126 to an intermediate frequency (" IF ") or transmit section frequency level. Module 128 includes

filters

130 and 136, mixer 132, and oscillator 134 to perform frequency conversion.

The output from module 128 in the IF range is provided to a switching module (shown as an IF switching module, used interchangeably throughout this specification) 138. The switching module 138 routes the output from module 128 to adjacent tiles 140A/140B, to a switching gateway subsystem 142, or to Tx portion 120B. Gateway subsystem 142 may be used to route signals between tile arrays.

Tx section 120B includes an "up-conversion" module (shown as "up-conversion to RF" or "up-conversion to Ku" (fig. 1D and 1G-1I) (used interchangeably throughout the specification)) 144, which "up-conversion" module 144 converts the input signal to an RF (radio frequency) signal based on the strength of the input signal from the Rx element. The module 144 includes a mixer 148 for converting the frequency of the input signal to an RF signal, an oscillator 146, and a filter 150. The RF signal output from the module 144 is provided to a High Power Amplifier (HPA)152, and the High Power Amplifier (HPA)152 amplifies the received RF signal output. The HPA 152 may be gallium arsenide (GaAs), silicon germanium (SiGe), gallium nitride (GaN), or any other amplifier type. The output from HPA 152 is sent by TX element 154. Similar to the RX elements, one or more Tx elements 154 may be combined to create a Tx chain.

In one aspect, tiles 120 are mounted to a backplane (not shown) that provides DC (direct current) power, commands, and signal connections to adjacent tiles. The backing plate may include heat pipes (not shown) for thermal control.

As described above, the Tx and Rx elements are interleaved at the same time. Since only one type of tile is used to construct the payload, it is cost effective. To isolate the Tx path from the Rx path, the Tx and Rx elements may be placed orthogonal to each other. Cross polarization isolation will provide some inherent isolation between the Tx path and the Rx path. Using both types of polarization would involve using two reflectors and two identical focal plane arrays, one of which is rotated 90 degrees relative to the other.

Another option to isolate the Tx signal from the Rx signal is to split the Tx and Rx functions into separate tiles (tiles). This option would use two reflectors but with two different types of focal plane array tiles.

Another solution to isolate the Tx signal from the Rx signal is to operate the Tx and Rx elements in half-duplex mode for a given beam if the beam uses satellite switched TDMA. If the transmit duty cycle is not 100%, the uplink transmission will be interleaved in time with the downlink transmission. The only isolation required in this implementation is between adjacent beams. Half-duplex will not limit the overall capacity of the payload, but may limit the maximum uplink and downlink rates of the beam.

In one aspect, the system 102 may be used for applications in which demand is relatively evenly distributed over a spatial coverage area and over time.

In one aspect, the focal plane array tile 120 components, i.e., the receive and transmit feed elements 122/154, LNA 126, lower frequency converter 128, HPA 152, up-converter 144, and switch module 138, may be mass produced and tiled (tiled) to form a payload. The manufacturing cost and assembly time of system 102 will be less than conventional HTS systems.

Fig. 1C illustrates another example of a focal plane array tile 156 (which may be referred to as tile 156) having an Rx portion 156A and a Tx portion 156B in accordance with an aspect of the present disclosure. Tile 156 has various components similar to those of tile 120, such as reject filter 124, LNA 126, module 128, HPA 152, module 144, and switch module 138. The common components of tiles 156 and 120 perform the same functions as described above and, therefore, the common components are not described again.

In addition to common components of tile 120, tile 156 includes phase shifter 158 and variable attenuator 160 in Rx portion 156A, and variable attenuator 162 and phase shifter 164 in transmit portion 156B. The

phase shifters

158 and 164 provide controllable phase shifting of the RF signal. The

variable attenuators

160 and 162 use the following circuitry: the circuit continuously or stepwise reduces the strength of the input signal without significant signal distortion while substantially maintaining a constant impedance match.

The phase shifters and attenuators of tiles 156 provide better amplitude and phase control across the feed element for a given beam. This may provide better illumination control of the main reflector and higher antenna efficiency.

Attenuators

160 and 162 may also be used to implement gain control to cause the downlink signal to operate at a known power level by compensating for uplink fading and path loss at the payload.

In one aspect, only the required amplifiers are activated at any given time. For example, the amplifier may be bussed and only activated when a frame is transmitted. The pipelining reduces heat dissipation and power consumption in the payload.

In another aspect, the switching function in a tile enables a different subset of elements to be activated at any given time. Unlike conventional horn feed reflectors, where the beam center is fixed, the switching function of the switching module 138 may be used to shift the beam peak and enable the beam to be directed to a single terminal. In a typical horn-fed reflector system, the roll-off from peak to edge is 4.5 dB. Being able to shift the peak by half the beam diameter will reduce the roll-off to 1.1dB, saving 3.4 dB. This will provide the same performance with less than half the power of a conventional horn feed system.

In one aspect, a satellite payload system is provided. The payload system includes a plurality of focal plane array tiles arranged in an array, the focal plane array tiles interfacing with the reflector for receiving and transmitting signals. A focal plane array tile from the plurality of focal plane array tiles includes a receiving portion, a transmitting portion, and a switching module. The receiving section includes: a first filter that isolates a reception signal from a transmission signal; a low noise amplifier that amplifies a reception signal; and a first frequency conversion module that converts a frequency of the received signal into an intermediate frequency. The transmitting part includes a second frequency conversion module that converts the frequency of the transmission signal into a radio frequency. The switching module receives the output from the receiving portion and switches the output to another focal plane array tile.

Active lens system 112: fig. 1D illustrates a focal plane tile 166 and a lens tile 168 of active lens system 112 according to an aspect of the present disclosure. In one aspect, the function of the focal plane array tile 120 described above with respect to fig. 1B/1C is split between the lens tile 168 and the focal plane tile 166, such that signal amplification is separated from signal feeding and switching. By separating the amplification from the feed array, the amplification requirements can be reduced, thereby using less power for each tile.

In one aspect, lens tile 168 includes an Rx portion 168A and a Tx portion 168B. The Rx elements 122B and TX elements 154B face outward toward the passive reflector 106 (fig. 1A).

Elements

122C and 154C face inward toward focal plane tile 166 with elements 122A/154A.

The lens tile 168 includes the phase shifter 158 in the Rx portion 168A and the phase shifter 164 in the transmission portion 168B. The lens tile 168 also includes a variable attenuator 160 in the Rx portion 168A and a variable attenuator 162 in the Tx portion 168B. The phase shifters and attenuators enable the lens tiles 168 to create phase and amplitude distributions across the lens, essentially providing their own focal length. This enables the lens tiles 168 to operate in a direct radiating configuration without passive reflectors and reduces the focal length and size of the feed array.

In one aspect, focal plane tile 166 provides a feed array using element 122A in Rx portion 166A and element 154A in Tx portion 166B. A Low Power Amplifier (LPA)170 in the receive section and a low power amplifier 172 in the transmit section may be used to maintain the signal level within the focal plane tile 166. Notably,

LPAs

170 and 172 are optional, and LPAs 170 and 172 may not be needed because signal loss between lens tile 168 and focal plane tile 166 is minimal.

The module 128 of the focal plane tile 166 is similar to the module 128 of the focal plane tile 120 of FIG. 1B described above. Similarly, the module 144 of the focal plane tile 166 is similar to the module 144 of the focal plane tile 120. The IF switching module 138 of the focal plane tile 168 also performs the same functions as the module 138 of the focal plane tile 120 described above with respect to fig. 1B. These common components of tile 166 and tile 120 are not described in detail.

In one aspect, the focal plane tile 166 may be mounted to a backplane that provides DC power and signal connections between adjacent tiles. The backplate may not require heat pipes because the power level at the focal plane tile 166 is low.

In one aspect, lens tile 168 can be mounted on a frame (not shown) that enables the lens tile to face inward toward focal plane tile 166 and outward toward passive reflector 106.

Notably, lens tile 168 does not perform frequency translation. It receives the transmitted signals at the back of the lens at the same frequency and then transmits them at the front. In one aspect, a can-like structure 174 as shown in FIG. 1E can be used to place the lens tile 168 and the focal plane tile 166. The can 174 places the active lens 168 on the top and the focal plane tile 166 on the bottom. The sidewall structures 176 are located between the lens and the focal plane tiles.

In one aspect, a satellite payload system is provided. The system includes a plurality of active lens tiles interfaced with a plurality of focal plane tiles interfaced with a reflector for receiving and transmitting signals. An active lens tile of the plurality of active lens tiles includes a receiving portion and a transmitting portion. The receiving portion of the active lens tile includes: a first filter for isolating a transmission signal from a reception signal of the transmission section; and a low noise amplifier to amplify the received signal. The transmitting portion of the active lens tile includes a high power amplifier to amplify the output of the phase shifter receiving the transmit signal.

A focal plane tile of the plurality of focal plane tiles includes a receiving portion, a transmitting portion, and a switching module. The receiving portion of the focal plane tile includes a first frequency conversion module to convert the frequency of the received signal to an intermediate frequency. The transmitting portion of the focal plane tile includes a second frequency conversion module that converts the frequency of the transmission signal to a radio frequency. The switching module receives an output from the receiving portion of the focal plane tile and switches the output to another focal plane tile.

Active reflector arrangement: FIG. 1F illustrates an aspect in accordance with the disclosureAn example of an active reflector system 114 having an active reflector tile 116 and a focal plane array tile 118. Service link 178 carries signals between active reflector tile 116 and passive reflector 106 (not shown in fig. 1F). The focal plane array tile 118 receives and transmits signals via an intra-payload link 180 between the active reflector tile 116 and the focal plane array tile 118. Signals at service links 178 and 180 may be isolated by circulators, frequency translation, or cross polarization, as described in detail below.

Fig. 1G illustrates active reflector tiles 182 and focal plane tiles 166 of active reflector system 114 in accordance with an aspect of the present disclosure. According to an aspect of the present disclosure, the active reflector tile 182 includes a circulator 195 in a receive (Rx) section 182A and a circulator 193 in a transmit (Tx) section 182B. A circulator is a passive, non-reciprocal three-port or four-port device in which an RF signal entering any port is sent to the next port in a rotating fashion. In this context, a port is a point at which an external waveguide or transmission line (e.g., a microstrip or coaxial cable) is connected to a device. For a three-port circulator, signals applied to the first port only exit the second port; a signal applied to the second port only exits the third port; the signal applied to the third port only exits the first port. The signals received via the service link 178 and the intra-payload link 180 may be isolated using

circulators

195 and 193 of the receive and transmit sections.

The remaining components of the active reflector tile 182 (e.g., the suppression filter 124, the LNA 126, the phase shifter 158, the variable attenuator 160 in the receiving section 182A, and the HPA 152, the phase shifter 164, and the variable attenuator 162 in the transmitting section 182B) and the focal plane array tile 166 (e.g., the switching module 138, the LPA 170, and the module 128 in the receiving section 166A, and the module 144 and the LPA 172 in the transmitting section 166B) function similarly to the respective components of the tiles described above with reference to fig. 1B-1D, and for the sake of brevity, these components are not described again.

Fig. 1H illustrates an active reflector tile 184 having a receiving portion 184A and a transmitting portion 184B in accordance with an aspect of the present disclosure. The receive section 184A includes a frequency converter 188A and the transmit section includes a frequency converter 188B for isolating signals at the service link 178 and the intra-payload link 180. Frequency converter 188A includes a filter 190, a mixer 192, and an oscillator 194. The frequency converter 188B includes a filter 196, a mixer 198, and an oscillator 199. The frequency of the signals at links 178 and 180 are isolated using frequency converters, mixers, and oscillators. The output from frequency converter 188A is sent to focal plane tile 166 via element 122C, while the output from frequency converter 188B is sent to focal plane tile 166 via element 154C.

The remaining components of the active reflector tile 184 (e.g., the suppression filter 124, LNA 126, phase shifter 158, variable attenuator 160 in the receive section 184A, and HPA 152, phase shifter 164, and variable attenuator 162 in the transmit section 184B) and the focal plane array tile 166 (e.g., the switching module 138, LPA 170, and module 128 in the receive section 166A, and the module 144 and LPA 172 in the transmit section 166B) function similarly to the respective components of the tiles described above with respect to fig. 1B-1D, and are not described again for the sake of brevity.

Fig. 1I shows a schematic view of an active reflector tile 186 having a receiving portion 186A and a transmitting portion 186B. Active reflector tiles 186 isolate signals received via service link 178 and intra-payload link 180 via

elements

197A, 197B, 122B, and 154B using cross polarization. If the payload internal link 180 is V-pol or Right Hand Circular Polarization (RHCP), the service link 178 will use H-pol or Left Hand Circular Polarization (LHCP).

The remaining components of the active reflector tile 186 (e.g., the suppression filter 124, LNA 126, phase shifter 158, variable attenuator 160 in the receive section 186A, and HPA 152, phase shifter 164, and variable attenuator 162 in the transmit section 186B) and the focal plane array tile 166 (e.g., the switching module 138, LPA 170, and module 128 in the receive section 166A, and the module 144 and LPA 172 in the transmit section 166B) function similarly to the respective components of the tiles described above with respect to fig. 1B-1D, and are not described again for the sake of brevity.

In one aspect, the tiled payload system described above can be used in various frequency bands including X, Ku, Ka, Q, V, and the like. The various tile systems 102, 112, and 114 may be customized for different antenna geometries, such as coaxial, offset feed, gurighure, cassegrain, or direct radiation. Various configurations of the present disclosure may be implemented using single or dual orthogonal polarizations.

In one aspect, a satellite payload system is provided. The system includes a plurality of active reflector tiles interfaced with a plurality of focal plane tiles interfaced with a reflector for receiving and transmitting signals. An active reflector tile of the plurality of active lens tiles includes a receiving portion and a transmitting portion. The receiving portion of the active lens tile includes: a first circulator to isolate a transmission signal from a reception signal of the transmission part; and a low noise amplifier to amplify the received signal. The transmitting portion of the active reflector tile includes: a second circulator to isolate a transmission signal from a reception signal; and a high power amplifier to amplify an output of the phase shifter receiving the transmission signal.

Tile array: fig. 2 shows an example of arranging individual tiles for payload systems 102, 112, and 114 in an array 200 for satellite payloads. The array 200 enables switching of multiple signals to create a signal path between one or a small subset of receive elements in the focal plane and one or a small subset of transmit elements on the focal plane, as described in detail above. Beamforming of the satellite payload is handled by the passive reflector or divided between the passive reflector and the active lens/active reflector tiles. Phase shifters or delay lines in active lenses or active reflectors enable tiles to focus signals. When this function is used in conjunction with a passive reflector, it can increase or decrease the overall focal length of the system. Reducing the focal length is desirable for satellite integration as this will reduce the overall size of the focal length array. The ability of the active lens or active reflector to focus the signal also enables the tile to be used in direct radiation mode without a passive reflector.

Dynamic power sharing using SSPA: in one aspect, the techniques disclosed herein are used to replace certain conventional HTS components, such as TWTAs, with solid-state power amplifiers (SSPAs). As described in detail below, power sharing between beams is enabled by selectively switching power to the SSPA on and off based on the traffic pattern and the number of beams needed to cover a particular geographic area.

Fig. 3A shows an example of a system 300 for power sharing between satellite beams at different times, i.e., at times 1, 2, and 3. The geographic regions are shown as 302, 304, and 306. The illustration of

beam powers

308, 310, and 312 is for time 1. The illustration of

beam powers

314, 316, and 318 is for time 2. The illustration of

beam powers

320, 322, and 324 is for time 3. The beam power is varied to accommodate changes in traffic patterns.

Conventionally, power sharing between beams is achieved by moving high power RF signals between downlink beams. This is achieved by power splitting the outputs of the TWTAs using the OMUX (see fig. 3B) or by using multiple TWTAs in an MPA (multiport amplifier) configuration connected by a Butler matrix (see fig. 3C).

TWTA is a vacuum tube amplifier that is often used in satellite applications due to its high power and efficiency. A typical TWTA includes an amplifier and Electric Power Conditioning (EPC) unit that may weigh 2kg to 3kg, may be 37cm by 9cm in size, has a saturated RF power of 100W to 200W, and has a saturated efficiency of 65%.

To share power across multiple spot beams, fig. 3B illustrates a conventional system in which a TWTA 326 receives an input 332 and generates an output. The output is provided to the OMUX 328 using a low loss waveguide.

The OMUX 328 has a plurality of circulators and cavity filters that divide the output spectrum of the TWTA output into different channels based on frequency. The OMUX 328 outputs 330A through 330C are then connected to the spot beam feeds using waveguides. The OMUX typically weighs about 1kg per output. Power may be routed to each output beam by an uplink carrier of a different frequency, and power may be moved from beam to beam by varying the drive level of each carrier.

A disadvantage of using OMUX to power share a single TWTA is that the power is limited to that of a single amplifier and the available spectrum must be divided into smaller channels. In most cases, TWTA is to divide power between only two to four beams at a time, which is undesirable. In addition, both TWTA and OMUX are heavy and costly to manufacture.

MPA provides some flexibility in power sharing, but is more complex. FIG. 3C shows an MPA 334 where a set of TWTAs 326A-326D are power devices that use a Butler matrix 336A/336B combination. Butler matrices 336A/336B are specific combinations of hybrid power splitters and combiners placed before and after the set of TWTAs 326A to 326D. The MPA 334 has a number of input ports and output ports equal to the number of TWTAs. The drive level at each input port determines the output level at the corresponding output port up to the combined power of all TWTAs in the MPA 334. Setting the input level at each input port enables the total power of the TWTAs in the MPA 334 to be arbitrarily divided between the output ports (338A-338C). Combining multiple TWTAs in the MPA creates a larger power pool that can be shared across more beams. Each output port (e.g., 338D) may be further divided into more beams (e.g., 330A through 330C) using the OMUX 328.

Power sharing by moving high power RF between beams is complex and expensive. TWTA, OMUX, butler matrices and connecting waveguides are large, heavy and complex. Each beam requires two to seven kilograms of equipment. Even in the best case, power can only be shared between less than twelve beams.

The present disclosure provides a better solution for a SSPA that is smaller in size, lower in quality, and less expensive than a TWTA. The SSPA provides a cost-effective solution to share DC power across beams instead of radio frequency power, thereby creating a simplified satellite payload. SSPAs are available in a variety of technologies including GaAs, SiGe, and GaN. GaN amplifiers are desirable for space applications because recent advances in the use of GaN on diamond substrates have resulted in amplifier efficiencies in excess of 50%. This may be less efficient than a typical TWTA, but the small size of the SSPAs enables them to be mounted near or on the beam feed, thereby eliminating waveguide losses of typically 1dB or more in TWTA-based systems.

As an example, a 16W Ku band GaN SSPA from Quorvo corporation (e.g., model TGA2760-SM) has dimensions of 0.8cm by 1.0cm by 0.2 cm. Although it may have a lower power than typical Ku band TWTAs, with a mass of less than 1 gram, it is at least 2000 times lighter and 18000 times less bulky than typical TWTAs. In other words, for the same mass as a TWTA, 200 times the RF power can be installed while still occupying 1/9 of a single TWTA volume. Thus, for the same mass as a TWTA, a greater amplifier power can be installed. This enables the power sharing system to move power between beams by selectively powering the amplifiers on and off. The total DC power remains constant, but which SSPAs to turn on or off determines where to allocate power for the satellite payload.

Fig. 3D shows an example of an SSPA-based system 340. The reflector 354 is used to generate a plurality of coverage beams 356A to 356N on the ground. The reflector 354 may be a solid reflector, a fixed mesh reflector, or an openable mesh reflector. The reflector 354 may take any arrangement, such as a center feed, cassegrain, grignard, on-axis, or off-set. Large diameter openable reflectors are desirable because high gain reduces the power requirements per beam, however, the adaptive aspects of the present disclosure are not limited to openable reflectors.

Each beam 356A to 356N is generated by one (single feed per beam) feed or multiple (multiple feeds per beam) feeds at the focal plane of the reflector 354. Communication between the focal plane of the satellite payload and the reflector is shown by 350 and the multiple beams from the reflector are shown by arrows 352. The feed means (feeds) may itself be a horn, patch, dipole, slot, dielectric rod or any similar technology. Each feed device is connected to one or more SSPAs 348A-348N. If multiple SSPAs are connected to the same feed device, they may be power devices combined using waveguides, stripline or microstrip combiners, or similar technologies. In the case where multiple feeds per beam and/or multiple SSPAs per feed are used, the signal path lengths are the same so that the SSPAs remain in phase without the need to use phase shifters. Each SSPA may be powered by a power supply signal 344, individually or in groups, and connected to an input signal source (346A-346N).

In case a plurality of SSPAs are connected to the feeding means, the SSPAs may be connected to the same or different signal sources, or the sources may be selectable. The number of SSPAs may exceed the available DC power on the satellite.

An on-satellite or on-ground controller 342 determines which SSPAs to power on and off at any given time within the DC power limits of the satellite payload. The controller 342 may also control the signals of each SSPA.

Fig. 3E illustrates an example of power sharing between satellite beams in accordance with an aspect of the disclosure. A group of aircraft may move from one region to another (i.e., from 302 to 306 via 304, and from 306 to 302 via 304). Different sets of SSPAs (constituting different antenna feeds) are powered, moving power from one beam to another. In one aspect, to keep the overall power consumption constant, while one beam is powered, the other beams may remain unpowered (e.g., while the SSPA of beam 1 is powered, the SSPAs of beam 2 and beam 3 are unpowered). This arrangement is useful for large openable reflectors for generating a large number of beams in sparse traffic areas.

On the other hand, it may be desirable to operate the beams at a power lower than the maximum power, and using multiple SSPAs per beam makes it possible to do so without losing any efficiency. Operation at reduced power consumption may be accomplished by reducing the input drive level. In another aspect, the bias voltage for the SSPA may be reset to reduce power. Feeding multiple SSPAs to each beam enables beam power to be varied without losing any efficiency by powering down a portion of the SSPAs feeding the beam while keeping the remaining SSPAs operating at their most efficient operating levels. By operating the system in an Automatic Level Control (ALC) mode without having to continuously adjust the uplink drive level to maintain the amplifier at a desired set point, the overall operational complexity of the system may be reduced. This enables greater power sharing control without reducing efficiency.

In one aspect, the beam power level is changed by turning off a portion of the SSPA. For example, as shown in fig. 3E, when beam 1358 has maximum traffic, each SSPA (348A to 348H) feeding beam 1 is powered and connected to signal 1. Beam 2360 may have less traffic and therefore only half of the SSPAs (shown by the 4 black triangles) feeding beam 2 may be powered and connected to signal 2 (346). Beam 3362 may have minimal traffic so only one quarter of the SSPA (shown by the two black triangles) is powered and connected to signal 3. The power level in each beam can be varied over time by powering the SSPAs on and off as long as the total number of SSPAs being powered does not exceed the total supplied DC power available at the satellite.

Fig. 3F illustrates a process 364 for power sharing using SSPAs in accordance with an aspect of the disclosure. The process begins at block B366. In block B368, power for the SSPA is initialized. In block B370, the controller 342 of the satellite payload is provided with information about the traffic coverage. In block B372, the controller 342 determines the number of beams that may be needed for coverage. In block B374, the controller 342 selectively turns on the SSPA. In an aspect, the SSPA for the first beam may have a greater power than the SSPA for the second beam.

In conventional single feed per beam systems, the optimum size of the feed for antenna efficiency often exceeds the desired spacing between feeds. This can be solved by: using smaller than optimal feed devices at the expense of reduced antenna performance or using multiple reflectors at the expense of added mass and complexity. The other solution is as follows: multiple feeds per beam using the same space as a single optimal feed would occupy. At the boundaries between beams, the feeds are shared by adjacent beams, where the individual feeds will overlap. However, in conventional power sharing applications, this requires a complex waveguide beam-forming network behind the feed device, which is typically heavier and more expensive than simply using multiple reflectors. The use of multiple feeds per beam and wherein multiple SSPAs per feed eliminates some of the disadvantages of conventional multiple feed per beam systems while retaining the ability to use a single reflector and maintaining high performance for optimal feed size.

The arrangement of SSPAs in multiple feeds per beam and where there are multiple SSPAs per feed is shown in fig. 3G. In this case, the optimal feeder size (optimal feed size)380 requires three feeders (feeds), but the spacing between the feeders is only one feeder apart. This creates an overlap 378 of the two feeds between the beams. The overlapping feed arrangement is powered by two SSPAs, one receiving input signal 1346A and the other receiving input signal 2346B. This creates the same effect as a waveguide beam forming network without weight and complexity.

Aspects of the present disclosure are not limited to the rate at which power may be reallocated between beams. In some cases, it may be desirable to permanently allocate the number of beams and SSPAs to serve fixed customers. In other cases, it may be desirable to dynamically reallocate power between beams to service traffic patterns that vary over a span of hours or minutes. In one aspect, power may be reallocated on a superframe basis in a manner that is effective as a beam hopping arrangement. Beam hopping will enable more beams to be active during a given time period, providing better granularity in terms of how resources are allocated and reducing uplink bandwidth/gateway requirements.

The adaptive aspect of the present disclosure has advantages over existing power sharing techniques. The use of small SSPA amplifiers enables power to be moved between beams at DC rather than RF levels. Conventional power sharing by moving high power RF between beams requires relatively large, complex, heavy and expensive components such as TWTA, waveguides, OMUX and MPA. Dynamic power sharing with SSPAs enables the entire payload to be built on a circuit board, making it lighter and easier to manufacture. When coupled with large openable mirrors, these lightweight payloads can generate hundreds or thousands of beams for the same payload mass and power as a conventional payload with tens of beams, and have greater power sharing flexibility.

Miniature HTS system: in one aspect, to reduce the cost and complexity of conventional HTS systems, the present disclosure provides a miniature HTS system that is less specialized and can be quickly manufactured and deployed to reduce the commitments and risks associated with conventional large HTS systems. A miniature HTS system is provided that has a smaller capacity and coverage area than a single large HTS satellite. A number of miniature HTS systems are deployed to provide coverage comparable to large HTS systems. As shown by

circles

400, 402, 404, 406 in fig. 4A, the use of multiple miniature HTS systems, rather than a single large HTS system, opens up less than ideal and less expensive rail positions for use in the east and west of north american and european orbital arcs. As shown by the circles between 408A and 408N in fig. 4B, as demand grows, capacity may be added to existing regions and coverage may be extended by adding more microsatellites to existing orbits. Multiple miniature HTS satellites may be added to one orbit site and cover different regions of the same orbit site or provide overlapping coverage regions. The rail positions typically comprise 0.1 degrees in longitude along the stationary arc of the earth, which forms a box-like region of about 75km by 75km at a radius of about 42165km from the center of the earth. Thus, the orbiter has available space to place multiple satellites.

The deployment of new miniature HTS systems is an adaptive process due to the relatively short build cycle. New microsatellites can be deployed where demand is growing fastest. Conversely, if demand grows slower than expected, the deployment of new satellites may spread out over a longer period of time.

In one aspect, a mini-HTS based deployment includes mini-satellites, preferably less than 400kg, which may be transmitted as secondary payloads on other satellite transmissions, either by themselves or in small groups, in most cases to Geostationary Transfer Orbit (GTO). The micro-satellites include an electric propulsion function so that they can reach the geostationary orbit (GSO) from the GTO with an available payload of 100kg to 150 kg. The power of the micro-satellites is in the range of 1kW to 3kW, thereby minimizing the cost of the satellites.

The microsatellite preferably uses openable reflectors so that a high Effective Isotropic Radiated Power (EIRP) can be achieved with as little payload Power as possible. Fixed or other deployable reflectors may also be used.

In one aspect, the microsatellite preferably uses small, light and efficiently SSPA amplifiers, preferably GAN amplifiers, that power a large number of antenna feeds and spot beams. As described above, the payload will use tile configuration and SSPA power sharing.

In one aspect, the microsatellite has its frequency plan adjusted to the available spectrum at a given orbital position using a flexible channelizer for the payload. The channeler is preferably an analog "elbow" channeler. In another aspect, a digital channelizer is used.

In one aspect, microsatellites are deployed individually or in groups at single or multiple orbits to cover the area for mobile services that is conventionally covered by a single large HTS satellite. Additional microsatellites may be added to the initial orbit to overlap the initial deployment and increase capacity, or to cover adjacent areas and extend coverage.

Fig. 4C illustrates a process 410 in accordance with an aspect of the disclosure. The process begins at block B412. In block B414, a geographic coverage area is determined based on the user traffic. In block B416, the number of microsatellites covering the coverage area is determined. In block B418, the microsatellite is deployed within the coverage area. In block B420, the number of microsatellites is adjusted based on the demand.

The use of smaller, simpler micro-satellites enables new satellites and new technologies to be brought to the market faster. This enables the satellite owner/operator to respond more to changing demands and reduces the risk of under capacity or over capacity in critical areas.

The long lead times of conventional HTS satellites mean that each new HTS satellite must meet not only the anticipated demand at the time of service, but also the demand years later. This requires forecasting demand for the next 6 to 8 years, which is risky and results in unused capacity when HTS is put into service. Unused capacity at the beginning of the life of HTS can be wasted. By dividing the capacity of a single large HTS satellite into multiple microsatellites means that each microsatellite is filled faster and less capacity is wasted throughout the entire life cycle of the microsatellite.

Thus, a method and system for a satellite has been described. It is noted that reference throughout this specification to "one aspect" (or "an embodiment") or "an aspect" means that a particular feature, structure or characteristic described in connection with the aspect is included in at least one aspect of the present disclosure. Thus, it is emphasized and should be appreciated that two or more references to "an aspect" or "one aspect" or "an alternative aspect" in various portions of this specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures, or characteristics referenced may be combined as suitable in one or more aspects of the disclosure, as will be appreciated by one of ordinary skill in the art.

While the present disclosure has been described above with respect to what is presently considered to be the preferred aspects thereof, it is to be understood that the disclosure is not limited to the above description. On the contrary, the disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A satellite payload system, comprising:

a plurality of focal plane array tiles interfaced with a reflector for receiving and transmitting signals;

wherein a focal plane array tile of the plurality of focal plane array tiles comprises a receiving portion, a transmitting portion, and a switching module;

wherein the receiving part includes: a first filter that isolates a reception signal from a transmission signal; a low noise amplifier that amplifies the reception signal; and a first frequency conversion module that converts a frequency of the reception signal into an intermediate frequency;

wherein the transmitting part includes a second frequency conversion module that converts the frequency of the transmission signal into a radio frequency; and

wherein the switching module receives an output from the receiving portion and switches the output to another focal plane array tile.

2. The system of claim 1, wherein orthogonal polarizations are used between receive elements at the receive part and transmit elements at the transmit part to isolate the receive signal from the transmit signal.

3. The system of claim 1, wherein output from the receiving section is routed to the transmitting section through the switching module.

4. The system of claim 1, wherein the receiving section comprises a first phase shifter for phase control of the receive signal and the transmitting section comprises a second phase shifter for phase control of the transmit signal.

5. The system of claim 1 wherein the plurality of transmit elements of the plurality of focal plane array tiles are grouped together to form a transmit chain for transmitting signals.

6. The system of claim 1 wherein the plurality of receive elements of the plurality of focal plane array tiles are grouped together to form a receive chain for receiving a signal.

7. The system of claim 1, wherein the transmitting section includes an amplifier to amplify the output of the second frequency conversion module.

8. A satellite payload system, comprising:

a plurality of active lens tiles interfaced with a plurality of focal plane tiles interfaced with a reflector for receiving and transmitting signals;

wherein an active lens tile of the plurality of active lens tiles comprises a receiving portion and a transmitting portion;

wherein the receiving portion of the active lens tile comprises: a first filter for isolating a transmission signal from a reception signal in the transmission unit; and a low noise amplifier that amplifies the reception signal; and

wherein the transmitting portion of the active lens tile includes a high power amplifier to amplify an output of a phase shifter receiving the transmission signal;

wherein a focal plane tile of the plurality of focal plane tiles comprises a receiving portion, a transmitting portion, and a switching module,

wherein the receiving portion of the focal plane tile comprises a first frequency conversion module to convert the frequency of the received signal to an intermediate frequency;

wherein the switching module receives an output from the receiving portion of the focal plane tile and switches the output to another focal plane tile.

9. The system of any one of the preceding claims, wherein the plurality of active lens tiles and the focal plane tile are placed in a pot-shaped structure such that the active lens tiles are placed above the focal plane tile.

10. The system of any one of the preceding claims, wherein output from the receiving portion of the focal plane tile is routed to the transmitting portion of the focal plane tile by the switching module.

11. The system of any one of the preceding claims, wherein the receiving portion of the active lens tile comprises a first phase shifter for phase control of the receive signal.

12. The system of any of the preceding claims, wherein the plurality of transmit elements of the plurality of active lens tiles are grouped together to form a transmit chain for transmitting signals.

13. The system of any of the preceding claims, wherein a plurality of receive elements of the plurality of active lens tiles are grouped together to form a receive chain for receiving a signal.

14. The system of any one of the preceding claims, wherein the transmitting portion of the focal plane tile comprises an amplifier to amplify the output from the second frequency conversion module.

15. A satellite payload system, comprising:

a plurality of active reflector tiles interfaced with a plurality of focal plane tiles, the focal plane tiles interfaced with a reflector for receiving and transmitting signals;

wherein an active reflector tile of the plurality of active lens tiles comprises a receiving portion and a transmitting portion;

wherein the receiving portion of the active lens tile comprises: a first circulator for isolating a transmission signal from a reception signal in the transmission unit; and a low noise amplifier that amplifies the reception signal; and

wherein the transmitting portion of the active reflector tile comprises: a second circulator isolating the transmission signal from the reception signal; and a high power amplifier that amplifies an output of the phase shifter receiving the transmission signal;

wherein the transmitting portion of the focal plane tile includes a second frequency conversion module that converts the frequency of the transmit signal to a radio frequency; and

16. The system of claim 15, wherein the plurality of active reflector tiles and the focal plane tiles are arranged in an array.

17. The system of claim 15, wherein output from the receiving portion of the focal plane tile is routed to the transmitting portion of the focal plane tile by the switching module.

18. The system of claim 15, wherein the receiving portion of the active reflector tile includes a first phase shifter for phase control of the receive signal.

19. The system of claim 15, wherein the active reflector tiles use cross polarization to isolate the receive signal from the transmit signal.

20. The system of claim 15, wherein the active reflector tiles use frequency conversion to isolate the receive signal from the transmit signal.