CN111211827B

CN111211827B - Tile type satellite payload system and related method

Info

Publication number: CN111211827B
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: 2023-05-26
Anticipated expiration: 2039-11-21
Also published as: CN111211827A; CN116667909A

Abstract

To a tiled satellite payload system 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 an active lens tile, a focal plane array tile, and a reflector. The third system includes an active reflector tile, a focal plane array tile, and a reflector. Yet another system enables 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 type satellite payload system and related method

Cross Reference to Related Applications

According to 35usc 119 (e), the present patent application claims the priority of U.S. provisional patent application serial No. 62/770485, entitled "Tile Based Satellite Communications Payloads and Satellite Dynamic Power Sharing Using SSPAs", filed 11/2018, and U.S. provisional patent application serial No. 62/778199, entitled "A System of Micro High Throughput Satellites for Mobility Services", filed 12/11/2018, 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 send and receive information. Satellites typically use a communication "payload" that transmits and receives signals.

Current technology, particularly for streaming audio/video, requires a higher bandwidth for satellite payloads. High throughput satellites (High Throughput Satellite, HTS) are used to meet 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 satellite power to be concentrated 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. The transponder is the basic unit of the 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 payloads are complex, unique and often hand-made. For example, the HTS payload internal waveguide layout of KaSat may have multiple (e.g., 2500) customized waveguides connecting various spot beams (e.g., 80) and multiple (e.g., 65) traveling wave tube amplifiers (Traveling Wave Tube Amplifier, TWTA). TWTA is used to support high Radio Frequency (RF) power (e.g., greater than 100W). Typically, each waveguide section is custom made and manually placed within the payload. TWTA uses 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. Thus, constructing a conventional HTS payload is time consuming and cost prohibitive. Furthermore, conventional HTS components are large and heavy, which presents design challenges in meeting the increased bandwidth requirements. Thus, HTS systems require better architectural solutions.

In conventional satellite systems, power sharing between satellite beams is achieved through a TWTA, a cavity filter output multiplexer (Output Multiplexer, OMUX), and a Multi-Port Amplifier ("MPA"). These components are complex and heavy and allow only power sharing between a limited number of beams.

The distribution of user traffic may change over time at the earth's surface. This may occur for fixed applications because different time zones have different circadians and for mobile applications the user terminal moves throughout the day. The change in user traffic distribution over time is particularly evident in the aeronautical traffic mode, in which the aircraft fleet 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 area into smaller spot beams in an attempt to improve satellite performance and economy. Differentiating into smaller beams results in the situation where the mobile traffic creates independent peaks in time for each beam. Providing peak capacity in each beam results in wasted capacity throughout the day. There is a need for a better solution for power sharing between satellite beams.

HTS systems using multiple beams have steadily replaced wide beam satellites for mobile services. Typically, as described above, HTS-based payloads use multiple spot beams to increase the capacity obtained from the same track (orbital slot). Disadvantages of HTS payloads are their size, complexity, time to market, cost, and lack of flexibility. For example, typical HTS systems range in mass from 3000 kg to 6000 kg, with thousands of hand-made parts. Constructing and deploying HTS systems typically takes 3 to 4 years. Furthermore, most HTS systems are customized and tailored to specific rail sites, coverage areas, and ground stations. Typical conventional HTS systems can cost between 3 and 6 billion dollars, making them a risk and expensive investment. There is a need for a better solution for conventional HTS systems that can effectively 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 interfacing with reflectors (interleaved) for receiving and transmitting signals. The focal plane array tile of the plurality of focal plane array tiles includes a receiving portion, a sending portion, and a switching module. The receiving section includes: a first filter that isolates the received signal from the transmitted signal; a low noise amplifier that amplifies a reception signal; and a first frequency conversion module that converts the frequency of the received signal to an intermediate frequency. The transmitting section includes a second frequency conversion module that converts the frequency of the transmission signal to radio frequency. The switching module receives the output from the receiving section and switches the output to another focal plane array tile.

In another aspect, a satellite payload system includes a plurality of active lens tiles that interface with a plurality of focal plane tiles that interface with a reflector for receiving and transmitting signals. The active lens tiles of the plurality of active lens tiles include 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 that amplifies the received signal. The transmit section of the active lens tile includes a high power amplifier that amplifies the output of the phase shifter receiving the transmit signal.

The focal plane tiles of the plurality of focal plane tiles include 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 transmitted signal to 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 reflectors for receiving and transmitting signals. The active reflector tiles of the plurality of active lens tiles include a receiving portion and a transmitting portion. The receiving portion of the active lens tile includes: a first circulator that isolates a transmission signal of the transmission section from a reception signal; and a low noise amplifier that amplifies the received signal. The transmitting portion of the active reflector tile includes: a second circulator isolating the transmit signal from the receive signal; and a high power amplifier that amplifies an output of the phase shifter that receives the transmission signal.

The focal plane tiles of the plurality of focal plane tiles include a receiving portion, a sending 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 transmitted signal to 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.

Drawings

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

FIG. 1A illustrates an example of a multiple satellite payload system 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 disclosure;

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

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

FIG. 1E illustrates an arrangement for using the active lens tile and focal plane tile 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 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 disclosure;

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

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

FIG. 2 illustrates an example of arranging payload tiles in 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 (solid state power amplifier, SSPA) in a satellite payload in accordance with an aspect of the present disclosure;

FIG. 3E illustrates one example of selectively powering an SSPA of a satellite payload in accordance with an aspect of the disclosure;

FIG. 3F illustrates a process for selectively powering an SSPA in accordance with an aspect of the 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 multiple spot beams;

fig. 4B illustrates the use of a multi-spot beam using microsatellites, according to one aspect of the present disclosure; and

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

Detailed Description

As used herein, the terms "component," "module," "system," and the like are intended to refer to a computer-related entity, a software-executed 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 component may be stored on, for example, a non-transitory computer/machine readable medium including, but not limited to, an ASIC (application specific integrated circuit), a CD (compact disc), a DVD (digital video disc), a ROM (read only memory), a hard disk, an EEPROM (electrically erasable programmable read only memory), a solid state memory device, or any other storage device. Conditional processing/routines may be expressed by or when there are qualifiers that are used interchangeably herein and are intended to have the same meaning.

In one aspect, the technology disclosed herein provides an economical and efficient solution for HTS ("high throughput satellite") payloads. Novel payload architectures/configurations are disclosed that use mass-produced Integrated Circuit (IC) modules and are laid down (tiled) together to form a payload. The payload systems disclosed herein are lighter, cheaper, and easier to assemble than conventional systems. In addition to standard transponder functions, the described architecture also supports a frame switching function (frame switching functionality) to support beam hopping (also known as satellite switching Time Division Multiple Access (TDMA)).

In one aspect, payload tiles (payload tiles) using similar techniques with similar transmit and receive functions are disclosed. These tiles are used to feed deployable or openable reflectors (deployable or unfurlable reflector), support a large number of spot beams (e.g., hundreds or thousands), and provide gain to support high bandwidths 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 techniques 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. The system 102 includes a plurality of focal plane tiles 104 that receive beams from the passive reflector 106 and transmit beams to the passive reflector 106. Details regarding system 102 and 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 a 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, the active reflector system 114 (which may also be referred to as a 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 relative 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. The active lens system 112 and the active reflector system 114 may be configured to operate in a direct radiation mode without the passive reflector 106. Furthermore, while for simplicity, fig. 1A shows a coaxial configuration, other arrangements such as offset feeds, grigay (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 a focal plane array tile 104 of a system 102 in accordance with an aspect of the disclosure. A plurality of focal plane array tiles are arranged in an array to serve as satellite payloads. The various components of focal plane array tile 120 may be fabricated with integrated circuit components using standard fabrication techniques.

In one aspect, the tile 120 includes a receive (Rx) portion 120A for processing a received signal and a transmit (Tx) portion 120B for processing a transmitted signal having interleaved (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 rejection filter (reject filter) 124, which rejection filter 124 isolates the received signal from noise in the transmit section 120B. In one aspect, orthogonal polarization may be used to isolate the received signal from the transmit section noise.

The output from filter 124 is amplified to an operating level by a Low Noise Amplifier (LNA) 126. The output from the 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 the 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 the module 128 to adjacent tiles 140A/140B, to the switching gateway subsystem 142, or to the Tx portion 120B. Gateway subsystem 142 may be used to route signals between tile arrays.

The Tx part 120B includes an "up-conversion" module (shown as "up-conversion to RF" or "up-conversion to Ku" (fig. 1D and 1G to 1I) (used interchangeably throughout the specification)) 144, and the "up-conversion" module 144 converts an input signal to an RF (radio frequency) signal based on the intensity 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. 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 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 back plate may include heat pipes (not shown) for thermal control.

As described above, the Tx element and the Rx element 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 element and the Rx element may be placed orthogonal to each other. Cross-polarization isolation will provide some inherent isolation between the Tx and Rx paths. Using two types of polarization would involve using two reflectors and two identical focal plane arrays, with one array 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 staggered in time with the downlink transmission. The only isolation needed in this implementation is between adjacent beams. Half duplex will not limit the overall capacity of the payload, but may limit the maximum uplink rate and maximum downlink rate of the beam.

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

In one aspect, focal plane array tile 120 components, i.e., receive and transmit feed elements 122/154, LNA 126, lower frequency converter 128, HPA 152, up-converter 144, and switching module 138, may be mass produced and laid down (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 Rx portions 156A and Tx portions 156B in accordance with an aspect of the disclosure. Tile 156 has various components similar to those of tile 120, such as suppression filter 124, LNA 126, module 128, HPA 152, module 144, and switching module 138. Common components of tiles 156 and 120 perform the same functions as described above, and thus, common components are not described again.

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

Phase shifters

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

variable attenuators

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

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

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.

On the one hand, only the required amplifiers are activated at any given time. For example, the amplifier may be mainline (key-lined) and only activated when a frame is sent. The pipelining reduces heat dissipation and power consumption in the payload.

In another aspect, the switching function in the tile enables activation of different subsets of elements 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 peaks and enable the beam to be directed to a single terminal. In a typical horn feed reflector system, the roll-off from peak to edge (roll-off) is 4.5dB. Being able to shift the peak by half the beam diameter will roll-off to 1.1dB saving 3.4dB. 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 a reflector for receiving and transmitting signals. A focal plane array tile from a 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 the received signal from the transmitted signal; a low noise amplifier that amplifies a reception signal; and a first frequency conversion module that converts the frequency of the received signal to an intermediate frequency. The transmitting section includes a second frequency conversion module that converts the frequency of the transmission signal to radio frequency. The switching module receives the output from the receiving section 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 an active lens system 112 in accordance with an aspect of the present disclosure. In one aspect, the functionality of focal plane array tile 120 described above with respect to fig. 1B/1C is split between lens tile 168 and 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 element 122B and TX element 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.

Lens tile 168 includes phase shifter 158 in Rx section 168A and phase shifter 164 in transmit section 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 shifter and attenuator enable the lens tile 168 to create a phase and amplitude distribution across the lens, essentially providing its own focal length. This enables the lens tile 168 to operate in a direct radiation configuration without a passive reflector and reduces the focal length and size of the feed array.

In one aspect, focal plane tile 166 provides a feed array using elements 122A in Rx portion 166A and elements 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 signal levels within the focal plane tile 166. Notably,

LPAs

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

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 tiles 166 may be mounted to a backplane that provides DC power and signal connection between adjacent tiles. The back plate may not require a heat pipe because the power level at the focal plane tile 166 is lower.

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

Notably, the lens tile 168 does not perform frequency conversion. 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 pot structure 174 as shown in FIG. 1E may be used to place the lens tile 168 and focal plane tile 166. The pot structure 174 places the active lens 168 on top and the focal plane tile 166 on the bottom. Sidewall structures 176 are located between the lens and the focal plane tile.

In one aspect, a satellite payload system is provided. The system includes a plurality of active lens tiles that interface with a plurality of focal plane tiles that interface 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 of the transmission section from a reception signal; 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 transmitted signal.

The focal plane tiles of the plurality of focal plane tiles include 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 transmitted signal to 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 configuration: fig. 1F illustrates an example of an active reflector system 114 having an active reflector tile 116 and a focal plane array tile 118 in accordance with an aspect of the disclosure. Service link 178 communicates signals between active reflector tile 116 and passive reflector 106 (not shown in fig. 1F). Focal plane array tile 118 receives and transmits signals via an intra-payload link 180 between active reflector tile 116 and focal plane array tile 118. The signals at service links 178 and 180 may be isolated by circulators, frequency conversion, or cross polarization, as described in detail below.

Fig. 1G illustrates an active reflector tile 182 and focal plane tile 166 of an 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) portion 182A and a circulator 193 in a transmit (Tx) portion 182B. A circulator is a passive, nonreciprocal, three-port or four-port device in which an RF signal entering any port is routed rotationally to the next port. Herein, a port is a point where an external waveguide or transmission line (e.g., microstrip line or coaxial cable) is connected to the device. For a three port circulator, the signal applied to the first port is only coming out of the second port; the signal applied to the second port only exits the third port; the signal applied to the third port only exits the first port. The

circulators

195 and 193 of the receive and transmit sections may be used to isolate signals received via the service link 178 and the intra-payload link 180.

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

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 receiving portion 184A includes a frequency converter 188A and the transmitting portion includes a frequency converter 188B for isolating the service link 178 from the signal at the intra-payload link 180. The frequency converter 188A includes a filter 190, a mixer 192, and an oscillator 194. Frequency converter 188B includes filter 196, mixer 198, and oscillator 199. The frequencies 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 of frequency converter 188B is sent to focal plane tile 166 via element 154C.

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

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

elements

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

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

In one aspect, the tile payload system described above may be used in a variety of frequency bands including X, ku, ka, Q, V and the like. The various tile systems 102, 112, and 114 may be tailored for different antenna geometries, such as coaxial, offset feed, gurley, cassegrain, or direct radiation. Various configurations of the present disclosure may be implemented using single orthogonal or dual polarization.

In one aspect, a satellite payload system is provided. The system includes a plurality of active reflector tiles that interface with a plurality of focal plane tiles that interface with the 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 of the transmission section from a reception signal; and a low noise amplifier to amplify the received signal. The transmitting portion of the active reflector tile includes: a second circulator to isolate the transmit signal from the receive 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 receiving elements in the focal plane and one or a small subset of transmitting elements in the focal plane, as described in detail above. The beamforming of satellite payloads is handled by a passive reflector or divided between passive reflectors and active lenses/active reflector tiles. Phase shifters or delay lines in the active lens or active reflector enable the tiles to focus the signal. When this function is used in combination 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 because it 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 technology disclosed herein is used to replace a particular conventional HTS component, such as a TWTA, by a Solid State Power Amplifier (SSPA). 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 required to cover a particular geographic area.

Fig. 3A illustrates 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 areas are shown as 302, 304, and 306. The illustrations of

beam powers

308, 310, and 312 are for time 1. The illustrations of

beam powers

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

beam powers

320, 322, and 324 is for time 3. The change in beam power is to accommodate the change in traffic pattern.

Conventionally, power sharing between beams is achieved by moving high power RF signals between downlink beams. This is achieved by using OMUX for power splitting of the output of TWTAs (see fig. 3B) or by using multiple TWTAs in an MPA (multiport amplifier) configuration connected by a Butler (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 an electric power regulation (EPC) unit may weigh 2kg to 3kg, may be 37cm by 9cm in size, has a saturated RF power of 100W to 200W, and has a saturation efficiency of 65%.

To share power across multiple spot beams, fig. 3B illustrates a conventional system in which TWTA 326 receives input 332 and generates output. The output is provided to 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 to 330C are then connected to the spot beam feed using waveguides. OMUXs typically weigh about 1kg per output. Power may be routed to each output beam through uplink carriers of different frequencies, 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, it is undesirable for the TWTA to divide power between only two to four beams at a time. In addition, both TWTA and OMUX are heavy and costly to manufacture.

MPA offers some flexibility in terms of power sharing, but is more complex. FIG. 3C shows an MPA 334 in which a set of TWTAs 326A-326D are power devices that use a combination of Butler matrices 336A/336B. Butler matrix 336A/336B is a specific combination of hybrid power splitters and combiners placed before and after the group of TWTAs 326A-326D. The MPA 334 has the same number of input ports and output ports as the TWTA. 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 arbitrary division of the total power of the TWTA in the MPA 334 between the output ports (338A-338C). Combining multiple TWTAs in an 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-330C) using 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 SSPA that is smaller in size, lower in mass, and cheaper than TWTA. SSPA provides an economical and efficient solution to share DC power across beams, rather than radio frequency power, to create a simplified satellite payload. SSPA is 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 exceeding 50%. This may be less efficient than typical TWTAs, but the small size of SSPAs enables them to be mounted near or on the beam feeding device, eliminating waveguide losses of typically 1dB or more in TWTA based systems.

As an example, the dimensions of a 16W Ku band GaN SSPA (e.g., model TGA 2760-SM) from Quorvo corporation are 0.8cm by 1.0cm by 0.2cm. Although it may have a power lower than that of a typical Ku band TWTA, less than 1 gram in mass, it is at least 2000 times lighter than a typical TWTA, but 18000 times smaller in volume. In other words, for the same mass as the TWTA, 200 times the RF power may be installed, while still accounting for only 1/9 of the volume of a single TWTA. Thus, for the same quality as the TWTA, a larger amplifier power can be installed. This enables the power sharing system to move power between beams by selectively powering on and off the amplifier. 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. Reflector 354 is used to generate a plurality of coverage beams 356A-356N on the ground. Reflector 354 may be a solid reflector, a fixed mesh reflector, or an openable mesh reflector. Reflector 354 may take any arrangement, such as a center feed, cassegrain, grignard, on-axis (on-axis), or off-set. A large diameter openable reflector is 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-356N is generated by one (single feed per beam) or multiple (multiple feeds per beam) feeds at the focal plane of reflector 354. Communication between the focal plane of the satellite payload and the reflector is shown by 350 and multiple beams from the reflector are shown by arrow 352. The feeding means (feeds) themselves may be horns, patches, dipoles, slots, dielectric rods or any similar technique. Each feed is connected to one or more SSPAs 348A-348N. If multiple SSPAs are connected to the same feed, they can be power devices combined using waveguides, striplines, or microstrip combiners, or similar technologies. In the case of multiple feeds per beam and/or multiple SSPAs per feeds, 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 individually or in groups by a power signal 344 and is connected to an input signal source (346A-346N).

In the case of connecting multiple SSPAs to the feed device, 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. Controller 342 may also control the signals of each SSPA.

Fig. 3E illustrates an example of power sharing between satellite beams according to an aspect of the disclosure. A group of aircraft may move from one region to another (i.e., from 302 via 304 to 306, and from 306 via 304 to 302). Power is moved from one beam to another by powering different SSPA groups (constituting different antenna feeds). In one aspect, to keep the total power consumption constant, while one beam is powered, the other beams may remain unpowered (e.g., while the SSPAs for beam 1 are powered, the SSPAs for beams 2 and 3 are not powered). This arrangement is useful for large openable reflectors for generating a large number of beams in a sparse traffic area.

On the other hand, it may be desirable to operate the beam at a power below the maximum power, and use multiple SSPAs per beam allows this to be done without any loss of efficiency. Operation with reduced power consumption may be accomplished by reducing the input drive level. In another aspect, the bias voltage for the SSPA can be reset to reduce power. By powering down a portion of the SSPAs feeding the beams while keeping the remaining SSPAs operating at their most efficient operating level, having multiple SSPAs feeding each beam enables the beam power to be changed without any loss of efficiency. By operating the system in an automatic level control (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 1 358 has maximum traffic, each SSPA (348A-348H) feeding beam 1 is powered and connected to signal 1. Beam 2 360 may have less traffic and therefore only half of the SSPA (shown by the 4 black triangles) feeding beam 2 may be powered and connected to signal 2 (346). Beam 3 362 may have minimal traffic and therefore 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 changed over time by powering the SSPAs on and off, as long as the total number of SSPAs powered does not exceed the total supplied DC power available at the satellite.

Fig. 3F illustrates a process 364 for power sharing using SSPA 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, information about the service coverage is provided to the controller 342 of the satellite payload. 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 SSPA. In one aspect, the SSPA for the first beam can have a greater power than the SSPA for the second beam.

In conventional single-feed per beam systems, the optimum size of the feeds for antenna efficiency often exceeds the desired spacing between the feeds. This can be solved by: a smaller than optimal feed is used at the cost of reduced antenna performance or multiple reflectors are used at the cost of added mass and complexity. Another solution is: multiple feeds per beam using the same space as a single optimal feed would occupy. At the boundary between the beams, the feed devices are shared by adjacent beams, wherein the individual feed devices will overlap. However, in conventional power sharing applications, this requires a complex waveguide beamforming network behind the feed, which is typically heavy and expensive compared to 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 feeds per beam systems while retaining the ability to use a single reflector and maintaining high performance for optimal feed dimensions.

An arrangement of multiple feeds per beam and wherein multiple SSPAs per feed are shown in fig. 3G. In this case, the optimal feeder size (optimum feed size) 380 requires three feeders, 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 is powered by two SSPAs, one SSPA receiving input signal 1 346a and the other SSPA receiving input signal 2 346b. This creates the same effect as a waveguide beamforming network without weight and complexity.

The various aspects of the present disclosure are not limited to the rate at which power can be redistributed among beams. In some cases, it may be desirable to permanently allocate the number of beams and SSPAs to serve the fixed customer. In other cases, it may be desirable to dynamically reallocate power between beams to service traffic patterns that vary over an hour or minute span. In one aspect, power may be reallocated on a super-frame basis in a manner that effectively acts as a beam hopping arrangement. Beam hopping will enable more beams to be active during a given period of time, providing better granularity in terms of how resources are allocated and reducing uplink bandwidth/gateway requirements.

The adaptive aspects of the present disclosure have advantages over existing power sharing techniques. The use of a small SSPA amplifier 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 SSPA 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 with greater power sharing flexibility.

Miniature HTS system: in one ofIn aspects, to reduce the cost and complexity of conventional HTS systems, the present disclosure provides miniature HTS systems that are 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 less capacity and coverage than a single large HTS satellite. A plurality 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 micro HTS systems instead of a single large HTS system opens up less ideal and cheaper rails to use in the eastern and western directions of north america and european rail arcs. As shown by the circles between 408A to 408N in fig. 4B, as demand increases, capacity can be added to existing regions and coverage can be extended by adding more microsatellites to existing orbits. Multiple miniature HTS satellites may be added to one orbital and cover different areas of the same orbital or provide overlapping coverage areas. The orbit typically comprises 0.1 degrees in longitude along an arc of earth rest, which forms a box-like area of about 75km by 75km at a radius of about 42165km from the center of the earth. Thus, the orbit has available space for placing a plurality of 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 most rapidly. Conversely, if demand increases slower than expected, deployment of new satellites may be spread out over longer periods of time.

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

The microsatellite preferably uses openable reflectors so that high effective isotropic radiated power (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 a SSPA amplifier, preferably a GAN amplifier, that is small, lightweight, and efficiently powers 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 adjusts the frequency plan of the microsatellite to the available frequency spectrum at a given orbit position using a flexible channelizer for the payload. The channelizer is preferably an analog "bent-tube" channelizer. In another aspect, a digital channelizer is used.

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

The use of smaller, simpler microsatellites enables new satellites and new technologies to be brought to the market more quickly. This allows the satellite owners/operators to respond more to changing demands and reduces the risk of insufficient capacity or excess purchasing power in critical areas.

The long lead time of conventional HTS satellites means that each new HTS satellite must meet not only the expected demand at the time of service, but also 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 HTS life is wasted. 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 life cycle of the microsatellite.

Thus, methods and systems for satellites have been described. Note 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 referred to may be combined as suitable in one or more aspects of the disclosure as would be recognized 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 present disclosure is not limited to the foregoing 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, the plurality of focal plane array tiles interfacing with the reflector for receiving and transmitting signals;

the focal plane array tiles of the plurality of focal plane array tiles comprise a receiving part, a sending part and a switching module;

wherein the receiving section includes: a first filter that isolates the received signal from the transmitted signal; a low noise amplifier that amplifies the reception signal; and a first frequency conversion module that converts the frequency of the received signal to an intermediate frequency;

the transmitting part comprises a second frequency conversion module, and the second frequency conversion module converts the frequency of the transmitting signal into radio frequency;

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

Wherein orthogonal polarization is used between a receiving element at the receiving portion and a transmitting element at the transmitting portion to isolate the received signal from the transmitted signal.

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

3. The system of claim 1, wherein the receiving section includes a first phase shifter for phase control of the received signal and the transmitting section includes a second phase shifter for phase control of the transmitted signal.

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

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

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

7. A satellite payload system, comprising:

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

Wherein the active lens tiles of the plurality of active lens tiles include a receiving portion and a transmitting portion;

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

wherein the focal plane tiles of the plurality of focal plane tiles comprise a receiving part, a sending part and a switching module,

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

the transmitting part comprises a second frequency conversion module, and the second frequency conversion module converts the frequency of the transmitting signal into radio frequency; and

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

8. The system of the preceding claim 7, wherein the plurality of active lens tiles and the focal plane tile are placed in a pot structure such that the active lens tile is placed above the focal plane tile.

9. The system of the preceding claim 7, 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.

10. The system of the preceding claim 7, wherein the receiving portion of the active lens tile comprises a first phase shifter for phase control of the received signal.

11. The system of the preceding claim 7, wherein a plurality of transmit elements of the plurality of active lens tiles are grouped together to form a transmit chain for transmitting signals.

12. The system of the preceding claim 7, wherein a plurality of receiving elements of the plurality of active lens tiles are grouped together to form a receive chain for receiving a signal.

13. The system of the preceding claim 7, wherein the transmit portion of the focal plane tile comprises an amplifier to amplify the output from the second frequency conversion module.

14. A satellite payload system, comprising:

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

Wherein the active reflector tiles of the plurality of active reflector tiles include a receiving portion and a transmitting portion;

wherein the receiving portion of the active reflector tile comprises: a first circulator that isolates a transmission signal of the transmission unit from a reception signal; and a low noise amplifier that amplifies the received signal; and

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

the transmitting part of the focal plane tile comprises a second frequency conversion module, and the second frequency conversion module converts the frequency of the transmission signal into radio frequency; and

15. The system of claim 14, wherein the plurality of active reflector tiles and the focal plane tile are arranged in an array.

16. The system of claim 14, 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.

17. The system of claim 14, wherein the receiving portion of the active reflector tile comprises a first phase shifter for phase control of the received signal.

18. The system of claim 14, wherein the active reflector tiles use cross polarization to isolate the receive signal from the transmit signal.

19. The system of claim 14, wherein the active reflector tile uses frequency conversion to isolate the receive signal from the transmit signal.