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Beaming internet from the middle of the woods, using an extra-large, pizza-sized satellite dish placed on top of your house, up to a satellite orbiting 550 kilometers outside
使用放置在房屋頂部的比薩大小的超大衛星天線,將互聯網從森林中央傳輸到 550 公里外的衛星軌道上
Earth's atmosphere, well, let's be honest, is technologically mind-blowing.
老實說,地球的大氣層在技術上令人驚歎。
What's even crazier is that the Starlink satellites move incredibly fast, around 27,000 kilometers per hour, and data is being sent back and forth between them at hundreds of megabits per second, all while the dish and satellite are continuously angling or steering the beam of data pointed directly between them.
更瘋狂的是,"星鏈 "衛星的移動速度快得令人難以置信,時速約為 2.7 萬公里,數據在它們之間以每秒數百兆比特的速度來回傳輸,而天線和衛星則在不斷調整角度或轉向直接指向它們之間的數據光束。
On top of that, the dish switches between different satellites every four or so minutes, because they move out of the dish's field of view rather quickly.
此外,碟形天線每隔四分鐘左右就會切換不同的衛星,因為它們很快就會移出碟形天線的視場。
If you have no clue as to how this is possible, stick around, because we're going to dive into the multiple key technologies which enable satellite internet to magically work.
如果您不知道這是如何實現的,請繼續閱讀,因為我們將深入探討使衛星互聯網神奇運作的多種關鍵技術。
First, we'll explore inside the satellite dish and see how it generates a beam of data that is able to reach space.
首先,我們將探索衛星天線的內部,看看它是如何產生一束能夠到達太空的數據的。
Second, we'll see how this dish continuously steers the beam so that it points directly at a satellite moving across the sky.
其次,我們將看到這種碟形天線是如何持續引導光束,使其直接指向天空中移動的衛星的。
And third, we'll dive into what exactly the dish and satellite are sending inside the beam that results in your ability to stream five HD movies or shows simultaneously.
第三,我們將深入探討天線和衛星在光束內發送的信號到底是什麼,從而使您能夠同時串流播放五部高清電影或節目。
This video is quite long as it's full of in-depth details.
這段視頻很長,因為裡面有很多深入的細節。
We recommend watching it first at 1.25x speed and then a second time at 1.5x speed to understand it as a complete technology.
我們建議先以 1.25 倍速觀看,然後再以 1.5 倍速觀看第二遍,以瞭解其完整的技術。
So stick around and let's jump right in.
所以,請不要走開,我們馬上開始。
First, let's start by clarifying the difference between a television satellite dish such as this one and the Starlink ground dish, which Elon Musk dubbed Dishy McFlatface, or Dishy for short.
首先,讓我們來澄清一下電視衛星天線(比如這個)與星鏈地面天線(埃隆-馬斯克稱之為 Dishy McFlatface,簡稱 Dishy)之間的區別。
TV dishes use a parabolic reflector to focus the electromagnetic waves which are the TV signals sent from broadcast satellites orbiting the Earth at an altitude of 35,000 km.
電視天線使用拋物面反射器聚焦電磁波,這些電磁波是從 35000 千米高空環繞地球運行的廣播衛星發送的電視信號。
TV satellite dishes only receive TV signals from space.
電視衛星天線只能接收來自太空的電視信號。
They can't send data.
它們無法發送數據。
Dishy, however, both sends and receives internet data from a Starlink satellite orbiting 550 km away.
然而,Dishy 可以從 550 千米外軌道上的 Starlink 衛星發送和接收互聯網數據。
While the Starlink satellite is 60 times closer than TV satellites, it's still an incredible distance to wirelessly send a signal and thus the beams between Dishy and the Starlink satellite need to be focused into tight, powerful beams that are continuously angled or steered to point at one another.
雖然 Starlink 衛星比電視衛星近 60 倍,但要無線發送信號,這仍然是一個令人難以置信的距離,是以 Dishy 和 Starlink 衛星之間的光束需要聚焦成緊密、強大的光束,並不斷調整角度或轉向,以指向對方。
Compare this to TV broadcast signals which come from a satellite the size of a van and whose signals propagate in a wide fan that covers land masses larger than North America.
相比之下,電視廣播信號來自一個麵包車大小的衛星,其信號的傳播範圍比北美的陸地面積還大。
Table-sized Starlink satellites, however, need to be in a low Earth orbit to provide for 20 millisecond latencies, which is critical for smoothly playing internet games or surfing the web, and as a result their coverage is much smaller.
然而,桌子大小的 Starlink 衛星需要位於低地球軌道,以提供 20 毫秒的延遲時間,這對於流暢地玩網絡遊戲或上網衝浪至關重要,是以其覆蓋範圍要小得多。
Thus, 10,000 or more Starlink satellites, all orbiting at incredibly fast speeds in a low Earth orbit, are required to provide satellite internet to the entire Earth.
是以,要向整個地球提供衛星互聯網,需要 1 萬顆或更多顆 Starlink 衛星,它們都在低地球軌道上以難以置信的速度運行。
Let's now open up Dishy McFlatface.
現在,讓我們打開 Dishy McFlatface。
At the back, we have a pair of motors and an ethernet cable that connects to the router.
在背面,我們有一對電機和一條連接路由器的以太網電纜。
Note that these motors don't continuously move Dishy to point directly at the Starlink satellite.
請注意,這些電機不會持續移動 Dishy,使其直接指向 Starlink 衛星。
They're used only for initial setup to get the dish pointed in the proper general direction.
它們僅用於初始設置,使天線指向正確的大方向。
Opening up Dishy, we find an aluminum structural backplate and on the other side we find a massive printed circuit board or PCB.
打開 Dishy,我們會發現一個鋁製結構背板,另一側則是一塊巨大的印刷電路板(PCB)。
One side has 640 small microchips and 20 larger microchips organized in a pattern with very intricate traces, fanning out from the larger to smaller microchips, along with additional chips including the main CPU and GPS module on the edge of the PCB.
一側有 640 個小型微芯片和 20 個較大的微芯片,它們以非常複雜的軌跡排列,從較大的微芯片向較小的微芯片扇形展開,PCB 板上的邊緣還有包括主 CPU 和 GPS 模塊在內的其他芯片。
On the other side are 1400-ish copper circles with a grid of squares between the circles.
另一面是 1400 個左右的銅圓圈,圓圈之間是方格網。
On the next layer, there's a rubber honeycomb pattern with small, notched copper circles and behind that we find another honeycomb pattern and then the front side of Dishy.
下一層是橡膠蜂窩狀圖案,上面有小缺口銅圈,後面是另一個蜂窩狀圖案,然後是 Dishy 的正面。
So what are we looking at?
我們在看什麼?
Well, in essence, we have 1,280 antennas arranged in a hexagonal honeycomb pattern with each stack of copper circles being a single antenna controlled by the microchips on the PCB.
實際上,我們有 1280 根天線,呈六角形蜂窩狀排列,每一疊銅圈就是一根天線,由 PCB 上的微芯片控制。
This massive array works together in what's called a phased array in order to send and receive electromagnetic waves that are angled to and from a Starlink satellite orbiting 550 kilometers above.
這個巨大的陣列以所謂的相控陣的方式協同工作,以向 550 公里上空軌道上的 Starlink 衛星發送和接收傾斜的電磁波。
Let's zoom in and see how a single antenna operates.
讓我們放大看看單根天線是如何工作的。
Here we have an aperture-coupled patch antenna composed of 6 layers, most of which are inside the PCB.
我們這裡的孔徑耦合貼片天線由 6 層電路板組成,其中大部分位於電路板內部。
It looks very different from the antenna of an old-school radio and is honestly incredibly complicated, so let's simplify it.
它看起來與老式收音機的天線大相徑庭,而且複雜得令人難以置信,所以我們還是簡化一下吧。
We'll remove a few of the layers for now and step through the basic principles of how we generate an electromagnetic wave that propagates out from this antenna.
現在,我們將去掉一些層次,逐步瞭解如何產生電磁波並從天線傳播出去的基本原理。
To start, at the bottom we have a microstrip transmission line feed coming from one of the small microchips.
首先,底部的微帶傳輸線饋電來自其中一個小型芯片。
This transmission line feed is just a copper PCB trace, or wire, that abruptly ends under the antenna stack.
傳輸線饋電只是 PCB 上的一條銅線,或稱導線,在天線棧下突然終止。
We send a 12 gigahertz high-frequency voltage, or signal, to the feed wire, which is a voltage that goes up and down in a sinusoidal fashion, going from positive to negative and back to positive once every 83 picoseconds, 12 billion times a second, or 12 gigahertz.
我們向饋線發送一個 12 千兆赫的高頻電壓或信號,這是一個以正弦波方式上升和下降的電壓,每 83 皮秒(每秒 120 億次)從正極變為負極,再變回正極。
Note that high-frequency electricity works differently from direct current or low-frequency 50 or 60 hertz household electricity.
請注意,高頻電的工作原理與直流電或 50 或 60 赫茲的低頻家用電不同。
For example, above the copper feed wire we have a copper circle with notches cut into it called an antenna patch.
例如,在銅饋線上方有一個銅圓,上面切有凹口,稱為天線貼片。
With DC, or low-frequency alternating current, there wouldn't be much happening because the patch is isolated, but with a high-frequency signal, the power sent to the feed wire is coupled or sent to the patch.
對於直流電或低頻交流電,由於貼片是隔離的,是以不會有太大影響,但對於高頻信號,發送到饋電線的功率會耦合或發送到貼片。
How exactly does this happen?
這究竟是怎麼發生的呢?
Well, as mentioned earlier, a 12 gigahertz signal is applied to the copper feed wire.
如前所述,12 千兆赫的信號被施加到銅饋線上。
When the voltage is at the bottom of its sinusoidal, or trough, we have a concentration of electrons pushed to the end of the feed wire, thus creating a zone of negative charge which corresponds to the maximum negative voltage.
當電壓處於正弦曲線的底部或谷底時,電子會被集中推向饋電線的末端,從而產生一個負電荷區,與最大負電壓相對應。
This concentration of electrons on the tip of the wire repels all electrons away, including the electrons on the top of the patch, and as a result, these electrons are pushed to the other side of the circular patch.
電子在導線尖端的聚集會排斥所有電子,包括貼片頂部的電子,是以這些電子會被推向圓形貼片的另一側。
Thus, one side of the patch becomes positively charged while the other becomes negatively charged, thereby creating electric fields between the patch and feed wire, like so.
這樣,貼片的一側帶正電,另一側帶負電,從而在貼片和饋電線之間產生電場,就像這樣。
However, when we reverse the voltage to the copper feed wire 42 picoseconds later, we have a concentration of positive charges, or a lack of electrons at the end of the wire, and thus the electrons in the patch flow to the other side.
然而,當我們在 42 皮秒後將電壓反向施加到銅饋線上時,銅饋線末端就會出現正電荷集中或電子缺乏的現象,從而使貼片中的電子流向另一端。
The voltage in the patch is flipped, and the direction of the electric fields are also flipped.
貼片中的電壓發生了變化,電場的方向也發生了變化。
Because the feed wire voltage oscillates back and forth 42 picoseconds between one peak and trough, the electric fields in the patch will also oscillate as the electrons, or current, flows back and forth.
由於饋電線電壓在一個波峰和波谷之間來回擺動 42 皮秒,貼片中的電場也會隨著電子或電流的來回流動而擺動。
If we pause the oscillation, we can see some of these electric field vectors, or arrows from the patch, are vertical, and because they're equal and opposite, they cancel out.
如果我們暫停振盪,就可以看到其中一些電場矢量或來自貼片的箭頭是垂直的,由於它們相等且相反,是以會抵消。
However, other electric fields are horizontal in the same plane of the patch, and are called fringing fields.
然而,在貼片的同一平面上還有其他水準電場,這些電場被稱為邊緣場。
These fringing fields are in the same direction, and thus they add to each other, resulting in a combined electric field pointing in this direction.
這些邊緣場的方向相同,是以它們會相互疊加,形成一個指向該方向的組合電場。
At the same time, electrons flowing from one side of the disk to the other, which is an electric current, generate a magnetic field with a strength and direction, or vector, perpendicular to the fringing electric field vector.
與此同時,從磁盤一側流向另一側的電子(即電流)會產生磁場,其強度和方向或矢量與邊緣電場矢量垂直。
As a result, we have an electric field pointing one way, and a magnetic field pointing perpendicular to that.
是以,電場指向一個方向,而磁場則與之垂直。
Let's move forward in time to where the voltage on the feed line becomes positive, and now we're at the peak of the sinusoid, 42 picoseconds later.
讓我們將時間向前推移,饋電線上的電壓變為正值,現在我們正處於正弦波的峰值,即 42 皮秒之後。
The charge concentrations, or voltage, as well as the current, is all flipped, and thus the electric and magnetic fields point in the opposite directions.
電荷濃度或電壓以及電流都發生了翻轉,是以電場和磁場指向相反的方向。
Electric and magnetic fields propagate in all directions, and by creating these oscillating fringing fields, we've generated an electromagnetic wave, which travels in the direction perpendicular to both the electric and magnetic field vectors.
電場和磁場向各個方向傳播,通過產生這些振盪的邊緣場,我們就產生了電磁波,電磁波沿著與電場和磁場矢量垂直的方向傳播。
Because the two sets of field vectors are not all in the same plane, but rather are curved, the propagating electromagnetic wave travels outwards in an expanding shell or balloon-like fashion, kind of like a light bulb on the ceiling.
由於兩組場矢量並不都在同一個平面上,而是彎曲的,是以傳播的電磁波會以一種膨脹的外殼或氣球狀的方式向外傳播,有點像天花板上的燈泡。
Let's simplify the visual, so we can see the peak and trough, or top and bottom, of each wave, and note that the trough is just a vector pointed in the opposite direction.
讓我們簡化一下視覺效果,這樣我們就能看到每個波浪的波峰和波谷,或者說波頂和波底,並注意到波谷只是一個指向相反方向的矢量。
Additionally, the strengths of these field vectors directly relate back to the voltage and signal that we originally sent to the copper microstrip feed wire at the bottom of the stack.
此外,這些場矢量的強度與我們最初發送到堆棧底部銅微帶饋線的電壓和信號直接相關。
Which means, if we want to make these electric and magnetic fields stronger, we just have to increase the voltage sent to the feed line.
這意味著,如果我們想讓這些電場和磁場變得更強,只需增加饋電線的電壓即可。
Just like a dimmer on a light switch, more power equals a brighter light.
就像電燈開關上的調光器一樣,功率越大,燈光越亮。
Thus far, we've been talking about this aperture-coupled patch antenna as transmitting, however it can also be used for receiving a signal.
到目前為止,我們一直在討論這種孔徑耦合貼片天線的發射功能,但它也可用於接收信號。
In this microchip, called a front-end module, we switch the antenna from transmit to receive and turn off the 12 GHz signal.
在這個被稱為前端模塊的微型芯片中,我們將天線從發射切換到接收,並關閉 12 GHz 信號。
When an electromagnetic wave from the satellite is directed towards DISHI, the electric fields from this incoming signal will influence the electrons in the copper patch, thus generating an oscillating flow of electrons.
當來自衛星的電磁波射向 DISHI 時,傳入信號的電場將影響銅貼片中的電子,從而產生電子振盪流。
This received high-frequency signal is then coupled to the feed line where it's sent to the front-end module chip which amplifies the signal.
然後,接收到的高頻信號被耦合到饋電線上,再送入前端模塊芯片,由其放大信號。
Thus, these antennas can be used to both transmit and receive electromagnetic waves, but not at the same time.
是以,這些天線既可用於發射電磁波,也可用於接收電磁波,但不能同時使用。
Two quick things to note.
有兩點需要注意。
First, as seen earlier, this antenna has many more layers, and is more complicated than we've discussed.
首先,如前所述,這種天線有更多層次,比我們討論的要複雜得多。
For example, here are two circular patches.
例如,這裡有兩個圓形補丁。
The bottom is used to transmit at 13 GHz, while the top to receive at 11.7 GHz.
底部用於 13 千兆赫的發射,頂部用於 11.7 千兆赫的接收。
Additionally, there are two H-slots and two feed wires to support circular polarization, a reflective plane in the back, and also there are multiple features for isolating the operation of one antenna from the adjacent antennas.
此外,還有兩個 H 型插槽和兩根饋線支持圓極化,背面有一個反射面,還有多種功能用於隔離一根天線與相鄰天線的工作。
We've included these and many more details in the creator's comments, which you can find in the English-Canadian subtitles.
我們在創作者的評論中收錄了這些和更多細節,您可以在英加字幕中找到。
The second note is that there are electromagnetic waves of all different frequencies from thousands of different sources, passing through every point on Earth.
第二點是,有來自成千上萬個不同來源的各種不同頻率的電磁波,通過地球上的每一個點。
Whether it be visible light from the sun, radio waves from radio or cell towers, or
無論是太陽發出的可見光、無線電或手機信號塔發出的無線電波,還是
TV signals from satellites or towers.
來自衛星或信號塔的電視信號。
Therefore, in order to block out all other frequencies of electromagnetic waves, these antenna patches are designed with very exact dimensions, so that they receive and transmit only a very narrow range of frequencies, and all the other frequencies outside this range are essentially ignored by the antenna.
是以,為了阻隔所有其他頻率的電磁波,這些天線貼片的設計尺寸非常精確,是以它們只能接收和發射一個非常狹窄的頻率範圍,而這個範圍之外的所有其他頻率基本上都會被天線忽略。
Let's move on and see how a single antenna can be combined with others in order to amplify the beam to reach outer space.
接下來,讓我們看看如何將單根天線與其他天線組合在一起,以放大波束,使其到達外太空。
This single antenna is only a centimeter or so in diameter, and using only it would be like turning on and off one light bulb and trying to see it from the International Space
這根天線的直徑只有一釐米左右,僅使用它就像打開和關閉一個燈泡,並試圖從國際空間站看到它一樣。
Station.
車站。
What we need is a way to make the light a few thousand times brighter, and then focus all the electromagnetic waves into a single, powerful beam.
我們需要的是將光亮度提高几千倍,然後將所有電磁波聚焦成一束強大的光束。
Consider the massive Mr. McFlatface PCB, 55 centimeters wide, with a total of 1,280 identical antennas in a hexagonal array.
考慮一下 "麥克弗萊特臉先生 "的巨型印刷電路板,它寬 55 釐米,六邊形陣列中共有 1280 根相同的天線。
The technique of combining all the antennas' power together is called beamforming.
將所有天線的功率組合在一起的技術稱為波束成形。
So how does it work?
那麼,它是如何工作的呢?
Well, let's first see what happens when we have two simplified antennas spaced a short distance away.
好吧,讓我們先來看看當兩根簡化天線相距不遠時會發生什麼。
As mentioned before, one antenna generates an electromagnetic wave that propagates outwards in a balloon shape.
如前所述,一根天線產生的電磁波呈氣球狀向外傳播。
At every single point in space, there's only one electric field vector with a strength and direction, and thus, the two antennas' oscillating electric field vectors combine together at all points in space.
在空間的每一個點上,只有一個具有強度和方向的電場矢量,是以,兩根天線的振盪電場矢量在空間的所有點上都結合在一起。
In some areas, the electric fields from the antennas are pointing in the same direction with overlapping peaks, and thus, add together via constructive interference.
在某些區域,來自天線的電場指向同一方向,峰值重疊,是以會通過建設性干擾相加。
And in other locations, they're opposite with one peak on one trough, and thus, they cancel each other via destructive interference.
而在其他位置,它們則相反,一個波峰對一個波谷,從而通過破壞性干擾相互抵消。
We can now see that the zone where they add together constructively is far tighter, or more focused, than a single antenna alone.
我們現在可以看到,它們建設性地結合在一起的區域要比單獨的一根天線緊密得多,或者說更加集中。
When we add even more antennas, the zone of constructive interference becomes even more focused in what is called a beam front.
當我們增加更多天線時,建設性干擾區域會變得更加集中,形成所謂的波束前沿。
Thus, by adding 1280 antennas together, we can form a beam with so much intensity and directionality that it can reach outer space.
是以,將 1280 根天線加在一起,我們就能形成一個強度和方向性都很強的光束,可以到達外太空。
Now you might be thinking that the strength of one antenna duplicated 1280 times over would result in a combined power of, well, 1280 times a single antenna.
現在你可能會想,將一根天線的強度複製 1280 倍,其綜合功率就是一根天線的 1280 倍。
But you'd be mistaken.
但你錯了。
The effective power and range of the main beam from all these antennas combined is actually closer to 3500 times that of a single antenna.
所有這些天線的有效功率和主波束範圍加起來實際上接近單個天線的 3500 倍。
The quick explanation is that by having these patterns of constructive and destructive interference, it's as if we took a single antenna, multiplied it by 1280, and then placed a whole bunch of mirrors around it, and left only a single hole for the main beam to exit through.
簡單的解釋是,有了這些建設性和破壞性干擾模式,就好比我們把一根天線乘以 1280,然後在其周圍放置了一大堆鏡子,只留下一個孔供主光束通過。
The long explanation requires a ton of math and physics, so let's move on.
冗長的解釋需要大量的數學和物理知識,所以讓我們繼續往下看。
Dishy McFlatface and the Starlink satellites undoubtedly have some rather complicated science and engineering inside.
Dishy McFlatface 和 "星鏈 "衛星無疑擁有相當複雜的科學和工程技術。
And to fully comprehend it all, you have to be a multidisciplinary student.
要完全理解這一切,你必須是一個多學科的學生。
To help you do that, check out Brilliant, which is sponsoring this video.
為了幫助您做到這一點,請查看贊助本視頻的 Brilliant 公司。
Brilliant is an amazing tool for learning.
輝煌是一個了不起的學習工具。
They teach a wide range of STEM topics in hands-on, interactive ways, many of which directly relate to Starlink and other cutting-edge technologies such as electric cars, quantum computers, rocketry, or neural networks.
他們以動手和互動的方式教授各種 STEM 課題,其中許多課題與星際鏈路和其他尖端技術(如電動汽車、量子計算機、火箭或神經網絡)直接相關。
For example, they have an entire course dedicated to waves and light, and another one on gravitational physics, which will greatly help in understanding Starlink and SpaceX rockets.
例如,他們有一整門課程專門討論波和光,還有一門課程是關於引力物理學的,這對理解 Starlink 和 SpaceX 火箭有很大幫助。
Brilliant is nothing like a boring textbook, but rather all the courses use interactive modules to make the lessons entertaining and to help the concepts stick in your head.
Brilliant 與枯燥乏味的教科書不同,所有課程都採用互動模塊,使課程寓教於樂,讓概念深入人心。
To really understand today's frontier technologies, and to help you become a revolutionary engineer and entrepreneur like Elon Musk, you have to be versed in a wide range of fields in science and engineering.
要真正瞭解當今的前沿技術,並幫助你成為像埃隆-馬斯克那樣的革命性工程師和企業家,你必須精通科學和工程學的各個領域。
We recommend you sign up, try out some of the lessons for free, and, if you like them, which we're sure you will, sign up for an annual subscription.
我們建議您先註冊,免費試聽一些課程,如果喜歡(我們相信您會喜歡),再註冊訂閱年度課程。
To the viewers of this channel, Brilliant is offering 20% off an annual subscription to the first 200 people who sign up.
對於該頻道的觀眾,Brilliant 為前 200 名註冊者提供年度訂閱 8 折優惠。
Just go to brilliant.org slash brancheducation.
請訪問 brilliant.org slash brancheducation。
You can find that link in the description below.
您可以在下面的說明中找到該鏈接。
Now let's continue exploring how a powerful beam can be continuously swept across the sky and then how we fill it with hundreds of megabits of data every second.
現在,讓我們繼續探索如何將強大的光束連續掃過天空,然後每秒向其發送數百兆位的數據。
As a quick refresher from before, here's an array of 1280 antennas and we fed them all with the same 12 GHz signal in order to create a laser-like beam propagating perpendicular to Dishi.
簡單回顧一下,這是一個由 1280 根天線組成的陣列,我們向所有天線饋送相同的 12 GHz 信號,以產生垂直於 Dishi 傳播的激光束。
However, as mentioned earlier, we need to be able to angle this beam so that it points directly at the Starlink satellite zooming across the sky at 27,000 km per hour.
不過,如前所述,我們必須能夠調整光束的角度,使其直接指向以每小時 27 000 公里的速度在天空中飛馳的 Starlink 衛星。
Using the motors isn't feasible because they would break within a month and aren't accurate enough.
使用電機是不可行的,因為它們會在一個月內損壞,而且不夠精確。
So the solution is to use what's called phased array beam steering.
是以,解決辦法是使用所謂的相控陣波束轉向。
Let's go back to our two antenna example.
讓我們回到兩根天線的例子。
Before, we were feeding the same signal to the two antennas and thus the antennas were in phase with one another.
之前,我們向兩根天線饋送相同的信號,是以兩根天線的相位是一致的。
Changing phase is critical.
轉換階段至關重要。
So quickly, changing the height or amplitude of the signal is done by changing the power sent to the antenna, thus making the signal stronger or weaker.
是以,要快速改變信號的高度或振幅,就必須改變發送到天線的功率,從而使信號變強或變弱。
The frequency is how many peaks and troughs or wavelengths there are in one second and changing the phase is shifting the signal left or right.
頻率是指一秒鐘內有多少個波峰和波谷或波長,改變相位就是將信號向左或向右移動。
Phase shifting is measured in degrees between 0 and 359 because if we shift the signal 360 degrees, or one full wavelength, then we're back at the beginning, exactly as if we were to loop around a circle.
相移的測量組織、部門是 0 至 359 度,因為如果我們將信號移動 360 度,或一個完整的波長,那麼我們就會回到起點,就像繞了一圈一樣。
For example, here's a signal with a 45 degree phase shift, here's another with a 180 degree shift, and then another with a 315 degree shift.
例如,這裡是一個相移 45 度的信號,這裡是另一個相移 180 度的信號,然後是另一個相移 315 度的信號。
Your eyes can't see differences in phase shifted visible light.
你的眼睛無法看到相移可見光的差異。
However, high-tech circuitry such as what's inside Dishi is really good at detecting and working with phase shifts.
不過,高科技電路(如 Dishi 內部的電路)在檢測和處理相位偏移方面確實非常出色。
So then, how do we use phase shifting to angle the beam and have it point directly at the satellite?
那麼,我們如何利用相移來調整光束的角度,使其直接指向衛星呢?
The solution is to phase shift the signal sent to one antenna with respect to the other antenna and, as a result, the timing of the peaks and troughs emitted from one antenna is different from the other.
解決的辦法是將發送到一個天線的信號相對於另一個天線進行相移,是以,一個天線發出的波峰和波谷的時間與另一個天線不同。
These peaks and troughs propagate outwards and the location of the constructive interference is now angled to the left with destructive interference everywhere else.
這些波峰和波谷向外傳播,現在建設性干擾的位置向左傾斜,其他地方都是破壞性干擾。
If we change the phase of the antennas again, the zone of constructive interference is angled to the right.
如果我們再次改變天線的相位,建設性干擾區域就會向右傾斜。
Therefore, by continuously changing the phase of the signal sent to the antennas, we can create a sweeping zone of constructive interference.
是以,通過不斷改變發送到天線的信號相位,我們就能創造出一個橫掃的建設性干擾區域。
Let's bring in six more antennas and simplify the visual so that we only see a section of the peaks from each wave.
讓我們再引入六根天線,簡化視覺效果,使我們只看到每個波峰的一部分。
Far away from the antennas, the waves join to form a wavefront that is a planar wave, kind of like ocean waves crashing on a shoreline.
在遠離天線的地方,波浪匯合成一個平面波的波陣面,有點像海浪拍打海岸線。
Just as before, by continuously changing the timing of when each wave peak is emitted by each antenna, we can change the angle at which the wavefront is formed, essentially steering the beam in one direction or another.
和以前一樣,通過不斷改變每個天線發射每個波峰的時間,我們可以改變波面形成的角度,從而將光束轉向一個方向或另一個方向。
And if we bring in more antennas in a two-dimensional array, we can now steer the beam in any direction within a 100-degree field of view.
如果我們在二維陣列中加入更多天線,現在就可以在 100 度視場範圍內將波束轉向任何方向。
Let's move back to view all 1280 antennas in DISHI.
讓我們返回查看 DISHI 的所有 1280 根天線。
In order to know the exact angle the beam needs to be pointed or steered, we use the
為了知道光束需要指向或轉向的確切角度,我們使用
GPS coordinates of DISHI from this chip over here, along with the orbital position of the
從這個芯片上獲得的 DISHI 的 GPS 座標,以及該衛星的軌道位置
Starlink satellite which is known in DISHI software.
DISHI 軟件中已知的 Starlink 衛星。
The software computes the exact set of 3D angles and the required phase shift for each of the antennas.
該軟件可為每個天線計算出精確的三維角度和所需的相移。
These phase shift results are then sent to the 20 larger chips called beamformers and each beamformer coordinates between 32 smaller chips called front-end modules, each of which controls two antennas.
然後,這些相移結果被髮送到 20 個較大的芯片(稱為波束形成器),每個波束形成器在 32 個較小的芯片(稱為前端模塊)之間進行協調,每個前端模塊控制兩個天線。
Every few microseconds, these computations are recalculated and disseminated to all the microchips in order to perfectly aim the beam at the satellite.
每隔幾微秒,這些計算結果就會重新計算並傳播到所有微芯片,以便將光束完美地瞄準衛星。
As a result, the beam can be steered anywhere in a 100-degree field of view.
是以,光束可以在 100 度視野內的任何地方轉向。
Here are a few quick notes.
下面是一些簡要說明。
First, the main beam, also called the main lobe, looks like this.
首先,主樑也叫主葉,看起來是這樣的。
However, constructive and destructive interference isn't perfect and, as a result, there are additional side lobes of lesser power.
然而,建設性干擾和破壞性干擾並不完美,是以會產生功率較小的附加側葉。
Third, Mr. McFlatface holds a single phased array.
第三,McFlatface 先生持有一個單相陣列。
However, on the Starlink satellite, there are, in fact, four phased array antennas.
然而,在 Starlink 衛星上,實際上有四個相控陣天線。
Two are used to communicate with multiple DISHIs and two are used to communicate with the ground stations to relay the internet traffic.
兩個用於與多個 DISHI 通信,兩個用於與地面站通信,以中繼互聯網流量。
And fourth, phased arrays are used in many applications and, interestingly, they're used on commercial airlines to allow for mid-flight internet.
第四,相控陣應用廣泛,有趣的是,它們還用於商業航空公司,以便在飛行途中上網。
So this video also tangentially explains how mid-flight internet works.
是以,這段視頻也切切實實地解釋了飛行中上網的原理。
Before we explore how actual data is sent, we want to mention that this video took a month to research, two dozen script revisions, and two months to model and animate.
在探討實際數據是如何發送的之前,我們想說的是,這段視頻花了一個月的時間進行研究,修改了二十多次腳本,又花了兩個月的時間製作模型和動畫。
If your mind is blown by the complexity of this technology and the depth of this video, click the subscribe button, like this video, write a comment below, and we'll be sure to create more videos like this one.
如果您被這項技術的複雜性和本視頻的深度所震撼,請點擊訂閱按鈕,喜歡本視頻,並在下面寫下評論,我們一定會製作更多類似的視頻。
The third topic we're going to dive into is how information gets sent between DISHI and the Starlink satellite.
我們要深入探討的第三個話題是 DISHI 和 Starlink 衛星之間的資訊傳輸方式。
For example, we've talked about high-frequency sinusoid-shaped electromagnetic waves, but that doesn't look anything like binary, and even less like your favorite TV show.
例如,我們曾討論過高頻正弦波形電磁波,但它看起來一點也不像二進制,更不像你最喜歡的電視節目。
So what's happening?
到底發生了什麼?
Well, DISHI and the satellite indeed send a signal that looks like this.
DISHI 和衛星確實發出了這樣的信號。
However, they vary the amplitude and the phase of the transmitted signal and then assign or encode 6-bit binary values to each different combination or permutation of amplitude and phase.
不過,它們會改變傳輸信號的振幅和相位,然後為每個不同的振幅和相位組合或排列分配或編碼 6 位二進制值。
With 6 bits, there are 64 different values, and thus we need 64 different permutations of amplitude and phase.
6 個比特有 64 種不同的值,是以我們需要 64 種不同的振幅和相位排列。
However, instead of listing all the permutations, it's more easily visualized by arranging the 64 different values in a graph, called a constellation diagram, as shown.
不過,與其列出所有排列組合,不如將 64 種不同的值排列成一個圖形(稱為星座圖),如圖所示,這樣更容易直觀地顯示出來。
Let's look at the point 011101 and draw a line from the origin to this point.
讓我們看一下 011101 點,從原點到這一點畫一條直線。
The distance from the origin is the amplitude of the signal, and the angle from the positive x-axis is the phase.
與原點的距離就是信號的振幅,與正 x 軸的夾角就是相位。
It's a bit like using polar coordinates.
這有點像使用極座標。
Thus for DISHI to send these 6 bits, it transmits a signal with an amplitude of 59% and a phase shift of 121 degrees.
是以,DISHI 要發送這 6 個比特,需要傳輸振幅為 59%、相移為 121 度的信號。
Then, if the next value being sent is 101000, the signal switches to an 87% amplitude or brightness and a 305 degree phase shift.
然後,如果下一個發送的值是 101000,信號就會切換到 87% 的振幅或亮度和 305 度的相移。
After that, it sends the next value with a different amplitude and phase shift.
之後,它會以不同的振幅和相移發送下一個值。
Each of these 6-bit groupings are called symbols, and they last for only 10 or so nanoseconds before the next symbol is sent.
每個 6 位分組被稱為符號,它們在下一個符號發送之前只持續 10 納秒左右。
Lots of times you see the signal scrunched up like this, however, because the frequency of the signal is just once every 83 picoseconds, or 12 gigahertz.
不過,很多時候你看到的信號都是這樣扭曲的,因為信號的頻率是每 83 皮秒一次,即 12 千兆赫。
And since a symbol lasts 10 nanoseconds, it's more accurate to have around 120 wavelengths per symbol before the next symbol is sent.
由於一個符號持續 10 納秒,是以在發送下一個符號之前,每個符號大約有 120 個波長,這樣更準確。
Because we're dealing on the order of pico and nanoseconds, that means that we can fit 90 million 6-bit groups or symbols, resulting in 540 million bits per second.
由於我們處理的是皮秒和納秒數量級的數據,這意味著我們可以容納 9000 萬個 6 位組或符號,即每秒 5.4 億比特。
However, note that this data transfer is shared between download and upload.
不過,請注意,下載和上傳之間共享數據傳輸。
Since this particular antenna can't transmit and receive data at the same time, about 74 milliseconds of every second is used to send data from DISHI to the Starlink satellite, and 926 milliseconds is used to send data from the satellite down to DISHI.
由於這種特殊的天線不能同時發射和接收數據,是以每秒大約有 74 毫秒用於從 DISHI 向 Starlink 衛星發送數據,926 毫秒用於從衛星向下向 DISHI 發送數據。
And for the sake of reducing latency, these time slots get distributed throughout a single second instead of grouping them all together.
為了減少延遲,這些時隙會分佈在一秒鐘內,而不是集中在一起。
This technique of sending 6-bit values using different variations of amplitude and phase is called 64-QAM, or Quadrature Amplitude Modulation, and is more complicated than we've discussed.
這種利用不同的振幅和相位變化發送 6 位數值的技術被稱為 64-QAM,即正交振幅調製,比我們討論的要複雜得多。
But let's not get sidetracked.
不過,我們還是不要跑題了。
Now that we have a stream of millions of 6-bit symbols yielding hundreds of megabits of data per second, in order to turn it into your favorite TV show, we use the Advanced Video
現在,我們有了數百萬個 6 位符號流,每秒產生數百兆位數據,為了將其轉換成您喜愛的電視節目,我們使用高級視頻
Codec, or H.264 format.
編解碼器或 H.264 格式。
You can learn more about that in our video that explores image compression, shown here.
您可以在我們探索圖像壓縮的視頻中瞭解更多資訊,請點擊此處。
I'm sure you have many questions, and by all means put them in the comments below.
我相信你們有很多問題,請在下面的評論中提出。
But before we finish, let's clarify two things.
但在結束之前,讓我們先澄清兩件事。
First, the scale of practically everything in this video is off.
首先,視頻中幾乎所有東西的比例都不對。
Here's the correct scale of DISHI and the Starlink satellite.
這是 DISHI 和 Starlink 衛星的正確比例。
However, DISHI is 550 kilometers away, which we can't correctly show.
然而,DISHI 距此 550 公里,我們無法正確顯示。
In stark contrast, the emitted electromagnetic waves are only around 2.5 centimeters apart, and thus, between DISHI and the satellite, there are around 22 million wavelengths, which is many more than the few waves that you see here.
與此形成鮮明對比的是,發射的電磁波之間的距離只有大約 2.5 釐米,是以,在 DISHI 和衛星之間,大約有 2200 萬個波長,這比你在這裡看到的幾個波長要多得多。
Additionally, in this animation, we're showing the wavelengths slowly making their way up and down, when actually it only takes around 2 milliseconds for an electromagnetic wave emitted from DISHI or the Starlink satellite to reach the other.
此外,在這個動畫中,我們顯示的是波長緩慢地上升和下降,而實際上從 DISHI 或 Starlink 衛星發出的電磁波到達對方只需要大約 2 毫秒。
The second clarification is that we disproportionately show DISHI emitting electromagnetic waves and sending them to the satellite.
第二個澄清是,我們不成比例地顯示 DISHI 發射電磁波並將其發送到衛星。
In reality, the satellite dishes more frequently in receive mode, and the steps and physics of receiving an electromagnetic wave are similar to emitting one, just in reverse.
實際上,衛星天線更經常地處於接收模式,而接收電磁波的步驟和物理原理與發射電磁波類似,只是相反而已。
That's pretty much it for how Starlink and DISHI send data to each other.
星鏈 "和 "DISHI "相互發送數據的方式大致如此。
The original script for this video was over 45 minutes long, so all the details that were cut got their own in the creator's comments, found in the English Canada subtitles.
這段視頻的原始腳本長達 45 分鐘,是以所有被刪減的細節都可以在加拿大英語字幕中找到創作者的評論。
Thank you to all of our Patreon and YouTube membership sponsors for helping to make this video.
感謝我們所有的 Patreon 和 YouTube 會員贊助商為製作本視頻提供的幫助。
Also, thank you to Colin O'Flynn at NewAeTechnology for lending us a Starlink DISHI PCB for imaging and research.
此外,還要感謝 NewAeTechnology 公司的 Colin O'Flynn 借給我們一塊用於成像和研究的 Starlink DISHI PCB。
This is Branch Education, and we create 3D animations that dive deep into the technology that drives our modern world.
這裡是 Branch Education,我們製作的三維動畫深入探討了推動現代世界發展的技術。
Watch another Branch video by clicking one of these cards, or click here to subscribe.
點擊其中一張卡片觀看分公司的其他視頻,或點擊此處訂閱。
Thanks for watching to the end.
感謝您觀看到最後。