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1 | VSAT technology and installation / Satellite dish installations - pictures and descriptions / The Impact of Low-Orbit Satellite Technology (LEO) On Modern Global Communications on: Apr 15th, 2025 at 2:32am |
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With the rapid development of satellite technology, low earth orbit (LEO) satellites have become a disruptive innovation. Located about 100 to 500 miles above the earth’s surface, these satellites have completely changed the way we communicate, collect data and monitor the earth. LEO satellites play a key role in many fields such as telecommunications, earth observation, scientific research and national security. It is expected that by 2029, the size of commercial constellations will increase from 35% to 70%, of which about 65% of the growth will be concentrated in communication applications, involving satellite networks spanning low earth orbit (LEO), medium earth orbit (MEO) and geosynchronous orbit (GEO) satellites. 1. Comparison of different satellite orbits GEO satellites rotate synchronously with the Earth at the same speed, so their position relative to the Earth is fixed, ensuring a fixed pointing angle from any location on the Earth’s surface. On a mobile platform, ground-based GEO directional antennas must continuously point to a designated GEO satellite. These traditional ground-based satellite antennas are large and expensive, have many moving parts, and require regular maintenance. MEO satellites, such as GPS, are often used for navigation. MEO satellites have their own advantages, but similar to GEO satellites, they are expensive to launch and maintain. Although GEO and MEO satellites each have their uses, they both have issues with latency and data rates. ![]() Satellites play an important role in promoting global connectivity. As shown in Figure 3, they have two main tasks: one is to communicate directly with the earth to provide support for many end-user terminals in different industries; the other is to transmit data back to the earth directly or via inter-satellite links (ISLs). As more LEO satellites are launched, communication speeds are significantly improved and coverage is expanding; the transmission of information from space to the earth becomes more convenient and has less latency. ![]() 2. Satellite basic components Satellites are complex systems that contain multiple functions depending on the mission; this article will focus on the transponder component inside the communications payload module. A transponder is a subsystem in the payload module that is responsible for sending and receiving signals; it usually contains amplifiers, receivers, and transmitters for communication purposes. ![]() 3. Integration of satellite and 5G networks Broadband services provided by large LEO satellite constellations are becoming increasingly popular around the world. This trend, coupled with the integration of satellite networks into the 5G ecosystem, is further driving the growth of the satellite communications market. In addition, cellular communications are becoming part of the satellite ecosystem. The introduction of 5G wireless technology in 3GPP Release 17 enables 5G systems to serve non-terrestrial networks (NTNs). NTNs are designed to expand global network coverage, especially in rural and remote areas, and facilitate direct connections between mobile devices, the Internet of Things (IoT), and commercial autonomous vehicles and satellites. This integration enables the satellite industry to fully leverage the scale of the 5G ecosystem. 3GPP Release 17 defines 5G New Radio (NR) NTN and 5G IoT NTN, as shown in Figure 4. It focuses on leveraging satellite transparent payload architecture and UEs with GNSS capabilities; Figure 4 shows the expected use cases for 5G NTN. ![]() Other application scenarios include… Areas with insufficient coverage such as agriculture, mining and forestry Disaster area communications when terrestrial communication networks are damaged Broadcasting information over a very wide area |
2 | VSAT technology and installation / Dish pointing and alignment / 2.4m C/X/Ku Band Automatic Flyaway Antenna Installation on: Mar 28th, 2025 at 3:11am |
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![]() 2.4m automatic flyaway antenna with C/X/Ku band is a satellite communication product developed by Antesky. This 2.4m C/X/Ku band automatic flyaway antenna can realize the reception and transmission of C, X, and Ku band signals, which has the characteristics of easy operation, high strength, portability, and stable performance. It integrates reset, satellite alignment, tracking, and stow to meet users’ emergency communication business. 2.4m manual flyaway antenna is also one of the best-selling products, which is in great demand for customer who requires receive and transmit signal in emergency communication. Our antenna can meet the requirements of CCIR 580-6 , ASIASAT and INTELSAT. In 2020, we have 1 set of 2.4m C band automatic flyaway antenna to Cote d’ivoire. and 2.4m ku band offset Portable flyaway satellite antenna in South Africa in 2021. Today, we will show you this 2.4m automatic flyaway antenna with C/X/Ku band in details. Please go ahead for the introduction and installations. Product Features of 2.4m automatic flyaway antenna with C/X/Ku band a) Easy to disassemble and assemble, stable structure, superior performance, fast satellite search, high safety. b) The configured GPS has high accuracy and the electronic compass has strong anti-interference ability, which ensures the stability and accuracy of the satellite function. c) The antenna automatic satellite time does not exceed 3 minutes (RMS). d) It has multiple protection functions such as automatic warning, mechanical limit, software limit, etc., and the antenna operation is safer. 2. Product composition of 2.4m automatic flyaway antennawith C/X/Ku band 2.4m automatic flyaway antenna components introduction ![]() 2.4m automatic flyaway antenna c ku x band feeds display ![]() 3. Antenna installation of 2.4m automatic flyaway antenna with C/X/Ku band Installation preparation-Product component list check There are 7 cases and the detailed components are as follows. ![]() ![]() Install and assemble 2.4m automatic flyaway antenna as below steps. ![]() |
3 | VSAT technology and installation / Dish pointing and alignment / Re: Antenna G/T overview on: Mar 24th, 2025 at 5:41am |
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Thank you |
4 | VSAT technology and installation / Dish pointing and alignment / Re: Antenna G/T overview on: Mar 22nd, 2025 at 3:10pm |
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You ask "Can the manufacturer's G/T value be trusted all the time?" I would say definitely YES, assuming you have placed a contract for an antenna plus low noise amplifier and the manufacturer has installed, adjusted and tested the antenna plus low noise amplifier. It is essential that you implement a contract acceptance test to show that the specified G/T is achieved. So the specified G/T will be met. Note also that achieving the specified antenna patterns and polarisation discrimination is similarly important. If it is a transmit antenna it must pass all testing to be allowed to operate by the satellite operator. If you contract out the whole task you don't have to worry, but the cost will be higher. You can save money if you buy the antenna (possibly second-hand or as parts) and assemble and adjust it yourself and choose your own low noise amplifier. It is up to you to make a design to meet whatever G/T you want to achieve. This means getting the gain high enough and attaching a sufficiently low noise temperature amplifier with a minimal loss waveguide. It is then up to you to get the antenna working well and carry out all the tests specified by satellite operator. You take the responsibility. Getting the sidelobe patterns and polarisation discrimination right has a lot to do with the antenna and feed manufacturers original design plus the skill of the assembler/installer in terms of panel alignments and feed positioning. See these links: System G/T calculator Examples of antenna noise temperature at different elevation angles Subreflector alignment |
5 | VSAT technology and installation / Dish pointing and alignment / Antenna G/T overview on: Mar 22nd, 2025 at 6:51am |
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What is the importance of measuring/calculating antenna G/T? As I understand, it tells us something about the receiving performance of the antenna, correct? A higher G/T ratio means the antenna has better sensitivity to weak signals, resulting in improved overall receiving performance. Thus, G/T is critical in designing and evaluating antennas, especially for communication with distant or low-power signal sources, such as satellites. Can the manufacturer's G/T value be trusted all the time? |
6 | VSAT technology and installation / Dish pointing and alignment / Re: Test RG 11 Cable on: Mar 20th, 2025 at 10:55pm |
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Thank you |
7 | VSAT technology and installation / Hub and VSAT satellite equipment for sale and wanted / Wanted: 750W Outdoor C-Band BUCs 1:1 System on: Mar 20th, 2025 at 1:07pm |
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750W C-Band 1:1 System Outdoor system with integral BUCs (standard C-Band range) for a dual carrier uplink. If you can help, email me eric@satsig.net reference 19/03/2025, 18:15 and I will pass on your email to the company wanting the kit. |
8 | VSAT technology and installation / Dish pointing and alignment / Re: Test RG 11 Cable on: Mar 15th, 2025 at 5:21pm |
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First check with DC ohms meter that the outer and inner conductors are good. Try wiggling about a bit in case of intermittent connection. The inner to outer should be open circuit. Look out for spurious tiny fragments of braid/sheath wire if shorted. For the frequency range you are interested in find some suitable signal source and a corresponding measuring device. Connect together with short known good cable and record the result. Insert the cable under test between the signal source and measuring device and measure again. The difference will be the cable loss. Compare with the manufacturer specification. SAFETY: If you are using a spectrum analyser as the measuring device, check for NO DC power on the cable, or use a DC block permanently on the spectrum analyser input. Example: The cable is used to connect LNB to indoor equipment. Connect the LNB output to spectrum analyser using using a DC block if necessary, with a very short (known good) cable. Record the LNB noise across the spectrum and any signals from DC to 2.5 GHz. Repeat with the cable under test and observe the difference. Regarding N type connectors: Note there are two types, 50 ohm and 75 ohm. RG11 cable is normally 75ohm. The 75 ohm male plug has a thinner centre pin that may intermittently connect, or not connect at all, if inserted into a 50 ohm female socket. If you have 75ohm male connector on the cable output it won't connect properly into a typical 50ohm spectrum analyser input socket. |
9 | VSAT technology and installation / HughesNet and Hughes HX VSATs / Hughes HX and HN modems wanted - quantity 50+ on: Mar 15th, 2025 at 4:19pm |
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Hughes HX90 Modem Hughes HX50 Modem Hughes HX200 Modem Hughes HN7000S Modem Hughes HN9260 Modem Hughes HN7000 Modem Hughes HN7700 Modem 50+ assorted wanted If you can help please advise me with pricing. eric@satsig.net I will forward to the potential buyer. |
10 | VSAT technology and installation / Satellite dish installations - pictures and descriptions / Work Principle of Parabolic Satellite Dish Antenna on: Mar 14th, 2025 at 7:48am |
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Satellite dishes rely on electromagnetic signals to communicate with Earth and orbiting satellites to provide services such as television broadcasts, Internet connectivity, and GPS navigation. Typically, signals operate within specific frequency bands, including the 12-18 GHz Ku-band for television or the 26.5-40 GHz Ka-band for high-speed data. This is obviously due to the fact that the power of DTH Ku-band signals is usually 10-100 watts, so they can cover a large area. Another band, Ka-band, supports faster data transmission rates of up to 50 Mbps, which is essential for Internet services. It is important to properly align the satellite dish with the specific frequency band to ensure minimal signal loss, allowing for efficient transmission and reception. The design and geometry of the antenna play a critical role in signal quality. A typical parabolic antenna has high gain, easily exceeding 35 dB for Ku-band signals, which enables it to amplify very weak signals from satellites thousands of kilometers away. Reception is best if the signal path between the antenna and the satellite remains within line of sight and free of obstructions such as buildings or trees. A slight mismatch of just 1 degree can result in a loss of up to 10-20% in signal strength, which can directly impact internet speeds or TV clarity. As a result, installations often require antennas with narrower beamwidths, and rural installations are best served with larger antennas that can capture weaker signals. Weather conditions can also affect the transmission and reception of signals. This phenomenon is called rain fade, and heavy rainfall can weaken high-frequency signals such as Ka-band, causing up to 10 dB of signal strength loss. To combat this, service providers typically install some kind of adaptive power control system on the satellite that increases the transmission power to compensate for rain fade. For example, during a storm, Ka-band internet service speeds may drop from 50 Mbps to 30 Mbps, while Ku-band signals typically only lose around 3-5 Mbps under similar conditions. In areas with more rainfall, the largest dish antenna will always benefit home users, as a 90 cm dish antenna will perform better than a 60 cm dish antenna in inclement weather. ![]() The most common and effective satellite antenna design is the parabolic dish, primarily because it focuses electromagnetic waves to a single point to maximize the signal. These antennas work by reflecting incoming satellite signals off a feed horn located at the focal point. A typical parabolic dish has a gain of about 35 to 45 dB at Ku-band frequencies and up to 55 dB at Ka-band frequencies, depending on size. For example, a 1.2-meter antenna operating in the Ku-band provides about 40 dB of gain, enabling clear reception of signals from satellites 35,000 kilometers away. The size of a parabolic dish directly determines its performance. Larger antennas provide narrower beamwidths, which minimize interference from nearby satellites and terrestrial signals. For example, a 90-cm antenna typically has a beamwidth of about 1.5 degrees, while a 1.8-meter antenna reduces that to about 0.75 degrees. This improvement is critical for applications that require high accuracy, such as when transmitting data over dense constellations of satellites. However, larger antennas are more sensitive to environmental factors such as wind and are therefore equipped with robust mounting systems to maintain alignment. Material selection is also an important factor in designing parabolic antennas. Most antennas are made of aluminum, which is both light and reflective. For example, an aluminum antenna with a surface accuracy of 0.5 mm will have the best signal reflection at frequencies up to 40 GHz used in Ka-band services. Large antennas designed for scientific applications may use carbon fiber composites to reduce thermal expansion and maintain surface accuracy despite temperature fluctuations. With such materials, the antenna can achieve the high gain required for applications such as deep space communications. 2. Frequency conversion Frequency conversion in satellite communications is a critical process that enables signals to be efficiently sent over long distances and processed by ground equipment. Satellites use high frequencies, ranging from 12 to 18 GHz in the Ku-band and 26.5 to 40 GHz in the Ka-band, to minimize interference and enable high data rates. However, all of these frequencies are not suitable for direct use by ground receivers, so satellite antennas use frequency converters to step them down to an intermediate frequency range, typically 950 MHz to 2150 MHz. This conversion enables the signal to be transmitted over standard coaxial cable with minimal loss. The LNB converter mounted on the dish is responsible for the frequency conversion. Modern LNBs have noise figures as low as 0.3 dB, which is much clearer than older models with noise figures as high as 0.7 dB. For example, an LNB operating in the Ka-band can amplify a weak satellite signal from -130 dBm to a level suitable for ground processing while simultaneously stepping the frequency down from 30 GHz to a manageable IF. This feature is critical for high-definition television broadcasts and high-speed internet services as it allows signals to be transmitted with minimal attenuation. Frequency conversion is also critical to reducing signal interference between multiple signals. Satellites operate by separating uplink and downlink signals using FDM. For example, in the Ku band, uplink frequencies operate in the 14-14.5 GHz range while downlink frequencies operate in the 11.7-12.2 GHz range. The LNB converts these high frequencies to IF for set-top box or modem compatibility. This ensures that there is no signal overlap between uplink and downlink; thereby ensuring quality communications. Lack of accurate frequency conversion can result in distorted or lost signals, which can severely impact services such as live streaming and video conferencing. 3. Propagation Path Satellite antennas require a clear line of sight to establish a stable connection with satellites in orbit. Antennas must have a clear path to the satellites because even small obstacles such as trees or buildings can weaken or completely block the signal. For example, obstructions can cause up to 15 dB of signal loss, which is extremely detrimental to the quality of service for applications such as satellite TV and the Internet. To avoid this, antennas are often installed high up, such as on rooftops, with elevation angles starting at 30 degrees and above to minimize the effects of obstructions. Geostationary satellites are located approximately 35,786 kilometers above the equator, and the distance from the equator to the geostationary satellites requires even more precise line of sight alignment. Within this range, an alignment error of 1 degree can result in the antenna being hundreds of kilometers away from the satellite, resulting in a complete loss of signal. Modern installation practices involve the use of a satellite signal meter to ensure alignment accuracy within 0.1 degrees. For residential installations, this level of accuracy is critical to maintaining stable service, especially for high-definition television, which requires a signal strength of -70 dBm or higher for good viewing quality. Weather conditions can also affect line of sight: rain, snow, or thick clouds can all cause signal degradation, commonly known as rain fade. Ka-band signals operating in the higher frequency range of 26.5-40 GHz are more susceptible to damage, with losses of up to 10 dB under extreme weather conditions. In contrast, Ku-band signals are less affected, with losses generally within 3-5 dB under similar conditions. This requires users in areas with frequent heavy rain to use oversized antennas or implement other error correction |
Email me: eric@satsig.net
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