Technical Background
Tiantong-1 is a high-orbit (GEO) synchronous satellite, which means it is located at a fixed position about 36,000 kilometers above the Earth's equator, synchronized with the Earth's rotation, and therefore always located above the same area. Since Tiantong-1 is a high-orbit satellite, its signal coverage is large and it can provide a wider range of communication services. A single high-orbit satellite can cover more than 40% of the Earth's surface, which is very beneficial for providing services in a fixed area. Within the coverage area, 24-hour uninterrupted communication can be achieved, and the service stability is high. "In addition, the high-orbit satellite system is relatively simple to build. For example, only three synchronous earth satellites are needed to cover most areas except the poles, which means that the system has fewer satellites and the cost-effectiveness of operation and in-orbit maintenance is relatively high." At present, Tiantong-1 satellites mainly cover China and its surrounding areas.
China's Beidou satellite also has communication functions. The Beidou satellite system consists of medium-orbit satellites, and its main functions are navigation and positioning. Its short message communication function is suitable for sending short messages and emergency assistance. The Tiantong satellite service focuses more on providing a communication experience similar to traditional mobile phones, including clear voice calls and flexible text message exchanges.
However, most of the traditional Tiantong equipment is used in Tiantong functional handsets, vehicle-mounted after-installation and other fields, and its reliability cannot meet the needs of vehicle-mounted pre-installation.
Technical Description
This external Tiantong antenna technical solution is intended to solve at least one of the technical problems existing in the prior art . Compared with the prior art, this solution has the following characteristics :
①Meet the needs of vehicle pre-installation
② To solve the problem of vehicle-mounted satellite phone communication, the support plate is used to adapt to the installation environment of the car. In addition, the metal symmetrical array plus the feeding network are used to improve the radiation efficiency and gain of the antenna to ensure the effect of satellite calls .
③ The external Tiantong antenna adopts a symmetrical array structure, and feeds equal amplitude and 90° phase difference excitation through the feed plate, so that the external Tiantong antenna works in a left-hand circular polarization state. Compared with the traditional microstrip antenna, the present invention has a higher overall efficiency and enhanced antenna radiation capability because the antenna radiation part adopts an all-metal design without dielectric loss. Since the external Tiantong antenna is used in the front installation of the vehicle, the metal fence is used to increase the equivalent metal coverage area of the antenna to offset the interference of the surrounding environment. The external Tiantong antenna changes the structural parameters of the antenna so that the antenna's directional pattern gain in the low-profile direction can also be guaranteed. This external Tiantong antenna is usually installed on consumer cars and is used in the field of satellite communications .
Implementation Data
|
Frequency (MHz) |
Left-hand circular polarization gain dBi |
||||||||
|
theta 0° |
theta 35° |
theta 45° |
theta 60° |
theta 70° |
|||||
|
max |
min |
max |
min |
max |
min |
max |
min |
||
|
1980 |
6.11 |
4.37 |
4.06 |
3.08 |
2.67 |
1.17 |
0.49 |
-0.74 |
-1.55 |
|
1995 |
6.54 |
4.32 |
4.03 |
3.18 |
2.61 |
1.41 |
0.61 |
-0.64 |
-1.44 |
|
2010 |
6.6 |
4.45 |
4.11 |
3.31 |
2.73 |
1.51 |
0.77 |
-0.56 |
-1.27 |
|
2170 |
6.42 |
4.36 |
3.97 |
3.13 |
2.58 |
1.28 |
0.56 |
-0.73 |
-1.54 |
|
2185 |
6.45 |
4.38 |
3.98 |
3.17 |
2.59 |
1.31 |
0.57 |
-0.75 |
-1.51 |
|
2200 |
6.29 |
4.31 |
3.92 |
3.07 |
2.59 |
1.21 |
0.51 |
-0.77 |
-1.56 |
Installation Requirements
① There is no metal obstruction directly above the external Tiantong antenna and within the 25° side tilt angle.
② It is best not to place the external Tiantong antenna around transmitting antennas with overlapping frequencies (such as 4G antennas, etc.).
This technical solution realizes the application of Tiantong external antenna in vehicle front installation for the first time. Compared with traditional handheld antenna, this external Tiantong antenna has higher efficiency and wider lobe width, which can meet the call effect in complex environment . Compared with traditional microstrip antenna, the antenna has higher efficiency and wider lobe width, which can meet the call effect in complex environment; through the all-metal symmetrical array structure, plus the feed plate excitation equal amplitude phase difference of 90° signal, circular polarization radiation is achieved, and the antenna efficiency is guaranteed.