Earth Station Antenna New Technology

I Brief Introduction

Satellite communication earth station antenna is one important aspect of antenna field. With the continuous development of satellite communication, technology of antenna used in satellite communication earth station has developed rapidly.

Firstly, it is development of antenna frequency. It develops from C-band to Ku-band. And it also opens satellite communication business at L, S, and X-band. Especially in recent years, it develops to EHP band, which is the milestone of antenna technology of satellite communication earth station. The typical case is that Antesky Science Technology Inc. takes the lead in researching and developing X-band small aperture antenna and L/S-band large aperture antenna successfully, which has been approved widely.

The start-up and popularization of spectrum multiplexing technology enables satellite communication antenna technology to break a new path in the aspects of polarization purity improvement, feed insertion loss reduction and antenna port isolation improvement.

The original frequency expansion has made encouraging achievement. For example, C-band antenna of satellite communication earth station has transmitted and received from 500MHz to 575 MHz while Ku-band receiving bandwidth is developing from 500MHz to 1800MHz.

Multi-frequency common feed technologys gradual mature has enabled C/Ku band to apply in project. 7.3M C&KU dual-band researched and produced by Antesky Science Technology Inc. has been sold out to European customers, and passed customers serious test, which becomes the milestone in this industry.

Multi-beam satellite communication earth station antenna enables a pair of antenna to independently transmit and receive some satellites simultaneously. In short, satellite communication earth station antenna has wider application because of development of satellite communication earth station antenna technology.

II New technology of satellite communication earth station antenna

Generally speaking, the following aspects of new technology are worth talking about.

1. Band development

The initial satellite communication is confined to C band because it uses radio window transmitted by satellite communication wave in this band. The spring-up of radio industry enables C-band microwave interference seriously severe especially in the large and medium cities. And particularly in developed countries, it has become public hazard. Thus C-band microwave interference is developed. Moreover, Ku-band satellite communication earth station antenna can be built in cities due to decrease in size of absolute diameter, which reduces the cost of station building and the cost of microwave transmission line. Now people focus their effort on higher frequency development, for example, EHP band. Antesky is researching 20/40GHz satellite communication antenna.

2. Spectrum multiplexing technology

The so-called spectrum multiplexing is to make one spectrum amphibious by polarization orthogonal. Spectrum multiplexing has two categories which are orthogonal circular polarization and orthogonal linear polarization. At present C-band uses circular polarization spectrum multiplexing mostly while Ku-band uses linear polarization spectrum multiplexing mostly. The core of spectrum multiplexing technology is realization of high polarization discrimination. As for circular polarization spectrum multiplexing, popular index of circular polarization axis ratio of antenna axis is 1.06, i.e. 0.5 dB. That is to say, polarization discrimination ratio of reverse rotation measure is -30.7dB. As for polarization spectrum multiplexing antenna axiss cross-polarization isolation or polarization discrimination, the popular index is about -35dB.

3. Broad-band technology

With the development of satellite communication, now people put their effort into broadening the original band. For example, the original frequency band of C-band satellite communication is 3.7 4.2GHz and 5.9256.250GHz, but transmit-receive bandwidth is 500MHz respectively. At present, it is extended to3625 42GHz and 58564250 and transmit-receive bandwidth is 575MHz respectively.

4. Low sidelobe technology

The development of satellite communication enables the number of satellites placed in a geosynchronous orbit to increase gradually. Angle interval of adjacent satellites has been thickened from 3to 2. Mutual interference of satellite system becomes a serious problem to people. Therefore, low sidelobe technology is needed to develop.

5. Dual-band and multi-band share feed technology

Making one satellite communication earth station antenna use two bands simultaneously will greatly reduce the cost of station building. Anteskys dual-band share feed technology is the notable achievement in this field. Dual-band feed share has great value for application. Now some international satellites has repeater at both C-band and Ku-band, which provides band use opportunity of space segment for C/Ku share feed antenna. The core of dual-band share technology is two separated band. For example, C-band and Ku-band make dual-band share feed system to realize good polarization performance. Antesky 7.3M C/Ku dual-band antenna has passed the whole test in Europe and obtained high approval.

6. Multi-beam satellite communication earth station technology

A satellite communication earth station antenna can independently transmit and receive some geostationary satellites, which is a new field of antenna technology of current satellite communication earth station.

Generally speaking, multi-beam antenna refers to more than two independent controllable antennas. Each beam can align a geostationary satellite, and independently receive and transmit signal. Each beam can independently realize satellite tracking. Therefore, antenna no longer rotates as a whole and tracking function is realized by controlling the rotation of each individual beam. For example, tracking is realized by moving each feed, etc.

Multi-beam satellite communication earth station antenna has phased-array antenna, multi-reflector antenna, spherical antenna and parabolic antenna.

7. Ship borne antenna, vehicle mounted antenna, flyaway antenna and airborne antenna

With the development of satellite communication, ship borne, vehicle mounted and flyaway satellite communication gradually comes out. There are special requirements for antenna that uses in satellite communication business. Therefore, antenna technology should have new breakthrough. Antesky 1.8m flyaway antenna and 1.2m flyaway antenna possess characteristics of small volume, light weight, stable and reliable communication and high precision reassembly, which has been widely acknowledged by the market.