So-called ‘flyaway’ mobile antenna systems are the staple of on-the-spot communications for industries all over the world. Once again, they are easy to transport, assemble and operate and are available in a wide range of sizes for different capabilities. They allow business to be conducted from remote locations by offering the same facilities that would normally be available in the office.
UK manufacturer Holkirk Communications fabricate systems for use by governments, international media organisations, the oil & gas industry, disaster recovery, medical organisations for SNG or VSAT & other Internet over satellite and data applications.
The ‘Tri-Sat’ range of antenna systems are renowned due to their compact size, light weight and powerful performance having been designed to excel in today’s ever demanding satellite communications industry.
The user friendly modular design allows for simple, fast and accurate satellite acquisition either as a manually controlled mount or as a fully auto-acquisition motorised mount controlled either locally via a touch screen or remotely via an ethernet port. The light weight and sturdy tri-pod design houses a truly versatile HPA cradle which can accommodate a wide range of third party HPA’s up to 400W in X, C, Ku and Ka-Bands, neatly doing away with the long lengths of fragile flexible waveguide normally associated with flyaway systems. The design of the tri-pod mount also means that other 3rd party antennas can be fitted allowing existing equipment to be cost effectively upgraded.
The main reflector is manufactured from high quality carbon fibre and is supplied in six easily assembled petals that employ a revolutionary spherical dowel locking mechanism.
The revolutionary design of the complete fly- away system allows for the ‘Tri-Sat’ to be transported in two easily manageable carry cases under 32kg that can be checked onto any commercial aircraft making the ‘Tri-Sat’ a totally flexible fly-away system.
Whilst the antenna and transmitter assembly must be exposed to the elements, the auto-acquisition controller and the test and monitoring baseband package can be located remotely as the option includes 5m & 25m cables with longer lengths available.
Tri-Sat is available as a manually controlled mount or can be upgraded with Holkirk's auto-acquisition controller. The transmission unit can be configured to incorporate up to 2 L-band MPEG 2 encoders, an L band modem, voice and data (up to 8 channels), with an option for an MPEG 4 encoder.
London-based company Link Communications’ LinkMobile Satellite Internet System allows users to access the Internet at broadband speeds from virtually anywhere that a vehicle is parked. It mounts easily on top of the vehicle or transportable platform and locks onto a selected satellite automatically at the click of a button. It also interfaces with the modem to enable service. The LinkMobile system provides coverage throughout the Americas, Caribbean, Europe, Middle East, Africa and Australia as long as there is a clear line of sight of the desired satellite. It is a rapid, robust, reliable and adaptable system.
Antenna solution for MIMO channels
Recent information theory results have demonstrated an enormous capacity potential of wireless systems with multiple antennas at both transmitter and receiver, so called multiple input, multiple output (MIMO) systems. An unfortunate aspect of MIMO systems is the high cost of multiple radio transceivers at the access point and at the user terminal. Furthermore, it is expensive to calibrate and maintain antenna arrays with many antenna elements. Recently, switched parasitic antennas (SPAs) have been subject of an increased interest in the literature, for improving capacity in indoor LANs, as a diversity antenna and for tracking of base-stations.
In a sense, SPA offers characteristics similar to an array antenna with several fixed beams, but is more compact in size, and might be more suitable on certain mobile equipments. This paper will examine the use of SPAs in MIMO systems, where the SPA is primarily used at the user equipment (UE), in a realistic flat fading environment. It has been observed that when the fades of the MIMO receive channels are correlated, the channel capacity can be significantly smaller than when the fades are independent and identically distributed (i.i.d.).
According to Mattias and Thomas’s research, it has been proved that the switched parasitic antenna is an available antenna solution for MIMO channels. |
