Micro-Ant Inc. is an innovative antenna design, development and manufacturing company whose engineers have extensive experience with reducing complex, sophisticated antenna systems to robust, low cost commercial, military, government and consumer products. The company recognizes the ever-growing need for new antennas to meet the changing requirements of the communication industry, and has built a foundation on its engineering talents to support these needs.
One of the results of these efforts is a new low profile, L-band mobile tracking antenna system. This advanced antenna system, designed for mobile tracking voice communication system application, features a unique low profile design, as shown in Figure 1. The antenna system also offers higher gain and better overall performance than most other systems currently available in the industry. In addition, it features an overall simpler design that reduces the cost of purchase to the consumer and end users.
Fig. 1 The low profile antenna system mounted on an SUV.
Several years ago, Mitsubishi and other well-known companies produced and manufactured their own mobile tracking terminals as one of their standard products. At the time, concerns about terrorism and disasters were not on the forefront of the nation’s mind and the demand for these systems was not high enough for companies to continue to manufacture product.
Since September 11, 2001, however, there has been an increasing demand for reliable two-way voice communication systems to support public safety, emergency response teams, homeland security and other special agencies. The demand for these systems remains high, while available reliable units are scarce. Some companies are even willing to find and purchase used systems in order to satisfy their immediate need.
While there is currently one other company manufacturing its own L-band mobile antenna system, the consumer has expressed that it is too big, too expensive and has some technical problems when used throughout parts of the US. Micro-Ant specifically designed its unit to address and support the concerns voiced by the consumer and has successfully produced a low profile, high performance, low cost system.
Micro-Ant’s Mobile Antenna System is designed for use with mobile satellite terminals communicating over the MSAT/MSV network and can be modified for compatibility with the Inmarsat network. The patented antenna technology can be applied to other frequency bands and applications, and provides a single axis-tracking antenna that features a proprietary printed circuit array with a shaped elevation beam. Figure 2 shows the antenna system’s gain characteristics vs. elevation angle for low, medium and high frequencies within the MSAT bands. This helps improve system receive gain vs. noise temperature (G/T) performance while resulting in a mechanically reliable and robust design. It is intended for use within the continental US, but may be adapted to other regions where service is provided. Tracking and acquisition is accomplished by measuring receive signals from the satellite, and by data from external sensors. The antenna includes a low noise amplifier (LNA), a high power amplifier (HPA) and tracking components.
Fig. 2 Micro-Ant MSAT antenna gain performance at (a) receive and (b) transmit for low, mid and high frequency operation.
The antenna system provides a secure two-way push-talk voice communication unit that can be used on a day-to-day basis. During a major crisis, however, its reliability is second to none. During emergencies and other events, the user has the flexibility to speak with a large group or team at the same time or choose a private one-on-one conversation. This reliable system allows individuals to communicate independent of geography and where cell phones may not work or land terminals are unavailable or do not provide steadfast service. The unit will provide unwavering voice communication with any line of sight system where it has a direct view of the satellite. In cases where it is blocked by a tunnel, building or other obstruction, the antenna will continue to point in the direction of the satellite for a sufficient period of time to allow rapid reaction acquisition.
Antenna System Characteristics
The L-band mobile tracking antenna system has been specifically designed to provide an ultra low profile suitable for any vehicular mounting, as shown in Figure 3, and features a state-of-the-art tracking algorithm that uses gyro stabilization to ensure stable signal lock. Its robust design includes a stylized high impact radome and aluminum-mounting base with fixed or magnetic mounting options available. The antenna can be configured to track either one of the MSV satellites, and will function without any modifications to the existing Mitsubishi terminals.
Fig. 3 The antenna system’s low profile design.
Table 1 lists the MSAT/MSV network antenna’s technical specifications. The antenna system’s electrical interface is via transmit, receive and data cables. DC power is supplied through either the transmit or receive cable.
Conclusion
An ultra low profile, L-band tracking antenna has been described that features high performance and state-of-the-art tracking for communications applications in the MSAT/ MSV or similar network. The antenna system features a mechanically reliable and robust design intended for use in the US, but may be adapted to other regions where such service is available. Additional information may be obtained via e-mail at info@micro-ant. com.