| | | | | capacity grows connectivity at T-1 rates and |
| Conformal Near Omni-Directional Antenna | | | | above may be supportable. Since availability of |
| Design for Unmanned Aerial Vehicles (UAV) | | | | cellular telephones over many continents is |
| Technical Abstract | | | | ubiquitous, it is easy to imagine its interconnection |
| TST proposes R&D of a conformal, | | | | to commercial aviation. The cell phone user may |
| switched array antenna (CSAA); a steerable | | | | then leave his phone in the ON state during flight |
| antenna capable of a nearly omni-directional field | | | | and continue its use as though he/she were still at |
| of regard (FoR) that exhibits modest gain over | | | | the airport or their office. The directional antenna |
| “omni”. Steering. This is achieved by RF | | | | for connection to cell towers is made practicable |
| switch-selecting of elements of the array which | | | | since an omni antenna can “see” too |
| include dipole or monopole elements and delay | | | | many cell towers simultaneously. Being able to |
| lines. This gain increase enables the following | | | | select only a few towers within the antenna |
| improvements: reduction of UAV transmitter | | | | beam’s footprint enables reliable connections |
| power requirements and the attendant heat loads, | | | | and suppresses interference from all of the other |
| improved interference and jamming suppression | | | | towers that may be visible with an omni antenna. |
| and improved Low Probability of Intercept (LPI) | | | | In these ways, the high gain conformal antenna is |
| performance. Also, reducing power and heat load | | | | a major enabling extension of the passenger cabin |
| lightens extends the mission duration. We | | | | to the business traveler’s daily environment |
| anticipate realization of a gain figure of 10 or | | | | where computation, internet, email, voice |
| more dB higher than that specified in the | | | | communications and teleconferencing are enabled. |
| solicitation. The CSAA has no active components | | | | The CSAA enables the air traveler’s IT. |
| requiring only switches, hybrids, delay lines and | | | | Commercialization must start with the |
| radiators. This enables use of corporate (rather | | | | technological feasibility determined through studies |
| than distributed) transmitters and receivers and | | | | and laboratory measurement. The technical |
| obviates the expense of custom ASIC of a | | | | community must be informed as to the potential |
| traditional phased array antenna. The proposed | | | | service extension. This awareness will engender |
| work will study and recommend radiator | | | | the formation of standards committees so that |
| geometry, elements and arrays, switch devices, | | | | an enlightened and focused set of protocols is |
| conductor and dielectric materials, coating | | | | established to then extend IP and cellular services |
| materials and methods as well as attachment | | | | to the air traveler. When this system is in use in |
| materials. We will develop a high fidelity simulation | | | | the commercial community, the DoD will exploit |
| model of the baseline antenna system, and | | | | the ensuing infrastructure for support of defense |
| thereby demonstrate coverage patterns for main | | | | agendas. This model of DoD-backed technology |
| lobe and side lobe characteristics. | | | | investment that is embraced and implemented by |
| | | | | the private sector and then used by DoD as part |
| | | | | of our defense infrastructure has happened over |
| | | | | the course of events in the US and on a global |
| Anticipated Potential Benefits | | | | basis. The best examples of this circular process |
| The anticipated benefits for commercial | | | | are GPS Navstar, IDCSP and related SATCOM |
| applications include moderate gain tracking | | | | systems, Internet itself and all of the secure |
| antennas that conform to automotive surfaces, | | | | intranets that handle Government traffic, etc. |
| and commercial aircraft, as well. The properties of | | | | There may come a time when military |
| low aerodynamic drag, steerability and low | | | | communications with aircraft will use some |
| implementation costs are attractive for these | | | | commercial infrastructure for ubiquitous |
| applications. Not only will this result in improved | | | | connectivity, and the conformal switched array |
| communications performance (longer range links, | | | | antenna will be a key enabling technology. |
| more reliable connectivity and high capacity) the | | | | Current tactical communications network |
| conformality will reduce drag and thus improve | | | | connectivity among highly mobile forces deployed |
| fuel economy. A phase 3 program is envisioned | | | | over the extended battlespace exhibits serious |
| where the CSAA basic taxonomy is applied over | | | | limitations on connectivity, capacity and security. |
| a large range of military air and terrestrial | | | | The extensive deployment of SINCGARS and |
| platforms. In a “Network on the Move” | | | | EPLRS radios in the field requires longer ranges |
| (NOTM) concept, many elements of a regiment | | | | and more highly reliable connections than are |
| may be interconnected to form a robust network | | | | currently enabled by line-of-sight distances for |
| where any element serves as a switch and | | | | which these radios are designed. The UAV |
| router. Physical connections are made or dropped | | | | communications relay platform is desired to |
| as the network geometry changes. The CSAA | | | | greatly extend the range of these radios by |
| may be truck mounted or even mounted as an | | | | providing “bent pipes” to extend the |
| integral part of a combatant’s helmet. The | | | | communications and position reporting mission |
| beams are steered via an embedded CPU and | | | | ranges. The UAV platforms must enable |
| inertial platform (i.e., a laser ring gyroscope) to | | | | connectivity by means of antennas and radio |
| maintain pointing. Beam discovery and tracking are | | | | repeaters. Since the UAV must be situated so |
| interesting challenges for a system design, but the | | | | that it can serve its designated area of the |
| robustness of such a network has a strong | | | | battlespace it’s visibility in all necessary |
| payoff. Where capacity increases are greatly | | | | directions is a critical requirement of the antenna |
| enabled (by a factor of 100 or more over that | | | | design. The realization of Omni-directionality is |
| needed for voice traffic), new on-board | | | | critical to the mission performance. We propose |
| commercial services such as in-flight internet | | | | to study an antenna design that provides this |
| connections at DSL rates and above for many | | | | connectivity and enables enhancement of the |
| passengers may be supportable. The air platform | | | | radio links through the use of directional antennas |
| antenna performance is the Key Enabling | | | | that can be steered in all necessary directions |
| Technology for this win-win strategy to be | | | | over the battlespace. In contrast to a traditional |
| developed. The remainders of the network | | | | Omni antenna, our approach provides substantial |
| elements, for the most part, have already been | | | | robustness to the links (better SNRs, lower |
| developed and exist in terrestrial internet | | | | interference and jamming vulnerability and lower |
| switches, routers, standards and protocols. Early | | | | intercept probability) but at the expense of some |
| services such as email, document transfer, JPEG | | | | additional system complexity. This |
| imagery and real-time high quality music may be | | | | performance/complexity trade-off is central to |
| enabled through visible internet radio gateways. As | | | | the proposed study. |