The problem outlined in the description section of the SBIR A00-136, Unmanned Aerial Vehicle {UAV} Antennas, points out the necessity of detecting signals for Signal Intelligence and Communications while conforming to available space and weight capacity of the UAV. The requirement applies to both fixed and rotary wing aircraft, each with its own aerodynamic limitations to carry appropriate sensor systems. Suggestions are presented for interchangeable (easy-on easy-off) B kit antennas which cover a limited band of frequencies and which may be installed for a particular intelligence gathering mission or several UAVs may be launched with each one configured to cover a different frequency band. Typically, antenna solutions for aircraft are designed as an afterthought after the airframe has been completed. While this approach will always impact the performance of larger aircraft to some extent, in the case of smaller airframe UAV's, the addition of discrete "add-on" antennas can add significant flight performance risk due to deleterious alterations to its aerodynamic properties. It is the purpose of this proposal to introduce a new approach to antenna/sensor design; namely, the utilization of the existing aircraft surfaces, wings and blades, as antenna structures. This concept is made possible through the utilization of microstrip patch elements [1], and microstrip reflectarrays [2]. The microstrip patch antenna is utilized for low frequency applications (i.e. < 5 GHz), while the microstrip reflectarray is optimum for frequencies greater than 5 GHz. The principal benefits of the proposed program are the proof of concept of simple applique type antenna systems which can be installed on a wide variety of military and commercial aircraft. This technology provides opportunities for the inclusion of advanced antenna technology on a much less invasive basis than conventional discrete antenna techniques. Such appliques may be integrated as portions of the fundamental airframe design, or they may be added to existing airframes with minimal aerodynamic performance impact.
