Research Projects

In Indian defence, especially in Unmanned Aerial Vehicles (UAV) design like Rustom – 2 model, drones have parabolic dish antennas placed at the front side of the UAV to send live video feed to the satellite which then interacts with the Ground Control Station (GCS). Due to the large size of the parabola antenna, the front side of the UAV has a large dome shaped structure which will introduce more drag (resistance to speed). This led to the development of Stealth UAV (S-UAV) named SWiFT with dimension 10×5 m², has planar transmitter and receiver array placed at different locations of the aircraft. Both the arrays are mechanically steerable, hence an additional motor and a larger space inside the S-UAV is mandatory for proper beam steering. This leads to congestion of components. So the need to save space without compromising on the performance, a shared aperture antenna array logic is used where the Transmitter (Tx) / Receiver (Rx) elements are placed in same location in an interleaved manner to get the desired gain and half power beam width, which also realizes the full duplex communication. Electronic beam steering is used to avoid the use of motors. A layer of metamaterial is also added at the skin of the aircraft to enhance the gain. The space allocation inside the S-UAV is 500×500×60 mm³, which is originally allocated to place the transmitter array antenna alone. Now, the challenge is to design the entire satcom array within the mentioned space. The scientific objective is to realize the below parameters which is similar to parabola antenna in Rustom - 2 and planar array in SWiFT, Transmitter array with bandwidth of (13.75 GHz – 14.5 GHz), peak gain of 38 dBi, half power beam width of 5⁰ and scanning range from 5⁰ to 80⁰ in θ plane, Receiver array with bandwidth of (10.7 GHz – 12.75 GHz), peak gain of 35 dBi, half power beam width of 7.5⁰ and scanning range from 5⁰ to 80⁰ in θ plane. The polarization of Tx/Rx array is linear. The model to be tested is, Three layers of dielectric with antenna elements of Tx/Rx designed on top of the first layer, the Tx feed network designed on top of second layer, the Rx feed network designed on top of third layer and an additional metamaterial layer on top of the three dielectric layers. To validate the model, Impedance, Coupling between elements, power division, Radiation and Scanning Range. The primary significance of the above design from application point of view is spacing in the S-UAV is largely saved with less design complexity and less cost without compromising on the required performance. If the model becomes successful, a huge research prospective will open to realize the design even smaller with even higher gain by working on the metamaterial layer and also on non-interleaving arrangement of Tx/Rx elements especially in the S-UAV.