Contents I. Introduction
With the advancements in technology in the field of UAVs and communication systems it is important to have compact antennas for various operations such as telemetry, telecommand and payload communication links which require large bandwidths [1]. Conventional compact antennas are microstrip radiating patches on grounded dielectric substrates. Microstrip antennas are low profile, light weight, easy to fabricate and conform but are limited by narrow bandwidths [2]. One of the major challenges in practical applications of microstrip antennas is bandwidth enhancement along with miniaturization. Different techniques such as shorting posts between patch and ground plane [3], meandered ground plane [4], slot loading [5], stacked shorted patch, feed modification, are used to increase the bandwidth and reduce size. Also there is increasing focus on millimeter wave bands, particularly 57–64 GHz frequency band as the federal communication commission has allocated it for unlicensed wireless systems [6]. Traditionally mm-wave antennas offer large bandwidths and high speed communication links compared to lower frequency bands [7], and their sizes vary from hundreds of micrometers to few millimeters, which increases the cost of the cumbersome process of bulk micromachining [8]. Also many of the mm-wave antennas consist of multilayered dielectrics with different relative permittivity of each layer [9], [10]. Small size and increased bandwidth usually results in lower gain which can be improved by forming an array of the unit cell [10]. Conformity of dual band mm-wave antennas for stable communication link and different functionalities adds to the complexity of design. This paper proposes a Dual band (Ka/V band) millimeter wave printed microstrip antenna patch shaped like a star which is fed by co-axial feed and is constructed on a single layer substrate using standard printed- (PCB) technology. The linear array designs are formed to improve gain. The antenna unit cell and arrays were simulated in Ansys HFSS. HFSS-IE was used for antenna placement study on the wing of UAV. The dimensions of the antenna were optimized to obtain highest possible bandwidth in both frequency bands. The unit cell of the antenna was fabricated and its return loss was tested. Section II. contains the design of the generic wing and unit cell, 1X2 array, 1X4 array designs. Section III. contains the return loss and radiation pattern simulations and case study of conformed 1X4 array. Section IV. contains the fabricated antenna measurement results.
