High Gain CP Antenna for Mobile Satellite Communications Numerically Evaluated under Various Packaging Materials

摘要

The designed CP microstrip antenna suitable forudmobile satellite communication was numerically evaluated usingudvarious packaging materials. The study is important to provideudsufficient information regarding the electrical propertiesudvariations of the constructed antenna in the presence of theudshielded media. Those worthwhile characterizations areudessentially required on the final packaging stage of the wholeudantenna unit and electronics circuits as an integratedudcommunication peripheral. The numerical evaluation is veryuduseful to be carried-out in order to select the appropriateudshielded cover. Based on the computation results, in free space,udthe antenna has large gain 16.5 dBi and excellent impedanceudmatching at S-Band (2 ??? 4 GHz) to provide the large operationudbandwidth approximately 1900 MHz. As the antenna systemudshielded using various plastics box cover there are significantudalterations on the targeted electrical properties such as theudreflection constant (Sud), the impedance bandwidth, axial ratioud(AR), and gain. While mobile satellite terminal, consisted ofudantenna unit and various electronics parts, was enclosed with theudpolyester, polycarbonate and polyvinylchloride (PVC) of theudplastic packaging materials types, the overall gain and bandwidthudachieved were 4 dBi and 1600 MHz (spans on the frequencyudrange from 1.5 GHz to 3.1 GHz), respectively. Meanwhile, theudgain and bandwidth are also altering as ABS (polyacrylonitrile),udpolypropylene and polyethylene used. These three protectiveudcover materials also affect the alteration of both bandwidth andudgain of the mobile satellite antenna. The two parameters, i.e.udbandwidth and gain, altered to approximately 1 GHz (at theudfrequency resonances 2.5 ??? 3.5 GHz) and 4 ??? 10 dBi, respectively. ud11