Miniaturization of GPS patch antennas based on novel dielectric ceramics Zn(1−x)MgxAl2O4 by sol–gel method

Effect of Zn Site for Ca Substitution on Optical and Microwave Dielectric Properties of ZnAl2O4Thin Films by Sol Gel Method

“…As increases, the optical decreases from 3.73 eV ( = 0.05) to 3.50 eV ( = 0.25). The optical bandgap analyses suggested that the increasing amount of Ca led to the decreasing optical due to the fact that calcium bandgap (3.2 eV) [30] is smaller than zinc (3.84 eV) [18,29]. From this experiment, the suggested bandgap of (Ca/Zn)Al 2 O 4 is between 3.50 eV and 3.73 eV which is applicable as for GPS application [29].…”

“…The and unloaded quality factor values were measured using an LCR spectrometer (HP 4284A) at frequency range 20 Hz to 1 MHz at room temperature. Abdullah et al [18]. The peaks correspond to (Ca/Zn)Al 2 O 4 which appeared at 29.375 ∘ (422).…”

“…Recently, there are many methods to prepare microwave dielectric ceramics such as solid state mixing reaction of zinc and aluminium oxides [11,12], coprecipitation [13], hydrothermal [14,15], microwave hydrothermal [16], 2 Advances in Materials Science and Engineering combustion [17], and sol gel methods [18,19]. Among the various methods, the sol gel method is a useful and attractive technique for the preparation of the ZnAl 2 O 4 nanostructure because it offers the advantages of good stoichiometric control and is high homogeneity, producing pure and ultrafine powders and is able to produce thin films at low temperature processing (<900 ∘ C) [20,21].…”

Development of performance‐improved global positioning system (GPS) patch antenna based on sol‐gel‐synthesized dual‐phase (Bi4Ti3O12)X – (CaCu3Ti4O12)1–X composites

“…This could lead to more effective interface effects that could lead to a higher dielectric constant at a specific composite concentration . Such giant dielectric composites may be suitable candidates for emerging size reduction of GPS antennas by 263 times instead of ZnAl 2 O 4 ceramic which has dielectric constant of 12.45 and 404 times that of Zn (1– X ) Mg X Al 2 O 4 , (1‐X)ZnAl 2 O 4 ‐XSiO 2 , Zn (1– X ) Ca X Al 2 O 4 , Ti X Zn (1– X ) Al 2 O 4 and Ca X Zn (1– X ) Al 2 O 4 . Based on these observations, BTO‐CCTO composite based GPS patch antennas are fabricated for the first time with cost‐effective technique.…”

“…reported that materials with high dielectric constant are particularly interesting for GPS applications at the L1 frequency of 1.575 GHz. Several papers were published in novel ceramic materials such as Zn (1– X ) Mg X Al 2 O 4 , (1− X )ZnAl 2 O 4 ‐ X SiO 2 , Zn (1– X ) Ca X Al 2 O 4 , Ti X Zn (1– X ) Al 2 O 4 and Ca X Zn (1– X ) Al 2 O 4 that are used for GPS patch antennas. The relative permittivity of these ceramics is measured in the frequency range from 20 Hz to 1 MHz at room temperature and average values of the dielectric constant are found to be around 6.00–8.57.…”