The relationship between the sintering temperature and the microwave dielectric properties of Mg-4(TaNb1-xVx)Og (MTNV) compounds were investigated in this study in order to reduce the sintering temperature of the compound. A small amount of V2O5 doping lowered the sintering temperature of the MTNV compounds. The variations in the dielectric constant and the quality factor of the MTNV compounds depended on the amount of V2O5 doping and the sintering temperature; a small amount Of V2O5 doping was effective in allowing low sintering temperatures without a detrimental effect on these dielectric properties. As a result, a dielectric constant of approximately 12 and a quality factor of approximately 200,000 GHz were obtained when the MTNV compounds with x = 0.2 was sintered at 1200 T. The temperature coefficient of resonant frequency of the MTNV compound with x = 0.025 slightly changed from -63 to -73 ppm/degrees C with an increased sintering temperature because of the presence of a secondary phase. (c) 2005 Elsevier Ltd. All rights reserved.