## 1 Introduction  
Recent demands for high-frequency electronic components are increasing, and ceramic-based compositions are extensively used in satellite communications, including DBS TV, GPS, Internet of Things (IoT), etc., and 5G telecommunications, cell phone, cell site, etc. Furthermore, microwave dielectric ceramics are widely used for filters, resonators, and mixers in wireless communication systems [1; 2; 3; 4]. In microwave telecommunications, microwave resonators fabricated by dielectric ceramics result in the miniaturization of microwave devices. Materials possessing the following dielectric properties are suitable for dielectric resonators [5; 6; 7; 8]: (1) Permittivity (\(\epsilon_{r}\)) > 20: The permittivity is an essential factor for component size reduction. (2) Quality factor (tan8, the inverse of the dielectric loss) > 30,000 (GHz): Lower insertion loss and steeper cut-off can be obtained due to a higher Q/ value, which ensured the lower dielectric loss of components. (3) Temperature coefficient of resonance frequency (\(\tau_{f}\)) \(<\pm 10\) ppm/\({}^{\circ}\)C: A near-zero \(\tau_{f}\) value (\(\epsilon\)\(\pm 10\) ppm/\({}^{\circ}\)C) is necessary for the stability of device performance even temperature changes enormously in the environment. Generally speaking, three parameters strongly affect the size, frequency selectivity, and temperature stability of the device to the system, respectively. MgTiO\({}_{3}\)-based ceramics, which possessed an ilmenite-type structure and trigonal space group R-3 have caught much attention and typical applications as dielectric resonators [9], filters, antennas, and so on for microwave communication systems due to its good microwave dielectric performance recently. MgTiO\({}_{3}\) sintered at 1350 \({}^{\circ}\)C was demonstrated excellent dielectric performance in microwave frequency: \(\epsilon_{r}\) \(\sim\)17, Q/ value \(\sim\)160,000 (at 7 GHz) and temperature coefficients of resonance frequency (\(\tau_{f}\)) \(\sim-51\) ppm/\({}^{\circ}\)C [10]. Furthermore, (Mg\({}_{0.6}\)Zn\({}_{0.4}\))TiO\({}_{3}\) sintered at 1200 \({}^{\circ}\)C with \(\varepsilon_{r}\) \(\sim\)19.8, Qf value \(\sim\)144,000 and \(\tau_{f}\sim-66\) ppm/\({}^{\circ}\)C have also been demonstrated as promising titanate candidate for broad applications in this microwave frequency. Some researchers pay attention to comprehensively investigate the effects of relative contents between Mg and Zn in (Mg\({}_{y}\)Zn\({}_{1-y}\))TiO\({}_{3}\) system [11; 12]. As a result, microwave dielectric performance of (Mg\({}_{y}\)Zn\({}_{1-y}\))TiO\({}_{3}\) highly depended on the content of Mg. It was reported that the partial replacement of Mg by B\({}^{2+}\) (B\({}^{2+}\) = Co, Ni, and Zn) increases the structural densification and upgrades the dielectric performance of MgTiO\({}_{3}\). (Mg\({}_{0.95}\)B\({}^{2+}\)\({}_{0.05}\))TiO\({}_{3}\) with an ilmenite-type structure has been documented to possess excellent dielectric performance [8; 13; 14]. Since the ionic radii of B\({}^{2+}\) (0.0745 nm of Co\({}^{2+}\), 0.068 nm of Ni\({}^{2+}\), and 0.082 nm of Zn\({}^{2+}\)) approach to that of Mg\({}^{2+}\) (0.072 nm), Mg\({}^{2+}\) ions can be replaced by B\({}^{2+}\) ions to form (Mg, B\({}^{2+}\))TiO\({}_{3}\) compound. However, the (Mg\({}_{0.95}\) B\({}^{2+}\)\({}_{0.05}\))TiO\({}_{3}\) shows a negative temperature coefficient (\(\gamma\)). In the previous study, combining some large positive \(\tau_{f}\) compensator with (Mg\({}_{0.95}\) B\({}^{2+}\)\({}_{0.05}\))TiO\({}_{3}\) is effective to obtain near-zero \(\tau_{f}\) value in the whole material system [14; 15; 16; 17; 18; 19; 20; 21]. It is noted that the second phase of Mg\({}_{0.95}\)B\({}^{2+}\)\({}_{0.05}\)Ti\({}_{2}\)O\({}_{5}\) (B\({}^{2+}\) = Co, Ni, and Zn) might deteriorate the dielectric performance of the (Mg\({}_{0.95}\) B\({}^{2+}\)\({}_{0.05}\))TiO\({}_{3}\) system, and we could not precisely evaluate the effect of Mg\({}_{0.95}\)B\({}^{2+}\)\({}_{0.05}\)Ti\({}_{2}\)O\({}_{5}\) phase [22; 23; 24; 25; 26; 27].