J. Mater. Sci. Technol. ›› 2025, Vol. 225: 288-296.DOI: 10.1016/j.jmst.2024.12.004

• Research Article • Previous Articles     Next Articles

LiMSiO4 (M = Ga, Sc and Y): Low-permittivity and high thermal conductivity microwave dielectric ceramics for millimeter-wave communications

Wei Wanga, Jian Baoa, Changhao Wanga, Guoqiang Hea, Xin Wanga, Diming Xua, Biaobing Jinb, Zhongqi Shic, Moustafa Adel Darwishd, Yawei Chene, Qixin Liange, Meirong Zhange, Di Zhoua,*   

  1. aElectronic Materials Research Laboratory, Key Laboratory of the Ministry of Education & International Center for Dielectric Research, School of Electronic Science and Engineering, Xi’an Jiaotong University, Xi’an 710049, China;
    bResearch Institute of Superconductor Electronics (RISE), School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China;
    cState Key Laboratory for Mechanical Behaviour of Materials, Xi’an Jiaotong University, Xi’an 710049, China;
    dPhysics Department, Faculty of Science, Tanta University, Al-Geish st., Tanta 31527, Egypt;
    eShenzhen Microgate Technology Co., Ltd., Shenzhen 518118, China
  • Received:2024-09-28 Revised:2024-11-18 Accepted:2024-12-08 Published:2025-08-01 Online:2024-12-16
  • Contact: *E-mail address: zhoudi1220@xjtu.edu.cn (D. Zhou).

Abstract: The advancement of millimeter-wave communication desires the ceramic substrate with low permittivity (ԑr) to meet the requirements of high transmission rates, low latency and wide bandwidth. However, the thermal conductivity of most low-ԑr ceramics is too low to deal with heat dissipation in millimeter-wave applications. In this paper, we reported novel dielectric ceramics LiMSiO4 (M = Ga, Sc and Y) with excellent performances of low ԑr (< 10) and high thermal conductivity (> 6 W mK-1). Their dielectric properties in both microwave and THz were investigated, where the LiGaSiO4 ceramic achieved the lowest ԑr of ∼5.2, the LiScSiO4 ceramic presented extremely low loss (Q × f ∼ 96,700 GHz, Q = 1/dielectric loss, f is resonant frequency), and the LiYSiO4 ceramic showed a positive temperature coefficient of f (TCF ∼ +32 ppm °C-1). The distinct dielectric behavior was subsequently studied by structure-performance relationship in terms of M-site cations and bond parameters using bond valence theory, Phillips-Van Vechten-Levine chemical bond theory and so on. Moreover, a 36 GHz microstrip array antenna was designed and simulated using the LiGaSiO4 ceramic substrate, obtaining high realized gain, high radiation efficiency and low sidelobe. The result demonstrated the great potential of LiMSiO4-type dielectric ceramics in millimeter-wave communications.

Key words: Low permittivity, Thermal conductivity, Microwave dielectric properties, Millimeter wave, Array antenna