Design of a High-Efficiency and -Gain Antenna Using Novel Low-Loss, Temperature-Stable Li₂Ti₁–_x(Cu_1/3Nb_2/3)_xO₃ Microwave Dielectric Ceramics

Abstract

Microwave dielectric ceramics are vital for filters, dielectric resonators, and dielectric antennas in the 5G era. It was found that the (Cu1/3Nb2/3)4+ substitution can effectively adjust the TCF (temperature coefficient of resonant frequency) of Li2TiO3 and simultaneously increase its Q × f (Q and f denote the quality factor and the resonant frequency, respectively) value. Notably, excellent microwave dielectric properties (εr (permittivity) ≈ 18.3, Q × f ≈ 77,840 GHz, and TCF ≈ +9.8 ppm/°C) were achieved in the Li2Ti0.8(Cu1/3Nb2/3)0.2O3 (LTCN0.2) ceramic sintered at 1140 °C. Additionally, the sintering temperature of LTCN0.2 was reduced to 860 °C by the addition of 3 wt % H3BO3, exhibiting superior microwave dielectric properties (ε r ≈ 21.0, Q × f ≈ 51,940 GHz, and TCF ≈ 1.4 ppm/°C) and being chemically compatible with silver. Moreover, LTCN0.2 + 3 wt % H3BO3 ceramics were designed as a patch antenna and a dielectric resonator antenna, both of which showed high simulated radiation efficiencies (88.4 and 93%) and gains (4.1 and 4.03 dBi) at the center frequencies (2.49 and 10.19 GHz). The LTCN0.2 + 3 wt % H3BO3 materials have promising future application for either 5G mobile communication devices and/or in low-temperature co-fired ceramic technology owing to their high Q, low sintering temperature, small density, and good temperature stability.

Near‐Zero Thermal Expansion Ba1−xSrxZn2Si2O7‐Based Microwave Dielectric Ceramics for 3D Printed Dielectric Resonator Antenna with Integrative Lens

“…As shown in Table 3, the compounds 0.95(0.9Zn 1.8 SiO 3.8 –0.1Ba 0.4 Sr 0.6 Zn 2 Si 2 O 7 )–0.05CaTiO 3 with comprehensive better microwave dielectric properties and CTE may be regarded as an ideal dielectric material in DRAs. [ 44,45 ]…”

The latest process and challenges of microwave dielectric ceramics based on pseudo phase diagrams

“…For co-doped substitution, Zn 1/3 Nb 2/3 , Mg 1/3 Nb 2/3 , and Co 1/3 Nb 2/3 addition into Li 2 TiO 3 could adjust the τ f from positive to negative [218][219][220]. Cu 1/3 Nb 2/3 doped ceramics with 3 wt% H 3 BO 3 were designed as a patch antenna and a dielectric resonator antenna [221]. The solid solution of Li 2 TiO 3 -MgO [222], Li 2 TiO 3 -ZnO [223,224], and Li 2 TiO 3 -Li 3 NbO 4 [225] attracted much interest of researcher owing to their high quality factor.…”

Sintering Characteristic, Structure, Microwave Dielectric Properties and Compatibility with Ag of Novel 3MgO-B2O3-xwt% Ba(CuB2)O5-ywt% H3BO3 Ceramics

“…In particular, with the emergence of 5G largescale antenna (Massive MIMO) technology, the number of antennas will increase exponentially. The demand of lters for signal frequency selection and processing will grow with the passage of time, thus the demand for low-temperature co-red ceramics (LTCC) will also increase signi cantly [8][9][10][11][12][13]. LTCC technology requires the dielectrics co re with high conductivity material electrodes.…”