Design and Fabrication of a C-Band Dielectric Resonator Antenna with Novel Temperature-Stable Ce(Nb_1–xV_x)NbO₄ (x = 0–0.4) Microwave Ceramics

Abstract

Vanadium(V)-substituted cerium niobate [Ce(Nb1–x V x )O4, CNVx] ceramics were prepared to explore their structure–microwave (MW) property relations and application in C-band dielectric resonator antennas (DRAs). X-ray diffraction and Raman spectroscopy revealed that CNVx (0.0 ≤ x ≤ 0.4) ceramics exhibited a ferroelastic phase transition at a critical content of V (x c = 0.3) from a monoclinic fergusonite structure to a tetragonal scheelite structure (TF–S), which decreased in temperature as a function of x according to thermal expansion analysis. Optimum microwave dielectric performance was obtained for CNV0.3 with permittivity (εr) of ∼16.81, microwave quality factor (Qf) of ∼41 300 GHz (at ∼8.7 GHz), and temperature coefficient of the resonant frequency (TCF) of ∼ –3.5 ppm/°C. εr is dominated by Ce–O phonon absorption in the microwave band; Qf is mainly determined by the porosity, grain size, and proximity of TF–S; and TCF is controlled by the structural distortions associated with TF–S. Terahertz (THz) (0.20–2.00 THz, εr ∼ 12.52 ± 0.70, and tan δ ∼ 0.39 ± 0.17) and infrared measurements are consistent, demonstrating that CNVx (0.0 ≤ x ≤ 0.4) ceramics are effective in the sub-millimeter as well as MW regime. A cylindrical DRA prototype antenna fabricated from CNV0.3 resonated at 7.02 GHz (|S 11| = −28.8 dB), matching simulations, with >90% radiation efficiency and 3.34–5.93 dB gain.

Novel microwave dielectric ceramics based on CaO–MoO3–La2O3 pseudo‐ternary phase diagram and the design of patch antenna

“…5G communication technology, with its large bandwidth, fast transmission speed, and low network latency, has become the foundation of “intelligent manufacturing” and “internet of everything.” 3 The mainstream 5G communication technology is primarily split into two paths nowadays: millimeter‐wave and centimeter‐wave (Sub‐6 GHz). 4 In the 5G centimeter‐wave technology, the 3.4–3.6 GHz frequency band is the mainstream commercial frequency band. 5 Currently, the commercial construction of centimeter‐wave technology has begun on a large scale and urgently requires significant quantities of high‐performance passive electronic components.…”

“…3 The mainstream 5G communication technology is primarily split into two paths nowadays: millimeter-wave and centimeter-wave (Sub-6 GHz) .4 In the 5G centimeter-wave technology, the 3.4-3.6 GHz frequency band is the mainstream commercial frequency band . 5 Currently, the commercial construction of centimeter-wave technology has begun on a large scale and urgently requires significant quantities of high-performance passive electronic components. Microwave dielectric ceramic (MWDC) is a crucial material widely used in microwave circuits to prepare many passive electronic components, including dielectric resonators, filters, and antennas .…”

Tunable Microwave Dielectric Properties in Rare-Earth Niobates via a High-Entropy Configuration Strategy To Induce Ferroelastic Phase Transition

“…The phase transition temperature ( T F–S ) is primarily influenced by the cation size of either the A-site or B-site. When a large rare-earth element occupies the A-site, the T F–S tends to decrease, and vice versa. − Interestingly, near-zero τ f values of LnNbO 4 can be regulated by ion substitution to tune the phase transition temperature. ,, The ferroelastic phase transition originates from a modification in spontaneous strain associated with lattice distortion, thereby providing an avenue for tuning the dielectric properties of LnNbO 4 through high-entropy strategies.…”

Characterization of pores in polished low temperature co-fired glass-ceramic composites for optimization of their micromachining

“…Ceramic composite materials are steadily conquering new areas of application, as desired functional properties can be specifically adjusted by combining material properties of matrix and filler in a sophisticated way. So is it for example possible to improve properties such as their mechanical strength [1][2][3] or energy density [4] and tune parameters like permittivity [5][6][7] or conductivity [8]. Widely used processes for the synthesis of such composites are spray pyrolysis [8,9] and powder-based sintering [1,6,7,10,11] which entail a porous material structure.…”

“…So is it for example possible to improve properties such as their mechanical strength [1][2][3] or energy density [4] and tune parameters like permittivity [5][6][7] or conductivity [8]. Widely used processes for the synthesis of such composites are spray pyrolysis [8,9] and powder-based sintering [1,6,7,10,11] which entail a porous material structure. Low temperature cofired ceramics (LTCC) are a group of glass-ceramic matrix composites that are densified by viscous flow as the major driving mechanism during the sintering process [12].…”