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In this paper, a compact quasi-TM₀₁₀ mode dielectric-loaded bandpass filter with 8th-order pseudoelliptic filtering function and symmetric positioning of 4 transmission zeros is analyzed and designed. The resonant frequency and field components of quasi-TM₀₁₀ mode of a cylindrical dielectric resonator (DR) were first calculated and simulated. Compared to the pure TM₀₁₀ mode, the unloaded Q factor of quasi-TM₀₁₀ mode can increase by 3000 to more than 8000 and then the dimensions of the single DR at 2.595GHz are π×34²×20 mm₃ (using ε_r = 45). The magnetic coupling and electric coupling between dielectric-loaded cavities are studied and the dielectric window is innovatively proposed to generate electric coupling and to avoid the use of metallic probes that are cumbersome to assemble. In final, a quasi-TM₀₁₀ mode double-layer filter with two pairs of symmetric transmission zeros is designed according to the cubic-like topology and fabricated and tested which exhibits close agreements between the simulated and measured results demonstrating the advantages of low insertion loss, very close-to-band rejections and compact configuration. The proposed filter has great potential for development in 5G mobile communication systems and microwave radar communication systems.