Abstract: This article depicts the design and practical development of a compact, high-selectivity and wideband bandpass filter (BPF) using GaAs-based integrated passive device (IPD) technology. First, the proposed BPF is designed by introducing lumped parameter resonators to achieve the performance of high-selectivity and wideband. Second, the working principles of the high-selectivity and wideband performance are further investigated. Finally, for demonstration, a compact high-selectivity wideband bandpass filter is designed, fabricated and measured using GaAs-IPD technology. This BPF works at the whole X-Band frequencies (from 6 GHz to 13 GHz) and the relative bandwidth is 74. 0%. Four transmission-zeros are realized, resulting in high-selectivity and good out-of-band performance. The chip size is 0. 05λ0 ×0. 03λ0. The simulated and measured results are compared to confirm the feasibility of the proposed design.