Bao-Shan Li

Design and implementation of an LTCC filter with high stopband rejection

A miniaturized and high stopband rejection bandpass filter(BPF) with three finite transmission zeros is presented in this paper. The BPF with a central frequency of 3.4 GHz and 200 MHz bandwidth is implemented in a novel distributed stripline configuration using LTCC (low-temperature-cofired ceramic) technology. A distinct feature of this filter is excellent out-of-band attenuation performance. The lower skirt of the passband is very steep. There is 36.5dB attenuation at 3.2 GHz, the input/output VSWR is less than 1.4. We employ Z-shape layer to produce the lower 2 transmission zeros. By properly controlling the cross-coupling between the second and the fourth resonator, transmission zero in higher skirt of the passband will be generated. Measurement results of mass production are shown to match well with the electromagnetic simulation, which validate the proposed structure. The overall size of the filter is 4.8mm×4.2mm×1.5 mm.

A Miniaturized and Low Insertion Loss LTCC Filter with Two Finite Transmission Zeros for Bluetooth Application

This letter outlines the design and manufacture of a miniaturized bandpass filter realized by low-temperature cofired ceramic (LTCC) technology for bluetooth applications. The bandpass filter with a central frequency of 2450 MHz and a 100 MHz passband is designed as a three-dimensional (3-D) structure based on lumped components. Experimental measurements were compared with modeling. The insertion losses in the passband (100 MHz) were less than 1.2 dB and the attenuation was more than 20 dB in the stop band. The area occupied by the filter is 1.6times0.8times0.6 mm3.

A miniaturized LTCC bandpass filter with low insertion loss and high image rejection within 6.5 to 7.1GHz frequency range

A low-temperature-cofired ceramic (LTCC) bandpass filter with low insertion loss and high image rejection is presented for super heterodyne microwave receiver within 6.5–7.1GHz band. By improving the filter cell structure, two transmission zeros can be generated to achieve wide-band image suppression from cascading filter cells. The presented method provides the design flexibility of locating these transmission zeros distributed in the lower and upper stopbands. To reduce insertion loss and size of the filter, a miniaturized LTCC three-stage bandpass filter with two transmission zeros in lower stopband has been implemented for experimental demonstration. The measured insertion loss is less than 1.0 dB at 6.8GHz, the measured image rejection from 5 to 5.6GHz is more than 42dB, the input/output VSWR is less than 1.5. The size of the miniaturized filter is only 2.5mm×2mm×1.2mm. The process yield of the LTCC filter is more than 90%.

Design and implementation of an miniaturized LTCC filter with high stopband rejection

A miniaturized and high stopband rejection bandpass filter(BPF) with three finite transmission zeros is presented in this paper. The BPF with a central frequency of 3.2 GHz and 200 MHz bandwidth is implemented in a novel distributed stripline configuration using LTCC (low-temperature-cofired ceramic) technology. A distinct feature of this filter is excellent out-of-band attenuation performance. The lower skirt of the passband is very steep. There is 34.6dB attenuation at 3.0 GHz, the input/output VSWR is less than 1.4. We employ Z-shape layer to produce the lower 2 transmission zeros. By properly controlling the cross-coupling between the second and the fourth resonator, transmission zero in higher skirt of the passband will be generated. Measurement results of mass production are shown to match well with the electromagnetic simulation, which validate the proposed structure. The overall size of the filter is 4.8mm×4.2mm×1.5 mm.

A Miniaturized P-Band Coupler with Multi-Layer Dielectric and High Performance

This paper presents a new compact 90deg hybrid coupler using multi-layer technology. In order to reduce an intrinsic circuit area of the hybrid coupler, a compact meandered line configuration and a new multi-layer structure design have been adopted. The configuration and structural dimensions of the multi-layer structure were designed and investigated through detailed 3-D electro-magnetic simulations. The measured insertion loss is less than 0.4 dB, and the phase imbalance is less than 3 degree with the frequency range from 380 MHz to 520 MHz. The overall dimension is as small as 16.5 mm times 12.2 mm times 1.66 mm.