Tunable active filters having multilayer structure using LTCC

et al. 2015

Materials

La1−xSrxTiO3+δ (LST) has been studied in many fields, especially in the field of microelectronics due to its excellent electrical performance. Our previous theoretical simulated work has suggested that LST has good dielectric properties, but there are rare reports about this, especially experimental reports. In this paper, LST was prepared using a solid-state reaction method. The X-rays diffraction (XRD), scanning electron microscope (SEM), broadband dielectric spectroscopy, impedance spectroscopy and photoconductive measurement were used to characterize the sample. The results show that the values of dielectric parameters (the relative dielectric constant εr and dielectric loss tanδ), dependent on temperature, are stable under 350 °C and the value of the relative dielectric constant and dielectric loss are about 52–88 and 6.5 × 10−3, respectively. Its value of conductivity increases with rise in temperature, which suggests its negative temperature coefficient of the resistance. In addition, the band gap of LST is about 3.39 eV, so it belongs to a kind of wide-band-gap semiconductor materials. All these indicate that LST has anti-interference ability and good dielectric properties. It could have potential applications as an electronic material.

Section: Introductionmentioning

confidence: 99%

Preparation and Electrical Properties of La0.9Sr0.1TiO3+δ

et al. 2015

Materials

“…By evaluating the even-and odd-mode input admittances, the transmission characteristic of the proposed filter could be calculated by (4)-(7). The magnetic coupling K C is equivalent to inductor L 4 in formula (7). When Y even =Y odd , five transmission zeros can be achieved near the passband of proposed filter, as shown in Fig.…”

Section: Filter Analysis and Designmentioning

confidence: 88%

“…In order to improve passband selectivity, the mixed E/M coupling technique can be introduced in the circuit of tunable BPF. In [7], the miniaturized tunable BPFs using LTCC technology was designed. The filter size is 5.6×5.6×3 mm 3 .…”

Section: Introductionmentioning

confidence: 99%

Compact tunable bandpass filter with improved stopband rejection and wide tuning range

Wei

IEICE Electron. Express

et al. 2013

A compact tunable bandpass filter (BPF) with wide tuning range and improved stopband rejection based on lowtemperature co-fired ceramic (LTCC) technique is presented. The axial coupling structure is employed to achieve a wide tuning range and increase resonator Q. To improve the stopband characteristics, Multiple transmission zeros (TZs) are introduced near the passband. A new tunable BPF with a 100% tuning range from 480 to 960 MHz has been designed and fabricated to verify the proposed method. The measured results are in good agreement with the electromagnetic (EM) simulation. The circuit only occupies 3.5×3.0×1.7 mm 3 .

Microw. Opt. Technol. Lett.

“…Many reported planar switchable BPFs were realized by using the printed circuit board technology, but suffered from large circuit area. Recently, the technology of low-temperature cofired ceramic (LTCC) has been widely utilized for size reduction because of its threedimensional (3D) circuit layout [5][6][7][8][9]. However, very little research on LTCC reconfigurable circuit has been done so far [9].…”

Section: Introductionmentioning

confidence: 99%

Novel LTCC switchable bandpass filter using vertically short-ended sir

Tang

Chen

et al. 2014

A novel compact low‐temperature cofired ceramic (LTCC) centrally loaded short‐ended stepped‐impedance resonator (SIR) is constructed in three‐dimensional (3D) environment and investigated to design a switchable bandpass filter (BPF). The size of the proposed SIR can be miniaturized greatly, because it is vertically folded in LTCC. The switchable passband of the BPF can be achieved by mounting PIN diodes on the surface of LTCC substrate. The simulated and measured results of the demonstration compact BPF are presented and show good switchable passband performance. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:999–1002, 2014