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1、 TAIYUAN UNIVERSITY OF SCIENCE & TECHNOLOGY 外文翻译题目:紧凑的高阶谐波抑制学 生 姓 名 _学 号 200822050101_班 级 电气082201H _ 所属院(系)电子信息工程系_指 导 教 师 _2012年6月9日Compact Multi-harmonic harmonic suppression Compact Multi-harmonic suppression LTCC Bandpass Filter Using Parallel Short-Ended Coupled-Line Structure Xu-Guang Wang, Y
2、oung Yun, and In-Ho Kang This paper presents a novel simple filter design method based on a parallel short-ended coupled-line structure with capacitive loading for size reduction and ultra-broad rejection of spurious passbands. In addition, the introduction of a cross-coupling capacitor into the min
3、iaturized coupled-line can create a transmission zero at the second harmonic frequency for better frequency selectivity and attenuation level. The aperture compensation technique is also applied to achieve a strong coupling in the coupled-line section. The influence of using the connecting transmiss
4、ion line to cascade two identical one-stage filters is studied for the first time. Specifically, such a two-stage bandpass filter operating at 2.3 GHz with a fractional bandwidth of 10% was designed and realized with low-temperature co-fired ceramic technology for application in base stations that n
5、eed high power handling capability. The measured and simulated results showed good agreement. Keywords: harmonic bandpass filter, LTCC. suppression, coupled-line, I. Introduction In recent years, compact, high-performance, and low-cost components for radio frequency (RF) applications have been the f
6、ocus of a great deal of research and industrial pursuit with the explosive growth of modern wireless communication services. One promising method for many miniaturizing and packaging technologies is to use low-temperature cofired ceramic (LTCC) on account of its multilayer structure and high unloade
7、d quality factor. The bandpass filter is an essential component in the RF front-end of communication systems. It passes the desired frequencies, rejects unwanted signals, and suppresses harmonics. However, as a result of the distributed characteristic of the transmission line, undesired spurious pas
8、sbands or harmonics are a problem for conventional filters and can seriously degrade their performance, which may be critical in certain applications. To find a way to suppress spurious responses, many studies have been carried out. Using the technique of photonic bandgap (PBG) and defected ground s
9、tructure (DGS) is one of the most popular approaches. The PBG structure was initially proposed in the optical field, and essentially comprises periodic etched defects on the back of a metallic ground plane which can provide effective and flexible control of the propagation of electromagnetic (EM) wa
10、ves along a specific direction or in all directions. Since it was applied to microwave and millimeter frequency-band applications, numerous novel PBG structures have been proposed for the design of both passive and active devices with the property of multi-harmonic suppressionHowever, Manuscript rec
11、eived July 6, 2008; revised Feb. 27, 2009; accepted Apr. 7, 2009. Xu-Guang Wang was with the Department of Radio Science & Engineering, Korea Maritime University, Busan, Rep. of Korea, and is now with the Department of Electronic Engineering, Sogang University, Seoul, Rep. of Korea. The DGS with per
12、iodic or nonperiodic arrays is another very practical approach because it can provide a rejection band in some frequency ranges. Compared with the PBG structure, which needs many units to build a filter, the DGS is simpler because only a few units can be used to construct a filter, and this results
13、in a smaller filter size. The rejection characteristic of the DGS is available to many microwave circuits, such as power-amplifier modules, planar antennas, power dividers and filters, and so on . However, due to the periodic structure of the PBG and DGS, these filters suffer from their large circui
14、t areas and specific circuit configurations, which seriously hinder their application to wireless communication systems. In this paper, we propose a compact multi-harmonic suppression LTCC bandpass filter based on the capacitive loading of the parallel short-ended coupled-line structure. This is a r
15、elatively simple way of reducing the coupled-line electrical length, which usually plays a decisive role in the filter size. On the other hand, the use of lumped elements can effectively suppress the spurious passbands. In addition, the cross-coupling capacitor and aperture compensation technique ar
16、e employed for better performance. Such a compact twostage bandpass filter working at 2.3 GHz with high power handling capability was implemented in a multilayer LTCC substrate and examined carefully. Design Theory 1. Size Reduction Method Figure 1(a) shows the generalized bandpass filter structure to be miniaturized in this design. The admittance inverter, which is a quarter-wavelength transmiss