摘要滤波器在无线通信电路系统中具有频带和信道的选择,并且可以抑制杂散、滤除谐波。其性能的优劣会对整个通信电路系统的性能指标有重要的影响。随着微波技术的发展,滤波器已经朝着高性能、小体积、便于集成化的趋势发展。微带线结构的滤波器由于其体积小、重量轻、结构简单、频带宽、易于实现等特点在微波集成电路中得到了广泛的应用。78813

滤波在对信号进行处理时会产生多方面的损耗而使电路性能降低，电路无法正常工作，实际滤波器的设计中为了减少这种损耗就会考虑到要进行一些特定的变换来，微带线的奇模，偶模通过接地板产生耦合效应，耦合效应会产生了奇模特性阻抗和偶模特性阻抗，构成了分布参数元件，级联若干个耦合微带线可以得到带通滤波器的特性。

在较短的时间周期内设计出一个高性能的滤波器在微波电路系统设计中非常重要，因为传统的滤波器设计方法非常复杂并且计算量大，然而近年来微波电路辅助软件的陆续发展，滤波器的设计就可以绕开传统复杂的理论计算和推导，并且结果误差几率也很小。本文中，为了提高滤波器的性能，缩短设计周期，介绍了一种传统的滤波器设计分析与ADS（Adwanced Design System）仿真模拟软件结合的设计方法，运用奇偶模原理与ADS仿真模拟软件相结合，进一步优化设计参数，设计出一个中心频率为3GHz，相对带宽为10%的微波平行耦合微带线带通滤波器，并详细地阐述了其设计原理以及计算方法，仿真结果表明，这种方法简单可行，并且各项参数符合设计要求。

毕业论文关键词  微波平行耦合微带线  带通滤波器  ADS  奇偶模

毕业设计说明书外文摘要

Title  Design of microwave parallel coupled microstrip line filter                   

Abstract The filter has the band and channel selection in a wireless communication system, and to suppress spurious and harmonic filter。 Its performance will have important influence on the performance of the whole communication system。 With the development of microwave technology, filter of high performance, small size, ease of integration requirements has become a trend。 Filter microstrip line structure because of its small size, light weight, simple structure, wide frequency band, easy realization, is widely used in microwave integrated circuit。

Filtering in the loss of signal processing to produce the circuit performance deterioration, the circuit does not work, actual filter design will be taking into account to some specific transformation to reduce this loss, microstrip line of odd mode and even mode through the ground floor coupling effect, coupling effect leads to produce the odd mode impedance and even mode characteristic impedance, composition and distribution of the parameters of the components, the cascade coupled microstrip lines can be bandpass filter characteristics are obtained。

The traditional filter design method for complex and large amount of calculation, so how to in a short period of design a high performance filter in microwave circuit system design is particularly important, with the development of microwave circuit CAD software, filter design can avoid the complex calculation and derivation and the error probability is also very small。 Therefore, how to design a high performance filter is of great significance to the design of the filter circuit。 In this paper, in order to improve the filter performance, shorten the design cycle, describes the simulation of a traditional filter analysis and design ads (Adwanced design system) simulation based on the hardware and software design method, using even and odd mode theory and ADS simulation simulation software combination, further optimization of the design parameters, design a center frequency to 3GHz, relative bandwidth is 10% of the microwave parallel coupled microstrip lines with band-pass filter, and its design principle and calculation method is described in detail, simulation results show that, this method is simple and feasible, and the parameters meet the design requirements。