The Td-scdma Lte Rf Pull Far Unit (rru) Filtering Module Design And Implementation

As one of the most prospective teconology standards of the4th gernerarion ofcommunication, TD-LTE system has much more advantages than the3rd generation ofcommnication,Such as Larger coverage area,higer communication quality,moremultimedia features and higer degree of intelligence,etc.And this kind of system alwaysadopt a radio-remote-unit (RRU) to reduce the costs of building base station facilities,which puts forward new requirements for the design of the system.The RF filter used in the front-end of a communication system has a greatinfluence on the system characteristics such as the system sensitivity,power capacityand anti-jamming capability. And the TD-LTE Remote Radio Head Unit has morestringent requirements on the filter indicator, mainly reflected on endless pursuit of lowinsertion loss, stringent wideband rejection and high power capacity,anti-environmental interference capability and miniaturization.The main work and innovation of this thesis around these difficulties are asfollows:1. A general Scheme which consists the filter unit of a band-pass filter and a low-pass filter forthe requirements of wideband rejection out of the passband.2. An efficient layout to improve space utilization for the specific interfaces anddimensions.3. A systematic analysis of the frequency characteristics of quarter-wavelengthcoaxial resonator.4. A compensation by rounding a corner between the resonator rod and the floor of thecavity for the contradiction of the power capacity and the quality factor,and a design ofa coaxial cavity filter with high selectivity and high-power capacity.5.An effective temperature compensation structure simulation design for a singleresonant structure, the fequency-drift of which is reduced to nearly zero.6. An effective design of a miniaturized coaxial low-pass filter using high and lowimpedance coaxial transmission line filled with teflon film,which reduces the spurious response of the bandpass filter.