Miniaturized Coupled Line Bandpass Filter Using Parallel PI Capacitor Networks in LTCC

• Main Authors: Yung-Chin Hung, 洪永晉
• Other Authors: Young-Huang Cho
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/51605755961408734215

碩士 === 華梵大學 === 電子工程學系碩士班 === 98 === Filter with based on short-ended parallel coupled lines,is very difficult to the design of miniatured. The need to reduce the couple line length to achieve the objective of the miniatured design, although capacitive loading of such coupled lines is a relatively simple means of reducing the line lengths but the degree of reduction in the fractional bandwidth of a filter due to the miniaturization is found to be identical to the degree of increase in the group delay at the center frequency of the coupled line. Neeed to compensate for bandwidth to solve the problem;In this paper, we propose miniaturized coupled line using parallel PI capacitor networks, bandwidth reduction ratio can using cross capacitors for compensation. Using parallel PI capacitor networks based on short-ended coupled lines to design a bandpass filter, the frequency response by Microwave office(AWR), found in the low frequency and high frequency out of band rejection have transmission zeros. Use of equivalent circuit structure symmetry to find reasons for transmission zero production and control. Final to achieve bandpass filter using LTCC technology,the size of the filter is only ,this study shows a compact, the rejection is more than 30dB forward 2GHz and beyond 3.5GHz, verify that the small size, low loss, high attenuation filter can be realized on LTCC