An Integrated RF Balun-filter with Enhanced Rejection Characteristics
In this invention, a newly proposed multi-layered integrated Radio Frequency (RF) balun-filter is proposed. This center-tapped transformer-based device works not only as a balun but also as a bandpass filter. Coupled resonant tanks are employed to perform a balun-type of operation, and thus, it can easily be designed by the traditional coupled-resonator filter theory. In addition, the device's filtering characteristics is enhanced by introducting a transmission zero at a specified frequency based on the extracted-pole technique. As two functional components, balun and bandpass filter, are integrated into one, it is expected that the overall size of a front-end module using this device can be significantly reduced. The proposed balun-filter has been successfully implemented in a multi-layered Low Temperature Co-fired Ceramic (LTCC) substrate, showing promising application potentials in miniaturization of RF front-end modules.
Inventor: Yeung, Lap Kun | Wu, Ke Li
Priority Number: US7825746B2
IPC Current: H03H000701 | H01P0001203 | H01P000510
US Class: 333185 | 333025 | 333204
Assignee Applicant: The Chinese University of Hong Kong
Title: Integrated balanced-filters
Usefulness: Integrated balanced-filters
Summary: Used in a radio frequency (RF) front-end module of a terminal device e.g. mobile phone, laptop computer, camera and printer and as a matching network, a balun and an extracted-pole bandpass filter for converting an unbalanced signal into a balanced signal or vice versa, and for bandpass-filtering a signal.
Novelty: Integrated balanced-filter for use in radio frequency front-end module, has electrical circuits, where one circuit has resonator positively coupled with another resonator, and third resonator negatively coupled with inductive unit
電子
計算機，通信和消費電子產品 /小工具
05/ENG/201
Inventor(s): Professor Ke Li WU, Department of Electronic Engineering
Patent Status: US Patent Pending
Licensing Status: Available for licensing
香港
