Design of Dual-Band Bandpass Filters for Cognitive Radio Application of TVWS Band

  • Kwon, Kun-An (Department of Electronic Engineering, Sogang University) ;
  • Kim, Hyun-Keun (Department of Electronic Engineering, Sogang University) ;
  • Yun, Sang-Won (Department of Electronic Engineering, Sogang University)
  • Received : 2015.08.11
  • Accepted : 2015.11.30
  • Published : 2016.01.31


This paper presents a novel design for dual-band bandpass filters. The proposed filters are applicable to the carrier aggregation of the TV white space (TVWS) band and long-term evolution (LTE) band for cognitive radio applications. The lower passband is the TVWS band (470-698 MHz) whose fractional bandwidth is 40 %, while the higher passband is the LTE band (824-894 MHz) with 8 % fractional bandwidth. Since the two passbands are located very close to each other, a transmission zero is inserted to enhance the rejection level between the two passbands. The TVWS band filter is designed using magnetic coupling to obtain a wide bandwidth, and the LTE band filter is designed using dielectric resonators to achieve good insertion loss characteristics. In addition, in the proposed design, a transmission zero is placed with cross-coupling. The proposed dual-band bandpass filter is designed as a two-port filter (one input/one output) as well as a three-port filter (one common input/two outputs). The measured performances show good agreement with the simulated performances.


Cognitive Radio;Cross Coupling;Dual-Band BPF;TV White Space


Supported by : Ministry of Science, ICT & Future Planning (MSIP)


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