DOI QR코드

DOI QR Code

Balanced RF Duplexer with Low Interference Using Hybrid BAW Resonators for LTE Application

  • Shin, Jea-Shik (Samsung Advanced Institute of Technology (SAIT), School of Electrical Engineering, Korea University) ;
  • Song, Insang (Samsung Advanced Institute of Technology (SAIT)) ;
  • Kim, Chul-Soo (Samsung Advanced Institute of Technology (SAIT)) ;
  • Lee, Moon-Chul (Samsung Advanced Institute of Technology (SAIT)) ;
  • Son, Sang Uk (Samsung Advanced Institute of Technology (SAIT)) ;
  • Kim, Duck-Hwan (Samsung Advanced Institute of Technology (SAIT)) ;
  • Park, Ho-Soo (Samsung Advanced Institute of Technology (SAIT)) ;
  • Hwang, Sungwoo (Samsung Advanced Institute of Technology (SAIT)) ;
  • Rieh, Jae-Sung (School of Electrical Engineering, Korea University)
  • 투고 : 2013.05.08
  • 심사 : 2013.06.29
  • 발행 : 2014.04.01

초록

A balanced RF duplexer with low interference in an extremely narrow bandgap is proposed. The Long-Term Evolution band-7 duplexer should be designed to prevent the co-existence problem with the WiFi band, whose fractional bandgap corresponds to only 0.7%. By implementing a hybrid bulk acoustic wave (BAW) structure, the temperature coefficient of frequency (TCF) value of the duplexer is successfully reduced and the suppressed interference for the narrow bandgap is performed. To achieve an RF duplexer with balanced Rx output topology, we also propose a novel balanced BAW Rx topology and RF circuit block. The novel balanced Rx filter is designed with both lattice- and ladder-type configurations to ensure excellent attenuation. The RF circuit block, which is located between the antenna and the Rx filter, is developed to simultaneously function as a balance-tounbalance transformer and a phase shift network. The size of the fabricated duplexer is as small as $2.0mm{\times}1.6mm$. The maximum insertion loss of the duplexer is as low as 2.4 dB in the Tx band, and the minimum attenuation in the WiFi band is as high as 36.8 dB. The TCF value is considerably lowered to $-16.9ppm/^{\circ}C$.

키워드

참고문헌

  1. P-A. Girard and M. Solal, "High Performance Single-Balanced Duplexer," IEEE/MTT-S Int. Microw. Symp. Dig., June 3-8, 2007, pp. 861-864.
  2. K.M. Lakin, "Thin Film Resonator Technology," IEEE Int. Frequency Control Symp., 2003, pp. 765-778.
  3. J.-S. Shin et al., "1-Chip Balanced FBAR Filter for Wireless Handsets," European Microw. Conf., Paris, France, Sept. 28-30, 2010, pp. 1257-1260.
  4. K.M. Lakin, "Bulk Acoustic Wave Coupled Resonator Filters," IEEE Freq. Control Symp., 2002, pp. 8-14.
  5. S.R. Gilbert et al., "An Ultra-Miniature, Low Cost Single Ended to Differential Filter for ISM Band Applications," IEEE/MTT-S Int. Microw, Symp. Dig., June 15-20, 2008, pp. 839-842.