Design of a Harmonic Suppressed Dual-Band Reconfigurable Bandpass Filter for Multistandard GNSS Receivers

This paper proposes a reconfigurable dual-band bandpass filter with independently tunable center frequencies that is intended to be integrated into reconfigurable multiband global navigation satellite system receivers. The center frequencies can be adjusted within the range of 1160-1280 MHz and 1530-1630 MHz for the two passbands, respectively. To achieve the design goal, the input and output feed lines are shared by a pair of quarter-wave uniform impedance resonators and a stub-loaded stepped impedance resonator with terminal-loaded varactor bias circuits. The electric length of the transmission lines is changed by using bias voltage to control the varactor diodes, thereby changing the operating frequencies of the dual-band filter's two passbands, and the independent reconfigurability of the two passbands is realized. The insertion loss is less than 1.5 dB and the return loss is better than 26 dB in all tuning ranges. The proposed dual-band reconfigurable filter demonstrates the flexibility of controlling the passband independently to be compatible with multistandard signals, which can accommodate the deployment of new GNSS standard specifications. © 2013 IEEE.