Title :
Design of tunable bandpass filter using PIN diode with constant absolute bandwidth
Author :
Jong-Hyun Lee ; Jae-Won Choi ; Xu-Guang Wang ; Sang-Won Yun
Author_Institution :
Dept. of Electron. Eng., Sogang Univ., Seoul, South Korea
Abstract :
This paper presents a tunable bandpass filter (BPF) for cognitive radio applications. The proposed two-pole BPF is implemented using lumped elements and the frequency tuning is realized by PIN diodes. Due to the L-C parallel circuit J-inverter, constant absolute bandwidth is achieved. 4 PIN diodes in each resonator and the capacitor bank are used to cover the desired frequency tuning range from 480MHz to 687MHz with 20MHz bandwidth. The circuit is theoretically analyzed, and the complete design process is described. The fabricated filter shows wide tuning range of 42.5% with insertion loss varying from 2.7dB to 3.8dB and good linearity. The 1-dB bandwidth of the filter is kept 20±1MHz.
Keywords :
LC circuits; UHF circuits; UHF diodes; UHF filters; UHF resonators; band-pass filters; capacitors; channel bank filters; circuit tuning; cognitive radio; invertors; network synthesis; p-i-n diodes; resonator filters; J-inverter; L-C parallel circuit; PIN diode; bandwidth 20 MHz; capacitor bank; cognitive radio application; constant absolute bandwidth; frequency 480 MHz to 687 MHz; frequency tuning; gain 1 dB; loss 2.7 dB to 3.8 dB; lumped element; resonator; tunable bandpass filter design; two-pole BPF; Band-pass filters; Bandwidth; Microwave filters; PIN photodiodes; Resonant frequency; Resonator filters; Tuning; PIN diode; Tunable bandpass filter; cognitive radio; constant bandwidth; lumped element;
Conference_Titel :
Microwave Conference Proceedings (APMC), 2013 Asia-Pacific
Conference_Location :
Seoul
DOI :
10.1109/APMC.2013.6695090
