Design of varactor tuned bandpass filter

Author

Golaszewski, Arkadiusz ; Zukocinski, Mateusz ; Abramowicz, Adam

Author_Institution

Inst. of Electron. Syst., Warsaw Univ. of Technol., Warsaw, Poland

fYear

2015

fDate

22-23 April 2015

Firstpage

1

Lastpage

4

Abstract

The tunable bandpass filter is presented. The filter is realized in microstrip technology employing two stepped-impedance resonators tuned with varactor diodes. The filter has constant absolute bandwidth of 30 MHz in the frequency range from 380 MHz to 920 MHz. The insertion loss is lower than 5 dB and return loss higher than 17 dB in the full tuning range. The out of band attenuation is higher than 40 dB at frequencies below the passband and is higher than 50 dB at frequencies above the passband. The first spurious modes are observed at 3 GHz. Absolute bandwidth and the time delay in the full tuning range change by 33% only while center frequency changes 242%.

Keywords

band-pass filters; circuit tuning; microstrip filters; resonator filters; varactors; bandwidth 30 MHz; frequency 380 MHz to 920 MHz; insertion loss; microstrip technology; out-of-band attenuation; return loss; stepped-impedance resonators; time delay; varactor diodes; varactor-tuned bandpass filter design; Band-pass filters; Filtering theory; Microstrip filters; Microwave filters; Optical filters; Resonator filters; Varactors; constant absolute bandwidth filter; frequency dependent coupling; microstrip filter; stepped-impedance resonators; varactor tuning; voltage tunable filter;

fLanguage

English

Publisher

ieee

Conference_Titel

Microwave Techniques (COMITE), 2015 Conference on

Conference_Location

Pardubice

Print_ISBN

978-1-4799-8121-2

Type

conf

DOI

10.1109/COMITE.2015.7120341

Filename

7120341