A Multi-Stub Lowpass Filter
- Resource Type
- Periodical
- Authors
- Chen, C.-J.; Sung, C.-H.; Su, Y.-D.
- Source
- IEEE Microwave and Wireless Components Letters IEEE Microw. Wireless Compon. Lett. Microwave and Wireless Components Letters, IEEE. 25(8):532-534 Aug, 2015
- Subject
- Fields, Waves and Electromagnetics
Communication, Networking and Broadcast Technologies
Signal Processing and Analysis
Microstrip
Power transmission lines
Transmission line measurements
Passband
Loss measurement
Wireless communication
Prototypes
Lowpass filter (LPF)
microstrip line
stepped-impedance
- Language
- ISSN
- 1531-1309
1558-1764
The stepped-impedance lowpass filter is modified by replacing the low-impedance lines with lowpass transmission lines. The modified stepped-impedance lowpass filter is called a multi-stub lowpass filter because it is largely composed of open-circuited stubs. For experimental verification of the multi-stub filters, we design a 1 GHz seventh-order Butterworth LPF. The proof-of-concept prototype is a compact design that fits into a circuit size of $0.09\lambda_{g}\times 0.136\lambda_{g}$ on an RO4003 substrate. The measurement results show that the multi-stub lowpass filter retains the characteristics of a Butterworth filter in the passband, while substantially improves the performance in the transition and stopband regions. It achieves state-of-the-art performance compared to lowpass filters in the literature.