Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6879441 | AEU - International Journal of Electronics and Communications | 2018 | 6 Pages |
Abstract
This paper presents the design of a compact, ultra-sharp roll-off lowpass filter using stepped impedance modified T-type with stepped impedance stub (SMTS). The position of the transmission zero obtained due to the SMTS transmission line can be varied by changing the impedances and electrical lengths of the stepped impedance shunt stub (SIS) of SMTS and therefore, different roll-off rates can be obtained. The design equations used to obtain the parameters of the proposed SMTS structure are derived using the even and odd mode analysis and this enables the designers to calculate the parameters for a specific cut-off frequency (fC). Two SISs are connected, one at the input and another at the output side of SMTS to achieve good stopband characteristics. Finally, a lowpass filter with fC = 1.24â¯GHz and having a transition band of 0.11â¯GHz from 1.24 to 1.35â¯GHz with corresponding attenuation levels of 3-40â¯dB (roll-off rate is 336.36â¯dB/GHz) is designed, fabricated and tested. Good agreement is found between the simulated and experimental results.
Keywords
Related Topics
Physical Sciences and Engineering
Computer Science
Computer Networks and Communications
Authors
Kanaparthi V. Phani Kumar, S.S. Karthikeyan,