In this paper we presented two simple
designsChebyshev 3-pole microstrip stepped-impedance lowpass
filter in L-band (1 GHz) and folded arm microstrip
lowpass filter which is widely being implemented in GPS
systems, mobile phones and defence telemetry. Various
shapes are designed, simulated and frequency is tuned by
altering the stub size and its position. According to the shape
of the devices these two filters can be implemented. These two
filters are designed for 1 GHz cut-off frequency at -3dB with
a passband ripples less than 0.1dB and it shows sharp
stopband 1 GHz – 4.9 GHz. Effective permittivity of the
substrate is 10.8 and height 1.27 mm. The stepped impedance
LPF is a traditional filter and folded arm filter is also stepped
impedance LPF but its inductive arm is bent at 900. Folded
arm filter is the miniaturized form of the traditional LPF.
The miniaturized LPF gives the same performance as the
traditional stepped impedance LPF. The filter is miniaturized
by folding its inductive arm at 900 and its dimensions are
optimized. Area of folded arm lowpass filter is reduced by
27.9% with respect to the traditional stepped impedance
lowpass filter. These LPF filters are designed and simulated
on Ansoft-HFSS platform. Its gives the satisfactory results
between theoretical and simulated ones.
Published In:IJCSN Journal Volume 5, Issue 5
Date of Publication : October 2016
Pages : 813-817
Figures :07
Tables :01
Inder Pal Singh : Shinas College of Technology
P.O. Box 77, PC 324, Shinas, Oman.
Praveen Bhatt : Samalkha Group of Institutions, Panipat, Haryana, India.
Traditional 3-pole stepped impedance microstrip lowpass
filter and the proposed 3-pole folded arm microstrip
stepped impedance lowpass filter show very good
response for the center frequency 1 GHz at -3 dB with
minor variations. In this paper we achieved to design for
the compactness of the filter without changing the
specification of the stepped impedance lowpass filter.
Proposed filter shows better and wide stop-band
characteristic and sharp rejection at stop-band. Total
dimensions occupied on the PCB board by stepped
impedance are 42.82 mm x 9.84 mm. Area of stepped
impedance lowpass filter is 421.3 mm2. Whereas total
dimensions occupied on the PCB board by folded arm
stepped impedance lowpass filter are 16.08 mm x 18.88
mm. Area of folded arm stepped impedance lowpass filter
is 303.5 mm2. We achieved to design miniaturized folded
arm stepped impedance lowpass filter by 27.9% in the area
occupied on the board. Insertion loss of folded arm filter is
7 dB less than the stepped impedance lowpass filter.
[1] K.Rajasekaran,
J.Jayalakshmi,T.Jayasanka,“International Journal of
Scientific and Research Publications, Volume 3, Issue
8, August 2013.
[2] J. Inder Bhal, “Average power handling capability of
multilayer microstrip lines”, International Journal of
RF and Computer-Aided Engineering, Volume 11,
Issue 6, 2001, pp. 385–395.
[3] G.L.Mathaei, L.Young & E.M.T. Jones, “Microwave
Filter impedance matching networks and coupling
structures,” Artech House, Dedham, Mass, 1980.
[4] S. Das, Dr. S.K.Chowdhury, “Design Simulation and
Fabrication of Stepped Impedance Microstrip line Low
Pass Filter for S-band Application using IE3D and
MATLAB” IJECT Vol. 3, Issue 1, Jan. - March 2012
[5] J. S. Hong, M. J. Lancaster, “Microstrip Filters for
RF/Microwave Applications”, John Wiley & Sons,
Inc., 2001, pp. 109-110
[6] K. C. Gupta, R. Garg, I. Bahl, and P. Bhartis,
Microstrip Lines and Slotlines, Second Edition, Artech
House, Boston, 1998.
[7] J.-L. Li, S.-W. Qu, and Q. Xue, “Compact
Microstriplowpass Filter with Sharp Roll-Off and Wide
Stop-Band,” Electron. Lett., vol. 45, no. 2, Jan. 2009,
pp. 110-111.
