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filterCombline

Create combline filter in microstrip form

Description

Use the filterCombline object to create a combline filter in the microstrip form.

Creation

Description

example

filter = filterCombline creates a default combline line filter using an Alumina substrate with the passband of the filter centered around 3.1 GHz.

example

filter = filterCombline(Name=Value) sets Properties using one or more name-value arguments. For example, filterCombline(ResonatorWidth=0.0016) creates a combline filter with a resonator width of 0.0016 meters. Properties not specified retain their original values.

Properties

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Order of the filter, specified as a positive scalar.

Example: filter = filterCombline(FilterOrder=4)

Data Types: double

Length of the resonator in meters, specified as a positive scalar or a vector of positive elements equal in size to FilterOrder.

Example: filter = filterCombline(ResonatorLength=0.007)

Data Types: double

Width of the resonator in meters, specified as a positive scalar.

Example: filter = filterCombline(ResonatorWidth=0.0017)

Data Types: double

Spacing between the resonators in meters, specified as a positive scalar or a vector of positive elements equal in size to (FilterOrder-1).

Example: filter = filterCombline(ResonatorSpacing=0.0008)

Data Types: double

Y-offset for each resonator in meters, specified as a positive scalar or a vector of positive elements equal in size to FilterOrder. If the value is a scalar, all the resonators have the same offset along the Y-axis.

Example: filter = filterCombline(ResonatorOffset=(0 0.1 0.2))

Data Types: double

Length of the input and output lines in meters, specified as a positive scalar.

Example: filter = filterCombline(PortLineLength=0.0014)

Data Types: double

Width of the input and output lines in meters, specified as a positive scalar.

Example: filter = filterCombline(PortLineWidth=0.0087)

Data Types: double

Y-offset for the input and output lines in meters, specified as a positive scalar.

Example: filter = filterCombline(FeedOffset=0.0087)

Data Types: double

Capacitor value in farad, specified as a positive scalar.

Example: filter = filterCombline(Capacitor=2e-12)

Data Types: double

Height of the combline filter from the ground plane in meters, specified as a positive scalar. For multilayer dielectrics, use the Height property to create the filter between the two dielectric layers.

Example: filter = filterCombline(Height=0.0028)

Data Types: double

Width of the ground plane in meters, specified as a positive scalar.

Example: filter = filterCombline(GroundPlaneWidth=0.0048)

Data Types: double

Type of dielectric material used as a substrate, specified as a dielectric object. The dielectric material in a filterCombline object with default properties is Alumina.

Example: d = dielectric("FR4"); filter = filterCombline(Substrate=d)

Type of metal used in the conducting layers, specified as a metal object. The type of metal in a filterCombline object with default properties is PEC.

Example: m = metal("Copper"); filter = filterCombline(Conductor=m)

Object Functions

chargeCalculate and plot charge distribution
currentCalculate and plot current distribution
designDesign coupled line filter around specified frequency
feedCurrentCalculate current at feed port
getZ0Calculate characteristic impedance of transmission line
layoutPlot all metal layers and board shape
meshChange and view mesh properties of metal or dielectric in PCB component
shapesExtract all metal layer shapes of PCB component
showDisplay PCB component structure or PCB shape
sparametersCalculate S-parameters for RF PCB objects

Examples

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Create a default combline filter.

filter = filterCombline
filter = 
  filterCombline with properties:

         FilterOrder: 3
     ResonatorLength: 0.0030
      ResonatorWidth: 0.0016
    ResonatorSpacing: 4.0000e-04
     ResonatorOffset: 0
      PortLineLength: 0.0011
       PortLineWidth: 0.0013
          FeedOffset: 3.0000e-04
           Capacitor: 1.0000e-12
              Height: 0.0012
    GroundPlaneWidth: 0.0050
           Substrate: [1x1 dielectric]
           Conductor: [1x1 metal]

View the filter.

show(filter)

Figure contains an axes object. The axes object with title filterCombline element contains 15 objects of type patch, surface. These objects represent PEC, feed, alumina, load.

Create a combline filter with the feed offset equal to zero.

filter = filterCombline('FeedOffset',0);

Visualize the filter.

show(filter);

Figure contains an axes object. The axes object with title filterCombline element contains 15 objects of type patch, surface. These objects represent PEC, feed, alumina, load.

Create a third-order combline filter with a different resonator offset.

filter = filterCombline(FilterOrder=3,ResonatorLength=[0.005,0.002,0.007],...
    ResonatorSpacing=[0.6e-3,1.2e-3],ResonatorOffset=[0.001e-3,0,0.5e-3], ...
    GroundPlaneWidth=12e-3);

Visualize the filter.

show(filter);

Figure contains an axes object. The axes object with title filterCombline element contains 15 objects of type patch, surface. These objects represent PEC, feed, alumina, load.

References

[1] Pozar, David M. Microwave Engineering. 4th ed. Hoboken, NJ: Wiley, 2012.

[2] Al-Yasir, Y., R.A. Abd-Alhameed, J.M. Noras, A.M. Abdulkhaleq, and N.O. Parchin. “Design of Very Compact Combline Band-Pass Filter for 5G Applications.” In Loughborough Antennas & Propagation Conference 2018 (LAPC 2018), 61 (4 pp.)-61 (4 pp.). Loughborough, UK: Institution of Engineering and Technology, 2018

[3] Hong, Jia-Sheng. "Microstrip Filters for RF/Microwave Applications". 2nd ed. Wiley Series in Microwave and Optical Engineering. Hoboken, N.J: Wiley, 2011.

Version History

Introduced in R2022b