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lcladder

Create LC ladder network

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Description

Use anlcladderobject:

  • To create an LC ladder filter.

  • To convert anrffilterobject to an LC ladder.

  • To model an LC circuit in cascaded stages using anrfbudgetobject or theRF Budget Analyzer应用程序。

LC ladder representation

Creation

Syntax

lcobj= lcladder(top,L,C)
lcobj= lcladder(rffilterobj)
lcobj= lcladder(___,lcname)

Description

example

lcobj= lcladder(top,L,C)creates an LC ladder objectlcobjand sets theTopology,Inductances, andCapacitancesproperties.

lcobj= lcladder(rffilterobj)creates a LC ladder objectlcobjfrom an RF filter objectrffilterobj.

lcobj= lcladder(___,lcname)creates an LC ladder objectlcobjand sets theNameproperty. Specifylcnameafter all other input arguments.

Input Arguments

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RF filter object, specified as anrffilterobject.

Example:lcobj= lcladder(rffilterobj)

Properties

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Topology type of the LC ladder, specified as one of the following:

  • 'lowpasspi'— Low-pass pi filter

  • 'lowpasstee'—Low-pass tee filter

  • 'highpasspi'— High-pass pi filter

  • 'highpasstee'— High-pass tee filter

  • 'bandpasspi'— Band-pass pi filter

  • 'bandpasstee'— Band-pass tee filter

  • 'bandstoppi'— Band-stop pi filter

  • 'bandstoptee'— Band-stop tee filter

Example:'lowpasspi'

Inductor values in the LC ladder, specified as aninductorobject or as a numeric scalar or two-element vector in henries.

Example:1e-9

Capacitor values in the LC ladder, specified as acapacitorobject or as a numeric scalar or two-element vector in farads.

Example:[2e-12 3e-12]

Name of the LC ladder object, specified as a character vector or string scalar.

Example:'lcfilter'

This property is read-only.

Number of ports in LC ladder object. specified as a positive scalar.

This property is read-only.

Terminal names of LC ladder object, specified as the cell vector,{'p1+' 'p2+' 'p1-' 'p2-'}. An LC ladder object always has four terminals: two terminals associated with the first port ('p1+'and'p1-') and two terminals associated with the second port ('p2+'and'p2-').

Example:{'p1+' 'p2+' 'p1-' 'p2-'}

Parent circuit nodes connected to LC ladder object terminals, specified as a vector of integers. This property appears only after the LC ladder object is added to a circuit.

Note

ParentNodesare only displayed after the capacitor has been added into a circuit.

Full path of the circuit to which the LC ladder object belongs, specified as character vector. This path appears only after the inductor is added to the circuit.

Note

ParentPath电容器h后只显示吗as been added into a circuit.

Object Functions

sparameters Calculate S-parameters for RF data, network, circuit, and matching network objects
groupdelay Group delay of S-parameter object or RF filter object orRF Toolboxcircuit object
clone Create copy of existing circuit element or circuit object
rfplot Plot S-parameter data

Examples

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Open Live Script

Create a low-pass pi LC ladder object with an inductor value of 3.18e-8 H and a capacitor value of 6.37e-12 F. Calculate and plot the s-parameters.

L = 3.18e-8; C = [6.37e-12 6.37e-12]; lpp = lcladder('lowpasspi',L,C)
lpp = lcladder: LC Ladder element Topology: 'lowpasspi' Inductances: 3.1800e-08 Capacitances: [6.3700e-12 6.3700e-12] Name: 'lcfilt' NumPorts: 2 Terminals: {'p1+' 'p2+' 'p1-' 'p2-'}
freq = 0:1e6:1e9; S = sparameters(lpp,freq); rfplot(S)

Figure contains an axes object. The axes object with xlabel Frequency (GHz), ylabel Magnitude (dB) contains 4 objects of type line. These objects represent dB(S_{11}), dB(S_{21}), dB(S_{12}), dB(S_{22}).

You can also add this LC ladder to a circuit.

c =电路;add (c[1 2 0 0]垂直距离)setports (c [1 0],[2 0])
Open Live Script

Design a low-pass pi LC ladder circuit.

L = 1e-9; C = [1e-12 1e-12]; lpp = lcladder('lowpasspi',L,C);

Design a default transmission line delay lossy and lossless objects.

tx1 = txlineDelayLossless; tx2 = txlineDelayLossy;

Create anrfbudgetobject to design an RF chain.

b = rfbudget([tx1 lpp tx2 ],2.1e9,-30,100e6,'Solver','HarmonicBalance')
b = rfbudget with properties: Elements: [1x3 rf.internal.rfbudget.Element] InputFrequency: 2.1 GHz AvailableInputPower: -30 dBm SignalBandwidth: 100 MHz Solver: HarmonicBalance WaitBar: true AutoUpdate: true Analysis Results OutputFrequency: (GHz) [ 2.1 2.1 2.1] OutputPower: (dBm) [ -30 -30.87 -30.87] TransducerGain: (dB) [-6.514e-10 -0.868 -0.8681] NF: (dB) [-2.132e-14 -2.132e-14 0.0001761] IIP2: (dBm) [ Inf Inf Inf] OIP2: (dBm) [ Inf Inf Inf] IIP3: (dBm) [ Inf Inf Inf] OIP3: (dBm) [ Inf Inf Inf] SNR: (dB) [ 63.98 63.98 63.98]

Use theshowcommand at the command line to visualize the RF budget chain in theRF Budget Analyzer应用程序。You can also do further analysis on this chain using the app. For more information, seeRF Budget Analyzer.

show(b)

lcladder.png

Version History

Introduced in R2013b

See Also

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