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insertUnitElement

Insert unit element into circuit object

    Description

    example

    unitEle = insertUnitElement(cktIn,cktElem,elePort,opFreq,Z0) inserts a new circuit with unit element unitEle into a circuit object cktIn at a given reference frequency opFreq and characteristic impedance Z0. The cktElem and elePort together determine the position of insertion of the unit element.

    Examples

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    Create a lowpass LC-Pi Chebyshev filter with a passband frequency of 1 GHz, a passband attenuation of 0.5 dB, and a filter order of 5.

    Fp = 1e9;          
    Ap = 0.5;        
    Ord = 5;           
    r = rffilter(FilterType="Chebyshev",ResponseType="Lowpass",Implementation="LC Pi",PassbandFrequency= ...
        Fp,PassbandAttenuation=Ap,FilterOrder=Ord);

    Convert the lumped elements of the RF filter to a distributed element using Richards' transformation.

    ri = richards(r,1e9)
    ri = 
      circuit: Circuit element
    
        ElementNames: {'C_tx'  'L_tx'  'C_1_tx'  'L_1_tx'  'C_2_tx'}
            Elements: [1x5 txlineElectricalLength]
               Nodes: [0 1 2 3 4 5 6]
                Name: 'unnamed'
            NumPorts: 2
           Terminals: {'p1+'  'p2+'  'p1-'  'p2-'}
    
    

    Insert a unit element at the edges of the circuit ri and the first circuit element C_tx at port 1, which operates at 1 GHz and has a characteristic impedance of 50 ohms.

    unitEle = insertUnitElement(ri,'C_tx',1,1e9,50)
    unitEle = 
      circuit: Circuit element
    
        ElementNames: {1x6 cell}
            Elements: [1x6 txlineElectricalLength]
               Nodes: [0 1 2 3 4 5 6 7]
                Name: 'unnamed'
            NumPorts: 2
           Terminals: {'p1+'  'p2+'  'p1-'  'p2-'}
    
    

    Insert a unit element at the edges of the circuit unitEle and the last circuit element C_2_tx at port 2, which operates at 1 GHz and has a characteristic impedance of 50 ohms.

    unitEle = insertUnitElement(unitEle,'C_2_tx',2,1e9,50)
    unitEle = 
      circuit: Circuit element
    
        ElementNames: {1x7 cell}
            Elements: [1x7 txlineElectricalLength]
               Nodes: [0 1 2 3 4 5 6 7 8]
                Name: 'unnamed'
            NumPorts: 2
           Terminals: {'p1+'  'p2+'  'p1-'  'p2-'}
    
    

    Apply Kuroda's transformation on the group of two elements.

    outObj =  kuroda(unitEle,'C_tx_p1_elem_UE','C_tx')
    outObj = 
      circuit: Circuit element
    
        ElementNames: {1x7 cell}
            Elements: [1x7 txlineElectricalLength]
               Nodes: [0 1 2 3 4 5 6 7 8]
                Name: 'unnamed'
            NumPorts: 2
           Terminals: {'p1+'  'p2+'  'p1-'  'p2-'}
    
    

    Input Arguments

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    RF circuit object, specified as a circuit object. Before inserting the unit element you must first apply Richards' transformation.

    Circuit element, specified as an index in the circuit or element names. The function inserts the unit element in a port of the circuit element you specify.

    Port number of the circuit element for inserting the unit element, specified as a positive scalar.

    Operating frequency at which the unit element is defined with LineLength = pi/4 radians, specified as a positive scalar.

    Characteristic impedance of the unit element, specified as a positive scalar.

    Output Arguments

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    Unit element, returned as a cktIn object. The output is a circuit similar to cktIn, but with a unit element inserted.

    The unit element is placed at the port elePort of the element of the circuit, cktElem. If cktElem is empty, 0 or numel(INOBJ.Elements)+1, the unit element is inserted at a port of the circuit cktIn itself.

    Introduced in R2021b