Two Port Network Transistor Configuration Conversions (h-Parameter Conversions)

[Eddie W. Shore]

Introduction

The program TRCONV converts h-parameter matrices for the following configurations of two-port networks:

* Common Base Transistor Configuration (CB)
* Common Emitter Transistor Configuration (CE)
* Common Collector Transistor Configuration (CC)

The h-parameter matrix, also known as a hybrid parameter, is a 2 x 2 matrix representation of a two port network.

H = [ [ h11, h12 ] , [ h21, h22 ] ] where:

[ [ V1 ], [ I2 ] ] = = [ [ h11, h12 ] , [ h21, h22 ] ] * [ [ I1 ], [ V2 ] ]

The h-parameter matrix takes into account the short circuit condition (h11, h22) and the open circuit condition (h12, h21) in the two port network.

The dimensions of the entries are:

h11: input impedance, in ohms (Ω)
h12: reverse voltage gain, dimensionless
h21: forward current gain, dimensionless
h22: output admittance, in seimens or mhos (1/Ω)

The resulting matrix from TRCONV is known as a y-parameter matrix.

HP Prime Program TRCONV

Code:

EXPORT TRCONV()
BEGIN
// 2019-03-10
// HP 67
LOCAL h11,h12,h21,h22;
LOCAL y11,y12,y21,y22;
LOCAL w1,w2,w3,w4,w5;
LOCAL t,l;

l:={"CE→CB","CB→CE","CC→CB",
"CB→CC","CC→CE","CE→CC"};

INPUT(
{{h11,[[0],[3]]},
{h12,[[0],[3]]},
{h21,[[0],[3]]},
{h22,[[0],[3]]},
{t,l}},
"TRANSISTOR CONVERSION",
{"h11: ","h12: ","h21: ",
"h22: ","Type:"}
);

y11:=1/h11;
y12:=−h12/h11;
y21:=h21/h11;
y22:=(h11*h22-h12*h21)/h11;

MSGBOX([[y11,y12],[y21,y22]]);

w1:=y11+y12+y21+y22;
w2:=−(y12+y22);
w3:=−(y21+y22);
w4:=−(y11+y12);
w5:=−(y11+y21);

IF t==1 OR t==2 THEN
RETURN [[w1,w2],[w3,y11]];
END;

IF t==3 THEN
RETURN [[y22,w3],[w2,w1]];
END;

IF t==4 THEN
RETURN [[w1,w5],[w4,y11]];
END;

IF t==5 OR t==6 THEN
RETURN [[y11,w4],[w5,w1]];
END;

END;

Example:

H = [ [ 150, 0.003 ], [ 68, 0.007 ] ]

CE → CB: [ [ 0.46562, -0.00562 ], [ -0.458973333333, 6.666666667E-3 ] ]

CC → CE: [ [ 6.666666667E-3, -6.646666667E-3 ], [ -0.46, 0.46562 ] ]

[conversion example]

Source:

"5. Transistors Configuration Conversion" HP 67-97 E.E. Pac I. Hewlett Packard. 1976

"h Parameter or Hybrid Parameter of Two Port Network" Electrical Concepts. 2019
https://electricalbaba.com/h-parameter-h...t-network/
Retrieved March 21, 2019

Blog Spot: https://edspi31415.blogspot.com/2019/03/...istor.html

[KeithB]

Thanks Eddie.
But I believe h-parameters and y-parameters are only of academic interest now. It is either SPICE models or S-parameters.

(People into noise calculations might still use y-parameters, so I may be off-base here)

[Eddie W. Shore]

Good to know Keith, thank you.