Hybrid parameters (or) h - parameters:-
- If the input current that is denoted as i_{1} and output Voltage that is denoted as V_{2} are takes as independent variables, input voltage V_{1} and the output current i_{2} can be written as shown below:
V_{1} = h_{11} i_{1} + h_{12} V_{2}
i_{2} = h_{21} i_{1} + h_{22} V_{2}
The four hybrid parameters that are h_{11}, h_{12}, h_{21} and h_{22} are defined like this
h_{11} = [V_{1} / i_{1}] with V_{2} = 0
= Input Impedance along with output part short circuited.
h_{22} = [i_{2} / V_{2}] with i_{1} = 0
= Output admittance along with input part open circuited.
h_{12} = [V_{1} / V_{2}] with i_{1} = 0
= reverse voltage transfer ratio along with input part open circuited.
h_{21} = [i_{2} / i_{1}] with V_{2} = 0
= Forward current gain along with output part short circuited.
The dimensions of h - parameters are like this:
h_{11} - ?
h_{22} - mhos
h12, h21 - dimension less.
- Since the dimensions are not alike, that is they are hybrid in nature, and these parameters are termed as hybrid parameters.
I = 11 = input ; 0 = 22 = output ;
F = 21 = forward transfer ; r = 12 = Reverse transfer.