Hybrid parameters (or) h - parameters:-
- If the input current that is denoted as i1 and output Voltage that is denoted as V2 are takes as independent variables, input voltage V1 and the output current i2 can be written as shown below:
V1 = h11 i1 + h12 V2
i2 = h21 i1 + h22 V2
The four hybrid parameters that are h11, h12, h21 and h22 are defined like this
h11 = [V1 / i1] with V2 = 0
= Input Impedance along with output part short circuited.
h22 = [i2 / V2] with i1 = 0
= Output admittance along with input part open circuited.
h12 = [V1 / V2] with i1 = 0
= reverse voltage transfer ratio along with input part open circuited.
h21 = [i2 / i1] with V2 = 0
= Forward current gain along with output part short circuited.
The dimensions of h - parameters are like this:
h11 - ?
h22 - 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.