"Z " 11 and " Z " 22 are simply the ordinary driving point impedances of a dipole, thus 73 + j43 ohms for a half-wave element ( or purely resistive for one slightly shorter, as is usually desired for the driven element ).
12.
The theorems of Gustav Kirchhoff and others and the ideas of Charles Steinmetz ( port also played a part in the development of the theory, and proved to be a more useful idea than network terminals . " A Reactance Theorem ", in which Foster introduces the idea of a driving point impedance, that is, the impedance that is connected to the generator.
13.
Where the Laplace-domain transfer functions and impedances in the above expressions are defined as follows : is the transfer function with the extra element present . is the transfer function with the extra element open-circuited . is the transfer function with the extra element short-circuited . is the impedance of the extra element . is the single-injection driving point impedance " seen " by the extra element . is the double-null-injection driving point impedance " seen " by the extra element.
14.
Where the Laplace-domain transfer functions and impedances in the above expressions are defined as follows : is the transfer function with the extra element present . is the transfer function with the extra element open-circuited . is the transfer function with the extra element short-circuited . is the impedance of the extra element . is the single-injection driving point impedance " seen " by the extra element . is the double-null-injection driving point impedance " seen " by the extra element.
