Читать книгу Handbook of Microwave Component Measurements - Joel P. Dunsmore - Страница 25

A special case of available power is the power available from the output of a network, when the network is connected an arbitrary source. In this case, the available power is only a function of the network and the source impedance and is not a function of the load impedance. It represents the maximum power that could be delivered to a load under the condition that the load impedance was ideally matched and can be found by noting that the available output power is similar to Eq. (1.47) but with the source reflection coefficient replaced by the output reflection coefficient of the network Γ₂ from Eq. (1.30) such that

(1.50)

When a 2‐port network is connected to a generator with arbitrary impedance, the output scattered wave into matched load is

(1.51)

Here the incident wave is represented as a_S rather than a₁ as an indication that the source is not matched, and Γ₁ is defined by Eq. (1.27). The output power incident to the load is

(1.52)

Combining Eqs. (1.52) and (1.50), the available power at the output from a network that is driven from a generator with source impedance of Γ_S is

(1.53)

With Γ₂ defined as in Eq. (1.30).