On the basis of the active networks design for microwave amplifier, and in view of mutual influence of input and output impedences of a microwave transistor, an adaptive recursive method for impedence matching is presented in this paper.

A general approach is presented for extending the useful operating frequencies and improving the performance of active networks realized by use operational amplifiers (OA S).

It was analyzed how to build the state equations of an active network containing an operational amplifier through the hybrid variable approach, which develops the application range of the hybrid variable approach.

The network equations of linear active networks that may contain controlled sources of all types are established, in which nodal voltages and cotrolling currents are adopted as the circuit variables.

The fault diagnosis problem of active network is studied in this paper with the emphasis upon its solvability and diagnosability.

This paper discuss the location of poles and zeros of network function and its instability,and the frequency-domain analysis of analysis of active RC network,emphasis two-orders low-pass negative-gain circuit,and the transient problem of one-order low pass circuit.