Transistor Design for Picture IF Stages

In addition to the conventional problems of sensitivity, bandwidth, and transient response, the transistor poses several new problems in television IF design due to its power gain mechanism. In particular, the resistive and capacitive components of output impedance dictate that matched power gain can be obtained only at or below matched bandwidth, and definite limits are thereby imposed on the loaded Q of each stage. Data are presented for high-frequency graded base transistors and high-frequency tetrode transistors. The over-all performance of a five-stage video IF is discussed in terms of: 1) single stage data, 2) stability requirements, 3) method of achieving agc, 4) agc and overload characteristics, 5) pole pattern, gain, and transient response, and 6) noise figure.