
Q OUT
Figure 1. Step Gain Amplifier, Simplified Schematic
Amplitude Calibration Attenuator @
Q2 is an emitter follower buffer driving a second pin diode attenuator, CR11 to CR14. The current through CR11 and CR12 is determined by the
21.4 MHz Output @
Qll and Q12 form the output stage for the Last Converter. Qll is an emitter follower driving a common emitter amplifier Q12.
Temperature Compensation Voltage Source @
Ql provides a voltage to set the current in CR8 to CR10 and CR15 to CR17. This voltage varies with temperature, changing the gain of the two
A6A3 3