Adopting negative feedback broadband amplifier circuit

Adopting negative feedback broadband amplifier circuit

The figure above shows a broadband amplification circuit using negative feedback. The amplifiers of this circuit all use transformer coupling, and the amplification part uses a combination of field-effect transistors and transistors.

In the circuit, the input signal is added to the center tap of the transformer Ti winding through the coupling capacitor, and then added to the gate of the field effect transistor through the primary winding of transformer T2. This method has the function of impedance conversion, increasing the 50 n input impedance to 200 n. n, the secondary winding of transformer Tz is the full pole load of VT1, and the gain of the amplifier depends on the secondary winding of T2 (25/3=8,33). VT2 is an emitter output amplifier mode, and the output impedance of 5011 can be obtained by selecting the coil tap.