Oscillator incorporating negative impedance network having current mirror amplifier

In a negative impedance network of the type which includes a current mirror amplifier having bipolar master and slave path transistors of a first conductivity type in master and slave paths, respectively, the improvement comprising:

• bias means for applying current through a path independent of both the master and slave paths to an interconnection of the control electrodes of the master and slave path transistors in inverse proportion to the voltage impressed across the slave path for making the current supplied by the slave path vary inversely to the voltage thereacross and thereby derive the negative impedance through the slave path, including
• a bipolar bias means transistor of a second conductivity type complementary to the first, said bias means transistor having an emitter electrode to which the collector electrode of said master path transistor is direct coupled, a collector electrode connected to the interconnection of the control electrodes of the master and slave path transistors to apply the bias current thereto, and having a bias electrode to which the voltage applied across the slave path is impressed;
• the master and slave path transistors having their emitter electrodes commonly connected to a reference voltage level,
• a supply voltage level being applied through a resistance to the collector electrode of the master path transistor;
• an intermediate voltage level between said supply voltage level and said reference voltage level being applied to both the base electrode of said bias means transistor and the collector electrode of the slave path transistor;
• and
• said intermediate voltage level being applied through a tuned inductance-capacitance circuit having an equivalent dynamic resistance, the negative impedance of the network being derived as the change in said intermediate voltage level divided by the change resulting therefrom in the level of current flow through the slave path and having a magnitude of at least the magnitude of said equivalent dynamic resistance to thereby result in oscillatory current flow through the slave path at the resonant frequency of said tuned circuit.