Resonator coupled differential amplifier
AssigneeGeneral Electric Company
InventorBert K. Erickson
Life of this patent
Estimating the term…
Abstract
In differential amplifier circuits of the type having first and second transistors, the emitter of each transistor is connected to a different current source and the emitters are coupled by a ceramic filter tuned to 455 KHz. In one embodiment, wherein the transistors have symmetrical resistive loads, an inductor is connected across the filter to tune out capacitance across the terminals of the filter. In another embodiment, the circuit includes an unbalanced and complex load. In yet another embodiment, the circuit has active load circuitry and an inductor is connected across the filter to tune out capacitance across the terminal of the filter.
Claims8
A bandpass amplifier circuit of the type which is responsive to a DC power supply, for band limiting and voltage amplifying a signal applied thereto comprising:
- (a) a first transistor having a base, a collector, and an emitter the first transistor being connected in base input configuration;
- (b) a second transistor having a base, a collector, and an emitter, said base being connected to ground through a capacitor;
- (c) means adapted for connection to the power supply for coupling a first voltage to the collector of the first transistor;
- (d) impedance means, adapted for coupling to the power supply, coupled to the collector of the second transistor;
- (e) means responsive to the power supply and coupled to the bases of the transistors for biasing each of the transistors in their active regions;
- (f) a first semiconductor current source circuit connected in series with the emitter of the first transistor;
- (g) a second semiconductor current source circuit connected in series with the emitter of the second transistor;
- (h) a series resonator coupling the emitters of the first and second transistors.
Dependencies are inferred from the claim text.