A biasing network for an RF transistor amplifier is provided wherein the bias varies smoothly and continuously from a value below turn on giving class B operation at low power inputs, to a lower valve giving class C operation at higher power levels, and finally, to a point where the DC dynamic impedance between the base and the emitter of the amplifier is extremely low, promoting maximum transistor gain and efficiency. Linear amplification at RF frequencies over the full range of power inputs is...

The band-limiting effects of parasitics are minimized in a two-stage amplifier wherein the active elements are operated in the common collector and the common base configurations. A pair of impedances Z.sub.1 and Z.sub.2 connect the emitter of one of the transistors to the emitter and the collector, respectively, of the other transistor. The collector of the latter transistor serves as the amplifier output terminal. Operating into a high impedance output load, the gain of the amplifier is given ...

A transimpedance amplifier having open-loop DC control is provided. The open-loop feedback control may provide a DC bias that is configurable based on the characteristics of an input device, such as, a photodiode or a magnetoresistor. The open-loop feedback control may provide quick recovery from voltage level variations and may provide stability for the amplifier.

An operational amplifier with reduced bias circuit noise. The present invention reduces the noise contribution of the non-inverting input bias circuit. This noise reduction is accomplished by reducing the bandwidth of the bias circuit by bypassing high frequencies to signal ground. This reduces the noise voltage developed across the bias circuit and thereby reduces the noise at the output of the amplifier.

An improved heterojunction bipolar transistor power amplifier circuit providing an efficient and linear amplifier comprising: a first heterojunction bipolar transistor (HBT) having a base emitter voltage; a power supply; a power supply resistor connected to the power supply causing DC current to flow through the first HBT which develops a resultant voltage equal to the base emitter voltage of the first HBT; at least two manifold base resistors; at least two output HBTs, each of which receive the...

An FET gate bias circuit having a Schottky barrier gate incorporated therein is provided which can prevent gate voltage variations and thus provide a high-performance, high-reliability GaAs FET amplifier. The FET gate bias circuit includes a PNP transistor having a collector connected to a negative power supply, an NPN transistor having a collector thereof grounded and an emitter connected to the emitter of the PNP transistor, a Schottky barrier gate FET having a source grounded and a gate conne...

An integrated circuit device (10) has an operational amplifier (12) and a charge pump (14) for creating a negative voltage level -Vcc. The operational amplifier (12) preferably has various sub-components. In particular, a bias generator (36) is included and connected to a neutral voltage level (31) isolated from the negative voltage level and providing current for operational amplifier (12). An input stage (38) has inputs (16 and 18) for receiving two input signals and maintains the input signal...

A microwave power amplifier having application in multiple beam phased antenna array systems including a biasing means connection to the base of a microwave transistor being responsive to radio frequency signals applied to the amplifier to automatically adjust the transistor bias level to maintain constant amplifier gain. The biasing means includes two voltage regulators with their outputs capacitively coupled via a fixed resistor having a value determined by the characteristics of the transisto...

Generally, and in one form of the invention, a bias circuit for a transistor amplifier comprising a nonlinear element which limits current flow in a transistor, whereby the output-signal amplitude of the transistor is limited and the transistor is protected from exceeding a maximum current level, is disclosed. In another form of the invention, a bias circuit for a transistor amplifier comprising a nonlinear element 44 which limits current flow through a base terminal of a bipolar transistor 48, ...

A common base amplifier (29) has an input (31) and an output (32). A transistor (33) has an emitter coupled to the input (31) of the amplifier (29), a collector coupled to the output (32) of the amplifier (29), and a base coupled to a voltage reference (34) provides low input impedance and unity current gain. A control circuit (38) controls a first bias circuit (36) and a second bias circuit (37). The second bias circuit (37) is coupled to the collector of the transistor (33) and provides a bias...