Northern Telecom Limited

M Jamal Deen

Duljit S Malhi

Zhixin Yan

Stephen J Kovacic

John Ilowski

William Kung

Robert A Hadaway

A gain-controlled amplifier for an integrated circuit includes a PNP gate controlled lateral bipolar transistor (GCLBT) which is configured in a common base configuration. The emitter electrode of the GCLBT is connected to a Bias-T having an inductor and a capacitor. The collector electrode of the GCLBT is coupled to a load capacitor, the capacitance of which is selected to alter the bandwidth of the amplifier. A gain control voltage is applied to the gate electrode of the GCLBT to control the amplifier gain. An input signal to be amplified is coupled to the emitter electrode of the GCLBT. An output signal, which is amplified in response to the gain control voltage, is provided from the collector electrode of the GCLBT. The gain-controlled amplifier can be used for an automatic gain control amplifier and also may be used for radio frequency and intermediate frequency amplifiers.

Gain-controlled amplifier and automatic gain control amplifier using

A gate controlled lateral bipolar junction transistor (GCLBJT) device for an integrated circuit and a method of fabrication thereof are provided. The GCLBJT resembles a merged field effect transistor and lateral bipolar transistor, i.e. a lateral bipolar transistor having base, emitter and collector terminals and a fourth terminal for controlling a gate electrode overlying an active base region. The device is operable as an electronically configurable lateral transistor. Advantageously a heavily doped buried layer provides a base electrode having a base contact which surrounds and encloses the collector. The surface region between emitter and collector is characterized by lightly doped regions adjacent and contiguous with the heavily doped emitter and collector, which effectively reduce the base width of the bipolar transistor and improve operation for analog applications.

Gate controlled lateral bipolar junction transistor

An integrated circuit is provided with particular application for high frequency modulation circuits, such as a mixer circuit, with reduced noise and gain. The circuit provides a novel application of a single device comprising a 4 or 5 terminal, gate controlled lateral bipolar junction transistor device, in the form of a merged MOS and lateral bipolar transistor. In a grounded base configuration, RF and LO signals are applied to the gate and emitter terminals respectively and provide for modulated output at the collector, and provides signal modulation with reduced noise compared with multi-device implementations of known mixer circuits using a summation circuit, diodes and FETs. Advantageously, operation of the device in the grounded base or grounded emitter configuration provides for strong modulation of the DC current gain, i.e. over 4 decades, as a function of gate voltage.

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Coquitlam, Canada

M Jamal Deen