Northern Telecom Limited

Zhixin Yan

Duljit S Malhi

M Jamal Deen

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

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.

Growing community of inventors

Burnaby, Canada

Zhixin Yan