A voltage feed-forward circuit, a multiplier using the voltage feed-forward circuit, and a power factor correction circuit using the multiplier. The voltage feed-forward circuit is used to maintain and output a peak voltage (Vff) of an input voltage (Vin), and includes first switch element (S1), a logic control unit (U1), a second switch element (S2), a first capacitor (C1), a third switch element (S3) and a second capacitor (C2). The first control signal (1) and the second control signal (2) begin to be provided at the same time, and the first control signal (1) stops being provided when a voltage of the second end of the first capacitor (C1) is greater than the peak voltage (Vff) of the input voltage (Vin).

A down converter, including first and second biasing circuits, mixer, and transformer coupled to receive amplifier output signal. The first and second biasing circuits each include a biasing transistor and a first and second node, respectively. Mixer includes first and second transistors coupled to first node and third and fourth transistors coupled to second node. The second and fourth transistors are coupled to a third node. The first and third transistors are coupled to a fourth node. Mixer also includes a first resistor coupled to the fourth node and a supply voltage node and a second resistor coupled to the third node and a supply voltage node. Transformer includes a primary winding coupled to receive the amplifier output signal and to a supply voltage and a secondary winding coupled to mixer and first biasing circuit at first node and coupled to mixer and second biasing circuit at second node.

The present invention disclosure provides a multiplier and a power factor correction circuit which the multiplier is applied. The multiplier comprises a Gilbert multiplier circuit comprising a first differential input stage, a second differential input stage and an output stage; a first differential voltage conversion circuit; a second differential voltage conversion circuit; and a bias current generating circuit; Wherein said output stage comprises: a current mirror unit comprising two current input terminals and a current output terminal; and a feedback control unit configured to ensure that the current output terminal does not output current when the voltage difference received by the multiplier is zero. The present invention is advantageous in improving the linearity of the multiplier and the accuracy of the output current of the multiplier output current.

A commutating circuit includes a single-ended mixer and a passive network. The single-ended mixer includes a differential local oscillator terminal. The passive network includes a plurality of inductors and a capacitor. The plurality of inductors can be coupled to the differential local oscillator terminal. The plurality of inductors can provide an impedance in accordance with a common mode or a differential mode. The commutating circuit can be implemented via a device, a system and/or a method.

A transistor cell can be modeled as a transistor with a collector, a base, and an emitter operating with a current at the collector to produce a minimum transconductance in the transistor cell that increases a current gain and improves at least one operating characteristic of the transistor cell. The operating characteristics include bandwidth, gain, and output power.

A frequency estimation signal generator component arranged to receive an input frequency signal and to generate therefrom a frequency estimation signal. The frequency estimation signal generator component comprises a counter component arranged to sequentially output a sequence of control signal patterns over a plurality of digital control signals under the control of an oscillating signal derived from the received input frequency signal terns. The frequency estimation signal generator further comprises a continuous waveform generator component arranged to receive the plurality of digital control signals and a weighted analogue signal for each of the received digital control signals, and to output a continuous waveform signal comprising a sum of the weighted analogue signals for which the corresponding digital control signals comprise an asserted logical state. The frequency conversion component is arranged to derive the frequency estimation signal from the continuous waveform signal output by the continuous waveform generator component

A mixing stage includes a first modulation stage that receives an input signal from a first common node of the mixing stage, a first local oscillator input that receives a local oscillator signal, and a first modulation signal output adapted to provide a first modulated signal. A second modulation stage of the mixing stage includes a second input that receives a phase inverted representation of the input signal from a second common node of the mixing stage, a second local oscillator input that receives the local oscillator signal, and a second modulation signal output adapted to provide a second modulated signal. A current generation circuit provides a supply current to the first common node and to the second common node. A current control circuit is adapted to superimpose an offset current to the current of at least one node of the first common node and the second common node.

A MMIC (microwave monolithic integrated circuit) based FET mixer and method for the same is provided. In particular, adjacent transistors, such as FETs (field effect transistors) share terminals reducing physical layout separation and interconnections. A smaller die size is realized with the improved system geometry herein provided.

A commutating circuit includes a single-ended mixer and a passive network. The single-ended mixer includes a differential local oscillator terminal. The passive network includes a plurality of inductors and a capacitor. The plurality of inductors can be coupled to the differential local oscillator terminal. The plurality of inductors can provide an impedance in accordance with a common mode or a differential mode. The commutating circuit can be implemented via a device, a system and/or a method.

A mixing stage includes a first modulation stage that receives an input signal from a first common node of the mixing stage, a first local oscillator input that receives a local oscillator signal, and a first modulation signal output adapted to provide a first modulated signal. A second modulation stage of the mixing stage includes a second input that receives a phase inverted representation of the input signal from a second common node of the mixing stage, a second local oscillator input that receives the local oscillator signal, and a second modulation signal output adapted to provide a second modulated signal. A current generation circuit provides a supply current to the first common node and to the second common node. A current control circuit is adapted to superimpose an offset current to the current of at least one node of the first common node and the second common node.