Provided is a FET resistive frequency mixing device having improved RF-LO and IF-LO isolations. The frequency mixing device includes: a field effect transistor (FET), a local oscillation matching circuit connected to a gate of the FET to transfer a local oscillation signal to the gate of the FET, a gate biasing circuit connected to the gate of the FET, a radio frequency (RF) matching circuit having a first terminal connected to a drain side of the FET and a second terminal serving as a RF terminal to receive or output a RF signal, an intermediate frequency (IF) matching circuit having a first terminal connected to the drain side of the FET and a second terminal serving as an IF terminal to receive or output an IF signal, and a series resonance circuit providing a path from the drain of the FET to ground for the local oscillation signal.

An active mixer for frequency conversion used in a wireless communication system improves conversion gain and noise figure by improving switching characteristics of a mixer using a LO signal without requiring additional power consumption of an active mixer block. Further disclosed is a method for improving conversion gain and noise figure of an active mixer. The active mixer includes a switching stage for receiving a LO signal and selectively performing a switching-on/off operation for frequency conversion, a body signal generator for generating a body signal to be applied to a body of an NMOS transistor of the switching stage based on the LO signal, and a voltage controller for controlling the body signal generator to selectively apply the body signal to the body of the NMOS transistor based on to the switching-on/off operation of the switching stage to control a threshold voltage of the transistor of the switching stage.

A distributed mixer is configured of an artificial transmission line of which an input end is connected to an LO terminal and a terminal end is connected to an IF terminal, an artificial transmission line of which an input end is connected to an RF terminal, FETs that perform frequency synthesis of LO signals and RF signals and that are disposed following the artificial transmission lines and of which gates are connected to the artificial transmission line and sources are grounded, a bias circuit that applies gate bias voltage to a terminal end of the artificial transmission line, a terminating resistor that connects the terminal end of the artificial transmission line and a ground, and a plurality of transmission lines provided between the artificial transmission line and a drain of each FET.

Techniques are provided for decorrelation of intermodulation products in mixer circuits. A circuit implementing the techniques according to an embodiment includes four switches. Each of the switches comprise a complementary pair of n-channel and p-channel metal oxide semiconductor (NMOS/PMOS) field effect transistors (FETs). The NMOS/PMOS FETs include a source port, a drain port, and a gate port. The gate port is configured to receive an oscillator signal. The circuit also includes electrical conductors to couple the four switches into a double-balanced passive ring configuration to generate an output signal as a mix of an input signal and the oscillator signal. The output signal includes a third order intermodulation (IM3) product. The circuit further includes a voltage bias generator to generate a bias voltage to bias the input signal and the output signal. The magnitude and phase of the IM3 product are determined, at least in part, by the bias voltage.

The present invention is to provide a mixing circuit, comprising: a first transistor; a second transistor; a third transistor; a first connection point connected to a gate terminal of the first transistor, a drain terminal of the second transistor and a source terminal of the third transistor; a second connection point connected to a source terminal of the first transistor and a gate terminal of the second transistor; and a third connection point connected to a drain terminal of the first transistor and a drain terminal of the third transistor.

A resistive mixer includes a LO matching circuit inserted between the gate of an FET and a LO terminal, a bias circuit that is connected to the gate and applies a bias voltage to the gate, an RF matching circuit inserted between the drain of the FET and an RF terminal, and an IF matching circuit inserted between the drain and an IF terminal. The source of the FET is grounded. The impedance of the RF matching circuit seen from the drain of the FET at an IF frequency is open-circuit, and the impedance of the IF matching circuit seen from the drain of the FET at an RF frequency is open-circuit.

An electrical circuit for providing an output signal based on a first input signal and a second input signal has: a mixer which is configured to receive and mix the first and second input signals in order to generate a mixer output signal and to switch on or off based on the first input signal, wherein a DC signal component of the mixer output signal depends on whether the mixer is switched on or off; and a downstream circuit which is configured to switch on or off based on the DC signal component of the mixer output signal and to provide the output signal based on the mixer output signal.

A negative capacitance circuit is connected between a drain and a source of the mixer transistor. With this configuration, the negative capacitance circuit is connected in parallel to a parasitic capacitance generated between the drain and the source of the mixer transistor, and the parasitic capacitance can be canceled out in a wide band by the negative capacitance circuit connected in parallel.

An embodiment integrated electronic device comprises a mixer module including a voltage/current transconductor stage including first transistors and connected to a mixing stage including second transistors, wherein the mixing stage includes a resistive degeneration circuit connected to the sources of the second transistors and a calibration input connected to the gates of the second transistors and intended to receive an adjustable calibration voltage, and the sources of the first transistors are directly connected to a cold power supply point.

Multi-input downconversion mixers, systems, and methods are provided with input switching in the intermediate frequency or baseband domain. One illustrative mixer embodiment includes: multiple differential pairs of transistors and multiple pairs of switches. Each differential transistor pair has their bases or gates driven by a differential reference signal, their emitters or sources connected to a common node having a current or voltage driven based on a respective one of multiple receive signals, and their collectors or drains providing a product of the differential reference signal with the respective one of the multiple receive signals. Each of the switch pairs selectively couples differential output nodes to the collectors or drains of a respective one of the multiple differential pairs, enabling the differential output nodes to convey an output signal that is a sum of products from selected ones of the multiple differential pairs.