A radio frequency (RF) front-end receiver having a passive mixer with feed-forward intermodulation distortion cancellation, or at least reduction. An example receiver generally includes a mixer having differential input terminals and differential output terminals and a baseband filter having inputs coupled to the differential output terminals of the mixer. The receiver also includes common-mode sensing circuitry coupled to the differential input terminals of the mixer and configured to sense a common-mode signal of a first differential signal present at the differential input terminals of the mixer. The receiver further includes a conversion circuit coupled to the common-mode sensing circuitry and configured to convert the common-mode signal to a second differential signal presented to the differential output terminals of the mixer and the inputs of the baseband filter.

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 disclosure relates to a pre-5th-generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-generation (4G) communication system such as long term evolution (LTE). An operation method of a device for upconversion in a wireless communication system is provided. The method includes receiving a first local oscillator (LO) signal, generating a second LO signal, based on the first LO signal and cross-coupled latches, receiving an input signal, generating an upconverted frequency, based on the second LO signal and the input signal, generating an output signal obtained by processing a harmonic component included in the upconverted frequency, and transmitting the generated output signal.

A unit cell for a resistive mixer includes a plurality of active devices arranged in series, wherein each of said plurality of active devices having a different output conductance. A resistive mixer includes a plurality of active devices connected in series with one another to form a unit cell.

An electrical circuit can have a local oscillator, a first mixer, a second mixer, and a delay element. The first mixer mixes an input signal with a local oscillator signal. The second mixer mixes the input signal with a delayed local oscillator signal, delayed by the delay element. The output signals from the first mixers are combined to form an output signal of the electrical circuit.

The present disclosure generally relates to the field of receiver structures in radio communication systems and more specifically to passive mixers in the receiver structure and to a technique for converting a first signal having a first frequency into a second signal having a second frequency by using a third signal having a third frequency. A passive mixer for converting a first signal having a first frequency into a second signal having a second frequency by using a third signal having a third frequency comprises a cancellation component for generating a first cancellation signal for cancelling second order intermodulation components by superimposing the first signal weighted by a cancellation value on the third signal; and a mixing component having a first terminal for receiving the first signal, a second terminal for outputting the second signal, and a third terminal for receiving the first cancellation signal, wherein the mixing component is adapted to provide the second signal as output at the second terminal by mixing the first signal provided as input at the first terminal and the first cancellation signal provided as input at the third terminal.

Systems, methods, and circuitries are disclosed for generating a desired signal from a received signal. In one example a signal cancellation system includes local oscillator (LO) downconverter circuitry, frequency offset (FO) signal estimation circuitry, and cancellation circuitry. The LO downconverter is configured to downconvert the received signal using an LO signal having an LO frequency to generate a downconverted received signal. The FO signal estimation circuitry includes FOLO generation circuitry configured to modify the LO signal to generate a FOLO signal having an offset frequency that is different from the LO frequency and FOLO downconverter circuitry configured to use the FOLO signal to downconvert a signal derived from the received signal to generate a downconverted FO signal. The cancellation circuitry is configured to cancel either the downconverted received signal or the downconverted FO signal from the received signal to generate the desired signal.

An apparatus is disclosed for a harmonic rejection filter with transimpedance amplifiers. In an example aspect, the apparatus includes a harmonic rejection filter with at least three input nodes, at least one output node, a first transimpedance amplifier, a first set of transimpedance amplifiers, and a scaling current converter. The at least three input nodes include a first input node, a second input node, and a third input node. The at least one output node includes a first output node. The first transimpedance amplifier is coupled between the first input node and the first output node. The first set of transimpedance amplifiers include a second transimpedance amplifier coupled to the second input node and a third transimpedance amplifier coupled to the third input node. The scaling current converter is coupled between outputs associated with the first set of transimpedance amplifiers and an input of the first transimpedance amplifier.

An apparatus is disclosed for a harmonic rejection filter with transimpedance amplifiers. In an example aspect, the apparatus includes a harmonic rejection filter with at least three input nodes, at least one output node, a first transimpedance amplifier, a first set of transimpedance amplifiers, and a scaling current converter. The at least three input nodes include a first input node, a second input node, and a third input node. The at least one output node includes a first output node. The first transimpedance amplifier is coupled between the first input node and the first output node. The first set of transimpedance amplifiers include a second transimpedance amplifier coupled to the second input node and a third transimpedance amplifier coupled to the third input node. The scaling current converter is coupled between outputs associated with the first set of transimpedance amplifiers and an input of the first transimpedance amplifier.

A method for initializing a phase adder circuit including a multiplier circuit with its two inputs receiving signals of frequency f.sub.o, a mixer circuit, an amplifier circuit, a low pass loop filter, and a voltage controlled oscillator (VCO), the method including: during a first phase, determining a reference voltage which when applied to the VCO causes it to produce a signal having a frequency of nf.sub.0; during a second phase, supplying a signal of frequency nf.sub.o to a first input of the mixer and a signal of frequency (nf.sub.o+f) to a second input of the mixer; and determining an adjustment signal which when applied to the amplifier circuit causes the amplifier circuit to output a signal having a DC component equal to the reference voltage; and during a third phase, forming a primary phase locked loop (PLL) circuit including the mixer, the amplifier circuit, the low pass loop filter and the VCO; and applying the adjustment signal to the amplifier circuit.