Provided is a sine wave multiplication device of simple configuration, broad input signal level range, and minimal fluctuation in characteristics due to temperature. A signal component that corresponds to a product of an input signal Si and the third harmonic wave of a first square wave W1 included in an output signal Su1; and a signal component that corresponds to a product of the input signal Si and the fifth harmonic wave of the first square wave W1 is canceled by: a signal component that corresponds to a product of the input signal Si and the fundamental wave of a second square wave W2 included in an output signal Su2; and a signal component that corresponds to a product of the input signal Si and the fundamental wave of a second square wave W3 included in an output signal Su3.

This disclosure provides systems, methods, and devices for wireless communication that support reconfiguring degeneration components in a converged RF transceiver supporting carrier aggregation across sub-6 GHz frequency bands and mmWave frequency bands. In a first aspect, an apparatus includes an input port configured to receive a mixer input signal; a first mixer forming at least a portion of an HRM mixer and coupled to the input port; a first configurable degeneration component of a first processing path coupled between the input port and the first mixer; and a controller coupled to the first degeneration component, wherein the controller is configured to control a first aspect of a first degeneration component. Other aspects and features are also claimed and described.

A harmonic rejection mixer that uses switched capacitors for amplitude control and uses two different duty cycle local oscillator (LO) signals for phase control for each harmonic. The harmonic rejection mixer uses 2-vector variable duty harmonic rejection. which allows for the harmonic rejection mixer to be less complex. consume less power, and/or use less components/space compared to conventional harmonic rejection mixers.

A modem includes a modulator and a demodulator. The demodulator includes a direct current removing (DCR) circuit to transition between an acquisition mode, where the DCR circuit operates with a first loop gain; and a tracking mode, where the DCR circuit operates with a second loop gain. The second loop gain is smaller than the first loop gain, and the timing of the transition between the acquisition mode and tracking mode is programmable.

A mixing module (40) comprises a switching mixer (400), controlled by a switch signal and configured to receive an inputting signal and generate an outputting signal; a modulating unit (402), coupled to the switching mixer (400) and configured to generate the switch signal; wherein a switching frequency of the switch signal is higher than an and is a specific multiple of inputting frequency of the inputting signal. The mixing module (40) controls the switching mixer (400) by using the switch signal which is much higher than the inputting frequency of the inputting signal; oversampling is performed on the inputting signal, so that the spectrum energy of the outputting signal is more concentrated, which can avoid the additional noise due to the introduction of sidelobes or harmonics.

An apparatus and a method. The apparatus includes passive mixers, wherein each of the passive mixers includes a first input for receiving BB.sub.I, a second input for receiving BB.sub.I, a third input for receiving BB.sub.Q, a fourth input for receiving BB.sub.Q, a fifth input for receiving a first clock signal with a unique phase shift within one of the passive mixers, a sixth input for receiving a second clock signal with a unique phase shift within one of the passive mixers, a seventh input for receiving a third clock signal with a unique phase shift within one of the passive mixers, an eighth input for receiving a fourth clock signal with a unique phase shift within one of the passive mixers, and at least one output; and a voltage-domain vector summation array connected to the output of each of the passive mixers.

A modem includes a modulator and a demodulator. The demodulator includes a direct current removing (DCR) circuit to transition between an acquisition mode, where the DCR circuit operates with a first loop gain; and a tracking mode, where the DCR circuit operates with a second loop gain. The second loop gain is smaller than the first loop gain, and the timing of the transition between the acquisition mode and tracking mode is programmable.

A receiver includes circuitry configured to determine one or more first local oscillator (LO) harmonics that correspond to one or more first spectrum segments of a down-converted received signal based on characteristics of the received signal. The one or more first LO harmonics of the received signal are amplified by applying one or more first transconductance coefficients to one or more first harmonic selective transinductance amplifiers (TIAs) corresponding to the one or more first spectrum segments. Digitized outputs of the plurality of harmonic selective TIAs are calibrated based on an amount of signal leakage between the plurality of spectrum segments of the down-converted received signal.

A system includes: a baseband phase generator configured to receive differential in-phase (I) and quadrature (Q) signals and configured to output N phase-shifted baseband signals, wherein N is greater than 4, further wherein the baseband phase generator comprises a plurality of notch filters configured to receive the I and Q signals; and an upconverter configured to receive the phase-shifted baseband signals, to perform mixing on the phase-shifted baseband signals, and to output a differential upconverted signal.

Embodiments of a mixer of a Near field communication (NFC) receiver device and a method for operating a mixer of an NFC receiver device are disclosed. In an embodiment, a mixer of an NFC receiver device includes an input unit from which an input signal is received, a sample and hold circuit configured to sample the input signal and to store electrical charge based on the sampled input signal in order to generate a differential output signal, a control unit configured to switch the sample and hold circuit between different operational modes based on whether the input signal is a single-ended input signal or a differential input signal, and a differential output unit from which the differential output signal is output. Other embodiments are also described.