A down-conversion mixer includes a converting-and-mixing module and a load module. The converting-and-mixing module performs voltage-to-current conversion and mixing with first and second differential oscillatory voltage signal pairs upon a differential input voltage signal pair to generate first and second differential mixed current signal pairs. The load module includes two RL circuits and a negative resistance providing circuit that cooperate to convert the first and second differential mixed current signal pairs into first and second differential mixed voltage signal pairs. Each RL circuit includes two variable resistors, and an inductor connected between the variable resistors.

The present invention provides a receiver including a first band group, a second band group and a mixer. The first band group includes at least one LNA, wherein the first band group is configured to select one first LNA to receive a first input signal to generate an amplified first input signal. The second band group includes at least one LNA, wherein the second band group is configured to select one second LNA to receive a second input signal to generate an amplified second input signal. The first band group and the second band group are coupled to a first input terminal and a second input terminal of the mixer, respectively, and the mixer receives one of the amplified first input signal and the amplified second input signal to generate an output signal.

A method for manufacturing a semiconductor device includes forming one or more fins extending in a first direction over a substrate. The one or more fins include a first region along the first direction and second regions on both sides of the first region along the first direction. A dopant is implanted in the first region of the fins but not in the second regions. A gate structure overlies the first region of the fins and source/drains are formed on the second regions of the fins.

A triple-balanced radio frequency (RF) mixer including a plurality of double-balanced mixer cells and a plurality of transformers is disclosed. Each of the plurality of transformers includes a primary and a secondary. Each primary is connected in series. Each secondary is connected across one double-balanced mixer cell of said plurality of double-balanced mixer cells. The triple-balanced RF mixer further includes a local oscillator (LO) port coupled to each of the plurality of double-balanced mixer cells in parallel, an output port coupled to each of the plurality of double-balanced mixer cells in parallel, and at least one non-ideality source providing at least one-non-ideality. The at least one non-ideality is cancelled at the output port.

An apparatus includes an RF apparatus, and a wideband multi-band matching balun. The wideband multi-band matching balun includes a multi-band balun, which includes at least one three-element frequency-dependent resonator (TEFDR). The wideband multi-band matching balun further includes a differential-to-differential matching circuit coupled to the RF apparatus. The differential-to-differential matching circuit includes at least one TEFDR.

The invention described herein is directed to different embodiments of a wireless communications device that can be used in many different applications, such as but not limited to a digital oversampling receiver adapted to select desired signals and to reject undesired signals. In one embodiment, a wireless communications device is disclosed that comprises an architecture for a receiver front end that obviates the need for high order passive circuitry or RC active circuitry to select desired signals and to reject undesired signals.

A down-conversion mixer includes a converting-and-mixing module and a load module. The converting-and-mixing module performs voltage-to-current conversion and mixing with a differential oscillatory voltage signal pair upon a differential input voltage signal pair to generate a differential mixed current signal pair. The load module includes a first transistor, a second transistor and a resistor-inductor (RL) circuit that cooperatively convert the differential mixed current signal pair into a differential mixed voltage signal pair. Each of the first and second transistors has a transconductance that varies according to a control voltage.

A double-balanced radio-frequency (RF) mixing digital-to-analog converter (DAC) apparatus includes a load network, a first set of resistive DAC driver circuits and a first mixing core. The first mixing core can receive first RF input signals from the first set of resistive DAC driver circuits and can provide a first mixed signal to the load network. The first mixing core includes a first input differential pair coupled to two first cross-coupled differential pairs. The first input differential pair can receive first RF input signals at respective first input nodes. Each of the two first cross-coupled differential pairs can receive first positive and negative local oscillator (LO) signals at corresponding first input nodes. The first mixing core can mix the first RF input signals with the first positive and negative LO signals.

A first balanced/unbalanced circuit is provided that splits a first mixed wave outputted from an even harmonic mixer into first and second split signals, outputs the first split signal that is in phase with the first mixed wave to a first output terminal, and outputs the second split signal that is opposite in phase to the first mixed wave to a second output terminal. Further, a second balanced/unbalanced circuit is provided that splits a second mixed wave outputted from the even harmonic mixer into third and fourth split signals, outputs the third split signal that is in phase with the second mixed wave to the second output terminal, and outputs the fourth split signal that is opposite in phase to the second mixed wave to the first output terminal.

Systems and methods are disclosed for compensating local oscillator leakage in a mixer. An example mixer includes a first double-balanced mixer core and a second double-balanced mixer. The first double-balanced mixer may comprise differential output nodes and may be configured to mix a first input signal with a first local oscillator signal. The second double-balanced mixer core may comprise second differential output nodes and may be configured to mix a second input signal with a second local oscillator signal. The second input signal may be approximately 180 out of phase with the first input signal. The second local oscillator signal may be approximately 180 out of phase with the first local oscillator signal. The differential output nodes may be electrically connected to the second differential output nodes, and the first double-balanced mixer core and the second double-balanced mixer core may be arranged to compensate for local oscillator leakage.