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 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.

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.

A radio frequency (RF) mixer is provided. The RF mixer includes two linear-in-the-amplitude-domain RF channels connected in parallel, with each of the two linear-in-the-amplitude-domain RF channels having of an input RF signal applied equally to each channel. Two controllable gain devices are structured to receive the input RF signal. A local oscillator (LO) communicates with both of the controllable gain devices, with one of the controllable gain devices receiving a signal from the LO directly, and the other controllable gain device receiving a signal from the LO after a phase of the LO signal is reversed by a phase inverter. Finally, an output of each of the linear-in-the-amplitude-domain RF channels is combined to form a common intermediate frequency (IF) output.

Techniques that facilitate reconfigurable transmission of a radar frequency signal are provided. In one example, a system includes a signal generator and a power modulator. The signal generator provides a radar waveform signal from a set of radar waveform signals. The power modulator divides a local oscillator signal associated with a first frequency and a first amplitude into a first local oscillator signal and a second local oscillator signal. The power modulator also generates a radio frequency signal associated with a second frequency and a second amplitude based on the radar waveform signal, the first local oscillator signal and the second local oscillator signal.

A radio receiver device is arranged to receive an input voltage signal at an input frequency and comprises: a first amplification circuit portion; a second amplification circuit portion; a current buffer circuit portion; and a down-mixer circuit portion. The first amplification circuit portion is arranged to amplify the input voltage signal to generate an amplified current signal which is input to the current buffer circuit portion. The current buffer circuit portion has an input impedance and an output impedance, wherein the output impedance is greater than the input impedance and is arranged to generate a buffered current signal. The down-mixer circuit portion is arranged to receive the buffered current signal and generate a down-converted current signal at a baseband frequency. The second amplification circuit portion is arranged to amplify the down-converted current signal to produce an output voltage signal.

Systems and methods are disclosed for improved linearity performance of a mixer. An example mixer includes switching circuit elements configured to be switched on and switched off based at least partly on a local oscillator signal and capacitors including a respective capacitor in parallel with each of the switching elements. The mixer is configured to mix the input signal with the local oscillator signal to thereby frequency shift the input signal.

Systems, methods, and circuitries are provided for a local oscillator (LO) signal distribution. An exemplary LO distribution network includes a common LO buffer configured to buffer an LO signal, a receive (RX) LO buffer, and a transmit (TX) mixer in a cascaded arrangement. The RX LO buffer is configured to receive the LO signal and buffer the LO signal and to provide the LO signal to an RX mixer. A first LO signal line and a second LO signal line are configured to conduct the LO signal from the common LO buffer to the RX LO buffer. The RX LO buffer is coupled to the first LO signal line and the second LO signal line. The TX mixer is also coupled to the first LO signal line and the second LO signal line.