A biasing scheme for a frequency multiplication circuit, and transceiver using LO signals provided by the frequency multiplication circuit are described. A frequency doubler is cascaded with a mixer to provide a mm-wave oscillator signal. The combination provides a frequency triple that of the LO frequency supplied to the frequency doubler from a PLL. A small-sized replica of the frequency doubler is used to determine biasing of transconductance devices of the frequency doubler. A voltage output of the replica is amplified and the difference between the output and a reference voltage is supplied as feedback to the control terminal of the transconductance devices to bias the transconductance devices to near threshold. The biasing is replicated at the frequency doubler to compensate for PVT variations. A PTAT current source tied to the output of the replica regulates an average output current of the frequency multiplication circuit.

A semiconductor device with a novel structure is provided. The semiconductor device includes a mixer circuit including a digital-analog converter circuit, a control circuit for controlling the digital-analog converter circuit, a power source control switch, and a plurality of Gilbert circuits. The plurality of Gilbert circuits each include an analog potential holding circuit for holding an analog potential output from the digital-analog converter circuit. The control circuit has a function of outputting a signal for controlling the analog potential holding circuit and the digital-analog converter circuit. The power source control switch has a function of stopping supply of a power source voltage to the control circuit in a period during which the analog potential held in the analog potential holding circuit is not updated. The analog potential holding circuit includes a first transistor. The first transistor includes a semiconductor layer including an oxide semiconductor in a channel formation region.

Various embodiments disclosed herein enable steerable, time division duplex (“TDD”) communications channels at millimeter-wave frequency bands. Among other things, embodiments disclosed herein provide improved steering accuracy and power distribution, lower power consumption, and potentially longer service life than previous transceiver systems.

A mixer includes a first unit mixer, a second unit mixer, a third unit mixer, and a fourth unit mixer that have the same configuration and a first combiner, a second combiner, and a third combiner that have the same configuration. The first to the fourth unit mixers each include a differential RF signal terminal. Output of the first unit mixer and output of the second unit mixer are combined by the second combiner. Output of the third unit mixer and output of the fourth unit mixer are combined by the third combiner. Output of the second combiner and output of the third combiner are combined by the first combiner. The output of the third unit mixer is input to the third combiner with the polarity being determined.

A configurable passive mixer is described herein. According to one exemplary embodiment, a passive mixer for a wireless receiver comprises a plurality of passive mixer cores coupled in parallel with each mixer core configured to receive a same set of radio frequency input signals and a separately driven set of local oscillator input signals. Further, each mixer core is configured to be separately enabled or disabled so that the passive mixer can be selectively configured during operation to convert the same set of radio frequency input signals to a set of downconverted output signals that satisfy a certain performance requirement or performance parameter of the passive mixer.

A combined mixer and filter circuitry is disclosed. The combined mixer and filter circuitry comprises a mixer comprising a first input, a second input and an output. The combined mixer and filter circuitry further comprises a filter comprising an active inductor and a first capacitor. The active inductor comprises a transistor having a first terminal, a second terminal and a third terminal and a resistor connected between the first terminal of the transistor and a voltage potential. The first capacitor is connected between the third terminal and a signal ground and the second terminal of the transistor is connected to the second input of the mixer.

An image rejection mixer includes a delay circuit for delaying one of first signals divided by a distribution circuit and a second signal provided to a second mixing circuit by the same delay amount d, or delaying the other one of the first signals divided by the distribution circuit and the second signal provided to a first mixing circuit by the same delay amount d.

To provide a mixer and a semiconductor device which each have a small circuit area and each of which operation capability is inhibited from being decreased due to heat. The mixer includes a differential portion, a current source, a first load, an input terminal, and a first output terminal; the differential portion includes a first and a second transistor; and each of the first and the second transistors includes a metal oxide in a channel formation region. A first terminal of each of the first and the second transistors is electrically connected to the input terminal and a current source and a second terminal of the first transistor is electrically connected to a first terminal of the first load and the first output terminal. The first load has a function of supplying a current between the first terminal and a second terminal of the first load by application of voltage to the second terminal of the first load, and the current source has a function of supplying a constant current to the current source from the first terminal of each of the first and the second transistors. The current source includes a transistor including silicon in a channel formation region, and the differential portion is positioned above the current source.

A transmitter that reduces 3.sup.rd order harmonic (HD3) and inter modulation distortion (IMD3) for a gm stage of a mixer while reducing flicker noise is disclosed. The transmitter may include a balanced mixer, a transconductance stage connected to the mixer, and a bias circuit. The bias circuit may include a programmable current source configured to provide a reference current. Further, the bias circuit may include a replica circuit configured to replicate a DC signal of the transconductance stage. The bias circuit may also include a bias transistor configured to level shift a bias signal obtained from a signal source based on the reference current and the DC signal of the transconductance stage as determined from the replica circuit.

The present disclosure discloses a harmonic rejection mixing circuit device and a receiver. In the harmonic rejection mixing circuit device, outputs of first and fourth mixers are combined with the input terminal of the fourth mixer being connected to a capacitor, the first mixer samples a first group of local oscillator (LO) signals, and the fourth mixer phase-invertedly samples the first group of LO signals, thus the noise introduced by a fundamental LO signal input to the first mixer may be eliminated using the double balance feature of the fourth mixer core, thereby ensuring a high signal-to-noise ratio of the receiver. Similarly, the noises introduced by fundamental LO signals input to second and third mixers may be eliminated respectively using the double balance features of the fifth and sixth mixer cores, thereby lowering the noise figure to ensure a high signal-to-noise ratio of the receiver.