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 processor may calibrate a first actuator electrically coupled to a transconductance stage of the frequency conversion circuit. The transconductance stage may be configured to receive a differential signal input. Calibrating a first actuator may adjust a first basis vector associated with a differential direct current (DC) output of the transconductance stage. A processor may calibrate a second actuator electrically coupled to receive the differential current output of the transconductance stage and electrically coupled to a set of commutating devices of the frequency conversion circuit. The commutating devices may be configured to receive differential LO inputs. Calibrating a second actuator may adjust a second basis vector associated with a differential impedance of the set of commutating devices. A processor may offset responsive to adjusting the first basis vector and the second basis vector, the first leakage basis vector and second leakage basis vector of the LO leakage signal.

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 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.

Embodiments of communications devices and methods for operating a communications device are described. In an embodiment, a communications device includes a complex multiplier configured to multiply a first input complex signal with a second input complex signal to generate an output complex signal, an amplifier configured to amplify an imaginary part of the output complex signal to generate an amplification result, a delay element configured to delay a rotation angle signal that is related to the second input complex signal, and a subtractor configured to subtract the amplification result from the delayed rotation angle signal to generate the rotation angle signal. Other embodiments are also described.

Embodiments of communications devices and methods for operating a communications device are described. In an embodiment, a communications device includes a complex multiplier configured to multiply a first input complex signal with a second input complex signal to generate an output complex signal, an amplifier configured to amplify an imaginary part of the output complex signal to generate an amplification result, a delay element configured to delay a rotation angle signal that is related to the second input complex signal, and a subtractor configured to subtract the amplification result from the delayed rotation angle signal to generate the rotation angle signal. Other embodiments are also described.

A circulator, comprising: a gyrator having a first side (1S) and a second side (2S) connected to a third port; a first transmission line section (TLS) having a 1 S connected to the 1 S of the gyrator and a 2S connected to a first port; a second TLS having a 1S connected to the first port and having a 2S connected to a second port; a third TLS having a 1S connected to the second port and having a 2S connected to the third port; a first cancellation path (CP) that is connected between the first port and the third port and introduces a current that is 90 degrees out of phase with a first voltage at the first port; and a second CP that is connected between the second port and the third port and introduces a current that is orthogonal to the current introduces by the first CP.

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.

A circuit comprising a differential transmission line and eight switches provides non-reciprocal signal flow. In some embodiments, the circuit can be driven by four local oscillator signals using a boosting circuit. The circuit can be used to form a gyrator. The circuit can be used to form a circulator. The circuit can be used to form three-port circulator than can provide direction signal flow between a transmitter and an antenna and from the antenna to a receiver. The three-port circulator can be used to implement a full duplex transceiver that uses a single antenna for transmitting and receiving.

A band-switching network includes a dual-band balun and a switch network. The dual-band balun includes a first output and a second output. The switch network includes a first switch and a second switch in which an input to the first switch is coupled to the first output and an input to the second switch is coupled to the second balanced output. The dual-band balun further includes a primary coil, a first secondary coil and a second secondary coil in which the first secondary coil is coupled to the first balanced output and the second secondary coil is coupled to the second balanced output. In one embodiment, the primary coil and the first secondary coil are coupled by a first coupling factor k.sub.1, and the primary coil and the second secondary coil are coupled by a second coupling factor k.sub.2 that is different from the first coupling factor k.sub.1.