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.

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 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.

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.

An active mixer for frequency conversion used in a wireless communication system improves conversion gain and noise figure by improving switching characteristics of a mixer using a LO signal without requiring additional power consumption of an active mixer block. Further disclosed is a method for improving conversion gain and noise figure of an active mixer. The active mixer includes a switching stage for receiving a LO signal and selectively performing a switching-on/off operation for frequency conversion, a body signal generator for generating a body signal to be applied to a body of an NMOS transistor of the switching stage based on the LO signal, and a voltage controller for controlling the body signal generator to selectively apply the body signal to the body of the NMOS transistor based on to the switching-on/off operation of the switching stage to control a threshold voltage of the transistor of the switching stage.

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 travelling wave mixer (TWM) is provided that includes an input artificial transmission line configured to transmit an input signal, an output artificial transmission line configured to transmit an output signal, a local oscillator (LO) artificial transmission line configured to transmit an LO signal, and a plurality of mixer stages connected in parallel between the output artificial transmission and the input artificial transmission line. Each of the mixer stages includes an input amplifier, a mixer and an output amplifier connected in series between the input artificial transmission line and the output artificial transmission line, where an input of the mixer receives an output of the input amplifier, and an output of the mixer is applied to an input of the output amplifier. Further, each of the mixer stages includes a phase-adjustable LO amplifier circuit connected between the LO artificial transmission line and an LO input of the mixer, where the phase-adjustable LO amplifier is configured to adjust an LO signal phase applied to the LO input of each mixer to null out a phase error in each mixer stage independently.

A travelling wave mixer (TWM) is provided that includes an input artificial transmission line configured to transmit an input signal, an output artificial transmission line configured to transmit an output signal, a local oscillator (LO) artificial transmission line configured to transmit an LO signal, and a plurality of mixer stages connected in parallel between the output artificial transmission and the input artificial transmission line. Each of the mixer stages includes an input amplifier, a mixer and an output amplifier connected in series between the input artificial transmission line and the output artificial transmission line, where an input of the mixer receives an output of the input amplifier, and an output of the mixer is applied to an input of the output amplifier. Further, each of the mixer stages includes a phase-adjustable LO amplifier circuit connected between the LO artificial transmission line and an LO input of the mixer, where the phase-adjustable LO amplifier is configured to adjust an LO signal phase applied to the LO input of each mixer to null out a phase error in each mixer stage independently.

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.

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.