Abstract: A method of duty cycle adjustment includes conditionally inverting an input clock into a conditionally inverted clock; and adjusting a duty cycle of the conditionally inverted clock in one direction in accordance with an integer that represents an amount of duty cycle adjustment, using an uneven clock buffer and a plurality of uneven clock multiplexers that are cascaded and incrementally activated as a value of the integer increments.

Abstract: A VCO (voltage-controlled oscillator) includes: a resonant tank having a parallel connection of an inductor, a fixed capacitor, a variable capacitor, a first temperature compensating capacitor, and a second temperature compensating capacitor across a first node and a second node, and configured to establish an oscillation of a first oscillatory voltage at the first node and a second oscillatory voltage at the second node; and a regenerative network placed across the first node and the second node to provide energy to sustain the oscillation. The variable capacitor is controlled by a control voltage, the first temperature compensating capacitor is controlled by a first temperature tracking voltage of a positive temperature coefficient, and the second temperature compensating capacitor is controlled by a second temperature tracking voltage of a negative temperature coefficient.

Abstract: A method of duty cycle adjustment includes conditionally inverting an input clock into a conditionally inverted clock; and adjusting a duty cycle of the conditionally inverted clock in one direction in accordance with an integer that represents an amount of duty cycle adjustment, using an uneven clock buffer and a plurality of uneven clock multiplexers that are cascaded and incrementally activated as a value of the integer increments.

Abstract: A self-loopback radio transmitter having a transmitter with a modulator configured to up-convert a first baseband signal into a first RF (radio frequency) signal in accordance with a first LO (local oscillator) signal, and a power amplifier configured to receive the first RF signal and output a second RF signal to be emitted by an antenna and a third RF signal to be looped back, wherein the third RF signal is magnetically coupled from the second RF signal; and a loopback network having a shielded serial inductor configured to receive the third RF signal and output a fourth RF signal, and a demodulator configured to down-convert the fourth RF signal into a second baseband signal in accordance with a second LO signal, wherein the shielded serial inductor has a serial inductor of spiral topology and a coil laid out on a lower metal layer.

Abstract: A SSB (single sideband) mixer is configured to mix a first signal with a second signal, both the first signal and the second signal being a four-phase signal, and comprises eight gated inverters, each receiving a respective phase of the first signal and conditionally outputting a respective current in accordance with a control of a respective phase of the second signal, wherein currents output from the eight gated inverters are summed to establish a third signal that is a two-phase signal.

Abstract: A transconductance amplifier includes a first MOS transistor configured to receive a first voltage at a first node and output a first current to a fifth node in accordance with a third voltage at a third node; a second MOS transistor configured to receive a second voltage at a second node and output a second current to a sixth node in accordance with a fourth voltage at a fourth node; a third MOS transistor configured to output a third current to the third node in accordance with a fifth voltage at the fifth node; a fourth MOS transistor configured to output a fourth current to the fourth node in accordance with a sixth voltage at the sixth node; and a source degeneration network placed across the third node and the fourth node.

Abstract: A programmable gain amplifier includes a programmable resistor ladder deployed across Nmax junction nodes and controlled by Nmax?1 resistor control signals, where Nmax is an integer greater than one; a common-gate cascode amplifier multiplexer comprising Nmax common-gate cascode amplifiers configured to receive Nmax internal voltages at the Nmax junction nodes and output Nmax output currents in accordance with Nmax amplifier control signals, respectively, to an output node that is loaded with a load; and an AC (alternate current) coupling capacitor configured to couple an input node to the first junction node.

Abstract: A four-stage gated ring oscillator having four gated amplifiers configured in a ring topology and comprising a first pair of gated amplifiers, controlled by a first phase of an two-phase input clock, interleaved with a second pair gated amplifiers, controlled by a second phase of the two-phase input clock; and two cross-coupling latches configured to provide cross-coupling between the first pair of gated amplifiers and the second pair of gated amplifiers.

Abstract: A voltage regulation system includes a voltage regulator configured to receive a first reference voltage and output a regulated voltage; a bias voltage generator comprising a diode-connect transistor configured to receive a bias current and output a reference gate voltage; and a plurality of switch-load circuits, each of said plurality of switch-load circuits comprising a common-drain transistor configured to receive power from the regulated voltage and control from the reference gate voltage via a switch controlled by a logical signal and output a supply voltage to load with a decoupling capacitor, wherein a size of the common-drain transistor is scaled from a size of the diode-connect transistor in accordance with a ratio between a current of the load and the bias current.

Abstract: A N-path filter includes a plurality of switch-capacitor circuits controlled by a plurality of logical signals, respectively, and joined at a common shunt node, each of said switch-capacitor circuit comprising: a respective switch configured to controllably connect the common shunt node to a respective middle node in accordance with a respective logical signals among said plurality of logical signals; and a respective balanced MOS (metal oxide semiconductor) capacitor connected to the respective middle node, wherein the respective balanced MOS capacitor exhibits a capacitance at the respective middle node with reference to a power supply node and a ground node.

Abstract: A multi-level signal transmitter includes an encoder figured to receive an input data and output a plurality of logical signal sets, each of said plurality of logical signal sets comprising a plurality of logical signals; and a plurality of tree-structured drivers configured to receive said plurality of logical signal sets, respectively, and jointly establish an output voltage at an output node, wherein each of said tree-structure drivers comprises a plurality of inverters configured to receive said plurality of logical signals of its respective logical signal set and jointly establish a joint voltage at a bifurcation node via coupling to the bifurcation node through a plurality of first-level weighting resistors, and a second-level weighting resistor configured to couple the bifurcation node to the output node.

Abstract: A N-path filter includes a plurality of switch-capacitor circuits controlled by a plurality of logical signals, respectively, and joined at a common shunt node, each of said switch-capacitor circuit comprising: a respective switch configured to controllably connect the common shunt node to a respective middle node in accordance with a respective logical signals among said plurality of logical signals; and a respective balanced MOS (metal oxide semiconductor) capacitor connected to the respective middle node, wherein the respective balanced MOS capacitor exhibits a capacitance at the respective middle node with reference to a power supply node and a ground node.

Abstract: An LC (inductor-capacitor) tank includes a primary 8-shape inductor and a serial LC network that are connected in parallel across a first node and a second node and laid out using a multi-layer structure fabricated on a substrate, wherein a magnetic coupling between the primary 8-shape inductor and the serial LC network is mitigated due to a layout symmetry, and a resonant frequency of the serial LC network is equal to three times of a resonance frequency of the LC tank.

Abstract: A VCO (voltage-controlled oscillator) includes: a resonant tank having a parallel connection of an inductor, a fixed capacitor, a variable capacitor, a first temperature compensating capacitor, and a second temperature compensating capacitor across a first node and a second node, and configured to establish an oscillation of a first oscillatory voltage at the first node and a second oscillatory voltage at the second node; and a regenerative network placed across the first node and the second node to provide energy to sustain the oscillation. The variable capacitor is controlled by a control voltage, the first temperature compensating capacitor is controlled by a first temperature tracking voltage of a positive temperature coefficient, and the second temperature compensating capacitor is controlled by a second temperature tracking voltage of a negative temperature coefficient.

Abstract: A LNA (low-noise amplifier) includes a matching network configured to provide a three-way coupling between an input node, a matched node, and a source node; a gate capacitor configured to provide AC (alternate current) coupling between the matched node and a gate node; a cascode amplifier configured to receive a gate voltage at the gate node and output an output voltage at an output node in accordance with a source degeneration at the source node; and a load network connected to the output node, wherein the matching network having a shunt inductor and a series inductor that are overlapped in layout to have a strong mutual coupling and a source degenerating inductor that is laid out in a close proximity to the shunt inductor to have a strong mutual coupling

Abstract: A dynamic amplifier includes a common-source amplifier configured to receive a gate voltage at a gate node and output a drain current to a drain node; a current mirror configured to mirror the drain current into an output current to an output current; a source capacitor connected to the source node; a load capacitor connected to the output node; a first switch configured to conditionally connect the gate node to an input voltage; a second switch configured to conditionally connect the gate node to a gate-resetting voltage; a third switch configured to conditionally connect the source node to a source-resetting voltage; a fourth switch configured to conditionally connect the drain node to a drain-resetting voltage; and a fifth switch configured to conditionally connect the output node to an output-resetting voltage.

Abstract: A multi-stage amplifier includes a first stage comprising a first common-source amplifier, a first inductive load network comprising a serial connection of a first load resistor and a first load inductor, and a first source network configured to receive a first signal and output a first load signal, and a first inter-stage inductor configured to couple the first load signal to a second signal; and a second stage comprising a second common-source amplifier, a second inductive load network comprising a serial connection of a second load resistor and a second load inductor, and a second source network configured to receive the second signal and output a second load signal, and a second inter-stage inductor configured to couple the second load signal to a third signal, wherein the first load inductor and the second load inductor are laid out to enhance an inter-stage inductive coupling.

Abstract: A multi-stage amplifier includes a first stage comprising a first common-source amplifier, a first inductive load network comprising a serial connection of a first load resistor and a first load inductor, and a first source network configured to receive a first signal and output a first load signal, and a first inter-stage inductor configured to couple the first load signal to a second signal; and a second stage comprising a second common-source amplifier, a second inductive load network comprising a serial connection of a second load resistor and a second load inductor, and a second source network configured to receive the second signal and output a second load signal, and a second inter-stage inductor configured to couple the second load signal to a third signal, wherein the first load inductor and the second load inductor are laid out to enhance an inter-stage inductive coupling.

Abstract: A reference load includes a parallel connection of a resistor load having a resistor and a transistor load having a plurality of transistors, wherein a temperature coefficient of the resistor load is positive, and a temperature coefficient of the transistor load is negative.

Abstract: A voltage-controlled delay buffer includes a plurality of inverters configured in a cascade topology to receive an input signal from a source circuit and output an output signal to an output circuit. The plurality of inverters includes a voltage-controlled inverter controlled by a control signal having a first voltage and a second voltage. The voltage-controlled inverter includes a PMOS transistor configured to assist a low-to-high transition of an outgoing signal, and an NMOS transistor configured to assist a high-to-low transition of the outgoing signal. Two varactors, one forward connected and the other backward connected are configured to adjust a delay of a transition of an incoming signal.; Another two varactors, one forward connected and the other backward connected, configured to adjust a delay of a transition of the outgoing signal in accordance with the first voltage and the second voltage.