A phase interpolator circuit has a first stage that selects a pair of phase vectors from among M available sets of pairs and a second stage that interpolates between the selected pair to phase align a sample clock. The interpolation functions applied to selected pairs of phase vectors can differ to account for integral non-linearity, duty-cycle distortion, phase errors, and crosstalk that vary between phase vectors.

There is provided an optical encoder including a phase shifter circuit, two multiplexers, two digital circuits and four comparators. The phase shifter circuit receives signals from an amplifier and outputs multiple phase shifted signals. Each of the two multiplexers receives a half of the multiple phase shifted signals and outputs two pairs of phase shifted signals, each pair having 180 degrees phase difference, respectively to two comparators connected thereto. Each of the two digital circuits controls the corresponding multiplexer to select the two pairs of phase shifted signals from the half of the multiple phase shifted signals.

A method includes connecting inputs of a first plurality of interpolation branches to a first clock signal, connecting inputs of a second plurality of interpolation branches to a second clock signal, and connecting inputs of a third plurality of interpolation branches to a third clock signal. The method also includes combining outputs of the first plurality of interpolation branches, the second plurality of interpolation branches, and the third plurality of interpolation branches to produce an output clock signal and adjusting a phase of the output clock signal by connecting an input of an interpolation branch of the third plurality of interpolation branches to the second clock signal.

A phase correction circuit includes: a test clock generation unit including a plurality of signal paths and configurable to generate a plurality of test clock signals in response to a plurality of selection signals and a plurality of phase control signals; a detection unit configured to generate a plurality of detection voltages using the plurality of test clock signals; and a control unit configured to generate the plurality of selection signals, detect phase skews of the plurality of signal paths according to the plurality of detection voltages, and generate the plurality of phase control signals for correcting the phase skews.

In described examples, a quadrature phase shifter includes digitally programmable phase shifter networks for generating leading and lagging output signals in quadrature. The phase shifter networks include passive components for reactively inducing phase shifts, which need not consume active power. Output currents from the transistors coupled to the phase shifter networks are substantially in quadrature and can be made further accurate by adjusted by a weight function implemented using current steering elements. Example low-loss quadrature phase shifters described herein can be functionally integrated to provide low-power, low-noise up/down mixers, vector modulators and transceiver front-ends for millimeter wavelength (mmwave) communication systems.

There is provided an optical encoder including a phase shifter circuit, two multiplexers, two digital circuits and four comparators. The phase shifter circuit receives signals from an amplifier and outputs multiple phase shifted signals. Each of the two multiplexers receives a half of the multiple phase shifted signals and outputs two pairs of phase shifted signals, each pair having 180 degrees phase difference, respectively to two comparators connected thereto. Each of the two digital circuits controls the corresponding multiplexer to select the two pairs of phase shifted signals from the half of the multiple phase shifted signals.

A millimeter wave (MMW) circuitry includes a phase modulation circuitry, a plurality of amplifier multiplier chain circuitries and a power combiner circuitry. The phase modulation circuitry is configured to receive input data and a plurality of divided input signals and to provide as output a plurality of phase modulation circuitry output signals. Each phase modulation circuitry output signal corresponds to a respective divided input signal. At least one phase modulation circuitry output signal has a nonzero phase relative to the divided input signals that is related to the input data. Each amplifier multiplier chain circuitry is configured to amplify and frequency multiply and phase multiply the respective phase modulation circuitry output signal to yield a respective power combiner input signal. The power combiner circuitry is configured to sum a plurality of power combiner input signals to yield an output signal. A modulation of the output signal is related to the input data.

A phase shifter includes a first capacitor connected to a first line to which a first input signal is input, a second capacitor connected to a second line to which a second input signal having a first phase difference with respect to the first input signal is input, and a combining circuit that is connected to the first line and the second line and that outputs a combined signal having a phase determined depending on a first capacitance ratio between the first capacitor and the second capacitor.

A filter circuit includes a filter that is disposed on a path connecting a common terminal and an input output terminal and uses a first frequency band as a pass band, a filter that is disposed on a path connecting the common terminal and an input output terminal and uses a second frequency band different from the first frequency band as a pass band, and a phase adjustment circuit that has an input terminal connected to the path and an output terminal connected to the path, and adjusts a phase of a signal in the first frequency band input from the path and outputs a signal having a phase different from a phase of the signal in the first frequency band to the output terminal, wherein the path and the path are paths through which a received signal passes.

A detection circuit is configured to detect phase information between two clock signals of different frequencies, and the two clock signals include a low frequency clock signal and a high frequency clock signal. The detection circuit includes: a signal generation module, configured to detect the low frequency clock signal at an edge of the high frequency clock signal to generate a to-be-sampled signal, and generate a target sampling signal when the high frequency clock signal is kept at a preset level and the low frequency clock signal meets a preset condition; and a sampling module, connected with the signal generation module and configured to detect the to-be-sampled signal at an edge of the target sampling signal to generate a detection result signal.