The present invention provides a filtering circuit comprising a poly phase filter and a quadrature phase detector. The poly phase filter comprises a first path, a second path, a third path and a fourth path. The first path is configured to receive a first input signal to generate a first clock signal. The second path comprising a first adjustable delay circuit is configured to receive the first input signal to generate a second clock signal. The third path comprising a second adjustable delay circuit is configured to receive a second input signal to generate a third clock signal. The fourth path is configured to receive the second input signal to generate a fourth clock signal. The quadrature phase detector is configured to detect phases of these clock signals to generate control signals to control the first adjustable delay circuit and the second adjustable delay circuit.

The present invention provides a filtering circuit comprising a poly phase filter and a quadrature phase detector. The poly phase filter comprises a first path, a second path, a third path and a fourth path. The first path is configured to receive a first input signal to generate a first clock signal. The second path comprising a first adjustable delay circuit is configured to receive the first input signal to generate a second clock signal. The third path comprising a second adjustable delay circuit is configured to receive a second input signal to generate a third clock signal. The fourth path is configured to receive the second input signal to generate a fourth clock signal. The quadrature phase detector is configured to detect phases of these clock signals to generate control signals to control the first adjustable delay circuit and the second adjustable delay circuit.

A device for wireless communications can include a phase selector, a coarse delay line, and a digitally controlled edge interpolator (DCEI). The phase selector receives an input signal and is coupled to the coarse delay line. The coarse delay line can provide one of a plurality of delay ranges. A DCEI, connected to the coarse delay line can provide a fine delay output signal.

A device for wireless communications can include a phase selector, a coarse delay line, and a digitally controlled edge interpolator (DCEI). The phase selector receives an input signal and is coupled to the coarse delay line. The coarse delay line can provide one of a plurality of delay ranges. A DCEI, connected to the coarse delay line can provide a fine delay output signal.

A variable delay circuit includes at least one first delay circuit and a second delay circuit. The first delay circuit includes multiple first delay elements connected in series and is configured to output a delay signal from a first stage first delay element that is a first stage of the first delay circuit. The second delay circuit includes at least one second delay element and multiple third delay elements connected in series. The second delay circuit is configured to output a delay signal from a first stage second delay element that is a first stage of the second delay circuit. The first stage first delay element and the first stage second delay element are connected in series. A delay signal obtained by delaying an input signal received at one circuit among the first delay circuit and the second delay circuit for a predetermined time duration is output from another circuit.

A variable delay circuit includes at least one first delay circuit and a second delay circuit. The first delay circuit includes multiple first delay elements connected in series and is configured to output a delay signal from a first stage first delay element that is a first stage of the first delay circuit. The second delay circuit includes at least one second delay element and multiple third delay elements connected in series. The second delay circuit is configured to output a delay signal from a first stage second delay element that is a first stage of the second delay circuit. The first stage first delay element and the first stage second delay element are connected in series. A delay signal obtained by delaying an input signal received at one circuit among the first delay circuit and the second delay circuit for a predetermined time duration is output from another circuit.

An aspect relates to an apparatus, including: a ring oscillator coupled between a first node and a first voltage rail; a control circuit coupled to the first node; a delay line coupled between a second node and the first voltage rail; and a voltage regulator including an input coupled to the first node and an output coupled to the second node.

An aspect relates to an apparatus, including: a ring oscillator coupled between a first node and a first voltage rail; a control circuit coupled to the first node; a delay line coupled between a second node and the first voltage rail; and a voltage regulator including an input coupled to the first node and an output coupled to the second node.

A digitally controlled delay line (DCDL) includes input and output terminals, and a plurality of stages that propagate a signal along a first signal path from the input terminal to a selectable return stage and along a second signal path from the return stage to the output terminal. Each stage includes a first inverter that selectively propagates the signal along the first signal path, a second inverter that selectively propagates the signal along the second signal path, and a third inverter that selectively propagates the signal from the first signal path to the second signal path. At least one of the first or third inverters includes a tuning portion including either a plurality of parallel, independently controllable p-type transistors coupled in series with a single independently controllable n-type transistor, or a plurality of parallel, independently controllable n-type transistors coupled in series with a single independently controllable p-type transistor.

A digitally controlled delay line (DCDL) includes input and output terminals, and a plurality of stages that propagate a signal along a first signal path from the input terminal to a selectable return stage and along a second signal path from the return stage to the output terminal. Each stage includes a first inverter that selectively propagates the signal along the first signal path, a second inverter that selectively propagates the signal along the second signal path, and a third inverter that selectively propagates the signal from the first signal path to the second signal path. At least one of the first or third inverters includes a tuning portion including either a plurality of parallel, independently controllable p-type transistors coupled in series with a single independently controllable n-type transistor, or a plurality of parallel, independently controllable n-type transistors coupled in series with a single independently controllable p-type transistor.