An example apparatus includes a polyphase transconductance-capacitor filter. The polyphase filter includes a DC bias voltage node, a plus in-phase filter unit, a minus in-phase filter unit, a plus quadrature-phase filter unit, and a minus quadrature-phase filter unit. Each filter unit respectively includes an input node, an output node, and a control node. The polyphase filter also includes a plus in-phase switch and a minus in-phase switch. The plus in-phase switch is coupled to the control node of the plus in-phase filter unit, the DC bias voltage node, and the input node of one or both of the plus quadrature-phase filter unit and the minus quadrature-phase filter unit. The minus in-phase switch is coupled to the control node of the minus in-phase filter unit, the DC bias voltage node, and the input node of one or both of the plus quadrature-phase filter unit and the minus quadrature-phase filter unit.

A phase interpolator is provided with a plurality of slices. Each slice includes a first switch for mixing a first clock signal into an interpolated output signal and a second switch for mixing a second clock signal into the interpolated output signal. In response to a high-resolution signal, at least one of the slices may switch on both the first switch and the second switch.

Described herein are systems and methods that allow for correcting a residual frequency offset in the GHz frequency range by using low-complexity analog circuit implementations of a broad-band frequency detector that comprises two analog polyphase filters in a dual configuration. Each filter comprises an RC network of cross-coupled capacitors that facilitate filters with opposite passbands and opposite stop-bands. In various embodiments, the outputs of the two filters are combined to obtain power metrics that when subtracted from each other, deliver a measure of the imbalance between the positive and negative halves of a frequency spectrum. Since the measure is substantially proportional to a frequency offset within a linear range spanning 5 GHz or more, the polyphase filters may be used in a broad-band frequency detector that, based on the measure, adjusts the frequency offset.

Described herein are systems and methods that allow for correcting a residual frequency offset in the GHz frequency range by using low-complexity analog circuit implementations of a broad-band frequency detector that comprises two analog polyphase filters in a dual configuration. Each filter comprises an RC network of cross-coupled capacitors that facilitate filters with opposite passbands and opposite stop-bands. In various embodiments, the outputs of the two filters are combined to obtain power metrics that when subtracted from each other, deliver a measure of the imbalance between the positive and negative halves of a frequency spectrum. Since the measure is substantially proportional to a frequency offset within a linear range spanning 5 GHz or more, the polyphase filters may be used in a broad-band frequency detector that, based on the measure, adjusts the frequency offset.

Systems, devices, and methods related to phase shifters are provided. An example true time-delay (TTD) phase shifter structure includes a signal conductive line disposed on a first layer of the structure; a first switchable ground plane comprising a first conductive plane disposed on a second layer of the structure; a second switchable ground plane comprising a second conductive plane disposed on a third layer of the structure, where the first, second, and third layers are separate layers of the structure; a first switch coupled between the first switchable ground plane and a first ground element, the first ground element disposed on the second layer; and a second switch coupled between the second switchable ground plane and a second ground element, the second ground element disposed on the third layer.

Systems, devices, and methods related to phase shifters are provided. An example true time-delay (TTD) phase shifter structure includes a signal conductive line disposed on a first layer of the structure; a first switchable ground plane comprising a first conductive plane disposed on a second layer of the structure; a second switchable ground plane comprising a second conductive plane disposed on a third layer of the structure, where the first, second, and third layers are separate layers of the structure; a first switch coupled between the first switchable ground plane and a first ground element, the first ground element disposed on the second layer; and a second switch coupled between the second switchable ground plane and a second ground element, the second ground element disposed on the third layer.

A filter circuit includes a polyphase filter used to generate a plurality of output signals with different phases according to a plurality of input signals. The polyphase filter includes a switch circuit and a feed-forward capacitor. The switch circuit has a control terminal used to receive a control voltage, a first connection terminal used to output one of the output signals, and a second connection terminal used to receive one of the input signals. The feed-forward capacitor has a first plate coupled to the second connection terminal of the switch circuit and a second plate coupled to the control terminal of the switch circuit.

An apparatus is disclosed for phase-shifting signals with a compensation circuit. In example implementations, an apparatus for phase-shifting signals includes a phase shifter having a first port and a second port. The phase shifter also includes a signal phase generator, a compensation circuit, and a vector modulator. The compensation circuit includes a first capacitor with a first capacitance and a second capacitor with a second capacitance. The first capacitance is different from the second capacitance. The signal phase generator is coupled between the first port and the compensation circuit. The vector modulator is coupled between the compensation circuit and the second port.

According to one embodiment, a transformer-based in-phase and quadrature (IQ) includes a differential balun having a first inductor and a second inductor. The first inductor has a first input terminal and a first output terminal. The second inductor has a second input terminal and a second output terminal. Additionally, the IQ generator circuit includes a third inductor magnetically coupled with the first inductor. The third inductor has a first isolation terminal and a third output terminal. The IQ generator circuit also includes a fourth inductor magnetically coupled with the second inductor. The fourth inductor has a second isolation terminal and a fourth output terminal. The IQ generator circuit additionally includes a first transistor coupled to the first input terminal of the first inductor. Further, the generator circuit includes a second transistor coupled to the second input terminal of the second inductor. The first transistor, the second transistor, the first inductor, and the second inductor form a part of a differential amplifier.

Described herein are systems and methods that allow for correcting a residual frequency offset in the GHz frequency range by using low-complexity analog circuit implementations of a broad-band frequency detector that comprises two analog polyphase filters in a dual configuration. Each filter comprises an RC network of cross-coupled capacitors that facilitate filters with opposite passbands and opposite stop-bands. In various embodiments, the outputs of the two filters are combined to obtain power metrics that when subtracted from each other, deliver a measure of the imbalance between the positive and negative halves of a frequency spectrum. Since the measure is substantially proportional to a frequency offset within a linear range spanning 5 GHz or more, the polyphase filters may be used in a broad-band frequency detector that, based on the measure, adjusts the frequency offset.