Abstract: An amplifier structure may include a first amplifier substructure having a first amplifier and a first filter structure and provide a first high frequency output signal and a first low frequency output signal having a frequency lower than a frequency of the first high frequency output signal. It may include a second amplifier substructure having a second amplifier and a second filter structure and provide a second high frequency output signal and a second low frequency output signal having a frequency lower than the frequency of the second high frequency output signal. It may include a first combination node configured to receive the first high frequency output signal and the second low frequency output signal and to provide a first amplified signal, and a second combination node configured to receive the first low frequency output signal and the second high frequency output signal and to provide a second amplified signal.

Abstract: Embodiments may comprise N-path filter circuitry with tunable radio frequency selectivity and up to 80 decibels per decade roll-off. The N-path filter may comprise at least one input transistor, wherein the at least one input transistor comprises a channel and a gate. A first end of the channel is coupled with a receiver circuitry input, wherein a second end of the channel is coupled with a load. The gate of the at least one input transistor is coupled with a clock circuitry input. The load may comprise a fourth order, all-pole driving point impedance. The impedance may shunt the second end of the channel to a circuit ground or a low voltage circuit rail via the impedance. And the impedance may comprise a first active impedance circuit coupled in series with a second active impedance circuit.

Abstract: Embodiments herein relate to an equalizer in a communication system. In an example implementation, the communication system is an optical system including a Vertical-Cavity Surface-Emitting Laser (VCSEL). A transfer function of the equalizer has two complex-zeroes to compensate for a group delay variation due to an underdamped complex-pole pair of the VCSEL optical response. The equalizer may include a first transistor having a control gate coupled to an input path, a drain coupled to an output path, and a source, and first, second and third paths coupled between the source and ground. The first path includes, in series, a resistor, a node and a capacitor, the second path includes a second transistor having a control gate coupled to the node, and the third path includes a capacitor. A tuning process can be used to achieve a desired frequency and quality factor.

Abstract: A filter includes a plurality of filtering paths. The plurality of filtering paths is driven by a corresponding plurality of local oscillator (LO) signals associated with an LO frequency. Each of the LO signals has a phase of a plurality of phases. Each filtering path of the plurality of filtering paths includes a plurality of signal generation branches. The plurality of signal generation branches is configured to receive a harmonic LO signal based on a fraction of the LO frequency, and generate an LO signal of the corresponding plurality of LO signals associated with the LO frequency using the harmonic LO signal.

Abstract: A tunable bandpass low-noise amplifier (LNA). The LNA includes a plurality of N-path filters and a plurality of cascode amplifiers. The cascode amplifiers are configured to amplify an input signal. Each N-path filter is coupled to a different one of the plurality of cascode amplifiers. The plurality of N-path filters are driven by local oscillator (LO) signals having different frequencies, and output nodes of the plurality of cascode amplifiers are coupled in parallel. The frequencies of the LO signals may be symmetrically spaced around a desired frequency (fLO). Each N-path filter may be coupled to a source of the common-gate device of the coupled cascode amplifier. The LO signals may be generated by a digital-to-time converter (DTC)-based frequency synthesizer. The frequencies of the LO signals supplied to the N-path filters may be adjusted to tune the bandwidth of the bandpass LNA.