Certain aspects of the present disclosure provide N-path filters with wider passbands and steeper rejection than conventional N-path filters with only a single pole in each filter path. These N-path filters also have a flatter passband with decreased passband droop. One example N-path filter generally includes a plurality of branches selectively connected with a common node, each branch of the N-path filter comprising a switch connected in series with an impedance comprising a common drain amplifier circuit. In certain aspects, the amplifier circuit may include a degeneration circuit for stability and/or a poly-phase feedback circuit to reduce in-band peaking.

Certain aspects of the present disclosure provide an N-path filter implemented using a generalized impedance converter (GIC) circuit. The GIC circuit is configured such that the N-path filter has a desired frequency response, which may include a wide passband with steeper rejection than a conventional N-path filter with only a single pole in each filter path. Certain aspects of the present disclosure provide an N-path filter having a frequency response with multiple concurrent passbands. In certain aspects, the N-path filter with multiple passbands is implemented using the GIC circuit. In other aspects, the N-path filter may include a bandpass response circuit where an inductance of the bandpass response circuit may be implemented using gyrators.

A wireless receiver with high linearity, having an out-band signal bypass filter, a mixer, and a baseband circuit. The out-band signal bypass filter has a first terminal and a second terminal respectively receiving a positive differential signal and a negative differential signal from a former-stage circuit, and the out-band signal bypass filter provides an out-band signal bypass path from the first terminal to the second terminal. The mixer receives a filtered signal from the out-band signal bypass filter. The baseband circuit is coupled to the mixer for generation of an in-phase signal and a quadrature phase signal.

The present invention discloses a gain-boosted n-path passive-mixer-first receiver. According to another aspect of the present disclosure, a gain-boosted n-path passive-mixer-first receiver is provided. The receiver includes a number n of switch-capacitor (sc) sets, a resistor, and a transconductance amplifier. The sc sets connect in parallel, and the sc sets have a first node and a second node. The resistor connects to the first node. The transconductance amplifier connects to the resistor and the second node.

According to another aspect of the present disclosure, a radio-frequency-to-baseband-function-reuse receiver with shared amplifiers for common-mode and differential-mode amplification is provided. The receiver includes two set networks connected in parallel. The set networks includes a first and a second input capacitors, a first and a second output capacitors, a first transconductance amplifier having an input terminal, a second transconductance amplifier having an input terminal, a first switch, and a second switch. The first and the second input capacitors connect to a first node. The first and the second output capacitors connect to a second node. The first transconductance amplifier connects between the first input capacitor and the first output capacitor. The second transconductance amplifier connects between the second input capacitor and the second output capacitor. The first switch connects between the input terminal of the first transconductance amplifier and the second node. The second switch connects between the input terminal of the second transconductance amplifier and the second node.

An N-path filter includes first signal paths connected in parallel with each other between signal terminals and second signal paths. Each of the first signal paths includes first and second switches connected to the signal terminals, and a base filter connected between the first and second switches. Each of the second signal paths includes a third switch connected to a signal terminal. The base filter includes a series arm element including a reactance component. The first and second switches modulate an input signal with a phase that completes one cycle across the signal paths, and the third switch modulates the input signal with a phase that completes one cycle across the signal paths. A phase of a drive signal to drive the second switch is opposite to a phase of a drive signal to drive the third switch.

Methods, systems, and computer readable media for a tunable filter employing feedforward cancellation are disclosed. According to one aspect, the subject matter described herein includes a tunable transmissive filter that includes a splitter for splitting an input signal into a first signal and a second signal, a first modifier circuit for modifying a characteristic of the first signal to produce a modified first signal, a second modifier circuit for using feedforward cancellation to modify a characteristic of the second signal to produce a modified second signal, the second modifier circuit including an N-path filter, N being an integer greater than 0; and a combiner for combining the modified first signal and the modified second signal to produce a filtered output signal having a bandpass response.

Methods and apparatus, including computer program products, are provided for receivers. In one aspect there is provided an apparatus. In some example embodiments, there is provided an apparatus. The apparatus may include a first N-path filter configured with at least a first passband, wherein the first N-path filter is coupled to a radio frequency input port providing at least a first carrier aggregation signal, a second carrier aggregation signal, and an interfering signal; a second N-path filter configured with at least a second passband, wherein the second N-path filter is coupled to the radio frequency input port providing at least the first carrier aggregation signal, the second carrier aggregation signal, and the interfering signal; and a combiner configured to subtract a first output of the first N-path filter from a second output of the second N-path filter. Related apparatus, systems, methods, and articles are also described.

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.

Ultra-Wideband (UWB) technology exploits modulated coded impulses over a wide frequency spectrum with very low power over a short distance for digital data transmission. Such UWB systems through their receivers may operate in the presence of interfering signals and should provide for robust communications. Accordingly, an accurate and sharp filter that operates at low power is required and beneficially one that does not require a highly accurate power heavy clock. Further, many UWB applications require location and/or range finding of other elements and it would therefore be beneficial to provide a UWB based range finding and/or location capability removing the requirement to add additional device complexity and, typically significant, power consumption.