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.

An adaptive capacitive filter circuit includes: a first terminal adapted to be coupled to a rectifier bridge output; a second terminal adapted to be coupled to a ground terminal; a first capacitor having a first electrode and a second electrode, the first electrode of the first capacitor coupled to the first terminal; a second capacitor having a first electrode and a second electrode, the second electrode of the second capacitor coupled to the second terminal; a first switch coupled between the second electrode of the first capacitor and the second terminal; a second switch coupled between the first terminal and the first electrode of the second capacitor; and a third switch coupled between the second electrode of the first capacitor and the first electrode of the second capacitor.

A method includes receiving a radio frequency (RF) input signal using at least one non-reciprocal circulator. The method also includes generating an RF output signal using at least one of multiple reflective filter elements. Each reflective filter element is configured to receive an RF signal from the at least one non-reciprocal circulator and to provide a filtered RF signal to the at least one non-reciprocal circulator. The reflective filter elements include amplitude change reflectors configured to modify amplitudes of the RF signal at different frequencies. The RF output signal represents the RF input signal as modified by the at least one of the reflective filter elements.

Apparatus and methods related to multipath bandpass filters with passband notches are provided herein. In certain configurations, a multipath bandpass filter includes multiple filter circuit branches or paths that are electrically connected in parallel with one another between an input terminal and an output terminal. The input terminal receives an input signal, and each filter circuit branch includes a downconverter that downconverts the input signal to generate a downconverted signal, a filter network that generates a filtered signal by filtering the downconverted signal, and an upconverter that upconverts the filtered signal to generate a branch output signal. The filter network includes at least one low pass filter and at least one notch filter to provide a passband with in-band notches. The branch output signals from the filter circuit branches are combined to generate an output signal at the output terminal.

A transceiver device includes a digital baseband circuit, a first circuit portion, and a second circuit portion. The digital baseband circuit is configured to analyze power of an input signal, in order to generate a first control signal and a second control signal. The first circuit portion has a first gain, and is configured to be selected according to the first control signal to process the input signal to generate output signals. The second circuit portion has a second gain higher than the first gain, and is configured to be selected according to the second control signal to process the input signal to generate the output signals. The first circuit portion includes an N-way filter circuit, and the N-way filter circuit is configured to modulate the input signal according to first oscillating signals to perform a filtering operation.

A radio frequency (RF) filter includes a signal conditioning circuit and a bandstop filter. The signal conditioning circuit receives a broadband RF signal that includes both a jamming signal at a jamming frequency and a signal of interest and generates a plurality of clock signals. Each of the plurality of clock signals has a substantially same frequency as the jamming frequency, but a different phase shift. The bandstop filter receives the RF signal and the plurality of clock signals. The bandstop filter attenuates signals within a bandstop centered at the frequency of the plurality of clock signals. A self-tuning N-path filter is provided.

A method includes receiving a radio frequency (RF) input signal using at least one non-reciprocal circulator. The method also includes generating an RF output signal using at least one of one or more reflective circuit elements. Each reflective circuit element is configured to receive an RF signal from the at least one non-reciprocal circulator and to provide a modified RF signal to the at least one non-reciprocal circulator. The RF output signal represents the RF input signal as modified by the at least one of the one or more reflective circuit elements.

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.

Adaptive RF filters based on modulated resonators are provided. The filter architecture is based on time-interleaved commutation of passive RF resonators. The architecture can behave as a two-port filter network, with a fully tunable instantaneous filter bandwidth. The filters are applicable as miniaturized, environment-aware RF signal processing components and can be used in mobile communications.

Apparatus and methods related to multipath bandpass filters with passband notches are provided herein. In certain configurations, a multipath bandpass filter includes multiple filter circuit branches or paths that are electrically connected in parallel with one another between an input terminal and an output terminal. The input terminal receives an input signal, and each filter circuit branch includes a downconverter that downconverts the input signal to generate a downconverted signal, a filter network that generates a filtered signal by filtering the downconverted signal, and an upconverter that upconverts the filtered signal to generate a branch output signal. The filter network includes at least one low pass filter and at least one notch filter to provide a passband with in-band notches. The branch output signals from the filter circuit branches are combined to generate an output signal at the output terminal.