Abstract: Reconfigurable direct radio frequency (RF) bandpass sampling receivers are disclosed that utilize analog interpolation filters to improve performance. The addition of the analog interpolation filter to the bandpass sampling receiver allows the quantization clock to be de-coupled from the RF sampling clock. As such, the quantization can be performed at a much slower rate than the initial RF sampling allowing the final analog bandwidth to be much narrower than the bandwidth of the first stage filter located before the high-speed sampler. The combination of a tunable bandpass filter, tunable bandpass sample clock and analog interpolation filter followed by a further stage of sampling and quantization at a slower rate than the bandpass sample clocking, therefore, provides significant advantageous by de-coupling the quantization sample rate from the high-speed sample rate. If desired, the analog interpolation filter may also be tunable. Other variations and implementations are also described.

Abstract: The present invention is a method and computer program for equalizing group delay and magnitude of a system for which a system response is known. The method and computer program are implemented via a finite impulse response (“FIR”) filter for the system, and the method broadly comprises the steps of: evaluating a desired response for the system as a function of an amplitude of the system and a phase of the system; separating the phase of the system into a linear component and a non-linear component; performing a first optimization by minimizing a weighted error between a desired response for the system and a cascaded response for the system as a function of an equalizing filter and a phase slope so as to obtain at least one local smallest error E(?) as a function of phase slope; and once the local smallest error E(?) is known, performing a second optimization to locate any existing global smallest error, wherein the global smallest error is within a set distance from the local smallest error.

Abstract: Nyquist folded bandpass sampling receivers are disclosed that utilize wideband filters and modulated sampling clocks to identify received signals. In operation, multiple Nyquist zones are allowed to fold on top of each other during sampling. Because the RF sampling clock is modulated, separate frequency modulations can be induced within each Nyquist zone. The signals that are folded together from different Nyquist zones can then be identified and distinguished. In particular, when the Nyquist zones fold on top of each other, the different signals from different Nyquist zones can be separated and identified based on the fact that the added modulation is different for each Nyquist zone. Thus, by using one or more clock modulations to induce frequency modulations that are Nyquist zone dependent, multiple Nyquist zones can be aliased together while still allowing for signals from different Nyquist zones to be separated and identified. Other variations and implementations are also described.

Abstract: Reconfigurable direct radio frequency (RF) bandpass sampling receivers are disclosed that provide direct RF sampling of an input signal spectrum passed through a bandpass filter that is tunable over a wide frequency range of interest and that is sampled based on the bandwidth of the filter rather than the bandwidth of the total frequency range of interest. The bandwidth of the filter may further be variable to provide for optimized search against a variety of signal bandwidths. The reconfigurable direct RF bandpass sampling receiver may be implemented with a single fixed clock for applications where the signals of interest lie in adjacent non-overlapping frequency channels. For applications requiring arbitrary tuning, the reconfigurable direct RF bandpass sampling receiver can also use a programmable or switched sampling clock to avoid the Nyquist sample boundaries that occur with bandpass sampling and thus provide sampling of arbitrary frequencies.

Abstract: Nyquist folded bandpass sampling receivers are disclosed that utilize narrow band filters in parallel with wideband filters to enhance reception of ultra wideband (UWB) pulses. The addition of the narrow band filter facilitates the reception of ultra wideband signal pulses and, therefore, extends the Nyquist folding bandpass sampling receiver to allow improved processing of ultra wideband (UWB) pulses. RF sampling circuitry utilizing a modulated sampling clock signal can then better capture UWB pulse signals.

Abstract: A swept bandpass filter for receiving frequency varying input signals is disclosed. More particularly, a swept bandpass filter frequency modulated continuous wave (FMCW) receiver and related method are disclosed that provide an efficient solution for FMCW signals. The swept bandpass architecture eliminates the need for front-end mixing circuitry and allows for sampling across one or more Nyquist zones within the swept frequency band.

Abstract: Systems and methods for analog to digital conversion that may be implemented using a digital to analog converter (DAC) to provide negative feedback to at least Partially cancel one or more signals (e.g., one or more interfering signals present with one or more desired signals, one or more strong desired signals etc.) at the analog input of an analog to digital converter (ADC), and that may be used to extend the effective dynamic range of an ADC. The effective dynamic range of an ADC may be extended by detecting and isolating signals and using digital adaptive digital filtering along with a digital to analog converter (DAC) to provide negative feedback to cancel the signal/s at the input of the ADC.