Topic
Bandwidth (signal processing)
About: Bandwidth (signal processing) is a research topic. Over the lifetime, 48550 publications have been published within this topic receiving 600741 citations. The topic is also known as: Bandwidth (signal processing) & bandwidth.
Papers published on a yearly basis
Papers
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TL;DR: In this paper, a coplanar waveguide fed quasi-Yagi antenna is used to achieve a wide bandwidth and cross-polarization better than -17 dB at 10 GHz.
Abstract: A novel coplanar waveguide fed quasi-Yagi antenna is presented. A wide bandwidth is achieved by using a broadband coplanar waveguide to a slotline balun. An X-band prototype has been realised which demonstrates a broad bandwidth (30%), –19 dB front-to-back ratio, and cross-polarisation better than -17 dB at 10 GHz.
111 citations
Patent•
25 Oct 2006TL;DR: In this paper, the authors demonstrate and reduce to practice methods to extract information directly from an analog or digital signal based on altering our notion of sampling to replace uniform time samples with more general linear functionals.
Abstract: A typical data acquisition system takes periodic samples of a signal, image, or other data, often at the so-called Nyquist/Shannon sampling rate of two times the data bandwidth in order to ensure that no information is lost. In applications involving wideband signals, the Nyquist/Shannon sampling rate is very high, even though the signals may have a simple underlying structure. Recent developments in mathematics and signal processing have uncovered a solution to this Nyquist/Shannon sampling rate bottlenck for signals that are sparse or compressible in some representation. We demonstrate and reduce to practice methods to extract information directly from an analog or digital signal based on altering our notion of sampling to replace uniform time samples with more general linear functionals. One embodiment of our invention is a low-rate analog-to-information converter that can replace the high-rate analog-to-digital converter in certain applications involving wideband signals. Another embodiment is an encoding scheme for wideband discrete-time signals that condenses their information content.
111 citations
Patent•
22 Apr 2003
TL;DR: In this article, a system and method for classifying signals occurring in a frequency band is proposed, where the accumulated signal data is compared against reference data associated with known signals to classify the one or more signals in the frequency band based on the comparison.
Abstract: A system and method for classifying signals occurring in a frequency band One or more characteristics of one or more signals in the frequency band are detected using any suitable technology, such as a device that can generate characteristics of signal pulses detected in the frequency band Data pertaining to the signal pulses is accumulated over time The accumulated signal data is compared against reference data associated with known signals to classify the one or more signals in the frequency band based on the comparison The accumulated data may include one or more characteristics selected from the group consisting of: pulse center frequency, pulse bandwidth, pulse duration, time between pulses and number of different active pulses, and wherein the reference data associated with each of a plurality of known signals comprises one or more characteristics selected from the group consisting of: pulse center frequency, pulse bandwidth, pulse duration and time between pulses The accumulated signal data is compared against the reference data, and depending on the degree of match with reference data, a signal can be classified Additional levels of signal classification processing may be performed
111 citations
TL;DR: In this paper, a new framework is proposed to further exploit TCM to enhance the performance of the orthogonal MIMO antennas by correlating the characteristic currents and near fields of modes with high modal significance in a given frequency band.
Abstract: Recent work has shown that, with the help of the Theory of Characteristic Modes (TCM), minor modifications of the terminal chassis can facilitate the design of orthogonal multiple-input-multiple-output (MIMO) antennas with viable bandwidth at frequencies below 1 GHz. Herein, a new framework is proposed to further exploit TCM to enhance the performance of the orthogonal MIMO antennas. By correlating the characteristic currents and near fields of modes with high modal significance in a given frequency band, a single feed may be designed to excite multiple modes, leading to enlarged bandwidth. Similarly, the correlation of characteristic currents and near fields across different bands provides candidate modes that can be excited for multiband operation using a single feed. Moreover, the impedance matching of these modes can be improved by additional structural manipulation. As proof of concept, a dual-band (818-896 MHz, 1841-2067 MHz), dual-antenna prototype was designed on a 130 × 66-mm2 chassis for Long Term Evolution (LTE) operation. Full-wave simulation results were experimentally verified with a fabricated prototype.
111 citations
TL;DR: In this article, low-finesse Fabry-Perot cavities are used in series to generate frequency combs with a large mode spacing in a way that allows its application to a large optical bandwidth.
Abstract: We use low-finesse Fabry–Perot cavities in series to generate frequency combs with a large mode spacing in a way that allows its application to a large optical bandwidth. The attenuation of laser modes closest to the pass bands of the cavity exceeds 70 dB for a filter ratio of m=20 relative to the resonant modes centered within the pass bands. We also identify the best cavity geometry to suppress spurious transmission of higher order transversal modes. Such a thinned out frequency comb can be used to calibrate traditional spectrographs for precision astronomy. In the time domain mode filtering generates a pulse train with a multiplied repetition rate. High-fidelity filtering, as described here, implies small variations of the pulse energies.
111 citations