We propose and demonstrate a tunable photonic radio frequency notch filter. The filter has a single delay line architecture and incorporates a new wavelength-selective true-time-delay. The time delay in the feed-forward ioop can be varied by simply changing the optical wavelength resulting in a shift of the null of the filter response. Application in radar systems is discussed.

An experimental demonstration of a non commensurate group delay line is presented using all-pass C section networks is presented. A quasi-arbitrary group delay response can be obtained by allowing C sections with different length and properly adjusting the number of C sections in the design. The proposed C-section networks are suitable for analog signal processing of broad bandwidth (a few giga...

A novel 1-to-64 (6-bit (2 6 )) optical true-time delay module that can provide linear time delays ranging from 0 to 443.03 picoseconds is presented. The bandwidth of the fully packaged module is determined to be as high as 539 GHz. This true-time delay module is employed to control an eight-element K-band phased array antenna system. Far field patterns covering 18 GHz to 26.5 GHz are measured a...

Speakers with defective velopharyngeal mechanism, produce speech with inappropriate nasal resonances across vowel sounds. The acoustic analysis on hypernasal speech and nasalized vowels of normal speech shows that there is an additional frequency introduced in the low frequency region close to the first formant frequency [1]. The conventional formant extraction techniques may fail to resolve cl...

This paper describes the design of FIR delay filters with prescribed number of zeros at ω = π and prescribed magnitude and group delay flatness at ω = 0 that minimize a squared error. Even though the flatness constraints are in general non-linear functions of the filter coefficients, we show the remarkable fact that for a subclass of the filters a simple orthogonal projection of least squared e...

We implemented all-fiber delay line using linearly chirped fiber Bragg gratings (CFBG), which can be applicable for reflectometry or optical coherence tomography (OCT). Compared with the previously reported delay lines, the proposed fiber-based optical delay line has in principle novel advantages such as automatic dispersion cancellations without additional treatment and a gain in optical delay...

Wire routing by optimizing channel assignment within large apertures, " in Proc. Abstract-It is an accepted practice in signal delay estimation to model MOS digital circuits as RC circuits. In most cases Elmore's delay definition is applied. This paper has several objectives. First, it shows that Elmore's definition is exactly equivalent to the group delay of the network at zero frequency. Seco...

The relevance of our definition for sensitivity in refractometric sensing, being the relative change of the transmittance of a certain output channel of an optical device over the change of the refractive index of the probed material, is discussed. It is compared to one based on spectral shift per refractive index unit change. Further, it is discussed how group delay and sensitivity are interre...

We developed a method for group delay and group delay dispersion measurements, based on location of interference resonance peaks. Such resonance peaks can be observed in transmittance or in reflectance when two mirrors are placed parallel to each other and separated by a thin air spacer. By using a novel approach, based on simultaneous processing of the data acquired for different spacer distan...

This article presents some new results concerning recursive filters design with approximately linear phase and Chebyshev stopband attenuation. The denominator polynomial D(z) of the transfer function H(z)=N(zJ/D(z) is used to obtain a maximally flat behavior for the delay in the passband, whereas N(t) describes equiripple amplitude in the stopband. The approach under consideration is based on z...