This paper presents a comparison of frequency pullability in oscillators using a single AT-cut crystal and those using two single AT-cut crystals connected in parallel operated with a series load capacitance or series load inductance at fundamental frequencies of 4, 10 and 19 MHz. Pullability describes how the operating frequency may be changed by varying the load capacitance. The paper also gi...

The properties of small finite size FSS for use particularly at long wavelengths are summarised. The intended use is the modification of the EM architecture of buildings at mobile radio frequencies. Introduction: At microwave and millimetre wave frequencies the physical sizes of Frequency Selective arrays are, in virtually all practical applications, large enough for the structures to be adequa...

We investigate the potential of using ultrasonic diffraction tomography technique for characterization of biological tissues. Unlike most of other studies where ultrasonic tomography operates at frequencies higher than 1 MHz, low-frequency tomography uses lower frequencies on the order of 0.3-0.5 MHz. Such a choice is due to low attenuation at these frequencies, resulting in higher precision of...

Frequency multipliers based on superlattice (SL) devices as nonlinear elements have been developed as radiation sources for a terahertz (THz) laboratory spectrometer. Input frequencies of 100 and 250 GHz from backward wave oscillators have been multiplied up to the 11th harmonic, producing usable frequencies up to 2.7 THz. Even at these high frequencies the output power is sufficient for labora...

A vast pool of frequency bands from 450 MHz to 3.6 GHz is available for deployment of LTE and LTEAdvanced networks. But with increase in the operating frequency path loss increases which in turn impacts the coverage area of a base station. Accordingly the number of base stations increases which leads to increase in the cost of deployment. Availability of spectrum in high frequency range is not ...

Locomotory muscles typically operate over a narrow range of contraction frequencies, characterized by the predominant fiber types and functional roles. The highest documented frequencies in the synchronous sound-producing muscles of insects (550 Hz) and toadfish (200 Hz) far exceed the contraction frequencies observed in weight-bearing locomotory muscles, which have maximum documented frequenci...

Nanomechanical resonators operating in vacuum are capable of detecting and weighing single biomolecules, but their application to the life sciences has been limited by viscous forces that impede their motion in liquid environments. A promising approach to avoid this problem, encapsulating the fluid within a mechanical resonator surrounded by vacuum, has not yet been tried with resonant sensors ...