Multi-frequency electrical impedance tomography (EIT) systems require stable voltage controlled current generators that will work over a wide frequency range and with a large variation in load impedance. In this paper we compare the performance of two commonly used designs: the first is a modified Howland circuit whilst the second is based on a current mirror. The output current and the output ...

We report on the effect of chromatic dispersion on coherence length and noise of Fourier Domain Mode Locked (FDML) lasers. An FDML laser with a sweep range of 100 nm around 1550 nm has been investigated. Cavity configurations with and without dispersion compensation have been analyzed using different widths of the intra-cavity optical band-pass filter. The measurements are compared to non-FDML ...

This paper describes the design of an all-npn openloop sample-and-hold amplifier intended for use at the front end of analog-to-digital converters. Configured as a quasidifferential topology, the circuit employs capacitive coupling between the input and output to achieve differential voltage swings of 3 V in a 3.3-V system. It also exploits the high speed of bipolar transistors to attain a samp...

An atom attached to a micrometer-scale wire that is vibrating at a frequency ∼100 MHz and with displacement amplitude ∼1 nm experiences an acceleration magnitude ∼109 m s−2, approaching the surface gravity of a neutron star. As one application of such extreme noninertial forces in a mesoscopic setting, we consider a model two-path atom interferometer with one path consisting of the 100 MHz vibr...

We report a 65 MHz-bandwidth triangular-shaped optical parametric oscillator (OPO) for squeezed vacuum generation at 860 nm. The triangle structure of our OPO enables the round-trip length to reach 45 mm as a ring cavity, which provides a counter circulating optical path available for introducing a probe beam or generating another squeezed vacuum. Hence our OPO is suitable for the applications ...

A 900-MHz phase-locked loop frequency synthesizer implemented in a 0.6m CMOS technology is developed for the Wireless Integrated Network Sensors applications. It incorporates an automatic switched-capacitor (SC) discrete-tuning loop to extend the overall frequency tuning range to 20%, while the VCO gain ( VCO) resulting from the CMOS varactor continuous-tuning is kept low at only 20 MHz/V in or...

This paper presents a temperature compensated logarithmic amplifier (log-amp) RF power detector implemented in CMOS 0.18μm technology. The input power can range from -50 to +10 dBm for RF signals ranging from 100 MHz to 1.5 GHz. This design attains a typical DR of 39 dB for a ±1 dB logconformance error (LCE). Up to 900 MHz the temperature drift is never larger than ±1.1 dB for all 24 measured s...

We report on an extended-cavity mode-locked laser based on an Yb:CALGO crystal operating either at 27 MHz and 93 fs pulse duration or at 15 MHz and 170 fs duration single-pulse regime. To the best of our knowledge this is the first demonstration of an extended-cavity oscillator based on Yb-doped crystal producing sub-100 fs pulses. The pulse energy was 24 nJ directly at the output of the oscill...

The specific absorption rate (SAR) from mobile telephones at horizontal and vertical positions is investigated in human adult and child heads wearing metal-rim spectacles and having metallic implants. The SAR values calculated by Finite Difference Time Domain (FTDT) method are compared to the actual ANSI/IEEE standards and to the 900/1800/2100 MHz electromagnetic radiation limits according to E...

Magneto-inductive cables for low (ca 100 MHz) radio frequencies are demonstrated in thin-film form. 20 cm long resonant elements are formed using double-sided patterning of copper-clad polyimide, based on single-turn inductors and parallel-plate capacitors that use the substrate as an interlayer dielectric. Continuous cables are formed by overlaying elements, in an arrangement that allows a hig...