A DC-offset cancellation scheme in the 5GHz directconversion receiver compliant with IEEE 802.11a wireless LAN standard is described in this paper. It uses the analog R~F4~~ i"a I oU feedback loop to eliminate the DC-offset at the output of the double-balanced mixer. The mixer has a simulation voltageA conversion gain of 13dB at 5.2GHz, noise figure of 9.67dB, -. 1) IIP3 of 7.6dBm. The solution...

In this paper we present an in-ground intrusion detection system for security applications. Here, an optical fibre pressure switch is directly connected to a standard digital input of a programmable logic controller (PLC). This is achieved using an intensiometric detection system, where a laser diode and Fibre Bragg Grating (FBG) are optically mismatched, resulting in a static dc offset from th...

We have investigated the RF power degradation of GaN high electron mobility transistors (HEMTs) with different gate placement in the source–drain gap. We found that devices with a centered gate show different degradation behavior from those with the gate placed closer to the source. In particular, centered gate devices degraded through a mechanism that has a similar signature as that responsibl...

This paper is devoted to the design of a sliding-mode control scheme for a buck-based inverter, with programmable amplitude, frequency, and dc offset, with no external sinusoidal reference required. A general procedure for obtaining an autonomous (time independent) switching surface from a time-dependent one is presented. For this surface, the system exhibits a zeroth-order dynamics in sliding ...

In linear IC's fabricated in a low-voltage CMOS technology, the reduction of the dynamic range due to the dc offset and low,frequency noise of the ampli$ers becomes increasingly significant. Also, the achievable aniplijier gain is often quite low in such a technology, since cascoding may not be a practical circuit option due to the resulting reduction of the output signal swing. In this paper, ...

1. Abstract This paper presents the features of Instrumentation Amplifier for biomedical applications. This Instrumentation Amplifier is a device created from Operational Tran conductance Amplifier. It is designed to have input high impedance , output low impedance, low DC offset, low noise , high common mode rejection ratio and high power supply rejection ratio. The circuit has been integrated...

This paper describes a CMOS capacitive sensing amplifier for a monolithic MEMS accelerometer fabricated by post-CMOS surface micromachining. This chopper stabilized amplifier employs capacitance matching with optimal transistor sizing to minimize sensor noise floor. Offsets due to sensor and circuit are reduced by ac offset calibration and dc offset cancellation based on a differential differen...

Out of the various existing ultrasonic power measurement techniques, the radiation force balance method using microbalance is most widely used in low power (below 1 W) regime. The major source of uncertainty associated with this technique is the error in ac voltage measurement applied to the transducer for the generation of ultrasonic waves. The sources that deteriorate the ac voltage measureme...

This paper analyses and explains from the systems point of view, microprocessor based protective relay (MBPR) systems with emphasis on differential equation algorithms. Presently, the application of protective relaying in power systems, using MBPR systems, based on the differential equation algorithm is valued more than the protection relaying based on any other type of algorithm, because of ad...

Estimation of fundamental frequency component of current and / or voltage signals is essential for relaying decision in most of the numerical algorithms used for the protection of power system components. Modern numerical relays generally use discrete Fourier transform for extracting the fundamental component from the post fault signals consisting of fundamental as well as non-fundamental frequ...