Topic
RF probe
About: RF probe is a research topic. Over the lifetime, 1862 publications have been published within this topic receiving 27765 citations.
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26 Apr 1991
TL;DR: In this paper, a temperature sensor (29) carried by and in thermally conductive relationship with an electrode (28) is connected for feedback to a control circuit (6) that modulates RF power applied to the electrode according to the signal received from the temperature sensor.
Abstract: Radiofrequency medical devices for ohmic heating of tissue of a patient include a temperature sensor (29) carried by and in thermally conductive relationship with a thermally conductive electrode (28). The sensor (29) is connected for feedback to a control circuit (6) that modulates RF power applied to the electrode according to the signal received from the temperature sensor (29). The control circuit (6) and RF power supply alternate between two operating modes. In the first mode the RF power supply applies RF power to the electrode (28). In the second mode the control circuit (6) senses a signal from the temperature sensor (29) in the absence of RF signal. The control circuit (6) compares the signal from the temperature sensor (29) to a set value and modulates the RF power applied to the electrode (28) in accordance with the set value.
484 citations
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TL;DR: It is shown that the RF-to-dc conversion efficiency is more than doubled compared to that measured with a single RF source, thanks to the proposed rectifier architecture.
Abstract: The aim of this paper is to show the possibility to harvest RF energy to supply wireless sensor networks in an outdoor environment. In those conditions, the number of existing RF bands is unpredictable. The RF circuit has to harvest all the potential RF energy present and cannot be designed for a single RF tone. In this paper, the designed RF harvester adds powers coming from an unlimited number of sub-frequency bands. The harvester’s output voltage ratios increase with the number of RF bands. As an application example, a 4-RF band rectenna is designed. The system harvests energy from GSM900 (Global System for Mobile Communications), GSM1800, UMTS (Universal Mobile Telecommunications System) and WiFi bands simultaneously. RF-to-dc conversion efficiency is measured at 62% for a cumulative ${-}{\hbox{10}}$ -dBm input power homogeneously widespread over the four RF bands and reaches 84% at 5.8 dBm. The relative error between the measured dc output power with all four RF bands on and the ideal sum of each of the four RF bands power contribution is less than 3%. It is shown that the RF-to-dc conversion efficiency is more than doubled compared to that measured with a single RF source, thanks to the proposed rectifier architecture.
297 citations
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10 Oct 2002
TL;DR: In this paper, a fully integrated RF switch is described including control logic and a negative voltage generator with the RF switch elements, which includes an oscillator, a charge pump, CMOS logic circuitry, level-shifting and voltage divider circuits, and an RF buffer circuit.
Abstract: An RF switch circuit and method for switching RF signals that may be fabricated using common integrated circuit materials such as silicon, particularly using insulating substrate technologies. The RF switch includes switching and shunting transistor groupings to alternatively couple RF input signals to a common RF node, each controlled by a switching control voltage (SW) or its inverse (SW_), which are approximately symmetrical about ground. The transistor groupings each comprise one or more insulating gate FET transistors connected together in a “stacked” series channel configuration, which increases the breakdown voltage across the series connected transistors and improves RF switch compression. A fully integrated RF switch is described including control logic and a negative voltage generator with the RF switch elements. In one embodiment, the fully integrated RF switch includes an oscillator, a charge pump, CMOS logic circuitry, level-shifting and voltage divider circuits, and an RF buffer circuit.
240 citations
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20 May 1998
TL;DR: In this article, a probe for testing integrated circuits at microwave frequencies employs a tapered coaxial transmission line to transform the impedance at the probe tips to the impedance of the test instruments.
Abstract: A probe for testing integrated circuits at microwave frequencies employs a tapered coaxial transmission line to transform the impedance at the probe tips (12) to the impedance of the test instruments. Mechanically resilient probe tip structures (12) allow reliable probing of non-planar circuits and the elastic probe body allows large overprobing without damage to the test circuit. Novel insulator structures (13) for the coaxial line allow easy and accurate assembly and high performance.
222 citations