Frequency multiplier

About: Frequency multiplier is a research topic. Over the lifetime, 10510 publications have been published within this topic receiving 110684 citations.

Electrosurgical generator and system

Abstract: In an electrosurgical generator for generating radio frequency power, the generator includes a radio frequency output stage having two or more output connections, and a power supply coupled to the output stage for supplying power to the output stage. A controller is operable to cause the generator to supply a blended output signal alternating constantly between a first output signal across the output connections in which the radio frequency output voltage developed across the output connections is limited to at least a first predetermined threshold value for cutting or vaporisation of tissue, and a second output signal across the output connections in which the radio frequency output voltage developed across the output connections is limited to a second threshold value for coagulation. There is also provided adjustment means, operable by a user of the electrosurgical generator, for changing between various preset settings for the blended signal, the preset settings each having a predetermined duty cycle of the blended signal that is limited to the first threshold value for cutting or vaporisation, and a predetermined duty cycle of the blended signal that is limited to the second threshold value for coagulation.

Optical frequency synthesizer for precision spectroscopy

Abstract: We have used the frequency comb generated by a femtosecond mode-locked laser and broadened to more than an optical octave in a photonic crystal fiber to realize a frequency chain that links a 10 MHz radio frequency reference phase-coherently in one step to the optical region. By comparison with a similar frequency chain we set an upper limit for the uncertainty of this new approach to 5. 1x10(-16). This opens the door for measurement and synthesis of virtually any optical frequency and is ready to revolutionize frequency metrology.

Electrosurgical generator and system for underwater operation

Abstract: A radio frequency generator for an electrosurgical system is provided, the system including an electrode assembly having two electrodes for use immersed in an electrically conductive fluid. The generator has control circuitry for rapidly reducing the delivered radio frequency output power by at least 50 % within at most a few cycles of the peak radio frequency output voltage reaching a predetermined threshold limit. In this way, tissue coagulation can be performed in, for example, saline without significant steam generation. The same peak voltage limitation technique is used in a tissue vaporisation or cutting mode to limit the size of the steam pocket at the electrodes and to avoid electrode burning. The generator has a push-pull output stage with a series-resonant output circuit, the output stage being driven by a radio frequency oscillator at a frequency which, in general, differs from the resonant frequency of the resonant output circuit. Power control is achieved by varying the ON-time of switching transistors forming the push-pull output pair and by altering the frequency spacing between the excitation frequency and the resonant frequency of the series-resonant output circuit. In an alternative embodiment, a bridge configuration using two push-pull pairs is used, yielding a further power control variable: the relative phase of the driving signals to the respective transistor pairs.

Electric surgical signal generator and electric surgical system

Abstract: PROBLEM TO BE SOLVED: To improve the efficiency of electric surgical system SOLUTION: An electric surgical signal generator, which operates in specially UHF(ultra-high frequency) or more higher frequency, has a circuit 32 that is for detecting reflective power, and a control device, which is connected to the detecting circuit for the frequency of output of radio frequency to be changed with monitoring the reflective power Then the output frequency is set the value that is according to the minimum reflective power level

A Silicon 60-GHz Receiver and Transmitter Chipset for Broadband Communications

Abstract: A 0.13-mum SiGe BiCMOS double-conversion superheterodyne receiver and transmitter chipset for data communications in the 60-GHz band is presented. The receiver chip includes an image-reject low-noise amplifier (LNA), RF-to-IF mixer, IF amplifier strip, quadrature IF-to-baseband mixers, phase-locked loop (PLL), and frequency tripler. It achieves a 6-dB noise figure, -30 dBm IIP3, and consumes 500 mW. The transmitter chip includes a power amplifier, image-reject driver, IF-to-RF upmixer, IF amplifier strip, quadrature baseband-to-IF mixers, PLL, and frequency tripler. It achieves output P1dB of 10 to 12dBm, Psat of 15 to 17 dBm, and consumes 800 mW. The chips have been packaged with planar antennas, and a wireless data link at 630 Mb/s over 10 m has been demonstrated