International Technology Roadmap for Semiconductors 2003の要求清浄度について － シリコンウエハ表面と雰囲気環境に要求される清浄度, 分析方法の現状について －

An RF-DC power conversion system is designed to efficiently convert far-field RF energy to DC voltages at very low received power and voltages. Passive rectifier circuits are designed in a 0.25 mum CMOS technology using floating gate transistors as rectifying diodes. The 36-stage rectifier can rectify input voltages as low as 50 mV with a voltage gain of 6.4 and operates with received power as low as 5.5 muW(22.6 dBm). Optimized for far field, the circuit operates at a distance of 44 m from a 4 W EIRP source. The high voltage range achieved at low load current make it ideal for use in passively powered sensor networks.

Efficient Far-Field Radio Frequency Energy Harvesting for Passively Powered Sensor Networks

The idea of wireless power transfer (WPT) has been around since the inception of electricity. In the late 19th century, Nikola Tesla described the freedom to transfer energy between two points without the need for a physical connection to a power source as an ?all-surpassing importance to man? [1]. A truly wireless device, capable of being remotely powered, not only allows the obvious freedom of movement but also enables devices to be more compact by removing the necessity of a large battery. Applications could leverage this reduction in size and weight to increase the feasibility of concepts such as paper-thin, flexible displays [2], contact-lens-based augmented reality [3], and smart dust [4], among traditional point-to-point power transfer applications. While several methods of wireless power have been introduced since Tesla?s work, including near-field magnetic resonance and inductive coupling, laser-based optical power transmission, and far-field RF/microwave energy transmission, only RF/microwave and laser-based systems are truly long-range methods. While optical power transmission certainly has merit, its mechanisms are outside of the scope of this article and will not be discussed.

Harvesting Wireless Power: Survey of Energy-Harvester Conversion Efficiency in Far-Field, Wireless Power Transfer Systems

More than a decade of research in the field of thermal, motion, vibration and electromagnetic radiation energy harvesting has yielded increasing power output and smaller embodiments. Power management circuits for rectification and DC–DC conversion are becoming able to efficiently convert the power from these energy harvesters. This paper summarizes recent energy harvesting results and their power management circuits.

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Micropower energy harvesting

More than a decade of research in the field of thermal, motion, vibration and electromagnetic radiation energy harvesting has yielded increasing power output and smaller embodiments. Power management circuits for rectification and DC-DC conversion are becoming able to efficiently convert the power from these energy harvesters. This paper summarizes recent energy harvesting results and their power management circuits.

A receiving device (1) includes a rectifying unit (10) which has rectifying elements (Q9, Q10) and rectifies a received signal which is inputted, a bias supply unit (Q1 to Q8, C1 to C4, 14, 15) which intermittently supplies the rectifying elements with a bias voltage (V) corresponding to a threshold voltage of the rectifying elements, a detecting unit (12, 132, 133) which detects presence or absence of the received signal based on an output of the rectifying unit; and a control unit (131) which stops supply of the bias voltage when the detecting unit detects the received signal.

Receiver device and remote control system

A radio apparatus capable of correcting a direct current offset with high accuracy in a short time is provided. A radio apparatus according to an embodiment includes a first amplifier amplifying a signal inputted to an input terminal with amplification gain determined by a variable resistor to generate a first amplified signal, and a second amplifier amplifying the first amplified signal to generate a second amplified signal. Further, the radio apparatus includes a first correcting unit correcting a direct current offset of the first amplifier, and a second correcting unit correcting a direct current offset of the second amplifier. The radio apparatus also includes a reference voltage source or reference current source supplying a reference voltage or reference current for referring a direct current offset to the first amplifier and the second amplifier, a gain controller controlling the amplification gain of the first amplifier; and a correction controller controlling the gain controller to set the amplification gain to maximum and controlling the first and second correcting units to perform correction of the second correcting unit based on the second amplified signal obtained by inputting the reference voltage or the reference current to an input terminal of the second amplifier, and thereafter perform correction of the first correcting unit based on the second amplified signal obtained by inputting the reference voltage or the reference current to an input terminal of the first amplifier.

Radio apparatus having first and second amplifiers and which performs direct current offset correction of the first and second amplifiers

PROBLEM TO BE SOLVED: To provide a start-up device in which a start-up signal detection certainty is improved and a start-up method. SOLUTION: The start-up device includes a storage unit for storing an identifier, a rectification unit for rectifying a received signal, a generation unit for comparing the received signal rectified by the rectification unit with a reference signal and generates a digital signal from the received signal, a determination unit for determining whether the digital signal includes the information on the identifier, a reference change unit for changing the reference signal when the determination unit determines that the received signal does not include the information on the identifier, and a start-up instruction unit for performing a start-up instruction to an electric equipment when the determination unit determines that the received signal includes the information on the identifier. COPYRIGHT: (C)2010,JPO&INPIT

Start-up device and start-up method

A 2 GHz up-converter uses 0.25 /spl mu/m CMOS. Current adding and self-switching mixers are used for 1 V operation. A -40 dBc LO leakage within a 20 mV offset is achieved using a DC offset canceller. The measurement results at 1 V supply are 6.7 dB conversion gain, 6.5 dBm OIP3, /spl plusmn/2 dB gain deviation from -33 to 75/spl deg/, and 49 mW consumption.

A 1 V 2 GHz CMOS up-converter using self-switching mixers

PROBLEM TO BE SOLVED: To provide a controller capable of easily estimating power transmission efficiency.SOLUTION: A controller according to an embodiment of the invention estimates the power transmission efficiency between a power transmission unit which includes a first coil and a first capacity connected in parallel/series to the first coil, and a power reception unit that includes a second coil and a second capacity connected in parallel/series to the second coil and receives the power from the power transmission unit via the connection between the first coil and the second coil. The controller has an estimation section that estimates the power transmission efficiency by comparing a first voltage detected at a first point in the power transmission unit and a second voltage detected at a second point in the power reception unit, or by comparing a first current detected at the first point in the power transmission unit and a second current detected at the second point in the power reception unit.

Shoji Otaka

Papers

Receiver device and remote control system

Radio apparatus having first and second amplifiers and which performs direct current offset correction of the first and second amplifiers

Start-up device and start-up method

A 1 V 2 GHz CMOS up-converter using self-switching mixers

Controller, wireless power transmission device and method of estimating power transmission efficiency