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 transformer-based dual band watt-level linear CMOS power amplifier is demonstrated for upcoming SDR mobile terminals. The proposed AM-PM distortion canceller improves ACLR of 3GPP WCDMA uplink signal by 2.6dB at 28.0dBm output power, and the designed interstage power distributor contributes to low-loss power supply for the driver stage and high common-mode stability. Moreover, a newly developed cascode biasing circuit guarantees AM-AM linearity of the PA in a wide supply voltage range from 2.5V to 3.6V. The test chip demonstrates peak output powers of 28.3dBm at 1.95GHz and 23.7dBm at 2.4GHz satisfying 3GPP WCDMA and IEEE802.11g spectrum masks with die area of 5.4mm2.

A 1.9/2.4GHz dual band CMOS power amplifier with integrated AM-PM distortion canceller

A quadrature modulator for generating a transmission signal includes an orthogonal signal generator configured to generate a first local signal and a second local signal orthogonal to the first local signal, a mix-adder configured to generate a first RF signal based on a first baseband signal, the first local signal, and the second local signal, and a mix-subtracter configured to generate a second RF signal based on a second baseband signal, the first local signal, and the second local signal. The quadrature modulator also includes an output subtracter configured to determine a difference between the first RF signal and the second RF signal and to generate the transmission signal based on the difference; and an amplitude adjuster configured to adjust an amplitude of the first baseband signal before feeding it to the mix-adder or adjust an amplitude of the second baseband signal before feeding it to the mix-subtracter.

Quadrature modulator and vector correction 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 method of setting a wireless link and a wireless system, whereby a wireless link can be established in response to the starting command of a user, etc. surely in the wireless system including two wireless devices, and the consuming power required therefor may be very small. SOLUTION: The method of setting the wireless link is the one performed in the wireless system between first and second radio devices 12, 11, and the first radio device 12 has an ultra-power-saving receiver. When receiving a predetermined wireless signal by the ultra-power-saving receiver, the intermittent broadcast of packets is transmitted during the term extended from the power-supply-on of the first wireless device 12 to the reception of the responding packet performed by the second device 11, without providing any transmission stopping term. COPYRIGHT: (C)2010,JPO&INPIT

Method of setting wireless link, and wireless system

A frequency converter includes a voltage-current converter circuit which generates a positive-phase input current signal and a negative-phase input current signal, a switching circuit which switches between the positive-phase input current signal and the negative-phase input current signal according to a positive-phase local oscillator signal and a negative-phase local oscillator signal to generate a positive-phase output current signal and a negative-phase output current signal, an amplifier circuit which current-voltage converts and amplifies the positive-phase output current signal and negative-phase output current signal to generate a positive-phase output voltage signal and a negative-phase output voltage signal, and a plurality of CR circuits which are inserted at least either between the voltage-current converter circuit and the switching circuit or between the switching circuit and the amplifier circuit and each of which includes at least one capacitor through which high-frequency components pass and at least one resistance through which low-frequency noise components pass.

Shoji Otaka

Papers

A 1.9/2.4GHz dual band CMOS power amplifier with integrated AM-PM distortion canceller

Quadrature modulator and vector correction method

A 1-V 2-GHz CMOS Up-Converter Using Self-Switching Mixers

Method of setting wireless link, and wireless system

Frequency converter and receiver and transmitter using the same