Abstract-Rectifiers are important energy converters and henceforth crucial building blocks for RFID applications. In the first half of the work, we have presented a design methodology for matching the rectifier input impedance with the antenna to maximize the rectifier power conversion efficiency. The proposed design approach uses the fundamental transconductance (Gm(1)) analysis to estimate the rectifier input impedance. In the second half, a comparison between various possible single-stage rectifier topologies implemented in a CMOS 0.18 µm technology operating at UHF-band is presented. Using voltage conversion efficiency as the FOM, the optimum rectifier topology for RFID application is determined.Index Terms-CMOS, impedance matching, radio frequency identification (RFID), rectifiers, ultra-high frequency (UHF).

Abstract-This paper describes a receiver system design for impulse-radio ultra-wideband (IR-UWB) that operates at two carrier frequencies-3.494 and 3.993 GHz-with a 10-Mbps data rate. To reduce the power consumption of the front-end amplifiers, a super-regenerative architecture is used. An integrated circuit, implemented in a CMOS 0.18-m technology and operating with a 1.5-V power supply, exhibits energy consumption of 0.24 nJ/bit with a measured sensitivity of 66 and 61 dBm at 3.494 and 3.993 GHz, respectively, with a BER of . Also included on the integrated circuit is an automatic tuning circuit based on a digital phase-locked loop that is used to set the resonant frequency of the super-regenerative block.Index Terms-Digital phase-locked loop, oscillator, receiver architecture, super-regenerative system, ultra-wideband communication, wireless sensor network.

Abstract-A platform to study ultrasound as a source for wireless energy transfer and communication for implanted medical devices is described. A tank is used as a container for a pair of electroacoustic transducers, where a control unit is fixed to one wall of the tank and a transponder can be manually moved in three axes and rotate using a mechanical system. The tank is filled with water to allow acoustic energy and data transfer, and the system is optimized to avoid parasitic effects due to cables, reflection paths and cross talk problems. A printed circuit board is developed to test energy scavenging such that enough acoustic intensity is generated by the control unit to recharge a battery loaded to the transponder. In the same manner, a second printed circuit board is fabricated to study transmission of information through acoustic waves.Index Terms-biomedical telemetry, energy scavenging, implanted medical devices, ultrasound, sensor networks, wireless communication.

Abstract-It is desirable in active medical implants to derive energy from external sources to charge a rechargeable battery. In this paper we have developed a novel system to transfer energy via ultrasound to a deep implanted medical device. Hence, an external base station is designed to transmitt energy and a 64-channel high-voltage driver is proposed for a spherical transducer array. Moreover, a shunt-C class-E power amplifier (PA) is employed as core element for the driver, showing a drain efficiency (DE) of 71% and a power added efficiency (PAE) of 57% including gate-driver switching loss. In addition, a cascaded of two low-drop-out (LDO) regulators is used within the implanted device to reduce rectifier ripple and to set the charge voltage for the micro-energy cell to 4.1 V. The LDOs are implemented in a CMOS 0.18 µm high-voltage (HV) technology and measurement along with simulated results are reported.Index Terms-CMOS, energy harvesting, implanted medical device, power management, healthcare, sensor networks.

Low power impulse radio-ultra wide band(IR-UWB) receivers have potential application in the area of wireless sensor networks. In this paper the possibility of superregenerative receivers for pulse detection is demonstrated. The super-regenerative receiver is implemented in a 0.18 µm CMOS process for a 500 MHz bandwidth (-3 dB) centered at 3.8 GHz. The receiver is operating at 1.5 V and consumes a peak current of 7.5 mA. The receiver shows a 16.5 mV amplitude difference between the presence and absence of a pulse at an average received power of -91.3 dBm at a pulse repetition rate of 1 MHz.