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ABSTRACT: An integrated CMOS ultrawideband wireless telemetry transceiver for wearable and implantable medical sensor applications is reported in this letter. This high duty cycled, noncoherent transceiver supports scalable data rate up to 10 Mb/s with energy efficiency of 0.35 nJ/bit and 6.2 nJ/bit for transmitter and receiver, respectively. A prototype wireless capsule endoscopy using the proposed transceiver demonstrated in vivo image transmission of 640 × 480 resolution at a frame rate of 2.5 frames/s with 10 Mb/s data rate.
IEEE transactions on bio-medical engineering 03/2011; 58(3):768-72. · 2.15 Impact Factor
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ABSTRACT: This paper presents an amplitude shift keying (ASK) transmitter for high-quality imaging in ingestible capsule endoscopy application. A carrier frequency of 900MHz is generated by a complementary LC voltage-controlled oscillator, and directly modulated with a digital baseband ASK signal by switching on and off a driver amplifier (DA). The modulated signal is amplified by the DA and transmitted through an inductive coupling. The transmitter has been fabricated in 0.18μm CMOS process. A peak output power of 1dBm can be transmitted and power consumption is 7.2mW at a data rate of 15Mbps.
Circuits and Systems (APCCAS), 2010 IEEE Asia Pacific Conference on; 01/2011
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International Symposium on Circuits and Systems (ISCAS 2011), May 15-19 2011, Rio de Janeiro, Brazil; 01/2011
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ABSTRACT: 900MHz QPSK/O-QPSK transmitter suitable for biomedical high quality imaging application is presented. The phase modulation is achieved by directly modifying the self-resonant frequency of a sub-harmonic injection-locked oscillator through capacitor bank switching. Due to the simplicity of the proposed architecture, implemented in 0.18μm CMOS technology, it consumes very low power of 3mW and 5.88mW with 1.2V and 1.4V supply voltages respectively, while transmitting at 50Mbps data rate. The transmitter can deliver output power of -3.3dBm at 1.4V supply with an EVM of 6.6%.
Solid State Circuits Conference (A-SSCC), 2010 IEEE Asian; 12/2010
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ABSTRACT: A low power wireless telemetry system for capsule endoscopy is presented in this paper. The proposed system is based on impulse-radio ultra-wideband (IR-UWB) technology, it consists of a UWB transmitter utilizing fast on-off LC VCO and a non-coherent UWB receiver using energy detection. The whole system is implemented in 0.18-μm CMOS process and integrated in a single chip with 3 mm × 4 mm chip size. The measurement results show that the transmitter consumes ultra low average power of 2.5mW at 10Mbps data rate and the receiver draw 40 mA current under 1.8V power supply. An ex-vivo animal experiment shows that the proposed system can successfully transmit the real-time image data out from the capsule to the external base station.
Robotics Automation and Mechatronics (RAM), 2010 IEEE Conference on; 07/2010
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IEEE International Solid-State Circuits Conference, ISSCC 2010, Digest of Technical Papers, San Francisco, CA, USA, 7-11 February, 2010; 01/2010
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ABSTRACT: This paper presents a dual-channel timed array transmitter for impulse radio ultra wide band wireless communication system. The transmitter can generate UWB pulses in two separate transmitter paths with tunable path delay difference of 0˜250 ps to achieve beamforming capability. Through injection locking with 800 MHz input reference, the generated UWB pulse centers at 4 GHz and covers 3˜5 GHz band with 10-dB side-lobe rejection. Fabricated in 0.18 μm CMOS technology, the transmitter consumes 37 mA at 10 Mbps under 1.8 V supply.
Solid-State Circuits Conference, 2009. A-SSCC 2009. IEEE Asian; 12/2009
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ABSTRACT: This paper presents a low-power CMOS RF front-end for 3-5 GHz non-coherent impulse-radio ultra-wideband (IR-UWB) receiver. The proposed front-end comprises a variable-gain low noise amplifier (VG-LNA), an active balun and an analog squarer. Current reuse topology has been adopted in both VG-LNA and active balun to reduce the power consumption. The squarer design is based on the quadratic law of MOSFET in saturation and the performance is optimized for 3-5 GHz UWB signal detection using cascode stage and active load. The VG-LNA has a measured maximum voltage gain of 33 dB/12 dB for high/low gain modes with minimum noise figure 3.7 dB/4.2 dB respectively. Measurements show that the proposed RF front-end achieves an input sensitivity of -91 dBm for UWB on-off keying (OOK) input signal at 1 Mbps pulse rate with an energy efficiency of 3.1 nJ/bit.
Solid-State Circuits Conference, 2008. ESSCIRC 2008. 34th European; 10/2008
