Chun-Huat Heng

A 60-GHz OOK Receiver With an On-Chip Antenna in 90 nm CMOS

A low power 60-GHz on-off-keying (OOK) receiver has been implemented in a commercial 90 nm RF CMOS process. By employing a novel on-chip antenna together with architecture optimization, the receiver achieves a sensitivity of -47 dBm at a bit-error rate (BER) of less than 10-3. Using a commercial transmitter with transmit power of 1.5 dBm, a transmission distance of 5 cm can be achieved at 1.2 Gbps data rate. In this design, the on-chip antenna minimizes the packaging loss, while energy detection at RF allows architecture simplification. Both techniques contribute to the receivers low power consumption of 51 mW, excluding test buffers. This leads to a bit energy efficiency of 28 pj/bit at 1.8 Gbps. The total die area is 3.8 mm2 with the on-chip antenna occupying almost half of it.

Low-Power Ultrawideband Wireless Telemetry Transceiver for Medical Sensor Applications

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.

Device Design and Scalability of a Double-Gate Tunneling Field-Effect Transistor with Silicon–Germanium Source

A novel double-gate (DG) tunneling field-effect transistor (TFET) with silicon–germanium (SiGe) Source is proposed to overcome the scaling limits of complementary metal–oxide–semiconductor (CMOS) technology and further extends Moores law. The narrower bandgap of the SiGe source helps to reduce the tunneling width and improves the subthreshold swing and on-state current. Less than 60 mV/decade subthreshold swing with extremely low off-state leakage current is achieved by optimizing the device parameters and Ge content in the source. For the first time, we show that such a technology proves to be viable to replace CMOS for high performance, low standby power, and low power technologies through the end of the roadmap with extensive simulations.

A Variational Approach to the Two-Dimensional Nonlinear Poisson's Equation for the Modeling of Tunneling Transistors

In this letter, we report a new approach to treat the 2-D nonlinear Poissons equation in the context of MOS devices and discuss its application in the modeling of tunneling field-effect transistors (T-FET). It is revealed that the narrowing of tunneling barrier in T-FET has different mechanisms before and after inversion layer is formed. Closed-form equation is obtained to describe the barrier narrowing in the presence of inversion layer.

A CMOS TV tuner/demodulator IC with digital image rejection

Superheterodyne TV tuners have been implemented in discrete forms using tunable RF and SAW IF filters. Integrating TV tuners in CMOS technology without them is a challenging task to cope with technical issues such as harmonic mixing and image. The image rejection in low- or zero-IF systems has been limited to 30-40 dB by analog imperfections such as I/Q path gain and phase mismatches. A single-chip low-IF TV tuner solution is proposed so that the image can be suppressed digitally using an image cancellation technique based on a complex one-tap LMS signal decorrelation algorithm. Programmable digital filtering and video/sound demodulation make a multistandard TV tuner feasible in the 48-860 MHz VHF/UHF band. The chip has a maximum gain of 63 dB and an input automatic gain control (AGC) range from -15 to 25 dB with 0.85-dB steps. It achieves an image and IF rejection of 60 dB, a peak carrier-to-noise ratio (CNR) of 55 dB, and a peak sound signal-to-noise ratio (SNR) of 44 dB without frequency modulation (FM) de-emphasis. The prototype occupies 6/spl times/6 mm/sup 2/ in 0.25-/spl mu/m CMOS and consumes 1 W at 2.5 V.

A CMOS Ultra Low-Power and Highly Efficient UWB-IR Transmitter for WPAN Applications

This brief presents an on-off LC oscillator-based ultrawideband impulse radio (UWB-IR) transmitter for long-range application. A thorough theoretical analysis of the pulse generation is provided. Implemented in a 0.18-mum CMOS, the transmitter works in the UWB lower band of 3-5 GHz and consumes an ultralow average power of 236 muW at 1.8-V power supply. UWB pulses with a bandwidth of 2 GHz and 10-dB sidelobe suppression are generated. The transmitter can deliver a large differential output swing of 4.9 V under 100-Omega load with the highest power efficiency of 25.4% to date. It is targeted for wireless sensor network (WSNs) and wireless personal area network (WPAN) applications.

A Multi-band CMOS Low Noise Amplifier for Multi-standard Wireless Receivers

A novel multi-band low noise amplifier (LNA) that allows simultaneous reception of signals from several wireless standards is designed and implemented using a 0.18-mum CMOS technology. The circuit topology consists of a 3-stage wideband LNA and 2 notch filters. The designed LNA can provide concurrent three bands over 0.935~5.825 GHz with measured gain (S21) of 15~24 dB, input reflection ratio (S11) of -35~-7 dB, noise figure (NF) of 4.4~4.78 dB, and 3rd order input intercept point (IIP3) of -15.3~-12.4dBm respectively. In addition, a minimum 8 dB of inter-band gain suppression is achieved. This work has achieved a better figure of merit (FOM) than other related works, in terms of gain, noise figure and power consumption trade-offs.

A 50-Mb/s CMOS QPSK/O-QPSK Transmitter Employing Injection Locking for Direct Modulation

A 50-Mb/s quadrature phase-shift keying (QPSK)/offset quadrature phase-shift keying (O-QPSK) transmitter suitable for biomedical high-quality imaging application is presented. Centered at 915 MHz, the phase modulation is achieved by directly modifying the self-resonant frequency of an LC voltage-controlled oscillator through capacitor bank switching. By eliminating many unnecessary building blocks in the conventional QPSK/O-QPSK transmitter, significant power and area savings are achieved. Implemented in 0.18- μm CMOS technology, it occupies an active core area of 0.28 mm2. With 305-MHz injection frequency and consuming 5.6 mW under 1.4-V supply, the transmitter achieves error vector magnitude (EVM) of 11.4%/5.97% for O-QPSK/QPSK modulation while delivering output power of -3 dBm at 50 Mb/s. By lowering the injection frequency to 101.67 MHz, it consumes 5.88 mW under the same supply voltages while delivering an output power of -3.3 dBm. The transmitter achieves measured EVM of 6.4% at 50 Mb/s under QPSK modulation.

A 0.92/5.3nJ/b UWB impulse radio SoC for communication and localization

UWB has shown great potential for short-range low data-rate low-power wireless communications. Recently, wireless body area networks for wearable and implant devices are emerging, which require energy-efficient radios to sustain longer battery life and potentially enable power supplied by energy harvesting [1]. Some energy-efficient UWB solutions have been reported [2–6]. However, only RF transceivers have been presented and the publications did not show a complete radio except in reference [6]. Also, location awareness for ambient intelligent sensor networks becomes the next important feature to implement besides communications [7]. UWB offers unique merit for accurate localization by using the narrow and wideband pulses. In this work, we present a complete impulse UWB SoC radio including RF transceiver and digital PHY. It can be configured as communication or localization or both modes, therefore enabling a uniform energy-efficient radio platform for WSN, WPAN, and WBAN applications.

Large Scale Triboelectric Nanogenerator and Self-Powered Pressure Sensor Array Using Low Cost Roll-to-Roll UV Embossing

Triboelectric nanogenerators (TENGs) have emerged as a potential solution for mechanical energy harvesting over conventional mechanisms such as piezoelectric and electromagnetic, due to easy fabrication, high efficiency and wider choice of materials. Traditional fabrication techniques used to realize TENGs involve plasma etching, soft lithography and nanoparticle deposition for higher performance. But lack of truly scalable fabrication processes still remains a critical challenge and bottleneck in the path of bringing TENGs to commercial production. In this paper, we demonstrate fabrication of large scale triboelectric nanogenerator (LS-TENG) using roll-to-roll ultraviolet embossing to pattern polyethylene terephthalate sheets. These LS-TENGs can be used to harvest energy from human motion and vehicle motion from embedded devices in floors and roads, respectively. LS-TENG generated a power density of 62.5 mW m−2. Using roll-to-roll processing technique, we also demonstrate a large scale triboelectric pressure sensor array with pressure detection sensitivity of 1.33 V kPa−1. The large scale pressure sensor array has applications in self-powered motion tracking, posture monitoring and electronic skin applications. This work demonstrates scalable fabrication of TENGs and self-powered pressure sensor arrays, which will lead to extremely low cost and bring them closer to commercial production.