Xiaojun Yuan

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.

Multiple Functional ECG Signal is Processing for Wearable Applications of Long-Term Cardiac Monitoring

In this paper, an integrated electrocardiogram (ECG) signal-processing scheme is proposed. Using a systematic wavelet transform algorithm, this signal-processing scheme can realize multiple functions in real time, including baseline-drift removal, noise suppression, QRS detection, heart beat rate prediction and classification, and clean ECG reconstruction. Utilizing the novel low-cost hardware architecture, the proposed ECG signal-processing scheme is implemented in application-specific integrated circuits with 0.18 μm CMOS technology. This ECG signal-processor chip achieves low area and power consumptions, and is highly suitable for wearable applications of long-term cardiac monitoring.

TSV Technology for Millimeter-Wave and Terahertz Design and Applications

The through silicon via (TSV) technology provides a promising option to realize a compact millimeter-wave (mmW) and terahertz (THz) system with high performance. As the fundamental elements in this system, transmission lines (T-lines) and interconnects are very important and therefore studied in this paper. A TSV-based substrate integrated waveguide (SIW) is also characterized. The results show that, the T-lines and interconnects are viable at frequencies lower than ~150 GHz whereas SIW can operate relatively well up to 300 GHz. In addition, two mmW components, i.e., a hairpin filter and a patch antenna, are designed by the TSV technology. Results of all the above passive components indicate that the low-resistivity silicon is the main cause of the total loss. Afterwards, two novel TSV-based topologies are proposed to efficiently integrate an antenna with active circuits for the mmW and THz applications.

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.

Millimeter-Wave Passives in 45-nm Digital CMOS

With dramatically increased ft and fmax, CMOS technologies have been widely applied in the design of millimeterwave circuits. To reduce the fabrication cost, digital CMOS processes may be used. Due to the lack of thick top metal and the reduced distance between the top metal and silicon substrates in a digital CMOS, the design of high-performance passives becomes very challenging, particularly in the millimeter-wave frequency regime. In this letter, passives with novel structures were fabricated in a 45-nm digital CMOS process. These passives, including transmission lines, spiral inductors, and metal-oxide-metal (MOM) capacitors, were designed and characterized up to 110 GHz. Their performance was compared with those fabricated using 180- and 90-nm RF CMOS processes. These passives achieved good performance in the millimeter-wave regime. A MOM capacitor has a self-resonant frequency higher than 110 GHz. An inductor achieves a quality factor of 24 at 70 GHz. These results show the feasibility of implementing the millimeterwave passives and systems in a 45-nm digital CMOS process.

A CMOS MedRadio Receiver RF Front-End With a Complementary Current-Reuse LNA

An ultra-low-power 401-406-MHz Medical Device Radiocommunications Service receiver RF front-end for biomedical telemetry applications is implemented using 0.18-μm CMOS technology. A single-ended complementary current-reuse low-noise amplifier (CCRLNA) is proposed that achieves a power gain of 20 dB, noise figure (NF) of 2.8 dB, IIP3 of -8.1 dBm, and second-order intercept point of +34 dBm while consuming only 150 μW at 1-V supply voltage. The total receiver RF front-end, including the proposed CCRLNA, in-phase/quadrature folded mixers, and local oscillator buffers, achieves a conversion gain of 28.7 dB, NF of 5.5 dB, and third-order intercept point of -25 dBm while consuming less than 500 μW from a 1-V supply voltage and occupying 0.7 mm2 of core die area.

A Low SIR Impulse-UWB Transceiver Utilizing Chirp FSK in 0.18

An ultrawideband transceiver employing chirp pulse modulation is proposed for LDR communication. In contrast to the Gaussian pulse, a transmitted pulse modulated with different chirps can maximize the transmitted energy under low supply voltage and is thus amenable to the voltage scalability of the advanced CMOS technologies. The binary data is encoded with different chirp frequencies and two identical pulses are sent per data bit to enable non-coherent demodulation which simplifies the receiver architecture. A demodulation calibration loop is also incorporated to optimize the SIR performance. In-band/out-of-band SIR as low as -21dB/-59 dB can be tolerated in order to achieve BER better than 10-3. Implemented in 0.18 μm CMOS, the transceiver can sustain data rates up to 20 Mbps, and achieve energy efficiency of 0.77 nJ/bit for transmitting and 2.7 nJ/bit for receiving under 1.8 V supply.

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Building on an efficient active and passive device modeling strategy, a 60 GHz OOK transceiver system including on-chip antenna in 90nm CMOS is designed. The key features of the circuits are small power consumption and size. With the modulator connected to an innovative artificial magnetic conductor (AMC) on-chip antenna, free space transmission at 2Gb/s is demonstrated. Also, an on-chip psuedo-link demonstrates 1Gb/s transmission, using only 26 pJ/bit for the modulator and 6 pJ/bit for the demodulator. The receiver consists of on-chip antenna, LNA with 20dB gain & 5.7dB noise figure, detector and limiting amplifier. Recovery of a 1.5Gb/s NRZ signal is demonstrated.

CMOS

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.