Dang Liu

9.2 A 13.3mW 500Mb/s IR-UWB transceiver with link-margin enhancement technique for meter-range communications

This paper describes a link margin enhancement method for high data rate impulse-radio ultra-wideband (IR-UWB) transceiver systems. To overcome a trade-off between link margin and spectrum compliance in the pulse based UWB system, a spectrum-efficient frequency hopping (FH) technique is proposed to increase average transmission power without violating the spectrum mask. An energy detection receiver is used to convert a frequency hopping signal to a baseband signal with the original bandwidth, thus improving the signal-to-noise ratio. A 500 Mb/s 7.25-9.5 GHz UWB transceiver is implemented in 65 nm CMOS. Having eight sub-bands with 50% overlap, the transceiver exhibits a meter-range communication capability with a 9 dB link margin enhancement. The transceiver consumes 13.3 mW from a 1 V supply, achieving an energy efficiency of 26.6 pJ/bit.

9.3 A 1mW 1Mb/s 7.75-to-8.25GHz chirp-UWB transceiver with low peak-power transmission and fast synchronization capability

Future binaural hearing-aid devices face severe energy constraints on the wireless links where the ear-to-ear link enables signal processing of sound for both ears to enhance speech intelligence and the ear-to-device link provides an audio channel to commercial electronics such as smart TVs, MP3 players, and smart phones. Due to the limited size of the battery (35 to 90mAh) especially for in-the-ear (ITE) and in-the-canal (ITC) types, a sub-mW transceiver is required for long operational time. A low-data-rate impulse-radio ultra-wideband (IR-UWB) transceiver [1] achieves low power consumption with aggressive duty-cycled operation, namely 1%, but suffers from the bit-level synchronization problem by the baseband. Moreover, the low-data-rate IR-UWB exhibits a high peak transmission power to maintain a sufficient average transmission power for the given link margin. The constant-envelope frequency-modulated ultra-wideband (FM-UWB) system in [2,3] features a low peak voltage and a steep roll-off spectrum, but the lack of duty-cycled operation makes it difficult to achieve low power. Narrowband WBAN transceivers such as the Bluetooth Low Energy (BLE) transceiver [4,5] offer good compliance with existing wireless SoCs, but the sub-mW power consumption is not feasible and they have a potential coexistence problem with existing Bluetooth devices. In this paper, a chirp-FSK-based UWB transceiver is proposed to significantly reduce the peak transmission power with relaxed duty-cycled operation for noninvasive, energy-efficient, and agile short-range communications.

A 7.6mW 2Gb/s proximity transmitter for smartphone-mirrored display applications

This paper describes a high data rate proximity transmitter design for high resolution smartphone-mirrored display applications. A 2Gb/s transmitter is designed with a low transmission power of -70dBm/MHz and a wide bandwidth of nearly 3GHz. A digital pre-correction method is employed in the transmitter to mitigate the inter-symbol interference problem. A carrier-based digital pulse shaping and a reconfigurable digital envelope generation methods are employed for robust operation by utilizing 20 phases from a 2GHz phase-locked loop. A 6.5-9.5GHz transmitter implemented in 65nm CMOS achieves the maximum data rate of 2Gb/s, consuming only 7.6mW from a 1V supply.

A 0.42-mW 1-Mb/s 3- to 4-GHz Transceiver in 0.18-

This paper describes a short-range transceiver architecture using frequency-hopped sinusoidal OOK pulses. Since signal bandwidth does not necessarily have to satisfy >500 MHz requirement like conventional ultra-wideband (UWB) pulses, the proposed transceiver named as a very-wide band (VWB) transceiver offers degrees of freedom to choose an optimum operation duty cycle in terms of energy efficiency, bandwidth efficiency, and communication range, while providing much lower operation duty cycle than that of narrow band OOK transceiver. The VWB transmission significantly relaxes the complexity of transceiver design without requiring advanced CMOS technology. In the transmitter, pulse generation circuit design is simplified with the duty-cycled sinusoidal signal compared to that in the impulse-radio UWB (IR-UWB) transmitter. In the receiver, an asynchronous energy detection topology is proposed to achieve robust energy detection by overcoming the synchronization issue as well as the saturation problem of the integrator circuit. A prototype 3-to-4 GHz VWB transceiver is implemented in 0.18

\mu \text{m}

\mu \text{m}

CMOS With Flexible Efficiency, Bandwidth, and Distance Control for IoT Applications

CMOS. The transceiver achieves the communication distance of >2 m at 1 Mb/s data rate with the peak-to-peak pulse amplitude of only 300 mV and the duty cycle of 0.6%, consuming 0.42 mW from a 1.8 V supply.

A 19.2mW 1Gb/s secure proximity transceiver with ISI pre-correction and hysteresis energy detection

This paper presents a 1Gb/s 6.5-to-8.5GHz transceiver for secure proximity communication systems. A prototype transceiver implemented in 65nm CMOS achieves the maximum data rate of 1Gb/s with the sensitivity of -53dBm and the communication range of 15cm. Consuming only 19.2mW, the proposed ultra-wideband (UWB) transceiver enables future applications such as smartphone-mirrored high-resolution display systems which require low power mainly for the transmitter in the smartphone, thus making it possible to further improve the transceiver performance with the complex receiver in the display equipment.

A 1.6Mb/s 3.75–4.25GHz chirp-UWB transceiver with enhanced spectral efficiency in 0.18μm CMOS

A chirp-UWB transceiver which transmits a 1.3 bit information in a single pulse clock period by embedding pulse position information in the chirp FSK modulation is implemented in 0.18μm CMOS. A digital-intensive chirp-UWB transmitter by employing digital ramp generator and a digitally-controlled oscillator (DCO) is designed. In the receiver, a dual-BPF based regenerative architecture is employed to relax the Q requirement. The proposed transceiver achieves the energy efficiency of 2.5nJ/b for the transmitter and 24.2nJ/b for the receiver at the data rate of 1.6Mb/s.

A 5.2–11.8MHz octa-phase relaxation oscillator for 8-PSK FM-UWB transceiver systems

An octa-phase differential relaxation VCO generating both triangular and rectangular waveform outputs is designed for 8-PSK subcarrier generation in FM-UWB transceiver systems. The VCO consists of cascaded quad-phase relaxation oscillators in which the second stage oscillator provides 45° phase shifting with pseudo injection locking. The 5.2-11.8MHz octa-phase VCO implemented in 0.18μm CMOS consumes 2.5mW from a 1.8V supply.

Energy-efficient proprietary transceivers for IoT and smartphone-based WPAN

This paper gives an overview of several energy-efficient short-range transceivers implemented for IoT and smartphone-based WPAN systems. For high data rate applications, an ultra-wideband (UWB) proximity transceiver for a smartphone-based sharing desktop platform with secure screen-mirrored display is presented. As to low data rate applications, wideband and narrowband transceivers based on proprietary modulation schemes such as very-wideband (VWB) and frequency-domain OOK (F-OOK) are introduced by considering energy efficiency, bandwidth efficiency, and communication distance.