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This paper presents a forwarded-clock receiver (RX) that consists of a weight-adjusting sign-sign Mueller-Muller clock and data recovery (CDR) and an adaptive decision-feedback equalizer (DFE) with a single shared error sampler. Only two samples per bit are utilized for both CDR and adaptive DFE, which minimizes clocking power consumption. In addition, a maximum-eye tracking algorithm is proposed to enhance the vertical eye margin without any extra high-speed analog circuitry. The RX fabricated in a 28nm CMOS technology achieves BER less than 10−12 with a 20dB-loss channel. It occupies an active area of 0.108 mm2, and consumes 56.65 mW at 28 Gb/s.

This paper presents a 36 GS/s data path that is based on CMOS logic. The proposed non-clocked delay generator achieves high bandwidth as well as produces near-1-UI delay by employing digitally controlled cross-coupled latches. In addition, the proposed 4-to-2 serializer with pre-charging/discharging transistors not only reduces a data-dependent jitter but also mitigates non-ideal effects such as charge injection and clock feedthrough by removing the floating nodes of the multiplexer. As a result, the 8-to-2 serializer has extremely low rms jitter of 146 fs and peak-to-peak jitter of 980 fs at the output node. Moreover, thanks to the simple architecture of the 8-to-2 serializer and the delay generator, power consumption is remarkably reduced. The data path that dissipates 21.87 mW from 1.2-V supply is implemented and laid-out in 28-nm CMOS technology.

This paper presents a low-power implementation of a 64 Gb/s PAM-4 transmitter (TX) by using 3-tap feed-forward equalization (FFE) and Gm-regulated active-feedback driver. The FFE tap generation is merged into serializer to minimize the overhead of FFE, by replacing a power-hungry delay generator. An active-feedback inverter based driver is also proposed to achieve a larger output swing compared with a resistive- feedback driver with limited output swing. The prototype chip is fabricated in 28nm CMOS technology and occupies 0.185 mm2. The proposed TX achieves the data rate of 64 Gb/s while consuming 97.2 mW, which exhibits the state-of-the-art energy efficiency of 1.5 p.J/b.

A Bulk acoustic wave (BAW) resonator is an essential component in the RF filter and duplexer of mobile devices. The BAW resonator consists of a piezoelectric layer sandwiched between a top electrode and a bottom electrode. In this paper, a novel BAW resonator structure is presented to reduce the electrical loss of electrodes and thereby lower insertion loss which is important to achieve low loss RF filter and duplexer. For that, the resonator is designed to have a gold band of 12 um wide and 2 um high on its perimeter in which half region is connected to the top electrode and the other half the bottom electrode near the perimeter, respectively. As results, insertion loss of the resonator is reduced from -0.05dB to -0.03dB at resonance frequency. Q-factor and electrode resistance are also improved from 995 to 1360 and 1.07Ω to 0.81Ω, respectively.

We investigate the performance of aluminum nitride (AlN) resonator based bulk acoustic wave (BAW) structure made with air edge reflector and gold (Au) edge electrode. BAW Resonators have been fabricated, some devices using a thick film of e-beam evaporated gold as edge electrodes at the border of the resonator on bottom, top electrode. The air reflectors provided at the border of the resonator suppress the acoustic wave leakage through lateral direction. We have developed the simulation and measurement for the improving of resonator quality. The influence of the frame width on resonator surface after applied the air edge reflector and the gold edge electrode in the performance of the BAW resonators is analyzed. The Q a (Q-factor at anti-resonance frequency) and the effective electro-mechanical coupling coefficient (kt2) which is essential to achieve low loss and wide band-width of RF filters is increased by 19 % and 3.4 %, respectively. Also, Insertion loss at S 21 parameter is improved significantly from −0.095 dB to −0.041 dB.

To suppress spurious mode of the BAW (Bulk Acoustic Wave) resonator, advanced lateral structures are proposed. Three different techniques of apodization, air-edge reflector and border frame are integrated. Firstly, apodization is the method to design a proper shape of resonator which avoids parallel edges. By doing so, spurious mode is significantly improved at main resonances. Secondly, air-edge reflector is the method which creates lateral air interface to suppress the acoustic wave leakage. The Q a (Q-factor at anti-resonance frequency) and kt2 are improved from 420 to 640 and 6.0% to 6.7%, respectively. Thirdly, border frame is a specific thickened frame in which lateral acoustic wave cannot propagate. The Q r (Q-factor at resonance frequency) and Q a are increased from 850 to 1040 and 550 to 1670, respectively. After three techniques are integrated, the maximum value of Q r and Q a are achieved 1130 and 1920, respectively. Three practical techniques considerably improved the Q-factor and kt2 of BAW resonator which are essential parameters for low loss and wide band of RF filter configuration.

A novel bulk acoustic wave (BAW) resonator structure with air edge reflectors is proposed. The air reflectors provided at the border of the resonator suppress the acoustic wave leakage travelling in lateral direction. The difference of acoustic impedance at the air edge interface is so large that the reflectivity is almost unity which indicates perfect reflection. As a result of optimized lateral structure, the Q-factor at antiresonance frequency (Qa) is improved significantly to 2740. Furthermore, the effective electro-mechanical coupling coefficient (kt2) which is essential to achieve wide band-width of RF filters is increased considerably by 14%. We also perform multi-physics simulation and investigate the effect of the lateral wave leakage for the BAW structures.

Cutting fluid in machining is important due to their role in reducing tool wear and improving surface finish. However, controlling the usage is imperative due to the ecological and/or economical and reasons. Minimum quantity lubrication (MQL) has recently emerged as a viable option to minimize the amount of fluid used in machining without sacrificing its lubrication and cooling in machining. This paper presents our effort to understand the parameters in the MQL process in order to expand its effectiveness in cutting operations. Although some literature regarding the influence of flow rates and nozzle directions is available, this information is insufficient. This paper studies three new parameters in the MQL process, namely the droplet size, the droplet size distribution, and the wetting angle. Confocal laser scanning microscopy (CSLM), wavelet filtering, and image processing algorithms were used to calculate the droplet geometry and distribution for various commercially available MQL oils. The wetting angles of the oils were measured by depositing oil droplets onto TiSiN and TiAIN coated inserts. The parameters studied are important to estimate the comparative performance of lubricant-coating pairs.

In this paper, a low temperature hermetic wafer level packaging (WLP) scheme for RF-MEMS devices such as micro-switches is presented. The real component with size 1mm/spl times/1mm is composed of two parts: cap substrate and device substrate, cap substrate has a via-in-cavity structure with cavity depth of 20/spl mu/m. High aspect ratio via hole is fabricated by inductive coupled plasma-reactive ion etching (ICP-RIE) and electroplated with Cu for electrical feed-through. Eutectic bonding is still the most commonly used packaging technology at present. For the purpose of hermetic sealing, Au-Sn multilayer metallization with a close square loop of 100/spl mu/m width have been sputtered onto cap wafer surface as soldering system. Deposition of cap wafer metallization should be finished in one high vacuum chamber process in order to prevent oxidation of Sn layer during producing process. And Ti-Ni-Au combination structure is deposited and patterned on device wafer in accordance with the sealing and interconnection areas in cap wafer. Bonding is performed in wafer level using eutectic bonder (TPS-2000A, BNP science) at a relative low temperature of 280/spl deg/C for heating in static N/sub 2/ ambience for a period of time. As-bonded wafers are then diced into pieces and subjected to a series of performance test for evaluation. Shear strength of two bonded interfaces are measured for sample cells by shear tester ROYCE 552 100K to evaluate mechanical property. RF characteristics insertion loss at 2GHz has measured by HP 8510C network analyzer probe station, a total packaging insertion loss less than 0.05DB could be achieved. For hermeticity test, specific test vehicles which have a large cavity of 0.5/spl times/0.5/spl times/0.05cm/sup 3/ are designed for helium leak test based on M1T-STD-883F since real device cavity has a tiny volume of only 600/spl times/600/spl times/30/spl mu/m/sup 3/, test vehicles indicate a maximum equivalent leak rate in air of 1.6/spl times/10/sup -8/ mbar.l/sec. Also residual gas analysis (RGA) test is performed for bonded device sample. Reliability tests like thermal shock and high temperature, high humidity storage test are also performed according to MIL-STD-883F. For samples before and after reliability tests, measurements also have been made for comparison to evaluate the quality and reliability of packaging structure.