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This paper proposed an X-band 6-bit passive phase shifter (PS) designed in 0.18 μ m silicon-on-insulator (SOI) CMOS technology, which solves the key problem of high integration degree, low power, and a small size T/R module. The switched-topology is employed to achieve broadband and flat phase shift. The ESD circuit and driver are also integrated in the PS. It covers the frequency band from 7.5 to 10.5 GHz with an EMS phase error less than 7.5°. The input and output VSWRs are less than 2 and the insertion loss (IL) is between 8-14 dB across the 7.5 to 10.5 GHz, with a maximum IL difference of 4 dB. The input 1 dB compression point (IP 1dB ) is 20 dBm.

A down-conversion in-phase/quadrature (I/Q) mixer employing a folded-type topology, integrated with a passive differential quadrature all-pass filter (D-QAF), in order to realize the final down-conversion stage of a 60 GHz receiver architecture is presented in this work. Instead of employing conventional quadrature generation techniques such as a polyphase filter or a frequency divider for the local oscillator (LO) of the mixer, a passive D-QAF structure is employed. Fabricated in a 65 nm CMOS process, the mixer exhibits a voltage gain of 7-8 dB in an intermediate frequency (IF) band ranging from 10 MHz-1.75 GHz. A fixed LO frequency of 12 GHz is used to down-convert a radio frequency (RF) band of 10.25-13.75 GHz. The mixer displays a third order input referred intercept point (IIP3) ranging from -8.75 to -7.37 dBm for a fixed IF frequency of 10 MHz and a minimum single-sideband noise figure (SSB-NF) of 11.3 dB. The mixer draws a current of 6 mA from a 1.2 V supply voltage dissipating a power of 7.2 mW.

This paper presents the design of a low power (LP) and a low noise figure (NF) quadrature demodulator with an on-chip frequency divider for quadrature local oscillator (LO) signal generation. The transconductance stage of the mixer is implemented by an AC-coupled self-bias current reuse topology. On-chip series inductors are employed at the gate terminals of the differential input transconductance stage to improve the voltage gain by enhancing the effective transconductance. The chip is implemented in 65-nm LP CMOS technology. The demodulator is designed for an input radio frequency (RF) band ranging from 10.25 to 13.75 GHz. A fixed LO frequency of 12 GHz down-converts the RF band to an intermediate frequency (IF) band ranging from DC to 1.75 GHz. From 10 MHz to 1.75 GHz the demodulator achieves a voltage conversion gain (VCG) ranging from 14.2 to 13.2 dB, and a minimum single-sideband NF (SSB-NF) of 9 dB. The measured third-order input intercept point (IIP 3 ) is -3.3 dBm for a two-tone test frequency spacing of 1 MHz. The mixer alone draws a current of only 2.5 mA, whereas the complete demodulator draws a current of 7.18 mA from a 1.2 V supply. The measurement results for a frequency divider, which was fabricated individually, prior to being integrated with the quadrature demodulator, in 65-nm LP CMOS technology, are also presented in this paper.

In order to improve the temperature stability of DC-contact RF MEMS switch, a thermal buckle-beam structure is implemented. The stability of the switch pull-in voltage versus temperature is not only improved, but also the impact of stress and stress gradient on the drive voltage is suppressed. Test results show that the switch pull-in voltage is less sensitive to temperature between -20 °C and 100 °C. The variable rate of pull-in voltage to temperature is about -120 mV/°C. The RF performance of the switch is stable, and the isolation is almost independent of temperature. After being annealed at 280 °C for 12 hours, our switch samples, which are suitable for packaging, have less than 1.5% change in the rate of pull-in voltage.

A dual-band, wide tuning range voltage-controlled oscillator that uses transformer-based fourth-order (LC) resonator with a compact common-centric layout is presented. Compared with the traditional wide band (VCO), it can double frequency tuning range without degrading phase noise performance. The relationship between the coupling coefficient of the transformer, selection of frequency bands, and the quality factor at each band is investigated. The transformer used in the resonator is a circular asymmetric concentric topology. Compared with conventional octagon spirals, the proposed circular asymmetric concentric transformer results in a higher quality-factor, and hence a lower oscillator phase noise. The VCO is designed and fabricated in a 0.18-μm CMOS technology and has 75% wide tuning range of 3.16–7.01 GHz. Depending on the oscillation frequency, the VCO current consumption is adjusted from 4.9 to 6.3 mA. The measured phase noises at 1 MHz offset from carrier frequencies of 3.1, 4.5, 5.1, and 6.6 GHz are −122.5, −113.3, −110.1, and −116.8 dBc/Hz, respectively. The chip area, including the pads, is 1.2 × 0.62 mm2 and the supply voltage is 1.8 V.

This paper presents a novel low noise amplifier (LNA) topology with image rejection (IR), called IRLNA. It achieves a high IR ratio using on-chip inductors with low quality factor. Two IRLNAs based on a standard 0.18-/spl mu/m CMOS technology are designed with L- and /spl pi/- resonant network, respectively. They have the same power consumption of 8 mW with one 1.8 V power supply. At the signal frequency of 5.25 GHz in the band of WLAN 802.11a, and with the image frequency at 3.25GHz, the simulation results show that the IR ratios achieve 71dB for L-resonant network and 92dB for /spl pi/-resonant network with on-chip inductors, and their noise figures are 1.4 dB and 1.7 dB, respectively.

In this paper, the design considerations and simulation results of a low-noise low-power radio frequency front end for 5-GHz WEAN receiver, which includes a low-noise amplifier and a downconversion mixer, are presented. Fabricated in 0.18-/spl mu/m CMOS technology, the front end achieves a noise figure of 1.4 dB, and a power gain of 28.4 dB while dissipating 11.2 mA from a 1.8-V supply.

This paper describes the design of a 1-GHz quadrature modulator for 802.11a WLAN systems with TSMC 0.18-/spl mu/m CMOS technology. By using an improved double-balanced mixer combined with a double-balanced mixer, a common-mode feedback circuit and an improved transconductance amplifier, the linearity of the modulator is improved. The experimental results show the modulator achieves -5 dBm for P/sub 1 dB/, -42 dB for LO-IF isolation, and a gain of 1.2 dB. The power consumption is 49 mW with a 1.8-V power supply.

A new strain gage bridge to PPM (Pulse Position Modulation) converter has been developed. It consists of a chopper amplifier and a voltage to time converter associated in a feed-back loop. This topology exhibits mainly an automatic offset cancellation capability, a ratiometric transfer function and an accuracy of 10 bits. Therefore, this converter is insensitive to offset drifts, and is well suited for long term monitoring of orthopedic implants.

Intracerebral hemorrhage (ICH) accounts for about 15% of strokes and leads to higher mortality. However, its underlying pathophysiologic mechanism remains gloomy, partially due to the lack of suitable animal models in research. Approximately 20% ICH cases are associated with the use of oral anticoagulants, warfarin for the most instances in clinic, especially following the long-term treatment. Even though the coumarin drugs has been used in rodents for comparison of standard-of-care effects in ICH studies, the elucidation of results must bear the significant differences of gyrencephalic brain structure, brain vasculature and various biological interactions affecting the hemorrhage and hemostasis between rodents and human being. Quite a few works have been reported in study of strokes, particularly, the cerebral ischemic stroke in cynomolgus monkeys (Macaca fascicularis) for its high homology to human. In order to establish a more clinical relevant model for ICH and saver anticoagulant research, we studied ICH in cynomolgus monkeys by injection of collagenase in brain and characterized the effect of warfarin treatment by MRI measurement. Following injection of type IV collagenase into internal capsule, distinct acute, sub-acute, and chronic phases of ICH were observed, with the highest level of cerebral hematoma volume at 3 days after ICH induction measured by a GE signa excite 1.5T MRI scanner. Pretreatment with 0.3 mg/kg of warfarin daily for 6 days significantly increased the hematoma volumes to proximal 10% of cerebral hemisphere compared to the 4% with saline treatment. In addition, the AUC of hematoma volume changes was also remarkably enlarged with the warfarin treatment as measured at different time points following ICH. Transfusion of 30 ml of autologous fresh frozen plasma (FFP) and injection of 1 mg Vitamin K reduced the effects of warfarin treatment in hematoma and AUC enlargement, and ameliorated ICH stroke associated symptoms. The results of coagulation tests were all in agreement with the warfarin associated effects on cerebral hematoma in cynomolgus monkeys. Our data demonstrated the successful establishment of ICH model in cynomolgus monkeys and the clinical relevant treatments, such as warfarin and FFP, can be incorporated as the controls for proper researches in ICH and its therapeutics. With the high similarity in brain and high cross reactivity in target to human, the cynomolugs monkey ICH model adds a valuable tool to evaluate new therapeutic approaches and the safety of novel anticoagulants, especially for the human target-specific interventions, such as plasma products, biologics, oligonucleotides, and peptides. Disclosures No relevant conflicts of interest to declare.