8 research outputs found
A low-power 802.11 AD compatible 60-GHz phase-locked loop in 65-NM CMOS
No full textA 60-GHz fundamental frequency phase locked loop (PLL) as part of a highly integrated system-on-chip transmitter with onchip memory and antenna is presented. As a result of localized optimization approach for each component, the PLL core components only consume 30.2 mW from a 1.2 V supply. A systematic design procedure to achieve high phase margin and wide locking range is presented. The reduction of parasitic and fixed capacitance contributions in the voltage controlled oscillator enables the coverage of the complete 802.11 ad frequency band from 57.2 to 65.8 GHz. A new 4-stage distribution network supplying the local oscillator (LO) signal to the mixer, the feedback loop and the external equipment is introduced. The prescaler based on the static frequency division approach is enhanced using shunt-peaking and asymmetric capacitive loading. The current mode logic based divider chain is optimized for low power and minimum silicon foot-print. A dead-zone free phase frequency detector, low leakage charge pump, and an integrated second-order passive filter completes the feedback loop. The PLL implemented in 65 nm CMOS process occupies only 0.6 mm2 of chip space and has a measured locking range from 56.8 to 66.5 GHz. The reference spurs are lower than -40 dBc and the in-band and out-of-band phase noise is -88.12 dBc/Hz and -117 dBc/Hz, respectively
A 94 GHz CMOS based oscillator transmitter with an on-chip meandered dipole antenna
No full textA miniaturized 94 GHz oscillator transmitter in 65nm CMOS is presented. An extremely small silicon foot-print of 0.25mm2 is achieved through meandering of the top-metal dipole antenna, conjugate matching between the oscillator and the antenna without impedance matching elements and efficient placement of the oscillator circuit within the antenna. The antenna demonstrates bandwidth of 90 to 99 GHz (10%) and a gain of -6dBi. The use of parasitic aware antenna-circuit code-sign strategy results in an accurate measured oscillation frequency of 94.1 GHz. The oscillator exhibits a measured output power of -25 dBm, phase noise of -88 dBc/Hz at 1 MHz offset and consumes 8.4mW from a 1V supply. © 2015 IEEE
60 GHz system-on-chip (SoC) with built-in memory and an on-chip antenna
No full textA novel 60 GHz transmitter SoC with an on-chip antenna and integrated memory in CMOS 65 nm technology is presented in this paper. This highly integrated transmitter design can support a data rate of 2 GBPS with a transmission range of 1 m. The transmitter consists of a fundamental frequency 60 GHz PLL which covers the complete ISM band. The modulator following the PLL can support both BPSK and OOK modulation schemes. Both stored data on the integrated memory or directly from an external source can be transmitted. A tapered slot on chip antenna is integrated with the power amplifier to complete the front end of the transmitter design. Size of the complete transmitter with on-chip antenna is only 1.96 mm × 1.96 mm. The core circuits consume less than 100 mW of power. The high data rate capability of the design makes it extremely suitable for bandwidth hungry applications such as unencrypted HD video streaming and transmission
A low-cost, non-invasive sensory device for early diagnosis of diabetic peripheral neuropathy
No full textUncovering the Cooling Potential by Water Circulation on the Hot Side of a Peltier Module
No full textThermolectric cooling offers several advantages over conventional refrigeration systems due to its light weight, environmental friendliness, silent operation, and no moving parts. In this work, a thermoelectric water cooling system is created in which water flowing at various flowrates removes heat produced on the hot side of the Peltier module. The cooling effect and coefficient of performance (COP) of the cooling system are experimentally determined at various flowrates of water on the hot side of the module. The cooling effect produced in water increases with the increase in flowrate. A similar trend is noticed for the COP of the system. The maximum cooling effect produced in water is 1363 W at 43 mL/s. The maximum COP of the system is 3.99
Frequency of Intraventricular Haemorrhage (IVH) in Early Preterm Neonates Born at DHQ Teaching Hospital Gujranwala
No full textObjective: The reported frequency of intraventricular hemorrhage in preterm neonates varied greatly. We determined the frequency of IVH in premature neonates in the pediatric unit of DHQ Hospital Gujranwala.
Materials & Methods: This cross-sectional study involved 282 very low birth weight neonates (birth weight <1500 gm.) delivered very preterm (gestational age <32 weeks). These neonates were assessed for intraventricular hemorrhage which was diagnosed on cranial ultrasound performed on 3rd day of life. The frequency of IVH was compared across various attributing factors i.e., gestational age at delivery, gender, birth weight, mode of delivery, and maternal antenatal steroids.
Results: The mean gestational age at delivery was 27.5±2.3 weeks while the mean birth weight was 1120.5±190.2 grams. 172 (61.0%) neonates were delivered vaginally while C-section was performed in 110 (39.0%) cases. 263 (93.3%) mothers received antenatal steroids. Intraventricular hemorrhage was diagnosed in 64 (22.7%) early preterm neonates. The frequency of IVH increased significantly with increasing prematurity; 24-27 weeks vs. 28-31 weeks (28.9% vs. 17.0%; p-value=0.017), decreasing birth weight; <1 kg vs. ?1kg (31.8% vs. 18.6%; p-value=0.014) and lack of antenatal steroids (52.6% vs. 20.5%; p-value=0.001).
Conclusion: The intraventricular hemorrhage was observed in 22.7% of early preterm neonates which advocates routine screening of preterm neonates for IVH so that timely identification and anticipated management may improve the outcome of such neonates. We also identified increasing prematurity, decreasing birth weight, and lack of antenatal steroids as potential attributing factors that can be used for risk stratification and management planning of such cases
Minimally invasive vs. conventional mitral valve surgery: a meta-analysis of randomised controlled trials
No full textObjectiveThe evidence underlying the efficacy and safety of minimally invasive mitral valve surgery (MIMVS) is inconclusive. We conducted a meta-analysis to evaluate whether MIMVS improves clinical outcomes compared with conventional sternotomy.MethodsWe searched MEDLINE (via PubMed), Embase, the Cochrane Library, and ClinicalTrials.gov from inception to January 2024 for all randomised controlled trials (RCTs), comparing MIMVS with conventional mitral valve surgery. RevMan 5.4 was used to analyse the data with risk ratio (RR) and mean difference (MD) as the effect measures.ResultsEight studies reporting data on 7 RCTs were included in our review. There was no significant difference in all-cause mortality, the number of patients requiring blood product transfusion, and the change from baseline in the SF-36 physical function scores between the MIMVS and conventional sternotomy groups. MIMVS reduced the length of hospital stay (MD −2.02 days, 95% CI: −3.66, −0.39) but did not affect the length of ICU stay, re-operation for bleeding, and the incidence of renal injury, wound infection, neurological events, and postoperative moderate or severe mitral regurgitation. MIMVS was associated with a trend toward lower postoperative pain scores (MD −1.06; 95% CI: −3.96 to 0.75).ConclusionsMIMVS reduced the number of days spent in the hospital and showed a trend toward lower postoperative pain scores, but it did not decrease the risk of all-cause mortality or the number of patients needing blood product transfusions. Further large-scale RCTs are required to inform definitive conclusions, particularly with regard to quality-of-life outcomes investigating functional recovery.Systematic Review RegistrationPROSPERO (CRD42023482122)
