A New Technique for the Design of Multi-Phase Voltage Controlled Oscillators

© 2017 World Scientific Publishing Company.In this work, a novel circuit structure for second-harmonic multi-phase voltage controlled oscillator (MVCO) is presented. The proposed MVCO is composed of (Formula presented.) ((Formula presented.) being an integer number and (Formula presented.)2) identical inductor–capacitor ((Formula presented.)) tank VCOs. In theory, this MVCO can provide 2(Formula presented.) different phase sinusoidal signals. A six-phase VCO based on the proposed structure is designed in a TSMC 0.18(Formula presented.)um CMOS process. Simulation results show that at the supply voltage of 0.8(Formula presented.)V, the total power consumption of the six-phase VCO circuit is about 1(Formula presented.)mW, the oscillation frequency is tunable from 2.3(Formula presented.)GHz to 2.5(Formula presented.)GHz when the control voltage varies from 0(Formula presented.)V to 0.8(Formula presented.)V, and the phase noise is lower than (Formula presented.)128(Formula presented.)dBc/Hz at 1(Formula presented.)MHz offset frequency. The proposed MVCO has lower phase noise, lower power consumption and more outputs than other related works in the literature.Peer reviewedFinal Accepted Versio

Postharvest characteristics of cut flowers of selected members of the family Myrtaceae : a thesis presented in fulfilment of the requirements for the degree of Master of Philosophy at Massey University, New Zealand

Stages of floral development were described for Eucalyptus ficifolia and Metrosideros collina 'Tahiti' flowers (Myrtaceae) attached and detached from plants. Vase solution treatments were applied to promote bud opening of cut flowers and to prevent postharvest stamen wilting and abscission in both species. Water uptake and mass of harvested flowers in both species declined rapidly when the pedicels were placed in water (control). Some flower buds did not open after harvest. The decline in water uptake and flower mass was greatly reduced by a vase solution treatment containing 2% sucrose, and 200 ppm hydroxyquinoline citrate (HQC) adjusted to pH 4 using citrate buffer. Vase solutions containing higher sucrose concentrations (more than 6%) and of greater acidity (pH<4) were not beneficial for vase life of both species. Cut flowers of both species held in the standard solution (2% sucrose, 200 ppm HQC adjusted to pH 4 using citrate buffer) were treated with ethephon (0-10,000 ppm) following pre-treatment with silver thiosulphate (STS) (0-2.0 mM). Ethephon treatments significantly induced stamen wilting, but had no effect on stamen or petal abscission in both species. Pre-treatment with 2 mM STS had no effect on the rate of stamen wilting, but significantly reduced stamen or petal abscission in both species. Cut flowers of M. collina 'Tahiti' held in the standard solution were treated with ethylene (0-5 ppm). Exogenous ethylene significantly promoted abscission of stamens and petals in M. collina 'Tahiti'. Treatment with 0.5 and 5 ppm ethylene also induced flower abscission. Ethylene emanation from untreated cut flowers from plants grown in two environments (greenhouse and outside) was also measured. Untreated cut flowers harvested from plants grown outside produced more endogenous ethylene than those from plants grown in the greenhouse. The abscission of M. collina 'Tahiti' probably results from a relatively high sensitivity to ethylene