title: Impulse TDR and its Application to Characterisation of Antennas

authors: McCabe, Steven Owen

subjects: Impulse TDR

abstract: Passive microwave systems are traditionally characterised in the frequency-domain with a vector network analyser (VNA). The measurement of antennas typically takes place in an anechoic chamber where the interference from spurious reflections and outside noise is minimised. Despite the high level of accuracy achieved with this approach, such facilities have high costs associated with them. Recent publications have demonstrated the characterisation of antennas using a step-function time domain reflectometer (TDR) along with frequency-domain processing techniques. Localisation of the measurement in time prior to transformation allows for the dismissal of unwanted spurious reflections, eliminating the need for an anechoic chamber. An alternative technique is proposed whereby an impulse generator is employed in place of the step generator in a TDR. The advantage conferred by "impulse TDR" (ITDR) is that more energy is available at higher frequencies than with conventional step TDR, leading to a higher bandwidth and signal-to-noise ratio (SNR). The theoretical result is compared with measurement.

text: Impulse TDR and its Application to Characterisation of Antennas Passive microwave systems are traditionally characterised in the frequency-domain with a vector network analyser (VNA). The measurement of antennas typically takes place in an anechoic chamber where the interference from spurious reflections and outside noise is minimised. Despite the high level of accuracy achieved with this approach, such facilities have high costs associated with them. Recent publications have demonstrated the characterisation of antennas using a step-function time domain reflectometer (TDR) along with frequency-domain processing techniques. Localisation of the measurement in time prior to transformation allows for the dismissal of unwanted spurious reflections, eliminating the need for an anechoic chamber. An alternative technique is proposed whereby an impulse generator is employed in place of the step generator in a TDR. The advantage conferred by "impulse TDR" (ITDR) is that more energy is available at higher frequencies than with conventional step TDR, leading to a higher bandwidth and signal-to-noise ratio (SNR). The theoretical result is compared with measurement.

year: 2011

title: Is there a connection between monetary unification and real economic integration? Evidence from regime-switching stationarity tests

authors: Holmes, Mark J.

subjects: real interest parity

abstract: We investigate the extent of real convergence among G7 economies in terms of long-run real interest parity. A novel approach is applied where unit-root tests of real interest differentials are embedded within a Markov regime-switching framework. Whereas standard univariate unit-root tests provide little support for parity, we find real convergence is present after allowing for regime switches in real interest misalignments. However, differentials across members of the euro zone are likely to exhibit greater persistence despite nominal convergence. It is non-sequitur to infer from monetary unification that nominal convergence is necessarily conducive to real interest realignments or preventive of misalignments.

text: Is there a connection between monetary unification and real economic integration? Evidence from regime-switching stationarity tests We investigate the extent of real convergence among G7 economies in terms of long-run real interest parity. A novel approach is applied where unit-root tests of real interest differentials are embedded within a Markov regime-switching framework. Whereas standard univariate unit-root tests provide little support for parity, we find real convergence is present after allowing for regime switches in real interest misalignments. However, differentials across members of the euro zone are likely to exhibit greater persistence despite nominal convergence. It is non-sequitur to infer from monetary unification that nominal convergence is necessarily conducive to real interest realignments or preventive of misalignments.

year: 2008

title: Niupepa: A historical newspaper collection

authors: Apperley, Mark

abstract: Niupepa is a collection of 42 newspaper titles published in New Zealand from 1842-1933, comprising a total of 21,000 pages in 1,750 issues. This collection forms a unique historical record of the language of the indigenous Mãori people, the evolution of the written form of this language, and of events and developments during the formative colonial history of our country. Using the Greenstone software from the New Zealand Digital Library this collection is now publicly available with full-text search capability.

text: Niupepa: A historical newspaper collection Niupepa is a collection of 42 newspaper titles published in New Zealand from 1842-1933, comprising a total of 21,000 pages in 1,750 issues. This collection forms a unique historical record of the language of the indigenous Mãori people, the evolution of the written form of this language, and of events and developments during the formative colonial history of our country. Using the Greenstone software from the New Zealand Digital Library this collection is now publicly available with full-text search capability.

year: 2001-05-01