Short-term interest rate futures as monetary policy forecasts

The prices of futures contracts on short-term interest rates are commonly used by central banks to gauge market expectations concerning monetary policy decisions. Excess returns - the difference between futures rates and the realized rates - are positive, on average, and statistically significant, both in the euro area and in the United States. We find that these biases are significantly related to the business cycle only in the United States. Moreover, the sign and the significance of the estimated relationships with business cycle indicators are unstable over time. Breaking the excess returns down into risk premium and forecast error components, we find that risk premia are counter-cyclical in both areas. On the contrary, ex-post prediction errors, which represent the greater part of excess returns at longer horizons in both areas, are correlated with the business cycle (negatively) only in the United States.futures rates, monetary policy, risk-premium

On-Wafer Calibration Algorithm for Partially Leaky Multiport Vector Network Analyzers

A new solution for multiport vector network analyzer calibration is presented in this paper. The error model is divided in two separate leaky halves, each of them with crosstalk terms, but without the leakage between the two sides. This error model is particularly useful for on-wafer measurements, when multisignal probes are employed and the crosstalk among probe fingers may dramatically affect the measurement accuracy.We will show that, with a simple choice of calibration standards, the new procedure takes the same time of a classical two-port line-reflect-match or thru-reflect-line calibration. The proposed algorithm is verified with measurements and simulations in both coaxial and on-wafer environments

Generalized mixed-mode S-parameters

This paper presents an innovative approach to extend the S-parameter definition to multiport networks having conventional single-ended and differential ports, as is the case for operational amplifiers, transformers and baluns. To give maximum generality to this technique, for example, allowing for complex -parameter reference impedances, the mathematical derivation will be carried out with the most general definition of the -parameters. The presented approach gives the same results already published for circuits with differential ports only when the required simplifications are applied

A simplified algorithm for leaky network analyzer calibration

A new algorithm for network analyzer calibration is presented. The error model includes leakage effects and can be applied to a general n-port NWA. The 2-port 16-term model becomes a special case of this new technique which is also hopefully suitable for the calibration problems of multiport on-wafer probing systems. Experimental results testify the effectiveness of the new approach

Simple Technique for source reflection coefficient measurement while characterizing active devices

This paper describes a simple, yet rigorous technique for fast and accurate determination of the source reflection coefficient during the characterization of microwave active devices. The solution consists in measuring the waves at the DUT reference plane under two different bias conditions. Since the DUT small signal impedance value depends on the bias voltage, the waves at the DUT input port changes as well. We proved that their measurements give enough information to compute the source reflection coefficient with accuracy suitable for most applications. The correction for systematic errors is based in the traditional error-box model and it does not require any exotic calibration procedures. Experimental results are presented and compared to data obtained with more traditional technique

Time domain reflectometry applied to MMIC passive component modeling

The time domain facilities of a network analyzer, combined with the tools of network synthesis, were recently used for experimental modeling of discontinuities in an S-parameter measurement set, so as to allow the instrument calibration directly to the ports of the device under test. The technique proved to be very useful in those cases where the discontinuities, that lie before the unknown device, cannot be isolated by the usual calibration methods, and therefore, since network synthesis deals only with frequency domain information, it is impossible to optimize the model's parameters, since they are affected by errors due to discontinuities. This paper describes a procedure which allows to isolate the response of the device under test, and to derive its complete model; when it to reach a reasonable accuracy it gives anyway a topology, which is a good starting point for other optimization routines that can be used for obtaining a better match, on a broad frequency band. This can be accomplished by optimzing the first approach topology to which other circuit elements have been added, so as to take into account second order effects especially at the higher frequencies. The technique was applied to model and characterize passive discrete components used in MMIC. The experimental results show the validity of the approac

Conformal Mapping Design Tools for Coaxial Couplers with Complex Cross Section

Numerical conformal mapping is exploited as a simple, accurate, and efficient tool for the analysis and design of coaxial waveguides and couplers of complex cross section. An implementation based on the Schwarz-Christoffel Toolbox, a public-domain MATLAB package, is applied to slotted coaxial cables and to symmetrical coaxial couplers, with circular or polygonal inner conductors and external shields. The effect of metallic diaphragms of arbitrary thickness, partially separating the inner conductors, is also easily taken into account. The proposed technique is validated against the results of the finite-element method, showing excellent agreement at a fraction of the computational cost, and is also extended to the case of nonsymmetrical couplers, providing the designer with important additional degrees of freedom

Recent Advances in Real-Time Load-Pull Systems

In this paper, some of the latest advances in real-time load-pull technologies will be described. A recently introduced ultralow-loss directional coupler, which has been designed and realized by the authors, provides a number of advantages when used in load-pull test sets. This device has been called the load-pull head. The new ultralow-loss load-pull head can transform any passive precalibrated load-pull system into an easily calibrated and accurate real-time load-pull test set, without losing highreflection- coefficient capabilities. Moreover, if used to realize an active loop, the load-pull head reduces the risks of oscillations and the amount of the loop amplifier output power. As an example application, measurements with a passive real-time load-pull setup of a 30-W laterally diffused MOS (LDMOS) transistor are presented. Furthermore, some advice to bypass the remaining unavoidable losses due to probes and cables is given.We will show, with measurements and with very simple calculations, that the combined use of load-pull heads, a passive tuner, and an active loop not only boosts the available ΓL but also decreases the loop amplifier output power, with a sensible reduction in the overall cost of the syste