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

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

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

Accurate on-wafer power and harmonic measurements of mm-wave amplifiers and devices

A novel integrated test system that accurately measures on-wafer S-parameters, power levels, load-pull contours and harmonics over 1 to 50 GHz is presented. The system measures power and S-parameters with single contact measurements and integrated hardware. There are two keys to this system: first, the network analyzer samplers are used as frequency-selective power meters with large dynamic ranges; second, all measurements are vector-corrected to the device under test reference planes. The capabilities and accuracy were demonstrated by measuring the power at the fundamental frequency and four harmonic frequencies of a 50-GHz traveling wave amplifier and the load-pull contours of a MODFET at 30 GH

A simple NWA calibration algorithm based on a transfer standard

A new two-port network analyzer (NWA) calibration technique is here presented. It uses a single two-port transfer standard plus a known reflectance to perform the calibration process. The transfer standard device has to be previously fully characterized with a traceable NWA. The technique here proposed uses less standards than any other up today calibration algorithm, which, on the contrary, requires at least three different devices. The paper presents the calibration algorithm along with some on-wafer experimental results which compare the new solution with a more traditional technique