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We report a monolithic microwave integrated-circuit (MMIC) comb generator capable of producing a repetitive narrow pulse (7.1 ps pulse duration) with sharp edges (4.2 ps falling time). The circuit was designed in a 250 nm indium phosphide (InP) heterojunction bipolar transistor (HBT) technology using differential pairs. We characterized the output signal with a 110 GHz sampling oscilloscope and de-embedded the band-limited frequency spectrum of the pulse in the circuit reference plane. We measured a pulse duration of 7.1 ps and a peak amplitude of −0.333 V. In the frequency domain, the comb generator provided −48.7 dBm of output power at 110 GHz when the circuit is fed with a 1 GHz input signal. [ABSTRACT FROM AUTHOR]

This paper investigates a unified theory to derive vector network analyzer calibration algorithms based on the T-matrix representation, by which means the line-reflect-match (LRM), line-reflect-match-match (LRMM), and the line-reflect-reflect-match (LRRM) calibrations are formulated. The proposed calibration theory is more general than other versions of LRM, LRMM, and LRRM in that an arbitrary known two-port device can be used as the line standard L, rather than a perfect thru or transmission line. Experimental verifications of the proposed theory using on-wafer calibrations from 0.5 GHz to 110 GHz are given. [ABSTRACT FROM AUTHOR]

The objective of this letter oriented toward micro-wave measurement of high-impedance devices using a conventional on-wafer probe station is multiple. First, we provided a quantification of the measurement uncertainty inherent to the setup when measuring capacitors in the range of 0.01–10 fF using both the reflection and transmission methods up to 50 GHz. In particular, we demonstrate a clear improvement when using the transmission method in series-through configuration. As a practical demonstration, on-wafer MOS voltage-tunable capacitors with capacitances ranging from 0.85 to 1.15 fF are extracted with uncertainties of 130 and 2 aF, respectively, for both reflection and transmission measurements at 10 GHz. Capacitance fluctuation related to the technological process on the order of 20 aF is then exemplary demonstrated using the series-through configuration. [ABSTRACT FROM AUTHOR]

The thru-reflect-match (TRM) calibration technique uses as standards a through connection of ports 1 and 2 of the vector network analyzer, two symmetrical highly reflecting loads, and two broadband loads (match) of impedance close to the measuring system impedance ( Z 0). The classical theory of the TRM calibration refers the calibration to the impedance of the load used as the match standard ( Z M), which is assumed as symmetrical. In practice, Z M may be frequency dependent. Moreover, as the frequency increases, the symmetry condition of the load used as match standard may become difficult to preserve, thus affecting the reference impedance definition and reducing the accuracy of the calibration. In this paper, the ABCD-parameters matrix formalism is used to introduce for the first time a generalized TRM calibration theory, allowing the use of either symmetrical or nonsymmetrical loads of arbitrary impedance as the match standard. [ABSTRACT FROM AUTHOR]

ABSTRACT Bipolar junction transistors (BJTs) in 0.18-μm silicon germanium (SiGe) BiCMOS technology are characterized from DC-67 GHz using on-wafer calibration standards along with an electromagnetic (EM)-based de-embedding technique. The common issue of narrow spacing between the interconnects in typical on-wafer calibration standards that causes calibration error and difficulty in load-standard design, is overcome with the proposed EM-based de-embedding. Appropriate spacing between the closely spaced interconnects is determined based on EM simulations. The parts of the interconnects including vias within the spacing, which have significant parasitics affecting the characterization accuracy at high frequencies and over wide frequency ranges that remain noncalibrated after calibration, are extracted using the EM-based de-embedding technique. The measured results of BJTs up to 67 GHz show that approximately less than 2-dB insertion loss and 15-deg phase differences are observed between the on-wafer characterizations with and without the EM-based de-embedding, demonstrating that the on-wafer characterization with EM-based de-embedding is useful for accurate characterization of devices at millimeter-wave two frequencies. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1285-1292, 2014 [ABSTRACT FROM AUTHOR]

In this paper, we introduce a novel technique for vector network analyzer (VNA) scattering parameter (S-parameter) device characterization. The presented approach is based on causal relationships that provide a connection between the real and imaginary parts as well as between the magnitude and phase of causal network functions. We discuss the problems encountered in the practical implementation of the dispersion relationships such as numerical evaluation of the singular integrals, finite bandwidth of the experimental data, reconstruction artifacts, and nonuniqueness of dispersion relationships. To reduce these problems, we use the generalized dispersion relationships with reference points (subtractions). We develop integral relationships with subtractions and corresponding estimates for error bounds. We show that an appropriate placement of the reference points can significantly reduce the errors caused by finite spectrum. We analyze the applicability of the developed dispersion relationships to the VNA measurements. We demonstrate that certain parameters can be measured with considerably higher accuracy compared with other parameters and that it is possible to select samples from the measured data that can be used as reference points for dispersive integrals. Based on these observations, we propose a device characterization technique that consists of the causality-constrained reconstruction of the sensitive parameters of the measured devices based on more accurately measured characteristics. The proposed technique allows one to accurately characterize the parameters, like quality factor of a high-quality (high-Q) inductors or loss tangent of low-loss transmission lines, of which direct measurement is normally not possible due to limited sensitivity and dynamic range of the VNA. To demonstrate the effectiveness of the proposed technique, we reconstruct the resistance and the quality factor of a high-Q inductor from the accurately measured inductance. [ABSTRACT FROM AUTHOR]

A reflection based and thru-less de-embedding technique for impedance and absolute power flow measurements suitable for on-wafer large-signal characterization of microwave transistors is proposed. The developed system was tested for both 50 Ω and non-50 Ω terminated passive and active devices and the results obtained are compared with those obtained with commercial instruments. © 2010 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2010. [ABSTRACT FROM AUTHOR]

We report on the application of Si and Al ion-implantation patterning to the fabrication of low-loss microwave transmission lines in high-temperature superconductor (HTS) thin films. Using this technique, we have fabricated coplanar waveguide (CPW) transmission lines in YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) thin films deposited on LaAlO/sub 3/ substrates. We have used both resonant and broadband measurements in order to characterize the performance of the resulting transmission line structures. For the broadband measurements, on-wafer calibrations were used to obtain accurate S-parameters and transmission line propagation constants up to 25 GHz. The propagation constants of the ion-implanted transmission lines do not differ significantly from those of lines patterned using conventional ion milling over the frequency range studied, with a value for the attenuation constant of approximately 0.03-0.04 dB/cm at 50 K and 10 GHz. The relatively low losses of the ion-implanted devices demonstrate the effectiveness of this method of patterning for HTS microwave device fabrication. [ABSTRACT FROM PUBLISHER]