We are currently exploring ways to improve the performance of SIS mixers above 700 GHz. One approach is to use NbTiN in place of Nb for all or some of the mixer circuitry. With its high gap frequency and low losses demonstrated up to 800 GHz, it should be possible to fabricate an all-NbTiN SIS mixer with near quantumlimited noise performance up to 1.2 THz. Using a quasioptical twin-slot two-jun...

As for all materials, the performance of concrete is determined by its microstructure. Its microstructure is determined by its composition, its curing conditions, and also by the mixing method and mixer conditions used to process the concrete. This paper gives an overview of the various types of mixing methods and concrete mixers commercially available used by the concrete industry. There are t...

—A compact 180° hybrid has been developed for use in balanced SIS mixers. The lumped-element circuit uses superconducting Nb conductors on a 1.4 mm x 0.5 mm quartz substrate and operates over 4-12 GHz. Index Terms—Superconducting microwave devices, microwave integrated circuits, hybrid junctions, lumpedelement microwave circuits, superconductor-insulatorsuperconductor mixers.

In this study, two different types of 90-degree hybrid mixers were designed and analyzed in an ISM (industrial, scientific, and medical) 2.4 GHz band. The first is a general type; the other, a low-distortion type. For the low-distortion type, the 1-dB compression point and the third interception point are increased about 3-dB. The proposed mixers have a major shortcoming with a significant pena...

A regression model for simulating residence time distribution (RTD) of turbulent flows in helical static mixers is proposed and developed to predict the residence time distribution in static mixers. An efficient method is required to estimate the RTD and the sole means of achieving this is through detailed regression model. The RTD was calculated numerically by regression model. The results of ...

AbstructWe report on the development of low-noise quasioptical SIS mixers for the frequency range 400-850 GHz. The mixers utilize twin-slot antennas, two-junction tuning circuits, and Nb-trilayer junctions. Fourier-transform spectrometry has been used to verify that the frequency response of the devices is well predicted by computer simulations. The 400-850 GHz frequency band can be covered wit...

Ever since the FCC allocated 7.5 GHz (from 3.1 GHz to 10.6 GHz) for ultra wideband (UWB) technology, interest has been renewed in both academic and industrial circles to exploit this vast spectrum for short range, high data rate wireless applications. The great potential of UWB lies in the fact that it can co-exist with the already licensed spectrum users and can still pave the way for a wide r...

This article introduces a four-element 300-GHz-band bi-directional phased-array transceiver (TRX). The TRX utilizes the same antenna, signal path, and local oscillator (LO) circuitry to operate either in transmitter (TX) mode or receiver (RX) mode. TX adopts outphasing technique increase average output power for higher order modulation schemes by utilizing two mixers that are connected directly...

Residual phase noise from local oscillators (LO) can be degraded by additive noise of on-chip local oscillator drivers/buffers in integrated circuit mixers. Reciprocal mixing of strong RF signals with the LO noise degrades the receiver sensitivity. Specification and evaluation of the LO noise degradation in integrated mixers will enable a system designer to compute the loss of sensitivity in th...

We consider the mixing of similar, cohesionless granular materials in quasi-two-dimensional rotating containers by means of theory and experiment. A mathematical model is presented for the flow in containers of arbitrary shape but which are symmetric with respect to rotation by 180 degrees and half-filled with solids. The flow comprises a thin cascading layer at the flat free surface, and a fix...