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Solid-state sources using diode based frequency multipliers are critical for radio astronomy and atmospheric studies, as well as many other important scientific applications. This talk describes many of the technological innovations that are now used to achieve these goals and two specific recent examples that demonstrate the current capability of this technology. The first is a ∼200 GHz varactor...
In this paper we present a modulation type and baud rate independent synchronous receiver concept for millimeter-wave and sub-millimeter-wave transceivers. The synchronous receiver includes an analog feed-forward carrier recovery and a phase-locked-loop block. The carrier is recovered at the receiver employing a strong local oscillator signal transmitted along with the complex modulated data. The...
We present a phase noise analysis on a frequency-modulated continuous-wave (FMCW) radars at millimeter wavelengths to achieve a transmit power up to 1 Watt. To attain high transmit power, we describe a FMCW radar design that satisfy two characteristics. First, high transmit/receive (T/R) isolation better than 80 dB, obtained through a quasioptical duplexing method and high directivity horns. Second,...
Functional Principal Component Analysis is applied to study the variability of spectra from a set of samples constituted by different types of hydrocarbons with low levels of water contents. The spectra were measured with a spectrometer working in the (sub-)terahertz band from 75 GHz to 110 GHz. The results of our first assessments indicate that the functional principal components allow for simultaneous...
A compact receiver MMIC for a 300 GHz wireless communication system has been developed in a 35 nm mHEMT technology. The circuit integrates an active frequency multiplier by three and a buffer amplifier for the LO signal, a single balanced, quadrature, fundamental resistive down-converter and an RF pre-amplifier. The chip measurements have shown that the receiver exhibits a conversion gain of −1 dB...
RAL Space and its project partner PRG are tasked with providing space-qualified heterodyne receiver front-ends operating between 165.5 GHz and 325 GHz for the Microwave Sounder (MWS), the Microwave Imager (MWI) and the Ice Cloud Imager (ICI) of the MetOp Second Generation (MetOp-SG) series of satellites. The preliminary design of the receiver front-ends is now complete. Extensive tests on performance...
We give a comparison of sensitivity and power estimates for heterodyne receivers operating at common atmospheric science bands using Schottky mixer or low-noise amplifier front ends. The receiver estimates rely on commercially available mixer systems and reported low noise amplifier data.
We present results on the performance of a cryogenically cooled all-Schottky solid-state heterodyne receiver targeting the 2.06 THz neutral oxygen line. The receiver front end features low-parasitic Schottky diode mixer chips that are driven by a local oscillator (LO) source using Schottky diode based multipliers. The multiplier chain consists of a 38 GHz oscillator followed by a set of three cascaded...
The operating frequency of InP high electron mobility transistor (HEMT) based amplifiers has moved well in the submillimeter-wave frequencies over the last couple of years. Working amplifiers with substantial gain in waveguide packages has been reported beyond 700 GHz. When cooled cryogenically, they have shown significant improvement in their noise temperature. This has opened up the real possibility...
There is a high need for >2 THz room temperature direct-detectors/harmonic-mixers to characterize THz optical sources, phase lock THz-QCLs as LO sources for multi-pixel receivers, and realize absolute frequency calibration sources for applications in astrophysics, earth science, and remote sensing. Thus, we have developed a WM-52 (WR-0.22) harmonic mixer for the 3–5 THz operation. The design, fabrication...
A limiting factor of GaAs Schottky diodes used as mixers in heterodyne receivers is their high intrinsic noise when compared to SIS or HEB devices. This work presents results on the numerical optimization of fundamental Schottky diode mixers, results which predict a significant improvement in the noise performance of current Schottky mixer technology in the THz band. The optimization of the Schottky...
We demonstrate multiplexing and demultiplexing for terahertz wireless data links in the 300 GHz band. Demultiplexing of real-time data streams at different carrier frequencies with different data rates is presented, and real-time bit error rates are characterized.
This article gives a description of the process followed at the Operations Support Facilities (OSF) of the Joint ALMA Observatory (JAO) to integrate the new receiver ALMA Band 5 in the array. Details about design, testing, screening criteria, performance and progress are given.
A fully-electronic high-speed transmission with a highly-integrated set of quadrature direct-conversion TX and RX modules in 130nm SiGe HBT technology operating in the 240 GHz transmission window is presented. In view of high packaging costs of the currently available THz communication front-ends, each of the modules is implemented as a single chip with a broadband silicon lens-integrated on-chip...
A 0.14 THz wireless communication system that can transmit data with bit rate of 5 Gbps in real time over more than 21 km is developed. Solid-state power amplifier and vacuum electronic amplifier are cascaded to achieve nearly watts output power. An all solid-state receiver running in room temperature with equivalent noise temperature of 1100 K is used. An experiment over 21 km is carried out with...
This paper presents a fully-integrated ultrawideband receiver MMIC for high data rate communication at 240 GHz operating with a LO frequency of 60 GHz. The chip was fabricated in a 35 nm InGaAs-based metamorphic high electron mobility transistor technology. It comprises a frequency doubler followed by a buffer amplifier in the LO path, a LNA in the RF path and a subharmonic single balanced downconverter...
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