Amplificador monolítico de bajo ruido en banda Ka con tecnología GaAs mHEMT

This document presents the design and measurement results of a monolithic low noise amplifier for the 26–36 GHz band. The 3x1 mm2 chip has been designed using the D01MH process from OMMIC foundry (0.13μm mHEMT, GaInAs-InAlAs with 40% indium content) and a home-made transistor model. On-wafer measurements show a gain of S21 = 30.9 ± 1.9 dB with a mean noise figure of NF = 1.8 dB in the band of interest (minimun NF = 1.4 dB at 31 GHz). Input return loss is generally better than 10 dB while output return loss is better than 15 dB in the same band

Cryogenic performance of a 3-14 GHz bipolar SiGe low-noise amplifier

The performance of silicon-germanium (SiGe) transistors under cryogenic operation is analysed. The design and characterization of a 3–14 GHz low-noise amplifier (LNA) using SiGe transistors at 300 K and at 13 K are presented. A three stage amplifier is implemented with bipolar transistors model BFU910F from NXP commercially available with a plastic package. The amplifier exhibits 36.8 dB average gain with average noise temperature of 103 K and 42 mW DC power consumption at 300 K ambient temperature. Whereas cooled down to 13 K ambient temperature, it provides 32.4 dB average gain, 11.4 K average noise temperature with a minimum of 7.2 K at 3.5 GHz and a DC power dissipation of 5.8 mW. The presented LNA demonstrates an outstanding performance at cryogenic temperature for a commercial plastic packaged transistor.The authors would like to thank the Spanish Ministry of Economy, Industry and Competitiveness for the financial support provided under the grant ESP2015-70646-C2-2-R

Calibration of a polarimetric microwave radiometer using a double directional coupler

This paper presents a built-in calibration procedure of a 10-to-20 GHz polarimeter aimed at measuring the I, Q, U Stokes parameters of cosmic microwave background (CMB) radiation. A full-band square waveguide double directional coupler, mounted in the antenna-feed system, is used to inject differently polarized reference waves. A brief description of the polarimetric microwave radiometer and the system calibration injector is also reported. A fully polarimetric calibration is also possible using the designed double directional coupler, although the presented calibration method in this paper is proposed to obtain three of the four Stokes parameters with the introduced microwave receiver, since V parameter is expected to be zero for the CMB radiation. Experimental results are presented for linearly polarized input waves in order to validate the built-in calibration system.The authors would like to thank The Spanish Ministry of Science and Innovation for financial support provided through the grants ESP2015-70646-C2-2-R, ESP2017-83921-C2-2-R and PID2019-110610RB-C2

Double square waveguide directional coupler for polarimeter calibration

A novel full-band square waveguide coupler design based on directional couplers which couple the TE10 and TE01 orthogonal modes in a square waveguide is presented. This waveguide coupler is aimed at the calibration of polarization receivers. This is composed of a pair of rectangular waveguide directional couplers, which are rotated 90° between them and both are coupled to the main square waveguide through each one of the square section walls. The coupler covers the full frequency band from 10 to 18.9 GHz. It has inherent low cross-polarization, which allows obtaining any known elliptically polarized wave at a square waveguide when a signal is applied to the couplers. The fabricated prototype of this coupler exhibits 31 dB of coupling, with flatness of ±3.8 dB and excellent cross polarization better than 50 dB over the whole band.This work was supported by the Spanish Ministry of Economy and Competitiveness under Grant ESP2015-70646-C2-2-R

Cryogenic broadband Q-band MMIC low-noise amplifier

The design of a broad-band monolithic cryogenic low-noise amplifier (MMIC LNA) in the Q band, aimed to be used in radio-astronomy receiver front-end modules is presented. A 70 nm gate-length GaAs mHEMT process from OMMIC foundry is used to manufacture the amplifier. An accurate model for the minimum noise bias point of the transistor has been obtained at room temperature. The amplifier design is based on a four stage monolithic common source transistor configuration. At 300 K, the amplifier shows an associated gain of 28 ± 1.1 dB and an average noise temperature of 145 K with a minimum noise temperature of 101 K at 45 GHz tested on wafer. When cooled down at 15 K, the average noise temperature is 18.4 K with a minimum of 13.5 K and 27.3 dB of associated gain. The DC power consumption is extremely low, 4.1 mW, at cryogenic temperatureThis work was supported by the Ministerio de Economía y Competitividad from Spain under the CONSOLIDER-INGENIO 2010 program CSD2010-00064 reference, and the research program FPI BES-2011- 046199

Ka-band full-hybrid cryogenic low- noise amplifier

This paper describes the design and implementation of a broad-band full-hybrid cryogenic lownoise amplifier (MIC LNA) in the 26 – 36 frequency band, aimed for the front-end module in radio-astronomy receivers. A metamorphic technology process (mHEMT) of 50 nm gate length is used to manufacture the transistor. Design is based on a three stage common source transistor configuration and surface mounted devices (SMD) with high quality factors. Therefore, gain and noise performance are improved compared with monolithic technology (MMIC). At room temperature the mean measured gain is G = 22.4 dB and the noise temperature is Tn = 175 K. When cooled to Tp = 13 K, insertion gain is Gi = 23.8 dB and the noise temperature is Tn = 26 K. The DC power consumption is extremely low, PDC = 5.7 mW at cryogenic temperatures.This work was supported by the Ministerio de Economía y Competitividad from Spain under the CONSOLIDER-INGENIO 2010 program CSD2010- 00064 reference, and the research program FPI BES- 2011-046199

Amplificador de bajo ruido basado en tecnología mHEMT para receptores de radio astronomía

This paper describes a broad-band amplifier with very low noise for the 26-36 GHz frequency range. The amplifier consists of a previously designed monolithic (MMIC) amplifier using a 100nm mHEMT process and a high performance discrete transistor placed in front of it, so that the overall noise is reduced while the gain is increased if compared with the MMIC. The transistor was manufactured using a 50 nm mHEMT process. At room temperature the average gain is 35.2 dB and a noise figure of 1.76 dB. When cooled to 16K, the average noise temperature is 19.1K with an associated gain of 39.4 dB and a DC power consumption of only 15.7 mW

Four-state full Q-band phase shifter using smooth-ridged waveguides

A novel four-state full Q-band waveguide phase shifter based on smooth-ridged sections is presented. The waveguide structure combines differential 90° and 180° phase shifters, whose combination provides the four-phase states (0°, 90°, 180°, and 270°) by appropriately controlling a set of millimeter-wave switches. Each differential phase shifter is performed using an E-plane continuous profile ridge to reach the 90° or 180° phase shift, respectively. The phase shifter module provides outstanding performance covering the full Q-band (33-50 GHz) with average phase results of 93.5°, 182.8°, and 270.6°.This work was supported by the Spanish Ministry of Economy and Competitiveness through the Consolider-Ingenio 2010 Program under Grant CSD2010-00064 and Grant ESP2015-70646-C2-2-R

Broadband polarimeter receivers at 30 and 40 GHz for cosmic microwave background measurement

Broadband radiometers at 30 and 40 GHz for QUIJOTE radio astronomy experiment are very sensitive receivers to perform scientific sky observations of the Cosmic Microwave Background (CMB). The aim of this experiment is the linear polarization percentage measurement of the received signals. Radiometers have cryogenically cooled Front-End Modules followed by room temperature amplification, correlation and detection modules. Their relative bandwidth is around 30%. There are 30 receivers (pixels) at 30 GHz and 29 receivers at 40 GHz. The radiometer scheme is based on two balanced branches, microwave correlation and direct detection. The manufactured receivers measure Stokes polarization parameters I, Q, and U simultaneously. This paper describes the principle of operation of polarimeter receivers, and present details of manufactured subsystems, integration and test results. Receivers integrate different technologies: waveguides, microstrip, Monolithic Microwave Integrated Circuits (MMIC) and active and passive devices. The receivers are currently under installation in El Teide Observatory, Tenerife (Canary Islands, Spain)

Relation between Droplet Size Distributions and Physical Stability for Zein Microfluidized Emulsions

Zein, a subproduct of the food industry and a protein, possesses limited applications due to its high hydrophobic character. The objective of this research was to investigate the influence of homogenization pressure and cycles on the volumetric mean diameter (D4,3), span values, and Turbiscan Stability Index (TSI) using the response surface methodology for microfluidized emulsions containing zein as a unique stabilizer. Results showed that homogenization pressure seems to be the most influential parameter to obtain enhanced physical stability and droplet size distributions, with the optimum being 20,000 psi. Interestingly, the optimum number of cycles for volumetric diameter, span value, and TSI is not the same. Although a decrease of D4,3 with number of cycles is observed (optimum three cycles), this provokes an increase of span values (optimum one cycle) due to the recoalescence effect. Since physical stability is influenced by D4,3 and span, the minimum for TSI is observed at the middle level of the cycles (2 cycles). This work highlights that not only volumetric diameter, but also span value must be taken into consideration in order to obtain stable zein emulsions. In addition, this study wants to extend the limited knowledge about zein-based emulsions processed with a Microfluidizer device