Modelado de componentes pasivos de montaje superficial en radiofrecuencia

In this paper, lumped-element models for surface mounted devices (SMD), capacitors and inductors, are presented. The parasitic and packaging effects of SMD are extracted, including the characterization of the interconnects. The equivalent circuit parameters are extracted from Sparameters tests. These models are suitable for microstrip mounted components, and in the frequencies range 100 MHz to 4 GHz. The modelling and extraction procedure is demonstrated for 0805 style components

Híbrido 180º de banda ancha en tecnología uniplanar para ondas milimétricas

This document presents the design, simulation and characterization of a hybrid-ring coupler using uniplanar technology, developed at millimetre-wave frequencies. The hybrid-ring coupler is designed using a combination of coplanar waveguide (CPW) and slotline transmission lines in order to achieve the phase difference response between the transmitted and coupled ports. The use of uniplanar technology makes a straightforward and fast implementation, and also offers an easy integration with other MIC or MMIC applications. The circuit is optimized to get the best phase results by tuning the slotline branch of the ring. Circuit characterization shows a wideband frequency response, around 17 GHz, in terms of phase difference (180º±5º) working up to 40 GHz

A 30 GHz planar array antenna using dipole-coupled-lens

Measurements of the radiation patterns from a planar array of bow-tie slot antennas coupled through an extended hemispherical lens are reported. The design operates over 10% bandwidth centred at 30 GHz with a return loss of 10 dB. A moderate directivity from the integrated lenses of 13 dB with half-power beamwidth (HPBW) of 10º is achieved. The reduced size of this design is suitable for the integration with millimetre wave circuits.This work was supported by the Spanish "Ministerio de Ciencia e Innovacion" through the projects ESP2004-07067-C03-01 and AYA2007-68058-C03-02

A wideband correlation and detection module based on substrate-integrated waveguide technology for radio astronomy applications

A wideband (30% relative bandwidth) correlation and detection module based on substrate-integrated waveguide (SIW) technology intended for a radio astronomy polarimeter is presented. The SIW circuit is a six-port network with two input ports that are correlated in two hybrid couplers and their corresponding output signals are routed to Schottky diode detectors, which are designed using microstrip technology and assembled within the same system. The designed SIW structure includes hybrid couplers, power dividers, a 90° phase shifter, and 90° bends, providing a real implementation of a functional system with improved bandwidth performance from 35 to 47 GHz. Experimental results are in concordance with simulations, and they validate the module operation for the proposed application.This work was supported by the Spanish Ministry of Economy and Competitiveness under Project AYA2013-49759-EXP

Conmutador de fase 180º de banda ancha a 30 GHz

The design, assembly and characterization of a phase switch in the Ka-band based on PIN diodes is presented. This phase switch has provided a 20 per cent of bandwidth at 30 GHz and a phase shift around 180º. The phase switch has been made with a broadband hybrid coupler on microstrip technology and commercial PIN diodes HPND-4005 from Agilent. Two different techniques to adjust the phase shift have been applied. Input and output matching better than 13 dB, return losses lower than 3 dB and a phase shift from 160º up to 174º have been obtained from 27 to 33 GHz

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

Novel full-band waveguide polar modulator for radio astronomy applications

A novel full-band (40% relative bandwidth) waveguide polar modulator (WPM) design based on a new architecture with two turnstile junctions and a nearly frequencyindependent differential 180° phase shift between orthogonal arms is presented. The use of suitably designed turnstile junctions together with antiphase waveguide-coaxial-waveguide transitions in reduced-height waveguide technology enables the improvement of bandwidth over previous WPMs with a very compact and simple solution. This design enables continuous rotation about its central axis at 40 revolutions/s, which makes the modulator suitable for receivers with significant 1/f noise such as cryogenic radiometers. The polar modulator presented in this paper is designed to be cooled down to cryogenic temperatures in order to reduce its contribution to the receiver noise. This design is suitable for radio astronomy applications due to its costeffective, compact design, and high quality performance as well as being readily scalable. A polar modulator in the Ka-band (26.5-40 GHz) has been designed to show a reflection better than -20 dB, an insertion loss around 0.3 dB, and a cross-coupling near -35 dB measured at room temperature (T = 298 K). This insertion loss is reduced by 30%, while the phase difference and cross-coupling maintain similar values when the polar modulator is cooled to approximately T = 80 K.This work was supported by the Spanish Ministry of Economy and Competitiveness under the CONSOLIDERINGENIO 2010 program and project CSD2010-00064

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

Filtro en banda W con alto rechazo en banda imagen

This paper describes the design and implementation of a filter in the 81-99 GHz frequency band, aimed for the front-end module in a radio astronomy receiver where the image band rejection is very important. Classic formulation is used to design the filter. The fine adjustment process of the filter is based on manufacture considerations through Scattering parameters simulation. Design is based on waveguide resonant cavities topology. Therefore, image band rejection and in band losses are improved compared with micro-strip line technology. Measurements show a flat response with only 0.4 dB insertion losses and 20 dB return loss. Image rejection is very high, 40 dB relative to the pass band