A Wideband Correlation and Detection Module Based on Substrate-Integrated Waveguide Technology for Radio Astronomy Applications

Juan Luis Cano,Angel Mediavilla,Enrique Villa,Eduardo Artal

doi:10.1109/tmtt.2018.2823305

Juan Luis Cano, Angel Mediavilla + Show 2 more

Open Access

https://doi.org/10.1109/tmtt.2018.2823305

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Abstract

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.

Highlights

S UBSTRATE-INTEGRATED waveguide (SIW) is a relatively new technology that is having an increasing interest since it was proposed by Deslandes and Wu [1]
The final election for the design of the correlation and detection module (CDM) in the QUIJOTE project was the waveguide technology, this paper presents the development of a full system implementing the correlation, detection, and level accommodation functionalities in Q-band (35–47 GHz, 30% instantaneous bandwidth) with most of the RF circuitry implemented in the substrate-integrated waveguide (SIW) technology
The power divider designed for the CDM uses an inductive metallic post at the T-junction together with two matching steps (w2, L2 and w3, L3) at the common port to obtain a good reflection in the whole frequency range of interest

Summary

INTRODUCTION

S UBSTRATE-INTEGRATED waveguide (SIW) is a relatively new technology that is having an increasing interest since it was proposed by Deslandes and Wu [1]. Modern radio astronomy receivers are multipixel cameras, where the increasing number of pixels is the current trend In this context, the SIW technology has a clear opportunity for the development of light, compact, highly integrated, and relatively cheap back ends. The QUIJOTE project [2], [3] is a multipixel radio astronomy ground-based experiment with the aim of characterizing the CMB polarization, among other scientific goals, through the measurement of the Q, U , and I Stokes parameters simultaneously from 10 to 47 GHz in different subbands The calculation of these Stokes parameters is carried out through the correlation and detection of the incoming signals.

PRINCIPLE OF OPERATION

CORRELATION AND DETECTION MODULE DESIGN

Module Integration

CHARACTERIZATION AND MEASUREMENT RESULTS

Findings

CONCLUSION