Banca de DEFESA: REILIAN DA SILVA MACILON

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : REILIAN DA SILVA MACILON
DATE: 26/08/2024
TIME: 14:00
LOCAL: AUDITÓRIO DO CTEC
TITLE:

Frequency-Selective Radome Absorbers Based on Interdigital Resonators for Radar Cross Section Reduction 

KEY WORDS:

Absorber, interdigital resonator (IR), frequency-selective surface (FSS), frequency-selective rasorber (FSR).

PAGES: 85
BIG AREA: Engenharias
AREA: Engenharia Elétrica
SUBÁREA: Telecomunicações
SPECIALTY: Teoria Eletromagnetica, Microondas, Propagação de Ondas, Antenas
SUMMARY:

Amid increasing advances in the detection capability of modern radar systems, stealth
technology aims to reduce the radar cross section (RCS) of a platform, making it difficult
to detect. Among the principles on which stealth technology is based, active systems
have stood out due to the various advantages they present. Due to their spatial filtering
characteristics, frequency-selective surfaces (FSSs) have been widely explored as
active systems. Considering the strong out-of-passband reflections in various direction,
bandpass FSSs can significantly reduce monostatic RCS, however they can cause large
bistatic RCS. In this context, a new structure, called frequency-selective radome absorber
or frequency-selective rasorber (FSR), has attracted the attention of researchers in recent
years. This type of structure combines the design of a bandpass FSS with a resistive
absorber FSS, to obtain two absorption bands (A) located on both sides of a transmission
band (T), also known as absorption-transmission-absorption (A-T-A). Therefore, it
is capable of reducing out-of-passband reflections in other directions. In this work, two
dual-polarization A-T-A FSRs based on interdigital resonators (IR) are proposed, whose
lossy FSS designs feature elements with four incorporated resistors and different layouts;
split-ring, crossed dipole, and square frame. The two rasorbers presented provide good
operational bandwidth, and have passbands around 9.7 GHz and 4.78 GHz, whose minimum
insertion losses (IL), under normal incidence, are 1.0 dB and 0.77 dB, respectively.
equivalent circuit models (ECM) for the proposed FSRs are presented with the aim of
explaining the parallel resonance in each case. The rasorber prototypes are fabricated
with low-cost FR-4 substrate in both layers, and measured for demonstration. The results
are very coherent when compared with those obtained in simulations. Due to their
symmetries, the presented FSRs have good angular stability. Therefore, it appears that
the proposed rasorbers are capable of reducing the RCS of communication systems operating
in different bands, contributing to making them stealthy. Finally, performance
comparisons with other FSRs implemented with parallel resonance in previous works are
presented.

COMMITTEE MEMBERS:
Presidente - 6345784 - ADAILDO GOMES D ASSUNCAO
Interno - 349732 - LAERCIO MARTINS DE MENDONCA
Interno - 3921178 - VALDEMIR PRAXEDES DA SILVA NETO
Externo à Instituição - ADAILDO GOMES D ASSUNCAO JUNIOR - IFPB
Externo à Instituição - JEFFERSON COSTA E SILVA - IFPB