Heckler, M.; Nova, E.; Elmarissi, W.; Basta, N.; Dreher, M. IET microwaves antennas and propagation Vol. 6, num. 12, p. 1381-1388 DOI: 10.1049/iet-map.2012.0055 Data de publicació: 2012-09-18 Article en revista
This study describes the design of a dual-band microstrip antenna with four isolated outputs. The proposed antenna has
been optimised to operate in the E5a/E5b and E1 bands of the European satellite navigation system Galileo. Each pair of outputs
delivers the signal in only one of the operating bands; hence the antenna operates also as a diplexer. The operation principle, the
design procedure and measured results are presented and discussed. It is demonstrated by means of measured results that the
designed antenna exhibits high isolation between its output ports and that good performance in terms of radiation pattern and
polarisation purity was obtained.
Brito, Z.; Llamas Garro, Ignacio; Navarro, G.; Perruisseau, J.; Pradell, L.; Giacomozzi, F.; Colpo, S. IET microwaves antennas and propagation Vol. 6, num. 6, p. 713-719 DOI: 10.1049/iet-map.2012.0077 Data de publicació: 2012-04-24 Article en revista
Compact closed-form mathematical expressions are presented for the effective permittivity, characteristic impedance and attenuation constant of coplanar waveguides with thick electrodes and high-frequency dispersion. Excellent agreements, for a wide range of frequencies, up to 100 GHz and for conductor thicknesses up to 40 m are found with full-wave finite-element results from commercial software (HFSS) in a margin of geometric parameter values and frequencies of interest for the design and optimisation of high-speed electro-optical modulators. The formulae are simple and specially tailored to the narrow gap widths and thick electrodes typical of electro-optical modulator applications. Other approaches to closed-form formulae for CPW parameters are also compared and analysed.
Gilabert, Pere L.; Montoro, G.; Vizarreta, P.; Berenguer-Sau, J. IET microwaves antennas and propagation Vol. 5, num. 8, p. 963-974 DOI: 10.1049/iet-map.2010.0368 Data de publicació: 2011-06-06 Article en revista
In this study, the behaviour of coupled microstrip transmission lines loaded with complementary spiral resonators
(CSRs) is analysed in depth. CSRs are constitutive elements for the synthesis of metamaterials with negative effective
permittivity which allows the suppression of undesired signals at a given frequency band. Several test prototypes have been
characterised and modelled for transmission, crosstalk interference, isolation and signal integrity (SI). Experimental results
reveal that CSRs provide a good solution to reduce crosstalk between parallel transmission lines in the radio frequency band
with a low impact in terms of the SI. A design methodology based on the equivalent circuit model for the description of the
proposed structures, including transmission lines and coupling parameters, is provided.