Multiple Order Dual-Band Active Ring Filters with Composite Right/Left Handed Cells

In this paper, a novel dual-band active filter topology is presented. The non-linear phase response of a composite right/left-handed cell is used to achieve the desired dual-band performance. Additionally, the proposed structure based on coupled ring resonators yields a very compact solution in which high-order implementations can be easily obtained by cascading multiple rings. The theoretical principles of this type of filters are analyzed in detail. Finally, three prototypes based on first-, second- and third-order structures validate the feasibility of this type of filters. Good agreement between simulations and measurements has been achieved

Noise Figure Measurement of Differential Amplifiers Using non-Ideal Baluns

This paper analyzes the noise and gain measurement of microwave differential amplifiers using two passive baluns. A general model of the baluns is considered, including potential losses and phase/amplitude unbalances. This analysis allows de-embedding the actual gain and noise performance of the isolated amplifier by using single-ended measurements of the cascaded system and baluns. Finally, measured results from two amplifier prototypes are used to validate the theoretical principles

Dual-Band Tunable Recursive Active Filter

This letter presents a novel recursive active filter topology that provides dual-band performance, with independent tuning capability in both bands. The dual-band operation is achieved by using two independent feedback lines. Additionally, linear phase shifters based on left-handed cells are included in these two branches in order to tune the center frequency of both pass bands

A De-Embedding Method to Characterize Differential

This paper analyses the noise and gain measurement of microwave differential amplifiers using two passive baluns. A model of the baluns that includes potential losses and unbalances has been considered. This analysis allows to de-embed the actual performance of the differential device from the single-ended measurements of the two-port cascaded system and the baluns. The method has been validated with measured results from a fully-differential amplifier prototype

Método de desembebido para la caracterización de amplificadores diferenciales usando baluns pasivos

This paper analyses the noise and gain measurement of microwave differential amplifiers using two passive baluns. A model of the baluns that includes potential losses and unbalances has been considered. This analysis allows de-embedding actual performance of the differential device from the single-ended measurements of the two-port cascaded system and the baluns. The method has been validated with measured results from a fully-differential amplifier prototype

Filtro Activo Recursivo con Divisores de Potencia Metamaterial Asimétricos

In this work, it is presented a recursive active filter implemented by means of unequal Wilkinson power dividers. These power combiners have been implemented by using metamaterial transmission lines based on complementary split ring resonators (CSRRs). The power dividers are designed in planar technology and thanks to the use of the metamaterial cells their dimensions have been reduced. Additionally, the designed recursive active filter presents a high gain and low noise at the same time that minimizes the number of employed lumped elements

Recursive Active Filter with Metamaterial Unequal Wilkinson Power Dividers

In this work, it is shown that it is possible to implement an unequal Wilkinson power divider with reduced dimensions by using metamaterial transmission lines based on complementary split ring resonators (CSRRs), in planar technology. In addition, this combiner has been used to implement a compact recursive active filter. Thanks to the use of the metamaterial combiner it is possible obtain a filter with small dimensions. Additionally, due to the asymmetry in the power divider it is possible obtain high gain and low noise at the same time that minimizes the number of lumped element

Diseño de amplificadores diferenciales de bajo ruido para antenas uwb en la banda baja del proyecto Ska

Differential amplifiers can be an appropriate solution in the implementation of radio astronomy receivers, due to their efficient interference and harmonic isolation. In this paper, two different topologies are presented. The first one consists of two single ended amplifiers in a balanced topology. The second one is formed by cascading two simple differential stages. Both circuits operate in the 300MHz to 1GHz bandwidth. Firstly, gain and noise characterizations of each amplifier have been done. Lastly, noise analysis of the whole reception system, formed by the antenna and the differential amplifiers, is presented

Diseño y Caracterización de un Array Activo de Banda Ancha para Radioastronomía

The Square Kilometre Array (SKA) radio-telescope will become a reality in 2020. Nowadays, many research groups are validating the technologies that will be necessary to build this enormous instrument. In order to cover the bandwidth between 70 MHz and 10 GHz, different antenna array designs and configurations will be used. This paper presents the design and characterization of a planar aperture array based on bunny-ear antennas, whose design is proposed to cover the midfrequency range of the telescope (from 300 to 1000 MHz). One of the main advantages of the present solution is its fully differential nature, which avoids the use of passive baluns, although it requires some especial considerations during the design and measurement processes