Synthesis of predistorted reflection‐mode hybrid prototype networks with symmetrical and asymmetrical characteristics

Fathelbab, Wael M.; Hunter, I.C.; Rhodes, John David

doi:10.1002/cta.143

Cited by 12 publications

(8 citation statements)

References 12 publications

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“…Note that, in general, the value assigned to determines the shape of (the shape of is instead imposed a priori). A particular case that can be found under specific conditions is the equally scaled traditional solution, which returns a solution coincident with , with computed by satisfying the well-known Feldtkeller equation (10) This solution is optimal since it produces the equi-ripple return loss in the passband and is directly obtainable from the lossless characteristic polynomials. This also univocally defines the bipartition of simplified poles, thus requiring no further calculations, but it does not offer degrees of freedom that are exploitable for design.…”

Section: A Nonredundant Networkmentioning

confidence: 98%

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A New Approach to the Synthesis of Microwave Lossy Filters

Oldoni

Macchiarella

Gentili

et al. 2010

IEEE Trans. Microwave Theory Techn.

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In this paper, we first present a novel synthesis method based on an even-and odd-mode decomposition. This method is capable of synthesizing a network under very general hypotheses and is, therefore, suitable for lossy filter design. To exploit the increased flexibility of this new synthesis method over the traditional lossy design techniques, we then introduce a new approach to the design of lossy filters based on the characteristic polynomials evaluation. This new technique can offer many advantages over traditional techniques, and the main one is that, once the transmission function of the filter is known using traditional methods, the reflection function can be constrained with a certain degree of freedom. A tradeoff between additional constraints and redundancy in the final network must be accepted. Finally, we present design examples and a practical realization, which validate this novel approach to the design of lossy filters.Index Terms-Lossy filters, microwave filter synthesis, polynomial filter synthesis.

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Section: A Nonredundant Networkmentioning

confidence: 98%

“…As the first-order section, the extracted pole section has been used (involving a phase shifter and a shunt arm with an inductor and a series reactance denoted via an "X") although the triplet section described in [10] can be chosen as well.…”

Section: Synthesis Examplesmentioning

confidence: 99%

A New Approach to the Synthesis of Microwave Lossy Filters

Oldoni

Macchiarella

Gentili

et al. 2010

IEEE Trans. Microwave Theory Techn.

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“…So it should be used together with the circulators or isolators, thus increasing the overall size. The predistorted reflection-mode filters are also the solutions of lossy filter [5], [6]. However, circulators, isolators or hybrid couplers are still required.…”

Section: Introductionmentioning

confidence: 99%

A hybrid method for flat-passband filter with nonuniform Q resonators and predistortion

Qiu

Wang

2014

2014 IEEE International Wireless Symposium (IWS 2014)

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A new synthesis method is proposed for the design of high-performance parallel connected lossy filters. Compared with the nonuniform Q method, where the Q distribution is determined by the sensitivities of a preset coupling matrix, our method can provide a flat passband with flexible combination of nonuniform Q resonators by utilizing the predistortion technique with an adaptive offset. Two generalized Chebyshev filters with different specific Qfactors are designed with the negative and positive distortion offsets. The proposed hybrid method has been validated by the perfect passband flatness achieved with both of them.

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“…Ideal 3-Port Circulator Fig. 19 -Equivalent circuit of a predistorted circuit model with a cascaded circulator [18].…”

Section: Predistorted Reflection Networkmentioning

confidence: 99%

“…Fig. 19 -Equivalent circuit of a predistorted circuit model with a cascaded circulator [18]. Group delay of synthesized responses: conventional synthesis (in black), lossy synthesis Q 0 =2000 (blue), Q 0 =5000 (green) y Q 0 =7000 (red).…”

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confidence: 99%

Synthesis and design of dissipative filters with improved performance

Padilla Díaz

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Connect, upload, download, share and transfer anything at anytime and anywhere is not a futuristic vision and is indeed a real demand on current and future wireless and fixed communication systems. From the point of view of service providers, efficient usage of the limited resources on the radio frequency (RF) spectrum is one of the biggest challenges. This technological challenge have to be faced from many different approaches and one is certainly the RF hardware equipment on the wireless devices, base stations and satellite equipment. Among the RF components into the RF chain, the filtering stage is without any doubt one of the most critical components, which usually have to be individual for any communication system or have to operate in a multistandard and multimode communication environment. Our devices are equipped with more and more radios and there are many scenarios where it is desirable from a user perspective to operate these simultaneously. Adding to the challenges, many of these bands are very close together and therefore require highly selective filters. When this happens it is essential that they can operate without detrimental mutual interference. These bands must be isolated to avoid interference. This demands for continuous research on filter a) performance improvement and b) size reduction. This is even more stringent in satellite equipment where the live of the device is longer and the size and weight of the equipment significantly contributes to the payload of the satellite and strongly affects the cost. The number of selective or channelizing filters in a satellite equipment are numerous and present into the input multiplexing, always present in any satellite transponder. Channel filters in input multiplexers take up a substantial portion of modern satellite payloads in terms of size and mass. High selective filters can be achieved by the use of high quality factor resonators on the implementation of high order filter with usually a complex configuration - several transmission zeros to increase and tailored the selectivity and equalization zeros to obtain a linear group delay response of the filter. Although several innovative technologies can achieve high performance filter with a considerable compact size, the required filter response flexibility and heritage demanded on the on-board satellite equipment, demands for using conventional technologies for the filter implementation. This results in bulky filter configurations, where a size reduction inherently involves a reduction on the quality factor, which in turn give rises into a degradation of the filter performance. The goal of this work is the implementation of a new class of filters with the used of lossy resonators. Note that success of this goal will result in high performance filter with reduced sized and suitable to be used in satellite equipment. The size reduction, in this novel class of filters, comes along an increment of the overall filter insertion losses, although the filter shape factor it is still high-performed. Although this limits the application of such new class of filters, there are very promising in RF input front-end architectures where the filter (or input multiplexer filtering stage) connects after and amplifier structures, as in a satellite equipment. This demands for achieving three intermediate goals: 1) create a new mathematical formulation of the filter response which considers the limited losses of the resonators from the very beginning, 2) provide the suitable synthesized network of the new filter topologies. This new topologies usually results in conventional topologies with an additional coupled resistive network which provides a selective dissipation along the filter band, and 3) evaluate the technological issues for the implementation of this new class of filters. The later objective have been achieved by the implementation of three prototypes. Conectar, cargar, descargar, compartir y transferir datos en cualquier momento y en cualquier lugar, no es una visión futurista y es de hecho una demanda real en los sistemas de comunicación inalámbrica y fijos actuales y futuros. Desde el punto de vista de los proveedores de servicios, el uso eficiente del espectro frecuencial es uno de los retos más grandes. Este desafío tecnológico requiere de muchos enfoques diferentes y uno de ellos es sin duda desde el punto de vista de los dispositivos de RF que forman los sistemas de comunicaciones. Entre los componentes dentro de la cadena de RF, la etapa de filtrado es sin ninguna duda uno de los componentes más críticos, y que en general debe ser único para cualquier sistema de comunicación y / o debe operar en un entorno de comunicación multiestándar. Los dispositivos actuales están equipados con más y más sistemas, que en muchos casos es deseable desde la perspectiva del usuario poder operar simultáneamente. Además muchos de estos sistemas se encuentran en bandas frecuenciales muy próximas entre sí y por lo tanto requieren de filtros muy selectivos. Cuando esto sucede, es esencial poder operar sin interferencia mutua. Esto exige de una investigación continua en el diseño de filtros, para) la mejora de su respuesta y b) reducción de tamaño. Estas demandas son aún más estrictos en equipos de satélites donde el tamaño y peso del equipo contribuye significativamente a la carga útil del satélite y afecta fuertemente al coste. El número de filtros selectivos o de canal en un equipo de satélite es grande y presente sobre todo en la multiplexación de entrada. Los multiplexores de entrada ocupan una parte sustancial de las cargas útiles de los satélites modernos en términos de tamaño y masa. Filtros altamente selectivos se pueden conseguir mediante el uso de resonadores con un factor calidad alto, con un gran número de resonadores y generalmente con una configuración compleja - varios ceros de transmisión para aumentar la selectividad y de ecualizar el retraso de grupo del filtro. Aunque varias tecnologías innovadoras pueden conseguir filtros de altas prestaciones con configuraciones compactas, la demanda por el uso de tecnologías convencionales en aplicaciones de espacio, exige el uso de configuraciones de filtro voluminosos, donde una reducción de tamaño implica inherentemente una reducción en el factor de calidad, que a su vez produce una degradación de las prestaciones del filtro. El objetivo de este trabajo es la implementación de una nueva clase de filtros con el uso de resonadores con pérdidas. Logro de este objetivo se traducirá en filtros de alto rendimiento con tamaño reducido y adecuado para ser utilizado en equipos de satélites. La reducción en las dimensiones, en esta nueva clase de filtros, resulta en un incremento de las pérdidas de inserción totales del filtro, aunque el shape factor del filtro corresponde al de un filtro de altas prestaciones. Aunque este incremento en las pérdidas de inserción puede limitar la aplicación de esta nueva clase de filtros, hay muchas arquitecturas donde el filtro (o etapa de filtrado multiplexor de entrada) se conecta después del amplificador, donde las pérdidas y prestaciones del sistema se ven compensadas, como es el caso de un equipo satelital. El éxito del objetivo final exige conseguir tres objetivos intermedios: 1) crear una nueva formulación matemática para la respuesta del filtro que considera las pérdidas de los resonadores desde el principio, 2) proporcionar la red sintetizada de las nuevas topologías de filtro. Estas nuevas topologías resultan en topologías convencionales con una red resistiva adicional que proporciona una disipación selectiva a lo largo de la banda de filtro, y 3) evaluar las cuestiones tecnológicas para la implementación de esta nueva clase de filtros.

show abstract

Synthesis of predistorted reflection‐mode hybrid prototype networks with symmetrical and asymmetrical characteristics

Cited by 12 publications

References 12 publications

A New Approach to the Synthesis of Microwave Lossy Filters

A New Approach to the Synthesis of Microwave Lossy Filters

A hybrid method for flat-passband filter with nonuniform Q resonators and predistortion

Synthesis and design of dissipative filters with improved performance

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