Optimized test PCBs for SAW / FBAR RF filters

Bilzer, H.; Pitschi, F.M.; Kiwitt, J.E.; Wagner, K.; Menzel, Wolfgang

doi:10.1109/ultsym.2004.1418094

Cited by 3 publications

(2 citation statements)

References 9 publications

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“…There are neither intentionally nor unintentionally artifacts included in the test setup (e.g., the sample printed circuit board (PCB)) or the application setup (e.g., PCB of wireless terminal). The measurements throughout the whole paper have been obtained using neutral PCBs, the electrical properties of which have been optimized in order to yield (a) minimal reflections, (b) minimal feed-through or cross-talk, and (c) minimal losses over the complete signal paths from the SMA connectors to the landing areas of the footprint [14], [15], [16].…”

Section: A Neutral Measurement Setupmentioning

confidence: 99%

High performance microwave acoustic components for mobile radios

Pitschi¹,

Kiwitt²,

Koch³

et al. 2009

2009 IEEE International Ultrasonics Symposium

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Due to their outstanding characteristics acoustic components, such as SAW and -later on -also BAW filters, have been key components in wireless communication systems from their very beginning. Regarding mobile radio handsets the primary field of application of acoustic components has moved to the RF front-end sections. Here, with the increasing demand for WCDMA-FDD capable mobile phones, duplexers, which allow to separate the TX and RX paths while being simultaneously connected to the antenna, have become indispensable.Regarding the specifications of the different operating bands the requirements on form factors, pass band characteristics, attenuations of the other signals (TX, RX, GPS, WLAN, . . . ), and isolations make them high performance components requiring a sophisticated acoustic as well as electromagnetic design. Due to the tough requirements imposed on the duplexers in terms of, e.g., center frequencies, spacings of RX and TX bands, relative band widths, and shape factors, they also require application-specific acoustic structures.As a consequence, in contrast to standard filters, duplexers are highly optimized components using leading-edge technologies. In order to achieve the best balance of the characteristic properties of the acoustic structures regarding, for instance, their quality factors, pole-zero distances, and temperature coefficients, the manufacturing processes of the acoustic chips are designed for the specific applications. Furthermore, optimizing the electrical characteristics a co-design of package and acoustic chip is applied.In this paper we provide an overview of the different types of duplexers that have been the result of the focused specialization and optimization efforts. We classify them according to the type of acoustic structures, matching circuitry, and package being used. So far, purely SAW-based and BAW-based duplexers as well as hybrid duplexers using both SAW and BAW chips have been reported. Most of the matching circuitry is integrated in, for instance, an LTCC package using a distributed approach based on a λ/4 line or a lumped approach comprising coils and/or capacitors. Sometimes the matching circuitry is realized externally on the PCB. Furthermore, we present recent integration successes, i.e., duplexer inserts, allowing the seamless integration of duplexers into modules without drawbacks on performance or module thickness.

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Section: A Neutral Measurement Setupmentioning

confidence: 99%

High performance microwave acoustic components for mobile radios

Pitschi¹,

Kiwitt²,

Koch³

et al. 2009

2009 IEEE International Ultrasonics Symposium

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“…In order to determine the performance of the SAW duplexer insert, we followed the proposal for the design of neutral test PCBs in order to minimize the losses, reflections, and crosstalk [2], [3]. The main facts of the test PCBs are listed in Table I.…”

Section: A Neutral Test Environment For Measurementmentioning

confidence: 99%

Characterization of SAW Duplexer Inserts for LTCC RF Front-End Modules by Simulation and Measurement

Koch

Pitschi

Kiwitt

et al. 2007

2007 IEEE/MTT-S International Microwave Symposium

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The growing demand for miniaturization of mobile terminals incites design engineers to integrate the required functionality of stand-alone active and passive discrete/integrated components of the RF section, such as, e.g., antenna switches, power amplifiers, and SAW filters, into compact modules. Although being a monolithic and complex component in which all sub-systems, formerly stand-alone components, are interlocked, each of them has to be designed and optimized individually and be pieced together in a later step of the development process for the final optimization. Therefore, an efficient design strategy and a neutral test environment for the characterization by both measurement and simulation of the isolated sub-systems are needed. Being able to provide this would allow design engineers to predict reliably the properties of the sub-systems integrated in the target module.In this paper we report on practical and theoretical issues regarding the integration of duplexing functionality into LTCC modules by means of duplexer inserts. Duplexer inserts provide the necessary potential for further height reduction that is required by future developments of modules. One of the key issues that we faced was the precise characterization of the performance of duplexer inserts in the module by both measurement and simulation. We investigated models of different complexity and, therefore, different accuracy and present first experimental results of the characterization of a W-CDMA 2100 duplexer insert. Hereto, we divided the module into its subsystems and applied our new, specifically designed, neutral test/design environments for duplexer inserts in order to evaluate the usability of different approaches. We obtained the best agreement of simulation and measurement for the most complex model.

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