Low Loss SAW Filter for Antenna Duplexer

Hikita, M.; Tabuchi, T.; Kojima, H.; Nakagoshi, A.; Kinoshita, Y.

doi:10.1109/ultsym.1983.198019

Cited by 20 publications

(4 citation statements)

References 5 publications

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“…Then, microwave ceramic (MWC) duplexers were used in mobile phones supporting, e.g., the Advanced Mobile Phone Service (AMPS), the German B-net, or the Nordic Mobile Telefone (NMT). In the very beginning the stringent requirements of low insertion loss in combination with high close-in attenuation as well as isolation could only be achieved by microwave ceramic duplexers [1]. Despite their outstanding properties regarding frequency stability over temperature and power handling capability SAW duplexers superseeded them from the market of mobile phones.…”

Section: Historymentioning

confidence: 99%

“…Nevertheless, MWC duplexers are still relevant in the market of base stations [2]. It was the development of high power durable metalizations for SAW devices that allowed to replace the dielectric filters by low-loss SAW filters in the 1980s, which were used for the first SAW duplexers [1]. With SAW technology having a great potential of miniaturization, it was tipping point regarding the application of SAW duplexers in mobile phones and -later on -terminals.…”

Section: Historymentioning

confidence: 99%

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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: Historymentioning

confidence: 99%

Section: Historymentioning

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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“…An electrical input signal is converted to an acoustic wave by the input transducer via the piezoelectric effect. The output transducer receives the acoustic waves and then converts it back to the electrical signal [14,15]. A BAW filter is also an electromechnical device, exploiting a different acoustic wave principle and are implemented on different substrate materials.…”

Section: Motivationmentioning

confidence: 99%

“…15 shows the measured NF as a function of blocker power for 0.7-GHz and 1.3-GHz LO-frequency, while the blocker offset was 80 MHz. The measured desensitization is only 0.6 dB for a 0-dBm blocker, and 3.5 dB for a 10-dBm blocker at 0.7 GHz LO.…”

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confidence: 99%

Saw-Less radio receivers in CMOS

Lien¹

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Smartphones play an essential role in our daily life. Connected to the internet, we can easily keep in touch with family and friends, even if far away, while ever more apps serve us in numerous ways. To support all of this, higher data rates are needed for ever more wireless users, leading to a very crowded radio frequency spectrum. To achieve high spectrum efficiency while reducing unwanted interference, high-quality band-pass filters are needed. Piezo-electrical Surface Acoustic Wave (SAW) filters are conventionally used for this purpose, but such filters need a dedicated design for each new band, are relatively bulky and also costly compared to integrated circuit chips. Instead, we would like to integrate the filters as part of the entire wireless transceiver with digital smartphone hardware on CMOS chips. The research described in this thesis targets this goal. It has recently been shown that N-path filters based on passive switched-RC circuits can realize high-quality band-select filters on CMOS chips, where the center frequency of the filter is widely tunable by the switching-frequency. As CMOS downscaling following Moore's law brings us lower clock-switching power, lower switch on-resistance and more compact metal-to-metal capacitors, N-path filters look promising. This thesis targets SAW

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Systems Impact of Modern Rayleigh Wave Technology

Hartmann

1985

Springer Series on Wave Phenomena

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Low Loss SAW Filter for Antenna Duplexer

Cited by 20 publications

References 5 publications

High performance microwave acoustic components for mobile radios

High performance microwave acoustic components for mobile radios

Saw-Less radio receivers in CMOS

Systems Impact of Modern Rayleigh Wave Technology

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