Topic
GSM frequency bands
About: GSM frequency bands is a research topic. Over the lifetime, 559 publications have been published within this topic receiving 5067 citations.
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Papers
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25 May 2004TL;DR: In this article, the authors investigated the effect of separation distance between the antenna and the user head, in addition to the relationship between the SAR and the antenna efficiency using a dual-band PIFA handset antenna.
Abstract: This paper reports a simulation and measurement study on SAR (specific absorption rate) using a dual-band PIFA (planar inverted-F antenna) handset antenna (GSM900/DCS1800). The study investigates the effect of separation distance between the antenna and the user head, in addition to the relationship between the SAR and the antenna efficiency. The SAR was experimentally measured using the DASY4 system and compared to the simulations.
24 citations
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22 Sep 2011TL;DR: In this paper, a frontend circuit for a wireless communication unit is proposed comprising at least two antenna feeds, at least one of them coupled to an antenna switch, and is prepared to operate a number of FDD frequency bands.
Abstract: A Frontend circuit for a wireless communication unit is proposed comprising at least two antenna feeds, at least one of them coupled to an antenna switch. The circuit comprises filters and duplexers and is prepared to operate a number of FDD frequency bands. Each FDD band comprises an Rx band for receive signals and a Tx band for transmit signals. The circuit provides a single band operation mode for each frequency band and aggregated band operation modes. In an aggregated band operation mode Rx signals can be received in two different frequency bands at the same time as well as Tx signals can be transmitted in at least one of the two different frequency bands. In addition TDD bands as well as GSM bands are covered, too.
23 citations
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TL;DR: A review of existing fire-detector types has been carried out along with the development of a low cost, portable, and reliable microcontroller based automated fire alarm system for remotely alerting any fire incidents in household or industrial premises.
Abstract: In this work a review of existing fire-detector types has been carried out along with the development of a low cost, portable, and reliable microcontroller based automated fire alarm system for remotely alerting any fire incidents in household or industrial premises. The aim of the system designed is to alert the distant property-owner efficiently and quickly by sending short message (SMS) via GSM network. A Linear integrated temperature sensor detects temperature beyond preset value whereas semiconductor type sensor detects presence of smoke or gas from fire hazards. The sensor units are connected via common data line to ATMega8L AVR microcontroller. A SIM300CZ GSM kit based network module, capable of operating in standard GSM bands, has been used to send alert messages. The system is implemented on printed circuit board (PCB) and tested under different experimental conditions to evaluate its performances.
23 citations
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TL;DR: In this paper, a simple inverted-U-shaped driven element operates frequency bands centered at 1710 and 2350MHz, which achieve a bandwidth based on 6-dB return loss from 1550 to 2490MHz for DCS, PCS, UMTS, and WLAN applications.
Abstract: This paper proposes a novel multi-band monopole antenna for PDA phone. A simple inverted-U-shaped driven element operates frequency bands centered at 1710 and 2350MHz, which achieve a bandwidth based on 6-dB return loss from 1550 to 2490MHz su-cient for DCS, PCS, UMTS, and WLAN applications. A low frequency meander path and an impedance matching stub with a truncated slit located at ground plane operates frequency band centered at 910MHz. The bandwidth from 868 to 995MHz covers the GSM 900 application band. The design procedures and both simulated and measured results are presented and discussed in this paper.
23 citations
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TL;DR: The use of GSM1800 type mobile phones can be considered safe, whereas GSM 900 and TETRA phones may cause considerable interference in hospital devices, which can result in life-endangering situations.
Abstract: Disturbances in hospital devices caused by cellular telephone signals were investigated. The interference sources were GSM900, GSM1800, and TETRA380 phones. The number of medical appliances tested was 23. Most measurements were taken in a semi-anechoic laboratory. To simulate the worst situation, the phones were adjusted to emit at their maximum power levels. No interference was observed if the distance from GSM1800 phone was over 5 cm. Corresponding safety distance for GSM900 phone was 70 cm, and for TETRA phones over 3 m. Hence, the use of GSM 1800 type mobile phones can be considered safe, whereas GSM 900 and TETRA phones may cause considerable interference in hospital devices, which can result in life-endangering situations.
22 citations