Showing papers on "GSM frequency bands published in 2010"

RF power module

Abstract: A technique is provided for achieving reduction in size of an electronic device with a power amplifier circuit, while enhancing the performance of the electronic device. An RF power module for a mobile communication device includes first and second semiconductor chips, a passive component, and first and second integrated passive components, which are mounted over a wiring board. In the first semiconductor chip, MISFET elements constituting power amplifier circuits for the GSM 900 and for the DCS 1800 are formed, and a control circuit is also formed. In the first integrated passive component, a low pass filter circuit for the GSM 900 is formed, and in the second integrated passive component, a low pass filter circuit for the DCS 1800 is formed. In the second semiconductor chip, antenna switch circuits for the GSM 900 and DCS 1800 are formed. Over the upper surface of the wiring board, the second semiconductor chip is disposed next to the first semiconductor chip between the integrated passive components.

The effect of exposure duration on the biological activity of mobile telephony radiation.

Abstract: In the present experiments we studied the effects of different durations of a single (continuous), daily exposure, ranging from 1 min up to 21 min, to the two established systems of digital mobile telephony radiation that are commonly used in Europe, viz. GSM 900 MHz (Global System for Mobile telecommunications) and DCS 1800 MHz (Digital Cellular System-referred to also as GSM 1800 MHz), on a well-tested biological model, the reproductive capacity of the insect Drosophila melanogaster. The insects were exposed to each type of radiation at an intensity of about 10 microW/cm(2), corresponding to a distance of 20 or 30 cm from the antenna of a DCS 1800 or a GSM 900 mobile phone handset, respectively. At these distances the bioactivity of mobile telephony radiation was found to be at a maximum due to the existence of a "window" of increased bioactivity around this value, as we have shown recently [1-4]. The results show that the reproductive capacity decreases almost linearly with increasing exposure duration to both GSM 900 and DCS 1800 radiation, suggesting that short-term exposures to these radiations have cumulative effects on living organisms. Additionally, our results show again that GSM 900 MHz radiation is slightly more bioactive than DCS 1800 MHz radiation, at the same exposure durations and under equal radiation intensities, as shown in our previous experiments [5].

A Meandered Loop Antenna for LTE/WWAN Operations in a Smart Phone

Abstract: —This paper presents a multiband meandered loop antenna for smart phone applications. The proposed antenna which features a meandered folded-loop generates two resonance modes in the LTE/GSM bands. The current distributions of the excited resonance modes are analyzed to investigate the mode characteristic. By using a capacitively coupled feed on the backplane, the impedance bandwidth is broadened to cover LTE/WWAN bands. The simulation performed in this research used a high frequency structure simulator (HFSS) to optimally design the antenna, and a practical structure was constructed for the test. Details of the various antenna parameters are presented and discussed in this paper.

The identification of an intensity 'window' on the bioeffects of mobile telephony radiation.

Abstract: Purpose: The increased bioactivity ‘windows’ of GSM 900 and 1800 MHz radiations, (Global System for Mobile telecommunications) revealed recently by us and published in this issue, manifesting themselves as a maximum decrease in the reproductive capacity of the insect Drosophila melanogaster, were examined to discover whether they depend on the intensity of radiation-fields.Methods: In each experiment, one group of insects were exposed to the GSM 900 or 1800 radiation at 30 or 20 cm distances, respectively, from the antenna of a mobile phone, where the bioactivity ‘window’ appears for each type of radiation and another group was exposed at 8 or 5 cm, respectively, behind a metal grid, shielding both microwave radiation and the extremely low frequency (ELF) electric and magnetic fields for both types of radiation in a way that radiation and field intensities were roughly equal between the two groups. Then the effect on reproductive capacity was compared between groups for each type of radiation.Results: The...

A meander pda antenna for gsm/dcs/pcs/umts/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.

Measurement of mobile radio propagation channel in ruins

Abstract: Within a running project, I-LOV1, wireless communication channel model for mobile communications is developed based on measurements in reconstructed disaster and salvage scenarios. Due to complex environment in ruins, great multipath interference can take place, which strongly impacts communication quality and localization accuracy. Besides numerous measurements investigated in environments such as urban, outdoor-to-indoor or indoor, only a few are in ruins. This paper presents the first results of channel propagation measurements under collapsed buildings at GSM 900 and GSM 1800 bands. Measurement campaigns were performed in two typical collapsed structures: stratified and chaotic rubbles. The statistical properties of path-loss (PL) and RMS delay spread (DS) are reported.

Rigorous design of RF multi-resonator power harvesters

Abstract: In this paper an integrated design methodology to predict the real RF to DC conversion capability of power harvesters is tackled. By combining nonlinear harmonic-balance-based analysis with electromagnetic simulation the method is able to compute the actual RF power at the rectifier input in general operating conditions: that is for any near-field /far-field behavior of the antenna and for any direction of incidence and polarization of the incoming RF wave. This approach makes use of a new definition of the rectifying antenna (rectenna) performance simultaneously accounting for its radiation and nonlinear behavior. The effectiveness of the method is demonstrated through the comparison between computed and experimental performance of a multi-band circularly polarized rectenna, both in rigid and wearable implementation. Such antennas have been designed to harvest RF energy from different wireless standards (GSM 900, GSM 1800 and WiFi), commonly present in civil environments.

Characterization of delay spread for mobile radio communications under collapsed buildings

Abstract: Numerous investigations of mobile radio communication have been conducted in environments such as urban, outdoor-to-indoor or indoor, only a few are in ruins. Within a running project, I-LOV, a study of a mobile radio propagation channel in urban search and rescue scenarios is conducted. Due to complex environment in ruins, great multipath interference can take place, which strongly impacts communication quality and localization accuracy. This paper focuses on the characterization of time dispersion in such scenarios at GSM 900, GSM 1800 and UMTS frequency bands. High resolution measurements have been performed under collapsed buildings and post-processing data analysis were executed. The mean delay and RMS delay spread has been investigated according to power delay profiles. The effect of frequency window function on impulse responses and delay spread is also researched.

Visualization and Analytical Measurement of Electromagnetic Radiation from Handheld Mobile Phones

Abstract: Mobile communication is where signal is transferred via electromagnetic wave through radio frequency and microwave signals. This signal produced electromagnetic radiation in the form of thermal radiation that consists of harmful ionizing radiation and harmless non-ionizing radiation. When using mobile phone, electromagnetic wave is transferred to the body in the form of thermal radiation that might cause health problems especially at the place near ear skull region for a certain period of time (talking time or operation time). In this analysis, the simulation and experimental analysis are carried out to examine the effect of electromagnetic radiation towards design phantom (dry phantom), water molecules and human volunteer when using the mobile phone for 45 minutes talking hour. This analysis is conducted in an anechoic chamber. Simulation is done using MATLAB’s software to show the radiation produced by the mobile phone. In the experimental analysis, thermal imaging technique is used to monitor and capture temperature distribution towards design phantom and human head. Two different design of mobile phone are used with internal (built-in) and external monopole antenna serving two different GSM frequencies GSM 900 and GSM 1800. The results show that mobile phones produced electromagnetic radiation (thermal) towards human head with high radiation produced by mobile phone with external antenna serving for GSM 900 MHz.

Evaluation of spectrum opportunities in the GSM band

Abstract: In this paper we explore the possibility of exploiting underutilized channels in the GSM bands. The secondary (unlicensed) users of the spectrum are the nodes of an overlay cognitive ad-hoc network, which opportunistically transmits in data channels left unused by the primary (licensed) system. The fundamental constraints for the secondary system are: 1) it uses the time slots/frequency channels (i.e. data channels) unused by the primary GSM system, 2) its operation does not degrade the performances of the primary system, 3) there is no exchange of signalling information between the primary and the secondary system to facilitate the secondary usage of spectrum, that is, the primary users are not cognitive aware. The focus is on the feasibility of the proposed approach, so that we consider a system level simulator based on a realistic GSM network deployed in the city of Bologna. In this context we evaluate the impact that the operation of the secondary users has on the performances of the primary system. In addition, we study the performances that can be obtained by the secondary system under the condition of marginal interference to the primary system. We will show that an appropriate choice of the frequency channel, makes the secondary usage of spectrum a valid approach to increase the operator's spectrum efficiency.

Photovoltaic Solar cell like Receiver for Electromagnetic Waves in VHF-UHF Bands

Abstract: This paper describes the photovoltaic solar cell like receiver for electromagnetic waves in VHFUHF bands and the application of photovoltaic solar cell in planar antenna structures. The radiating patch element of a planar antenna is replaced by a solar cell. The original feature of a solar cell (DC current generation) remains, but additionally the solar cell is now able to receive and transmit electromagnetic waves. , Esentially, the paper presents an experimental study on behaviour of a standard solar pannel as a receiver in the radio-tv and GSM bands. Received signals are compared with a physical planar antenna model (a z shape conductor) and no major difference exist. Othe investigations shows that between illuminated panel and the same pannel in dark (at night) the signal received is quite the same, even the semiconductor solar cell status is very different.

Coupled-fed PIFA with a loop feed for 8-band internal LTE/WWAN laptop computer antenna

Abstract: Owing to the LTE (long term evolution) which can provide much higher data rate than the existing GSM and UMTS mobile networks, the internal antenna that can cover LTE/WWAN operating bands is preferred for the modern mobile communication device. All the 8-band LTE/WWAN operating bands include: three LTE bands in the LTE700 (698~787 MHz), LTE2300 (2300~2400 MHz) and LTE2500 (2500~2690 MHz), four GSM bands in the GSM850 (824~894 MHz), GSM900 (880~960 MHz), GSM1800 (1710~1880 MHz) and GSM1900 (1850~1990 MHz), and one UMTS band (1920~2170 MHz). Although there are some small-size 5-band WWAN laptop computer antennas published [1]-[5], they generally cannot satisfy the 8-band LTE/WWAN operation. In this paper, we present a promising internal laptop computer antenna with an acceptable size of 80 × 10 × 4 mm3 for practical applications. The proposed antenna is a coupled-fed PIFA with a loop feed; it can generate two wide resonant modes in the lower and upper bands to cover the desired 8-band LTW/WWAN operation.

On-body flexible printed antennas for body-centric wireless communications

Abstract: This thesis considers wearable antennas that are useful for body-centric communication systems. Novel wearable printed monopoles with flexible neoprene substrates and drapable conductive elements have been designed, synthesized and measured with respect to their on-body performance. Starting with a comprehensive literature review of wearable antennas this work contains an introduction to wearable antenna designs, flexible materials for wearable antenna fabrication, human body models and the impacts of the human body on the efficiency of small wearable antennas. Definitions of material effective and total conductivity, the calculations of antenna Q and mutual couplings between antennas and the human body using the Method of Moment (MoM) are presented. Four types of flexible printed monopoles have been designed and measured. They are two single band monopoles for ISM (433.05 434.79 MHz) service, one multiband monopole for GSM 900 (890 960 MHz), DCS (1710 1880 MHz), PCS (1850 1990 MHz), UMTS (1920 2170 MHz), and WLAN2.4GHz (2400-2484MHz) frequency bands and a UWB band antenna (3.1-10.6GHz) respectively. Effects of the ground plane dimensions on printed monopoles are illustrated first by changing the dimensions thereof and subsequently by adding wing structures. The new designs yield improved impedance match for printed monopoles. It also shows how meander lines can used to miniaturize antennas and add additional resonances. Models of the human body were created in Microstripes, a 3D electromagnetic (EM) simulator, to analysis the impacts of the human body on the performance of the wearable antennas mentioned above.

Method, transceiver and communicaiton equipment used in multiband communication

Abstract: The combination of filters and switches is used to solve the non-linearity problems in GSM/W-CDMA transceiver front-end wherein one common antenna is used for both the GSM mode and the W-CDMA mode. Inparticular, separate Rx/Tx paths and switches in the Rx paths are used to provide cross-band isolation between bands. All of the switches in the transceiver are disposed after the filters in that noswitches are disposed between the filters and the antenna. Furthermore, bandpass filters are matched to one common node even if they are only disconnected at the output as long as the impedance at theoutput can be controlled.

Tetra (Terrestrial Trunked Radio) and GSM (Global System for Mobile Communications) dual-mode handset

Abstract: The invention relates to a Tetra (Terrestrial Trunked Radio) and GSM (Global System for Mobile Communications) dual-mode handset comprising a main control chip respectively connected with a human-computer interaction interface, a Tetra functional block and audio equipment and a GSM functional block connected with the main control chip, wherein the main control chip inputs a program controlling the switching of a Tetra mode and a GSM mode, and the audio equipment adopts a dual-mode selection switching switch. The invention can carry out communication by utilizing a Tetra protocol to quick call and establish trunking communication with the advantages of low background noise, and the like in Tetra network coverage areas but also can carry out communication by utilizing a GSM network with wider coverage ranges in areas not covered by Tetra network.

A Numerical Study of the Interaction between Handset Antennas and Human Head/Hand in GSM 900, DCS, PCS and UMTS Frequency Bands

Abstract: The interaction between human head/hand tissues and handset antennas is a cru- cial concept in mobile communications. Mobile handsets are used in proximity to user's body and this afiect the transmitted or received power of the handset and some other characteristics e.g., VSWR, radiation pattern. This paper presents a comprehensive study on the performance of various types of handset antennas (two internal, two external) next to human head and hand. The investigated frequency range covers GSM 900, DCS, PCS and UMTS frequency bands. Sim- ulations are performed on antennas next to a simplifled two layer cubical hand model and a six layer spherical head model. Radiation patterns and VSWR of these antennas are computed in free space as well as in the presence of head and hand. In addition, radiation e-ciencies of these handset antennas are computed in the presence of head and hand.

A novel notch filter LNA for use in multi-band, multi-standard cellular receivers

Abstract: A novel LNA with integrated notch filter for multi-band, multi-standard cellular communication is presented in this paper. The LNA is capable to serve multiple FDD bands of the LTE standard and its cobanded UMTS counterparts. Due to its architecture also TDD bands including GSM bands DCS1900 and PCS1800 and LTE TDD bands can be covered. Due to the integrated notch filter which is reused for all covered bands external interstage filters can be omitted thus saving PCB area and component costs. Exemplary for LTE band II, simulations reveal a noise figure of 1.96 dB at 1930 MHz and 10.3 dB selectivity at 80 MHz duplex distance. The inband-IIP 3 reaches −10.27 dBm, while IIP 3DPX = −10.4 dBm and IIP 3HDPX = −2.6 dBm. The circuit works from a 1.4 V supply, drawing 15.3 mA on a commercial 90 nm process.

Multi-path search device supporting transmission diversity mode detection and method thereof

Abstract: The invention provides a multi-path search device supporting transmission diversity mode detection and a method thereof, wherein the device is used for supporting the search and measurement of a WCDMA/GSM dual mode in a WCDMA cell during GSM CAMP and completing the physical layer work switching from the GSM mode to the WCDMA mode; the WCDMA/GSM dual mode chooses either the scramble primary phase computation or configuration, is outputted by an IQ data channel and introduces the coherent accumulation of the symbol data before the symbol power computation so as to realize the measurement of thereceived signal code power (RSCP), quick and accurate search of the multi-path border and the supply of reliable synchronization to a RAKE receiver; and in addition, the high-performance signal receiving is realized by using the multi-path power judgment obtained by the multi-path search and detecting the transmission diversity mode.

Spectrum decision in GSM band using a fuzzy logic controller

Abstract: In this paper we explore the possibility of exploiting underutilized channels in the GSM bands, by means of secondary use of spectrum. The secondary (unlicensed) users are the nodes of an overlay cognitive ad-hoc network, which opportunistically transmits in data channels left unused by the primary (licensed) system. The focus is on the feasibility of the proposed approach, so that we consider a system level simulator based on a realistic GSM network deployed in the city of Bologna. In this context we propose a fuzzy-based approach to select the most appropriate frequency carrier for secondary usage, and we evaluate the impact that the operation of the secondary users has on the performances of the primary system. In addition, we study the performances that can be obtained by the secondary system under the condition of marginal interference to the primary system. We will show that the use of fuzzy logic, makes the secondary usage of spectrum a valid approach to increase the operator's spectrum efficiency.

Electromagnetic field mitigation within a cavity with vehicle-like features

Abstract: This paper presents a method of electromagnetic field mitigation within a cavity with vehicle-like features at one of the GSM bands. The findings can be used for the potential electromagnetic field mitigation within resonant scenarios such as office environments and vehicle cabins.

Automated System for Measurement and Visualization of Electromagnetic Field in GSM 900, GSM 1800 and UMTS 2100 Bands

Abstract: This paper describes design and implementation of web based system for measurement of electromagnetic fields in GSM bands and visualization of the acquired results. Essential problems and their solutions are explained in details.

Dual-band high-efficiency radio-frequency power amplifier

Abstract: The utility model discloses a dual-band Doherty high-frequency radio-frequency power amplifier, which includes a main radio-frequency power amplifier module and an auxiliary radio-frequency power amplifier module, and an output terminal of the auxiliary radio-frequency power amplifier module is electrically connected with an output terminal of the main radio-frequency power amplifier module through an annular microstrip line. The power amplifier realizes the switch of the GSM frequency band and CDMA frequency band by the Doherty power amplifier, thereby overcoming a defect that the Doherty method allows a plate to only work on a frequency band, and saving cost.

Multi band combiner in mobile communication system

Abstract: PURPOSE: A multiple band combiner of a mobile communication system is provided to remove harmonic without an additional low pass filter by attenuating the harmonic of a UHF and GSM frequency through a diplexer. CONSTITUTION: A duplexer(11) performs the multiplexing about the bands of the low frequency domain as a first multiple diplexer. A combiner(10) makes the UHF and GSM signal into one signal. A triplexer(12) performs the multiplexing about the bands of the high frequency domain as a second multiple diplexer. A DCS, a WDCMA, and a WiMAX band signal are integrated into one signal through the triplexer. The integrated first multiplexing signal and second multiplexing signal are applied to a diplexer(13). The first multiplexing signal is passed through a low pass filtering action. The second multiplexing signal is passed through the high pass filtering action. The first and second multiplexing signals are integrated into one signal.

Tetra and GSM dual-mode handset

Abstract: The utility model relates to a Tetra and GSM dual-mode handset. The Tetra (Terrestrial Trunked Radio) and GSM (Global System for Mobile Communications) dual-mode handset comprises a master control chip and a GSM functional module, wherein the master control chip is respectively connected with a man-machine interaction interface, a Tetra functional module and an audio device; the GSM functional module is connected with the master control chip which inputs a program for switching the Tetra mode and the GSM mode; and the audio device adopts a dual-mode selector switch. The Tetra and GSM dual-mode handset has the benefits of not only being capable of carrying out communication at areas covered by Tetra network by utilizing the advantages of speed calling establishment of Tetra protocol, cluster communication, low-background noise and the like, but also being capable of carrying out communication by utilizing GSM network with wider covering range at areas covered by the Tetra network.

A meandered loop antenna for lte/wwan operations in a smart phone

Abstract: This paper presents a multiband meandered loop antenna for smart phone applications. The proposed antenna which features a meandered folded-loop generates two resonance modes in the LTE/GSM bands. The current distributions of the excited resonance modes are analyzed to investigate the mode characteristic. By using a capacitively coupled feed on the backplane, the impedance bandwidth is broadened to cover LTE/WWAN bands. The simulation performed in this research used a high frequency structure simulator (HFSS) to optimally design the antenna, and a practical structure was constructed for the test. Details of the various antenna parameters are presented and discussed in this paper.

High bandwidth indoor measurements

Abstract: Wideband indoor measurements employ a variety of techniques from off the shelf equipment such as network analysers, to custom designed channel sounders. Depending on the channel parameters, different architectures have been used which include single input single output (SISO), single input multiple output (SIMO) and multiple input multiple output (MIMO). This paper compares the different techniques and architectures. Examples of indoor passive measurements of the 3G and GSM bands using a spectrum analyser and the receiver of a wideband chirp sounder illustrate the dependence of the received signal strength on the floor level and the directionality of antennas. Active wideband indoor measurements in the 2 GHz band using a channel chirp sounder show the dependence of rms delay spread on path loss and the increase in channel capacity with the number of antenna.