Showing papers on "GSM frequency bands published in 2000"
Patent•
01 May 2000TL;DR: In this paper, an exciter matching circuit, interstage matching circuit and harmonic filter matching circuit (HF matching circuit) were proposed to match impedances at the input to a two-stage power amplifier, between the first stage (132) and the second stage (136) of the power amplifier (130), and at the output of the PLC for more than one frequency band of interest.
Abstract: An exciter matching circuit (125), interstage matching circuit (134), and harmonic filter matching circuit (140) match impedances at the input to a two-stage power amplifier (130), between the first stage (132) and the second stage (136) of the power amplifier (130), and at the output of the power amplifier (130) for more than one frequency band of interest. In a GSM/DCS dual band radiotelephone (101), the matching circuits (124, 134, 140) provide low return loss at 900 MHz when the dual band transmitter (110) is operating in the GSM mode. The harmonic filter matching circuit (140) also filters out signals at 1800 MHz, 2700 MHz, and high order harmonics. When the dual band transmitter (110) is in DCS mode, however, the matching circuits (124, 134, 140) provide a low return loss at 1800 MHz and filter out signals at 2700 MHz and harmonics of 1800 MHz.
49 citations
11 Jun 2000
TL;DR: In this article, the authors describe two CMOS resistive ring mixer MMICs for GSM 900 and DCS 1800 base station applications, which have the lowest measured conversion loss (5.5 dB, 5.8 dB) and highest associated input IP3 (19.4 dBm, 19.5dBm).
Abstract: This paper describes two CMOS resistive ring mixer MMICs for GSM 900 and DCS 1800 base station applications. These mixers have the lowest measured conversion loss (5.5 dB, 5.8 dB) and highest associated input IP3 (19.4 dBm, 19.5 dBm) published to date for passive CMOS mixer MMICs in these frequency bands.
38 citations
Patent•
30 Aug 2000TL;DR: In this paper, a multi-band transceiver for receiving and transmitting signals within selected GSM frequency bands is presented, where transmission and reception occur simultaneously and within the same time slot of a TDMA frame.
Abstract: A multi-band transceiver for receiving and transmitting signals within selected GSM frequency bands. Transmission and reception occurs simultaneously and within the same time slot of a TDMA frame. The transceiver includes a first local oscillator LO1 that selectively oscillates within a bandwidth corresponding to the selected GSM band and outputs a signal having a frequency fLO1. A second local oscillator LO2 selectively oscillates at a frequency corresponding to the selected GSM band and outputs a signal having a frequency fLO2. A receiver receives a signal having a frequency fRx and mixes the signals from the first and second local oscillators to generate a demodulating signal having a frequency fRx, wherein fRx = fLO1 ± fLO2. A transmitter having a loop architecture includes a VCO that generates a signal having a transmit frequency fTx equal to fRx minus a comparison frequency fCF, and a mixer that mixes the signal from the first local oscillator with the transmit signal to generate an IF signal having a frequency fIF = fLO2 ± fCF. A quadrature mixer that modulates the IF signal with baseband 'I' and 'Q' signals, and a phase detector that compares the phases of the IF signal and the signal from the second local oscillator and outputs a control voltage to the VCO.
36 citations
16 Jul 2000
TL;DR: A dual band microstrip patch antenna element, suitable for GSM 900/1800 base station operation, and to provide the required bandwidth for the GSM bands a double-layer structure is under analysis.
Abstract: A dual band microstrip patch antenna element, suitable for GSM 900/1800 base station operation is presented. The geometry consists on a smaller patch inside a larger one. Coupling and separation are provided by a U-slot. A single-layer structure has been designed, fabricated and tested. Good agreement has been obtained between theoretical and experimental results. To provide the required bandwidth for the GSM bands a double-layer structure is under analysis.
20 citations
07 Feb 2000
TL;DR: In this paper, the phase noise requirements for a Global System for Mobile Communications (GSM) receiver are summarized based on the reference sensitivity, the blocking requirement, and the assumption of C/I=9 dB.
Abstract: Designing voltage-controlled oscillators (VCO) for a Global System for Mobile Communications (GSM) receiver is a challenge due to the phase noise requirement. The requirement comes from the stringent in-band blocking characteristics in the GSM standard. Based on the reference sensitivity, the blocking requirement, and the assumption of C/I=9 dB, the calculated phase noise specifications are summarized in this paper. Because typical VCO phase noise roll-off around 1MHz offset has a slope of 20 dB or 30 dB per decade, the key specifications are at offsets of 600 MHz and 3 MHz for Mobile Station (MS) and 800 kHz for Base Transceiver Station (BTS). The table is sorted by the difficulty of the requirement, with the easiest (DCS 1800 MS) on the left and the most stringent (GSM 900 BTS) on the right.
19 citations
01 Jan 2000
TL;DR: In this paper, the authors present an Ansammlung of MSC-Einzugsbereichen with durchgangigem Numerierungsplan (z.B. gleicher nationaler Zielrufnummer; National Destination Code = NDC).
Abstract: In diesem Kapitel wird das digitale Mobilfunksystem Public Land Mobile Network (PLMN nach ITU-T: Q.1000 — Q.1063, Blue Book, 1988) beschrieben. Es umfast derzeit das Global System for Mobile Communications (GSM900) um 900 MHz sowie das Digital Cellular System (DCS1800) um 1800 MHz. In den USA wird ein 1900 MHz-System als Personal Communications System (PCS1900) aufgebaut. [BI, DA, EB, JU, LO, PA;, PR, TU, WA, Lu, et, ie]. Nach der ETSI-Empfehlung GSM 03.02 wird das PLMN zur offentlichen Bereitstellung landmobiler Telekommunikationsdienste durch Behorden oder zugelassene Privatbetreiber (Recognized Private Operating Agency = RPOA) aufgebaut und betrieben. Ein PLMN kann als Erweiterungsnetz z.B. zum ISDN betrachtet werden. Es ist eine Ansammlung von MSC-Einzugsbereichen mit durchgangigem Numerierungsplan (z.B. gleicher nationaler Zielrufnummer; National Destination Code = NDC) und einem durchgangigem Vermittlungsplan. MSCs sind die funktionalen Schnittstellen zwischen den Festnetzen und dem PLMN zum Rufaufbau. Funktional konnen die PLMNs als unabhangige Telekommunikationseinheiten betrachtet werden, obwohl unterschiedliche PLMNs durch ISDNIPSTN und PDNs zur Rufweiterleitung oder Transfer von Netzinformation verbunden werden konnen. Ahnliche Verbindungsarten konnen zum Zusammenwirken zwischen MSCs eines PLMN existieren.
18 citations
16 Jul 2000
TL;DR: In this paper, a dual-band microstrip patch antenna element is presented, which consists on a rectangular patch with double U slots and coaxial feeding for GSM 900/1800 base station antenna.
Abstract: A new dual-band microstrip patch antenna element is presented. The element configuration consists on a rectangular patch with double U slots and coaxial feeding. A prototype was designed, fabricated and tested to be used in a GSM 900/1800 base station antenna. Good agreement has been obtained between theoretical and experimental results. To provide the required bandwidth for both the GSM bands a double-layer structure is under analysis.
12 citations
Patent•
11 Apr 2000
TL;DR: In this paper, a method and apparatus to provide call origination without requiring full power in a time division multiple access (TDMA) cellular phone system is presented, where a time delay is derived from the time delay and the estimated distance is used to address a look-up table to arrive at a distance index (430).
Abstract: A method and apparatus to provide call origination without requiring full power in a time division multiple access ('TDMA') cellular phone system (fig.2, fig.4). A time delay is measured (410) from the beginning of a timeslot containing a request (400) for a call setup to the beginning of the request (400). An estimated distance is derived from the time delay (420). The estimated distance is used to address a look-up table to arrive at a distance index (430). A power level index (440) is selected from the minimum of either the distance index (430) plus a fixed integer or a maximum value. The fixed integer is a value greater than zero and is based on the propagation characteristics of the particular cell. The maximum value is the power level that will sustain an acceptable signal quality at a cell site boundary. The power level index (440) is then used to address the look-up table to arrive at assigned power level (450).
11 citations
16 Jul 2000
TL;DR: In this article, a dual-band microstrip patch antenna element is presented, which consists on a rectangular patch with 8 shorting pins and coaxial feed, and a prototype was designed, fabricated and tested to be used in a GSM 900/1800 base station antenna.
Abstract: A dual-band microstrip patch antenna element is presented. The element configuration consists on a rectangular patch with 8 shorting pins and coaxial feed. A prototype was designed, fabricated and tested to be used in a GSM 900/1800 base station antenna. Good agreement has been obtained between theoretical and experimental results. To provide the required bandwidth for both GSM bands a double-layer structure is under analysis.
8 citations
Patent•
11 Sep 2000
TL;DR: In this paper, the authors proposed a simple high-frequency power amplifier in which the GSM and the EDGE, whose gains are considerably different from each other, are incorporated, for reducing generation of noise.
Abstract: PROBLEM TO BE SOLVED: To provide a simple high-frequency power amplifier in which the GSM(global system for mobile communications) and the EDGE(enhanced data rates for GSM evolution), whose gains are considerably different from each other, are incorporated. SOLUTION: In the high frequency power amplifier of a multi-stage amplifier configuration that is used for a GSM mode or an EDGE mode through switching, a 1st stage amplifier consists of a dual-gated MOSFET, in the EDGE mode, an APC(automatic power control) signal or a selected and fixed level is applied to a 1st gate electrode of the dual-gated MOSFET, a fixed level or the APC signal is applied as a Vgs (Vgs1, Vgs2, Vgs3) of each TR from the 1st stage to the 3rd stage, so as to match the gain in the EDGE mode with a gain in the GSM mode so, for reducing generation of noise.
6 citations
TL;DR: In this paper, the ability of a microstrip fed printed dipole which has an integrated balun to operate at dual frequency bands is demonstrated, and the results of the voltage standing wave ratio and radiating characteristics are presented for a printed dipoles operating at both GSM and DCS frequency bands.
Abstract: The ability of a microstrip fed printed dipole which has an integrated balun to operate at dual frequency bands is demonstrated. Experimental and simulated results of the voltage standing wave ratio and radiating characteristics are presented for a printed dipole operating at both GSM and DCS frequency bands.
16 Jul 2000
TL;DR: In this paper, various cylindrical geometries of dielectric resonator antennas (DRA) are investigated and a design is proposed for a mobile telephone handset, suitable for the GSM 900 system.
Abstract: In response to increasing demand for compact efficient antennas, various cylindrical geometries of dielectric resonator antennas (DRA) are investigated in this paper. These DRA geometries offer significant reduction in volume, making them potential candidates for use in compact applications such as mobile communication handset. Approximate theory of PMC walls developed for predicting resonant radiation frequency of different DRA geometries, gives good agreement with available experimental results. Volume minimization for compact DRA designs is also discussed and a design is proposed for a mobile telephone handset, suitable for the GSM 900 system.
01 Oct 2000
TL;DR: In this article, a fractional-n frequency synthesizer that uses AC-modulation to obtain the desired fractional division value is presented, and a detailed noise analysis is performed.
Abstract: This paper presents a fractional-n frequency synthesizer that uses AC-modulation to obtain the desired fractional division value. After a brief presentation of the synthesizers' key elements a detailed noise analysis follows. Measurements from the prototype synthesizer validate the very good phase noise performance which is predicted by theory. The realized high frequency resolution can be used to compensate the frequency error of the reference crystal oscillator in a typical GSM transceiver.
Patent•
13 Apr 2000TL;DR: In this paper, a frequency synthesis system for a dual-band transceiver using a 3/1 local oscillator for reception and transmission in the lower frequency band (Rx1, Tx1) was proposed, where a single band-switched voltage-controlled oscillator can be used for frequency adjustment in all four possible operating modes.
Abstract: The invention relates to a frequency synthesis system which for a dual-band transceiver uses a 3/1 local oscillator for reception and transmission in the lower frequency band (Rx1, Tx1) and transmission in the upper frequency band (Tx2)/reception in the upper frequency band (Rx2), so that a single band-switched voltage-controlled oscillator can be used for frequency adjustment in all four possible operating modes The system provided for in the invention can be used, for example, in high-integration dual-band mobile parts for GSM 900/1800 mobile telephone communications