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.

Device for automatically turning down volume during mobile phone call inside vehicle

Abstract: The utility model provides a device for automatically turning down the volume during a mobile phone call inside a vehicle. If a phone call is detected inside the vehicle, the volume of vehicle sound equipment is automatically turned down, and when the phone call is finished, the volume is restored. Therefore, the defect that hand-operated muting operation of the driver causes distractions is overcome. A signal induction module is composed of an antenna, a frequency divider, a mobile phone signal processor and a frequency modulator. A processing module includes a single-chip microcomputer. An execution module includes a drive circuit and a vehicle sound equipment circuit. A mobile phone signal is divided by the frequency divider into four paths of signals: one path is subjected to TD-SCDMA processing and TD-SCDMA frequency modulation; one path is subjected to WCDMA processing and WCDMA frequency modulation; one path is subjected to CDMA2000 processing and CDMA2000 frequency modulation; and one path is subjected to GSM processing and GSM frequency modulation. The four paths of signals are integrated for digital processing and output. The obtained signal passes through a signal amplification circuit and the drive circuit, and is output to a sound equipment volume adjusting circuit.

Method for implementing frequency selection of GSM frequency selector by using frequency hopping synchronization

Abstract: The invention relates to a method for implementing frequency selection of a GSM frequency selector by using frequency hopping synchronization, which comprises the following steps: firstly, radio-frequency signals are coupled to a frequency hopping synchronization control module, and frequency hopping synchronization information is obtained; secondly, the frequency hopping synchronization control module changes parameters of a frequency synthesizer according to the frequency point time series, the frequency synthesizer controls voltage controlled oscillators, and the voltage controlled oscillators output intrinsic signals; thirdly, the frequency hopping synchronization control module controls a switch at a time slot among GSM frames to switch between the two voltage controlled oscillators so as to output different intrinsic signals to be provided for intrinsic input ports of an upper mixer and a lower mixer so that the GSM frequency selector selectively receives the radio-frequency signals. The invention can improve the wireless network quality, effectively reduces the interference to a base station and the interference among the frequency points, improves the use reliability and has stronger practicability.

A Compact Planner MIMO Antenna for GSM, DCS, PCS, UMTS, LTE, WLAN and 5G Application

Abstract: A compact planner multiband multi-input multi-output (MIMO) antenna is proposed and its performance is studied. This MIMO antenna covers multiple frequency bands of the mobile communication system. The proposed work introduce dual-monopole symmetrical MIMO antenna with the slotted ground surface. The antenna resonates at three bands 870-2510MHz, 3580-3750MHz, and 5530-5670MHz which covers GSM 900, DCS 1800, PCS 1900, UMTS-1900/2100,LTE2100/2300,WLAN2400/3600/5600andsuitablefor next generation mobile communication (5G) in sub-6GHz bands, also. The proposed antenna uses a quarter oval type structure in the middle of monopole to achieve higherbandwidth. Inadditiontothatsurfacecurrentdistribution,radiationpattern, gain,andECCparametersarealsoanalyzed.

Directional and dual-frequency omnidirectional combined vehicle antenna

Abstract: The invention relates to a directional and dual-frequency omnidirectional combined vehicle antenna. The directional and dual-frequency omnidirectional combined vehicle antenna comprises a dual-frequency omnidirectional antenna assembly, a directional antenna assembly, an antenna feed assembly and the horizontal common floor. The antenna floor is designed into two separate split structures, the twoseparate split structures are connected through capacitive coupling, the lower floor is connected with a vehicle top metal plate, a technical problem of metal vehicle top interference on a low frequency omnidirectional antenna is solved, moreover, UHF and GSM bands are realized through a dual-frequency omnidirectional antenna, and antenna miniaturization and the compact structure are realized. Ashielding problem of the directional antennas on the omnidirectional antenna is further solved, through cleverly arranging the two directional antennas and one UHF/GSM dual-frequency omnidirectional antenna, the omnidirectional antenna is arranged at the middle of the upper floor, the position is relatively high, the directional antennas are arranged at left and right ends of the lower floor, theposition is relatively low, and thereby interference of the later on the previous is reduced.

Design of tri-band ENZ SIW sensor for microwave testing of materials in 3G and 4G GSM bands

Abstract: This paper presents a novel tri-band epsilon-near-zero (ENZ) substrate integrated waveguide (SIW) based microwave sensor for microwave material testing at global system for mobile communications (GSM) bands. The prototype RF sensor is designed, simulated, and tested for the microwave characterization of materials in 3G and 4G frequency bands. The proposed design provides a substantial reduction in the sensor size, and facilitates complex permittivity measurement at multiple frequencies with reasonable sensitivity as compared to the conventional SIW based sensors. The device is fabricated using multiple layers of FR4 substrate, and the RF signal is coupled using SMA connectors which is then tested for various reference samples. The measured data are found to be in good agreement with their reference values thus validating the proposed design methodology.