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.

Multiple Frequency Band Planar Antenna for Different Applications

Abstract: A multiple band microstrip antenna is proposed in this paper. The antenna introduced has various GSM 900 and DCS 1800 smartphone capabilities. It is also used at 2.4 GHz for the application of Wi-Fi, Bluetooth and wireless local area network (WLAN). The proposed is based on FR4 epoxy with a limited ground plane on backside of the substrate with overall length × width is 50 × 90 mm. The suggested one shows strong resonance properties at several 0.9 GHz, 1.8 GHz, 2.45 GHz and 3.5 GHz frequencies. Antenna has return loss below −10 dB at multiple frequencies. Proposed antenna has reasonable gain at these frequencies. All the results are performed using 3D electromagnetic simulation software at high frequency for designing and simulating.

Transmitter filter arrangement for multiband mobile phone

Abstract: A filter arrangement for use in a multiband dual-mode mobile phone. In particular, the mobile phone is operable in a W-CDMA mode and a band-reject filter comprising at least a series and a shunt acoustic-wave resonators is used to create a deep notch at the receive frequency band. The band-reject filter further includes a plurality of inductive elements for matching static capacitance of the resonators at the passband frequency. The mobile phone is also operable in 1800 and 1900 GSM bands. The band-reject filter is operatively connected to a harmonic trap in order to eliminate the third harmonic of these GSM bands. The mobile phone is also operable in the lower GSM band, for which a harmonic filter can share an antenna path with the band-reject filter.

GSM Based Security Lock Using Linear Actuator

Abstract: Security describes the protection of life and property. There are doors to keep people out, key locks and chain reinforce the mode of security. Doors are being made of metals not wood anymore. Influential persons in our society have bullet proof doors to ensure a good measure of security of self and family. This has brought about the need to review the reliability of already existing systems and look into the possibility of creating better system that are smarter and more secure. The existing system largely consists of physical lock and keys. The problem with existing system is that it can cause security issues with the case of burglaries. The burglar can grapple with vault key and study it which can cause considerable damage to the property and valuable materials in the safe. Also, physically locks can be opened by lock picks. The main idea of designing the GSM based security locking system is to provide many modern security features than manual operated mechanical lock. The proposed locking system uses Microcontroller, GSM modem, switching circuit, relay and Linear Actuator.

Integrated RF-DC converter for wireless sensor networks

Abstract: This paper describes an RF-DC converter that contains a dual-band PCB antenna designed for GSM 900 MHz and 2.45 GHz ISM frequency range, integrated matching network and rectifier in 180nm CMOS technology. Design of integrated low-power RF-DC rectifier and impedance matching network in two frequency ranges is demonstrated.

Call method for implementing dual standby in dual-mode mobile terminal

Abstract: A call method for implementing dual standby in a dual-mode mobile terminal, wherein the dual-mode mobile terminal is a dual-mode mobile terminal operating under both GSM and PHS, and the method comprises: (a) when there is a call in the dual standby state, if the terminal determines that it is a PHS call and the frequency point of the GSM mode is 1800M, then turning off the GSM frequency point of 1800M, Once it is completed successfully, then going to the next step, (b) completing the normal call flow and attempting to switch the standby frequency point of GSM mode to 900M, if failed, then attempting to turn on the GSM frequency point of 1800M again, so as to return to the dual standby mode, if both of above are failed, then turning off the GSM mode and returning to the single standby state of the PHS mode. When the dual-mode mobile terminal is in the dual standby state, if there is a call in either of the modes, the radio frequency affecting the communication quality greatly will be turned off, so as not to interfere with another mode, therefore the call quality could be guaranteed.