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A concept for multiple-input, multiple-output antenna arrays, integrated in an ultra-thin full metal cover laptop computer, is proposed. The antennas are for octa-band wireless wide area network (WWAN) and triple-band wireless local area network (WLAN) operation. The proposed solution makes use of the gap between the metallic display lid and keyboard chassis to form notch and slot antenna arrays, thereby removing the need for additional protrusions or openings. Simulated as well as measured performance is presented. The notch antenna array for WWAN exhibits wide impedance bandwidth, with more than 24 dB isolation from 690 MHz to 3 GHz, and a total efficiency better than -2.5 dB. The slot antenna array for WLAN shows more than 12 dB isolation and a total efficiency of more than -3 dB. Both arrays exhibit a very low envelope correlation coefficient of less than 0.1 within their respective frequency bands.

The integration of an on-chip folded dipole antenna with a monolithic 24-GHz receiver manufactured in a 0.8-mum SiGe HBT process is presented. A high-resistivity silicon substrate (1000 Omega ldr cm) is used for the implemented circuit to improve the efficiency of the integrated antenna. Crosstalk between the antenna and spiral inductors is analyzed and isolation techniques are described. The receiver, including the receive and an optional transmit antenna, requires a chip area of 4.5 mm2 and provides 30-dB conversion gain at 24 GHz with a power consumption of 960 mW.

A novel technique for enhancing the impedance bandwidth of wireless terminal antennas is presented. By introducing resonant short circuit transmission lines to the long sides of the chassis edges, an effective electrical shortening of the terminal ground plane is achieved. This effect has been used to realize terminal ground planes with resonant lengths at high frequencies, such as GSM 1800/1900 MHz or UMTS 2 GHz, thereby extending the impedance bandwidth. The proposed technique has been validated by simulations and measurements. Three typical applications are presented where the introduction of wavetraps improves the bandwidth and/or in-band performance

In this paper we present results of efficiency optimizations in conjunction with increased CIGS deposition rates. Furthermore, we describe Solibro's recent technology improvements for higher module efficiencies and our roadmap for further efficiency improvements. Our results indicate that with co-evaporation of CIGS absorbers high module efficiencies can be realized at high dynamic deposition rates. Various improvements have recently been introduced in Solibro's CIGS production process, which led to a champion module efficiency of 14.4% (total area, externally confirmed). Solibro's efficiency roadmap shows that the technology is capable of producing average efficiencies of 17% within the next 3 years.

An on-ground internal antenna for FM radio reception in mobile phones is proposed and evaluated. By combining a parasitic loop radiator with a driven active monopole antenna, a dual resonant frequency response is achieved with an average effective antenna efficiency of −22.5 dB over the frequency band 88–108 MHz. The total volume of the antenna is 0.93 cm3 with a height above ground of 4 mm. A comparison with the conventional solution of re-using the headset cord as the antenna is included.

Application-perceived throughput plays a major role for the performance of networked applications and user experience and thus, for network selection decisions. To support the latter, this tutorial paper investigates the process of user-perceived throughput in GPRS and UMTS systems seen over rather small averaging intervals, based on test traffic mimicking the needs of streaming applications, and analyzes the results with aid of summary statistics. These results reveal a clear influence of the network, seen from variations and autocorrelation of applicationperceived throughput mostly on the one-second time scale and indicate that applications have to cope with significant jitter when trying to exploit the nominal throughputs. In GPRS, the promised average throughputs are not reached in downlink direction; instead, significant packet loss occurs. Furthermore, with aid of causality arguments for an equivalent bottleneck, bounds for the extra delay of the first packet sent via mobile links is derived from throughput measurements.

An antenna concept for FM radio reception in mobile phones is proposed and evaluated. By resonating a loop or monopole radiator with a shunt element and connecting the antenna to a high-impedance low noise amplifier, an equivalent antenna efficiency of −24±3 dB is achieved over the entire band of 88 – 108 MHz despite having high-Q gain characteristics and without using control voltages for frequency tuning. Due to the resonant frequency behavior ≫45 dB isolation against co-located transmitting antennas is realized, thereby preventing the amplifier from being saturated during simultaneous operation. A comparison with the hands-free cord and other possible internal solutions is included.

A technique for reducing the antenna induced electromagnetic fields in the vicinity of the earpiece speaker in mobile phones is presented, thereby improving the hearing aid compatibility (HAC). By introducing resonant quarter-wave short-circuited transmission lines to each long side of the chassis edges, the earpiece speaker section of the chassis is electrically decoupled from the antenna section. The proposed technique has been validated through simulations and measurements.

The field of portable terminal antenna design has witnessed a remarkable evolution during the last decade, mainly as result of the increasing requirements set by the mobile phone industry. Less than 10 years ago mobile phones were used exclusively for voice communication, utilizing a single wireless system (e.g. GSM) and a single frequency band (e.g. 900 MHz). The terminal antenna was external; either a retractable rod, or to make it smaller, folded together into a coil/helix. In the mid 90’s, frequency bands at 1800 MHz in Europe and 1900 MHz in the US were allocated to increase the network capacity, thus creating a need for antennas supporting two separate frequency bands, so called dual-band antennas. The first phone1 with this feature appeared on the market in late 1997. 1998 saw the first internal antenna (single-band however) in a commercial phone2, a concept that had been proposed already in 1982 [1]. These antennas were non-obtrusive and thus retained the aesthetics and increased the mechanical ruggedness of the phone. Dual-band internal solutions was first presented in the literature in 1997 [2] with commercial phones using the technique available in mid-19993. A couple of years later, the consumer requirement of global roaming (e.g. Europeans wanting to use their mobile phones in the US and vice versa) led to the development of triple band phones, featuring triple band antennas (900/1800/1900 MHz). Around the same time, Bluetooth modules, with a separate internal antenna, and FM radio receivers, using the earpiece cord as antenna, started to become standard features in phones. In early 20034, a new cellular network called 3G (or UMTS/WCDMA), using a separate frequency band, started world-wide deployment. In about 5 years time, wireless terminals went

During recent years, it has become evident that mobility functions will have a profound impact on current and future wireless networks. Users expect service connectivity anywhere and anytime without having to think about the underlying communication systems used at that particular moment in time. On this background, this paper presents a ready-to-deploy implementation of a mobility framework that supports seamless communication and represents an important enabler for adaptive applications through its simple QoS feedback mechanism. The framework selects the best available network through a decision algorithm that takes advantage of both experience with different network types for certain types of services and a link performance monitoring concept. The impact of the proposed framework on performance in terms of processing and throughput overhead is also discussed.

In this paper, the matched performance of a dual band PIFA antenna is reported. The transducer power gain of the matched antenna is optimized over the popular commercial wireless communication bands of 824-960 MHz and 1710-1990 MHz using only one matching network. The antenna matching network was designed using the simplified real frequency technique and it was realized employing 0.18μm Si-processing technology. It is exhibited that realized matching network can be used for mass production for commercial use in multi band wireless communication systems.

In this paper, matched performance of a double band PIFA antenna is reported. The transducer power gain of the antenna is optimized over the commercialized wireless communication bands of 824-960 MHz and 1710-1990 MHz using only one matching network. In the design process, several commercially available computer aided design packages with variety of different matching network topologies were employed. The best result was obtained by using the Simplified Real Frequency Technique, which in turn yields an "easy to implement circuit topology". The matched antenna provides an average transducer power gain of -1.6±0.4 dB in 824-960 MHz and -2.2±0.5 dB in 1710-1990 MHz. Inst. Electronics, Information Communication Eng., IEICE Japan,IEEE MTT-S,URSI,EuMA,IEEE MTT-S Japan Chapter

Based on the need for secure and reliable mobile communication, this paper investigates the application-perceived throughput of an end-to-end (E2E) VPN connection using IPSec over GPRS. GPRS is of particular interest regarding performance issues due to its wide deployment but limited capacity. To this end, different encryption and authentication algorithms are considered. The throughput is measured on small time scales and interpreted with aid of summary statistics, histograms and autocorrelation coefficients. The results reveal a clear influence of the network and the chosen security solution, seen from variations of application-perceived throughput on the one-second time scale, which has to be considered when assessing the appropriateness of network for a specific task. The different statistical metrics considered will later be used in our research to maintain the security and Quality of service (QoS) of the service decided by the user.

Miniaturization, low cost and excellent performances at microwave and millimeterwave applications represent the main leitmotivs of the future mass market communication systems. Consequently, a novel "MEMS above IC" technology has developed in order to allow the elaboration of post-processed micro-machined passive components on top of SiGe circuits to realize a complete short-range communication receiver centered at 24 GHz. The developed technology is based on the use of : -a thick organic layer (BCB), which is employed as a dielectric membrane, -metallizations to realize the passive metal layer and also the vias to interconnect the active circuits with the post-processed passive components, -and a bulk silicon micromachining. This 'above IC' technology presents many advantages, as it uses conventional equipments of microelectronics and is in adequation with high frequency applications. A specific attention has been carried out in order to assure the compatibility of the post-process steps and the IC’s. This has been performed through the choice of the adequate technological steps, which had to present a low temperature budget. The compatibility of each step has been evaluated with a specific test protocol on SiGe transistors. It implies static and dynamic characterisation of these transistors as well as low frequency noise measurements. Each step has been validated, even the bulk silicon micromachining. Design rules have thus been defined in order to localize the silicon etching without any damage on the ICs.

In order to meet user expectations and to be of efficient help for people using or implementing Intelligent Transport Systems and Services (ITS), mobile ITS-related services need efficient support from the underlying communication systems, which in turn requires profound knowledge of those needs. As a first step towards an optimal automatic choice of communication technologies in order to provide for seamless communications, this paper groups services into generic groups and presents a framework to classify their needs in terms of availability, performance, security and cost in a generic manner. These needs are consequently seen from the user's perspective, but formulated in a way such that they can be matched towards known network parameters. Upon comparing needs with offers, the feasibility of a certain communication technology for a certain type of service can be determined both proactively and reactively, which helps to automatically select the right kind of connectivity in order to yield the desired degree of availability, performance, security and cost. We motivate for instance the need for determining and monitoring application-perceived speeds, a multi-level security models and the one-stop service concept. We also provide an example on how these needs can be matched to offers by different networks.

The paper presents an IQ-demodulator for use in a 24 GHz direct conversion receiver. The circuit has been monolithically implemented in a commercial SiGe HBT process production line using a standard (20 /spl Omega/cm) substrate. Measured results show a conversion gain of 11 dB, a LO/RF isolation of 35 dB and a 1-dB compression point of -10 dBm while consuming 101 mA at 3 V Vcc.

The integration of an on-chip dipole antenna with a monolithic 24 GHz receiver manufactured in a 0.8 /spl mu/m SiGe HBT process is presented. A high resistivity silicon substrate (1000 /spl Omega/cm) is used for the implemented circuit to improve the efficiency of the on-chip antenna. The receiver, including the receive and an optional transmit antenna, requires a chip area of 7.3 mm and delivers 33 dB conversion gain at 24 GHz.

A new laser-induced fluorescence detector for capillary electrophoresis (CE) is described. The detector is based on transverse illumination and collection of the emitted fluorescent light via total internal reflection along the separation capillary. The capillary is coated with a low refractive index fluoropolymer and serves as a liquid core waveguide (LCW). The emitted light is detected end-on with a CCD camera at the capillary exit. The observed detection limit for fluorescein is 2.7 pM (550 ymol) in the continuous-flow mode and 62 fM in the CE mode. The detector is applied to DNA sequencing. One-color G sequencing is performed with single-base resolution and signal-to-noise ratio approximately 250 for peaks around 500 bases. The signal-to-noise ratio is approximately 50 for peaks around 950 bases. Full four-color DNA sequencing is also demonstrated. The high sensitivity of the detector is suggested to partly be due to the efficient rejection of scattered laser light in the LCW. The concept should be highly suitable for capillary array detection.

A printed dipole antenna with integrated balun is presented. The radiating structure is a two-element dipole with resonances at 900 and 1700 MHz, with the balun providing one extra resonance at each band. By co-designing the radiating element with a Marchand balun modified for dual-band operation, an antenna covering the cellular bands 824-960 and 1710-2170 MHz has been achieved. Measurements on a fabricated antenna on low-cost FR-4 substrate show antenna efficiencies of >80 and >70% in the lower and upper band respectively. Despite the use of a dual-element radiator, the radiation pattern that is close to omni-directional H-plane is obtained

A modified earpiece cord is proposed and evaluated as a wideband antenna for DVB-H reception. By winding the cord into a high-impedance RF choke at one-quarter wavelength distance from the handset connection, a stable wideband input impedance is achieved. Using two-chip components for impedance matching, the complete UHF band can be covered with >35% antenna efficiency. Measured and simulated results are presented with good agreement.

A switched beam antenna concept suitable for low-cost millimetre-wave applications is presented. The concept uses multiple travelling-wave patch arrays that together with the beam selection switches are realised on a single substrate, where the antenna and circuits are etched from the same metal layer. With its simple design and building practice, the concept provides good producibility at frequencies up to approximately 80 GHz. An experimental study is presented in which four-beam antennas for 24 GHz are built and measured.