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A simple dual band 802.11a/b antenna system fabricated on a double-sided printed circuit board (PCB) is described. This low profile antenna, which is 0.8 mm in thickness and 6/spl times/40 mm in width and length respectively, is mounted onto the top of a laptop metal display frame. The antenna system has an average gain better than -1 dBi in the 2.4 GHz band and -2.7 dBi in the 5 GHz band on the horizon plane.

Many antenna types can be used for laptop integrated wireless applications. However, the most popular ones are the inverted-F (INF) and slot antennas or the variations of these two types due to their simple design, easy integration, low cost and overall performance. The goal of this paper is to highlight the characteristics of these two types of antennas.

As hundreds of enterprises strive to connect their businesses with mobile applications, there is a remarkable trend towards the integration of antennas into devices once tethered to networks. Several wireless communication standards, for example Bluetooth and IEEE 802.11b, operate in the 2.4 GHz Industrial Scientific and Medical (ISM) unlicensed band. The inverted-F (INF) antenna's simple design, ease of integration, low cost and overall reliable performance makes it one of the most viable candidates for device integration in the ISM space. The objective of this paper is to investigate the effect of antenna placement on the impedance and radiation characteristics of a given INF antenna for laptop applications.

A MMW setup is presented for measuring complex impedance and radiation patterns in an anechoic chamber while contacting the antenna with a coplanar probe. Measurement and simulation results of a 60 GHz Vivaldi antenna are shown to demonstrate the setup performance.

The 2.4 GHz ISM band has become very popular and is now widely used for several wireless communication standards, such as Bluetooth and IEEE 802.11b. For higher data rates, IEEE 802.11a devices in the 5.15-5.35 GHz band are required. For world-wide applications, an antenna covering the 5.15-5.85 GHz range is needed. The design and analysis of a new dual band antenna are presented. The proposed antenna is targeted for the 2.4-2.5 GHz and 5.15-5.35 GHz bands. The antenna is suitable for use in hand-held or other mobile devices and offers advantages in size, cost, and performance. The antenna can be built on a single-sided printed circuit board (PCB) or stamped from thin sheet metal. The antenna can also be built as an on-board antenna to reduce manufacturing costs. Future study will concentrate on extending the antenna bandwidth to cover the 5.15-5.85 GHz frequency range.

A 1 V 3.8-5.7 GHz VCO was designed and fabricated in a 0.13 /spl mu/m SOI CMOS process. This VCO features differentially-tuned accumulation MOS varactors that (a) provides 40% frequency tuning when biased between 0 to 1 V, and (b) rejects common-mode noise such as flicker noise. At 1 MHz offset, the phase noise is -121.67 dBc/Hz at 3.8 GHz, and -111.67 dBc/Hz at 5.7 GHz. The power dissipation is between 2.3 to 2.7 mW depending on the centre frequency. When V/sub DD/ is reduced to 0.75 V, the VCO only dissipates 0.8 mW at 5.5 GHz.

A low-voltage 3.0-5.6 GHz VCO was designed and fabricated in an 0.13 /spl mu/m SOI CMOS process. This VCO features a single-loop horseshoe-shaped inductor and an array of band-switching accumulation MOS (AMOS) varactors. This results in good phase noise and a wide tuning range of 58.7% when tuned between 0 to 1.4 V. At a 1 V Supply (V/sub DD/) and 1 MHz offset, the phase noise is -120 dBc/Hz at 3.0 GHz, and -114.5 dBc/Hz at 5.6 GHz. The power dissipation is between 2 and 3 mW across the whole tuning range. The buffered output power is -7 dBm. When VDD is reduced to 0.83 V, the VCO dissipates less than 1 mW at 5.6 GHz.

A 40 GHz fully-monolithic complementary VCO fabricated in IBM 0.13 /spl mu/m partially-depleted SOI CMOS technology is reported. The VCO operates at 1.5 V supply and draws 11.25 mW of power. The measured phase noise at 40 GHz is -109 dBc/Hz at 4 MHz offset from the carrier. At 1.5 V and 2 V V/sub DD/, the tuning range is 9% and 15% respectively, and the output power is -8 dBm and -5 dBm respectively. The VCO occupies a chip area of only 100 /spl mu/m by 100 /spl mu/m.

Two performance parameters are used to define integrated antennas for laptop applications. One is SWR, and another is the average antenna gain. Based upon link budget models and system requirements, the integrated antennas should have a 2:1 SWR bandwidth, wide enough to cover the 2.4 GHz ISM band to ensure a wireless system to have reliable, high data rate performance over a useful range or coverage area. The antenna should have average gain values similar to that of an isotropic radiator. The average gain value can be used in a communication link budget model to predict system level performance such as throughput and range. The antenna polarization is not a critical parameter for laptop applications since laptops are primarily used in indoor environment where there is high scattering and mixing of signals. As one would expect, the best location for integrated antennas in laptops is to place the antenna on the laptop display as high as possible. But using this location forces a design trade-off between the antenna's "visibility" and the necessity of a lossy feed cable, since wireless cards are usually placed in the base of a laptop. The ultimate system cost, time to market and performance are consciously traded off for each and every application.

A monopole antenna with two branches, but still having one feed point, is proposed for the dual-band cellular applications. Simulation results of a dual-band antenna are presented. As shown in the results, the input impedances at the center of both bands are about 50 /spl Omega/. Therefore, an additional matching network is not necessary. This means there is no efficiency loss due to adding matching networks. The radiation patterns are basically omnidirectional. Although the GSM and DCS bands are used here, similar results can be obtained for the 900 MHz and 2.4 GHz ISM bands. The antenna can be made on a single-sided printed circuit board.

In this paper, the simulation results of a dual band access point antenna for WLAN applications have been presented. As shown in the results, the input impedances at the center of both bands are about 50 ohms. Therefore, an additional matching network is not necessary. This means there is no efficiency loss due to adding matching networks. The radiation patterns are basically omnidirectional. Although the 2.4 GHz and 5 GHz bands are used here, similar results can be obtained for the GSM and DCS band, and 900 MHz and 2.4 GHz ISM bands. The grounded monopoles with the same length are used in the analysis. However, different lengths can be used for radiation pattern control, especially to reduce the gain variations in the 5 GHz band. Furthermore the design ideas presented here can be used for tri-band applications if the grounded monopoles with different lengths are used.

The design and analysis of a new directional antenna is presented. This antenna can be used in a hand-held device or instruments requiring an antenna radiating in a particular direction. The antenna has a small size, and can be built on a single or double sided printed circuit board. It can also be built as a on-board antenna to reduce manufacturing cost. The antenna presented consists of two dipoles. The two dipoles are placed in parallel and very close to each other. The antenna has a radiation pattern very similar to that of a two element Yagi antenna having one driven element and one director, a front-to-back ratio more than 10 dB, and a gain more than 3 dBd. No matching network is required since the antenna is designed for a 50 ohms input impedance at the center frequency of a band. The method of moments, particularly, the reaction technique, is used for the analysis.

Advances in wireless communications technology are currently developing very rapidly. The 900 MHz and 2.4 GHz ISM bands are widely used for a variety of applications. As an example, many laptop computers use the 900 MHz band for wireless printer and modem connections and the 2.4 GHz band for wireless LAN and Bluetooth applications. The 1.8 GHz PCS band is also under consideration for data services. As a result, the demand for a antenna operating at three bands is increasing. Dual-band antennas with one feed have some advantages over multi- feed antennas and were proposed for cellular applications. These antennas can also be used for dual-band ISM applications. We extend the results of the dual-band antenna proposed by Liu (see IEEE Antennas and Propagation Society International Symposium and URSI Radio Science Meeting, Proceedings, Orlando, Florida, vol.3, p.1578-81, July 1999, Proceedings of the XXVIth General Assembly of the International Union of Radio Science, Toronto, Canada, p.61, August 1999, and IEEE Antennas and Propagation Society International Symposium and URSI Radio Science Meeting Proceedings, Salt Lake City, Utah, vol.3, p.1302-1305, July 2000) to tri-band applications. The antenna proposed here consists of a monopole and two or four branches as shown. The branches are circumferentially connected to the monopole a short distance away from the monopole feed point. The branches are parallel to and a small distance away from the monopole. The branches on the same band have the same length. In this design, the center monopole, roughly speaking, works for the 900 MHz band, while the branches work for the 1.8 and 2.4 GHz bands.

Dual-band antennas with one feed have some advantages over multi-feed antennas and were proposed for cellular applications. These antennas can also be used for dual-band ISM applications. The antenna, proposed by Liu (see IEEE Antennas and Propagation Society International Symposium and URSI Radio Science Meeting Proceedings, Orlando, Florida, vol.3, p.1578-81, 1999) consists of a monopole and one or more branches as shown. The branches have an equal length and are circumferentially connected to the monopole a short distance away from the monopole feed point. The branches are parallel to and a small distance away from the monopole. In this design, the center monopole, roughly speaking, works for the low band, while the branches work for the high band. We study the effects of the number of branches and the branch height on the antenna performance. The method of moments is used to find the input impedance of the antenna, while the genetic algorithm is used for searching the resonating monopole and branch lengths for a given number of branches, branch height and the distance between the monopole and the branches.

A monopole antenna is proposed for dual-band ISM applications. The 900 MHz band spans from 902 to 928 MHz centered at 915 MHz, and the 2.4 GHz band spans from 2.4 to 2.5 GHz centered at 2.45 GHz. With proper design this antenna will outperform previously proposed antennas.

AC power lines have been considered as a convenient and low-cost medium for intra-building automation systems. We investigate the problem of estimating the channel order and root mean squared (RMS) delay spread associated with the power lines, which are channel parameters that provide important information for determining the data transmission rate and designing appropriate equalization techniques for power line communications (PLC). We start by showing that the key to the RMS delay spread estimation problem is the determination of the channel order, i.e., the effective duration of the channel impulse response. We next discuss various ways to estimate the impulse response length from a noise-corrupted channel estimate. In particular, four different methods, namely a signal energy estimation (SEE) technique, a generalized Akaike information criterion (GAIC) based test, a generalized likelihood ratio test (GLRT), and a modified GLRT, are derived for determining the effective length of a signal contaminated by noise. These methods are compared with one another using both simulated and experimentally measured power line data. The experimental data was collected for power line characterization at frequencies between 1 and 60 MHz.

Millimeter and sub-millimeter waves have been the focus of intensive research activities over the past several years. Application of these technologies has advanced beyond traditional high-cost niche uses - mostly related to radio astronomy and space applications - to embrace widespread new consumer applications, some of which show significant market potential. Increased opportunity to exploit these bands is in part created by the spectrum availability that enables extremely high data rates and the inherent miniaturizability of the radio front-ends. This naturally drives concomitant advancements in semiconductor technology at mm-waves and sub-millimeter waves that lower technology deployment cost and make it affordable for applications such as home multi-gigabit wireless systems, active and passive high resolution imaging for medical diagnostic or civil security applications, automotive radar, and body-area networks.

A slot antenna implemented in a thin cavity-down ceramic ball grid array (CBGA) package in low-temperature cofired ceramic (LTCC) technology is reported. The antenna, intended for use in highly integrated 60 GHz radios, has achieved an acceptable impedance band width from 59 to 65 GHz and a peak gain of 11 dBi at 61.5 GHz with an estimated efficiency of 94%.

This paper presents a planar embedded dualband antenna for the 2.4 GHz wireless local area network (WLAN) and ultra-wideband (UWB) applications. A partial elliptic with a rectangle tail on the front side of a PCB forms the planar antenna for the UWB applications (3.1-10.6 GHz). The smooth change in the feed of the antenna achieves a good impedance match between the feed cable and the antenna. A strip on the back side of the PCB connected to the front side with a metal strip on the side or via through the PCB produces a resonance for the 2.4 GHz WLAN or Bluetooth (BT) application. The proposed antenna was simulated assuming free-space conditions, and fabricated onto a piece of a thin PCB. Both the impedance and radiation performance of the antenna embedded into the display of a laptop computer were experimentally measured and then optimized. The measurement shows that the proposed antenna is capable of providing a good impedance match and acceptable gain across the 2.4-2.5 GHz WLAN/BT band and the 3.1 -10.6 GHz UWB band. Furthermore, this antenna features a low profile and low cost solution, and can be readily embedded into the thin covers of laptop computers or other portable devices.

The design and analysis of a new triband antenna have been presented. The antenna is suitable for use in hand-held or other mobile devices and offers advantages in size, cost, and performance. The antenna can be built on a double-sided printed circuit board (PCB) or stamped from thin sheet metal. The antenna can also be built as an on-board antenna to reduce the manufacturing cost. The antenna design is patent pending.

This paper presents dual-band antenna structures for portable applications. The antenna can be stamped from sheet metal or manufactured on a single-sided PCB. No additional impedance matching is necessary. The antenna structure is simple, but it has high efficiency and reasonable SWR bandwidth.