Dual-frequency electronically tunable CPW-fed CPS dipole antenna

A CPW-fed coplanar strip (CPS) dipole antenna is presented which operates at dual frequencies. A wideband CPW-to-CPS balun was designed and used. Dual-frequency operation of the CPS dipole antenna was realised by introducing a small gap in the length of the dipole. Varactors were integrated with CPS dipoles to form integrated antennas. The CPS dipole antenna was electronically tuned by varying the varactor bias voltages. Measurements showed good results of dual operating frequencies, frequency range, and antenna pattern     

Switchable CPW-fed slot antenna for multifrequency operation

A CPW-fed slot antenna including pin diodes for multifrequency operation within a frequency octave and more is presented. The use of GaAs beam-lead pin diodes limits the influence of the parasitic resistance and reactance presented by surface mount diodes. The simplicity of the structure results in a simplified and compact biasing circuit     

CPW-fed compact meandered patch antenna for dual-band operation

By inserting a meandering slit at the edge of a rectangular patch printed in a single layer and fed by a coplanar waveguide (CPW) transmission line, a novel compact dual-frequency antenna is obtained. The designed antenna, with, including ground plane, only 20 mm in height and 30 mm in width, can operate at both 2.0 and 5.32 GHz bands and provide sufficient bandwidths for the UMTS and WLAN systems, respectively.     

Compact CPW-fed dual-band antenna

A novel coplanar waveguide (CPW) antenna is proposed for dual-band WLAN applications. It comprises a rectangular patch, a rectangular notch cut at the lower edge of the patch and a CPW transmission line. The rectangular patch together with the ground plane of the coplanar waveguide radiates at the lower frequency band, 2.4 GHz for IEEE 802.11b/g, while the rectangular notch resonates in the upper band, 5.2/5.8 GHz for IEEE 802.11a. The designed antenna is only 32 × 5 mm, which can provide stable omnidirectional radiation patterns with an average gain of 2 dBi in both the bands. The antenna is very compact and suitable for 2.4 and 5.2/5.8 GHz WLAN operations.     

A CPW-fed dual-frequency monopole antenna

A new dual-frequency design of coplanar waveguide (CPW)-fed monopole antenna is proposed and experimentally studied. The proposed antenna utilizes the advantages of the CPW line to simplify the structure of the antenna into a single metallic level, thereby making easier the integration with the microwave integrated circuits. The two operating modes of the proposed antenna are associated with various lengths of two monopoles, in which the longer monopole works for the first resonant mode and the shorter monopole works for the second mode. Moreover, by increasing the width of the longer monopole, a broadband dual-frequency operation is demonstrated. Experimental results show that the impedance bandwidth, determined from 10-dB return loss, of the two operating frequencies can both be greater than 14%. Details of the experimental results are presented and discussed.     

Compact CPW-fed dual-frequency monopole antenna

By introducing an extended conductor line to a rectangular meander monopole, a novel compact dual-frequency monopole antenna is proposed. The proposed antenna is fed using a 50 /spl Omega/ CPW transmission line, is printed in a single metal layer, and therefore is easily constructed. The designed antenna can operate at 900 and 1800 MHz bands and provide sufficient bandwidths for the GSM and DCS systems, respectively.     

Dual-frequency disc antenna studied by cavity method

A double-stub adjusting procedure is used to obtain quasi-identical input impedances and radiation patterns at both resonances of a dual-frequency microstrip antenna. In addition, the cavity method is adapted so as to be applied for the evaluation of radiation pattern as well as the input impedance of the above-mentioned antenna.     

Dual-frequency planar inverted-F antenna

Cellular telephone handsets are now being designed to have dual-mode capabilities. In particular, there is a requirement for internal antennas for GSM and DCS1800 systems. This paper describes a novel planar dual-band inverted-F antenna for cellular handsets, which operates at the 0.9-GHz and 1.8-GHz bands. The dual-band antenna has almost the same size as a conventional inverted-F antenna operating at 0.9 GHz and has an isolation between bands of better than 17 dB. The bandwidths of the antenna are close to those required for the above systems. Good dual-band action is also obtained for other frequency ratios in the range of 1.3-2.4. Studies also show that the dual-band antenna can operate with one or two feeds. A finite-difference time-domain analysis has been shown to give calculated results close to those measured     

Very ultra-wideband printed CPW-fed slot antenna

A very ultra-wideband compact microstrip slot antenna targeting the 3.1-10.6-GHz frequency band is presented. The proposed antenna is a simple printed slot antenna with a novel radiator, which is fed by a 50 Omega CPW line. The measured return loss extends from 2.8-33.4-GHz, about 169-. The proposed antenna has a compact size of 24-25-mm. The measured radiation patterns confirm that the antenna shows an approximately omnidirectional radiation pattern.     

CPW-fed ultra-wideband antenna with compact size

A coplanar waveguide (CPW)-fed ultra-wideband (UWB) antenna with compact size is presented. The entire size of the antenna is as small as 30times13times1.6timesmm. The measured and simulated impedance bandwidth defined by voltage-standing wave ratios <2 is from 3.1 to more than 10.6 GHz. The proposed antenna exhibits a nearly omni-directional radiation pattern with very compact size, which is suitable for various portable UWB systems.     

Broadband dual-frequency meandered CPW-fed monopole antenna

A coplanar waveguide meandered feedline is introduced to obtain a broadband dual-frequency operation of a planar monopole antenna. The modified feeding technology can lead to good impedance matching in a wide dual-band covering 2.4/5.2 GHz WLAN operations. A prototype of the proposed antenna has been constructed and tested. Good radiation characteristics of monopole-like patterns, 23.3 and 29.5% bandwidths, and 2.41 and 4.21 dBi peak antenna gains for the lower and upper bands, respectively, have been obtained.     

共面波导馈电的频率可重构印刷单极子天线

提出了一种间接改变天线辐射体长度的方法。该方法通过改变天线馈线中地导体的长度,间接地改变天线辐射体的长度,有效避免了有源开关对天线辐射性能的影响。为验证此方法,设计了一个共面波导馈电的频率可重构印刷单极子天线,该天线利用PIN二极管来改变馈电端地的长度。实验结果表明:控制开关的工作状态,可使天线的谐振频率发生明显的变化。相应的中心频率分别为1.9 GHz和2.3 GHz,相对阻抗带宽分别为20.8%和17.2%。     

CPW-fed capacitive H-shaped narrow slot antenna

A miniature printed H-shaped narrow slot antenna fed by a coplanar waveguide (CPW) is proposed for WLAN applications in the 2.4 GHz band. The antenna with a simplified open-end tuning stub is also proposed. The prototype has been designed and fabricated and found to have a bandwidth of 13.5%, and the radiation pattern measured at resonance is very close to omnidirectional in the H-plane. The characteristics of the proposed antenna has been investigated using simulation software HFSS and experimental results. The measured and simulated results show excellent agreement.     

CPW-fed log-periodic dumb-bell slot antenna array

A coplanar waveguide (CPW) fed log-periodic dumb-bell slot antenna array is presented. Due to the log-periodic structure and dumb-bell slot, the proposed antenna operates as a frequency independent antenna. The antenna is printed on a substrate with a single metal layer and therefore is easily constructed. The measured return loss and radiation patterns are also included.     

A 150-GHz CPW-fed tapered-slot antenna

An easy method for increasing the substrate thickness of tapered slot antennas (TSA) is presented. With this method, antennas three times thicker compared with conventional designs can be realized, with an almost unchanged performance. The method has been successfully applied to a 150-GHz TSA on quartz substrate. The antenna has been carefully examined theoretically and measured with a field measurement system to determine both amplitude and phase of the radiated field. Finally, and based upon our results, a twin TSA is proposed and theoretically investigated.     

Compact CPW-fed Sierpinski fractal monopole antenna

A novel compact and uniplanar CPW-fed Sierpinski fractal monopole antenna is presented. A fractal radiating element represents the fourth iteration of the Sierpinski gasket with scale factor /spl delta/=1.5. The antenna is printed on a single layer dielectric substrate and fed by 50 /spl Omega/ CPW transmission line. The multiband operation of the planar fractal structure is confirmed experimentally.     

Broadband printed CPW-fed circular slot antenna

A broadband printed CPW-fed circular slot antenna is proposed. This antenna is composed of a circular slot fed with a 50 /spl Omega/ CPW line through a circular patch. A parametric study was carried out to optimise the proposed structure, and the simulated and measured results show that the proposed design offers an ultra-wide bandwidth of 143.2% (from 2.3 to 13.9 GHz).