We propose a compact planar ultrawideband (UWB) antenna with 3.4/5.5 GHz dual band-notched characteristics. The antenna consists of a beveled rectangular metal patch and a 50 Omega coplanar waveguide (CPW) transmission line. By etching two nested C-shaped slots in the patch, band-rejected filtering properties in the WiMAX/WLAN bands are achieved. The proposed antenna is successfully simulated, designed, and measured showing broadband matched impedance, stable radiation patterns and constant gain. An equivalent circuit model of the proposed antenna is presented to discuss the mechanism of the dual band-notched UWB antenna. A UWB antenna and a single band-notched one are also provided for references.

A Compact Ultrawideband Antenna With 3.4/5.5 GHz Dual Band-Notched Characteristics

Surface scattering antennas provide adjustable radiation fields by adjustably coupling scattering elements along a wave-propagating structure. In some approaches, the scattering elements are patch elements. In some approaches, the scattering elements are made adjustable by disposing an electrically adjustable material, such as a liquid crystal, in proximity to the scattering elements. Methods and systems provide control and adjustment of surface scattering antennas for various applications.

Surface scattering antenna improvements

The paper presents a study of coplanar waveguide (CPW) fed circular disc monopole antenna for ultra-wideband (UWB) applications. A circular disc monopole printed on a dielectric substrate and fed by a 50 /spl Omega/ CPW on the same layer can yield an ultra-wide -10 dB return loss bandwidth with satisfactory radiation patterns. The performance and characteristics of the antenna are investigated in order to understand its operation. Good agreement has been obtained between the simulation and experiment.

http://ap-s.ei.tuat.ac.jp/isapx/2004/pdf/1B2_4.pdf

Study of CPW-fed circular disc monopole antenna for ultra wideband applications

A printed planar elliptic patch juxtaposed with the ground pattern in a single substrate providing an ultra-wideband impedance bandwidth is presented. The ultra-wideband property for the proposed antenna is achieved by using a new impedance-matching technique of cutting a notch at the ground pattern opposite the microstrip line. The concavity of the ground pattern serves as an effective means for adjusting the gap between the radiating element and the ground plane. With suitable size of notch chosen, the impedance bandwidth of the proposed antenna can be enhanced. Details of the proposed antenna design and measured results are presented and discussed.

Planar elliptical antenna for ultra-wideband communications

Described embodiments include an antenna system and method. The antenna system includes a surface scattering antenna that has an electromagnetic waveguide structure and a plurality of electromagnetic wave scattering elements. The plurality of electromagnetic wave scattering elements are distributed along the waveguide structure, have a respective activatable electromagnetic response to a guided propagating electromagnetic wave, and produce a controllable radiation pattern. A gain definition circuit defines a radiation pattern configured to acquire a possible interfering signal. The defined antenna radiation pattern has a field of view covering at least a portion of an undesired field of view of an associated antenna. An antenna controller establishes the defined radiation pattern in the surface scattering antenna by activating the respective electromagnetic response of selected electromagnetic wave scattering elements. A correction circuit reduces an influence of the received possible interfering signal in a contemporaneously received signal by the associated antenna.

Antenna system facilitating reduction of interfering signals

A longitudinally-slotted ridge waveguide antenna array with a compact transverse dimension is presented. To broaden the bandwidth of the array, it is separated into two subarrays fed by a novel compact convex waveguide divider. A 16-element uniform linear array at X-band was fabricated and measured to verify the validity of the design. The measured bandwidth of S11les-15 dB is 14.9% and the measured cross- polarization level is less than -36 dB over the entire bandwidth. This array can be combined with the edge-slotted waveguide array to build a two-dimensional dual-polarization antenna array for the synthetic aperture radar (SAR) application

A broadband slotted ridge waveguide antenna array

A compact CPW-fed monopole antenna composed of an elliptical monopole patch and a coplanar trapeziform ground plane is introduced. The simulated and experimental results demonstrate that this antenna achieves a ratio impedance bandwidth of 21.6:1 for VSWR les 2, and exhibits a nearly omnidirectional radiation pattern, while its area is only about 0.19 lambda1 times 0.16 lambda1 where lambda1 is the wavelength of the lowest operating frequency. By comparing with various designs, it is shown that its bandwidth broadening comes from three factors: the optimum elliptical monopole shape, a trapeziform ground plane and a tapered CPW feeder.

Compact Elliptical Monopole Antenna With Impedance Bandwidth in Excess of 21:1

A new T-shaped monopole antenna with a CPW feed line is presented. The theoretical analysis is based on the finite-difference time-domain (FDTD) method. The novel antenna is designed, fabricated, and then measured. The measured results, which agree with the numerical calculations very well, are given. The measured bandwidth of the antenna is approximately 116% for VSWR ≤ 2.0. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 43: 50–52, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.20372

A novel wideband coplanar-fed monopole antenna

This paper presents a dual-band eight-element multiple-input multiple-output (MIMO) array using a multi-slot decoupling technique for the fifth generation (5G) mobile communication. By employing a compact dual-loop antenna element, the proposed array obtains two broad bandwidths of 12.2% and 15.4% for sub-6GHz operation. To reduce the mutual coupling between antenna elements, a novel dual-band decoupling method is proposed by employing a multi-slot structure. The proposed MIMO array achieves 15.5-dB and 19.0-dB isolations across the two operating bands. Furthermore, three decoupling modes generated by different bent slots can be independently tuned. Zero ground clearance is also realized by the coplanar arrangement of the antenna elements and decoupling structures. The proposed MIMO array was simulated, fabricated, and measured. Experimental results agree well with the simulations, showing that the dual-band MIMO array has good impedance matching, high isolation, and high efficiency. In addition, the envelope correlation coefficient and channel capacity are calculated and analyzed to validate the MIMO performance of the 5G terminal array. Such a dual-band high-isolation eight-element MIMO array with zero ground clearance is a promising candidate for 5G or future mobile applications.

/pdf/dual-band-eight-element-mimo-array-using-multi-slot-36k7a24s0g.pdf

Dual-Band Eight-Element MIMO Array Using Multi-Slot Decoupling Technique for 5G Terminals

A compact coplanar rectangular monopole antenna fed by a tapered coplanar waveguide (CPW) feeder in the middle of a trapeziform ground plane is introduced. By using the tapered CPW feeder, the impedance bandwidth of the antenna is enhanced by a factor of about 1.7 times compared with a 50Ω CPW feeder. The measured ratio impedance bandwidth reaches about 10.7:1, covering frequencies from 0.76 to 8.15 GHz. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 1242–1244, 2006; Published online in Wiley Inter-Science (www.interscience.wiley.com). DOI 10.1002/mop.21666

Wei Wang

Papers

A broadband slotted ridge waveguide antenna array

Compact Elliptical Monopole Antenna With Impedance Bandwidth in Excess of 21:1

A novel wideband coplanar-fed monopole antenna

Dual-Band Eight-Element MIMO Array Using Multi-Slot Decoupling Technique for 5G Terminals

Tapered CPW-fed printed monopole antenna