A Tri-band-notched UWB Antenna with Low Mutual Coupling between the Band-notched Structures

A compact printed U-shape ultra-wideband (UWB) antenna with triple band-notched characteristics is presented. The proposed antenna, with compact size of 24×33 mm2, yields an impedance bandwidth of 2.8-12GHz for VSWR<2, except the notched bands. The notched bands are realized by introducing two different types of slots. Two C-shape half-wavelength slots are etched on the radiating patch to obtain two notched bands in 3.3-3.7GHz for WiMAX and 7.25-7.75GHz for downlink of X-band satellite communication systems. In order to minimize the mutual coupling between the band-notched structures, the middle notched band in 5-6GHz for WLAN is achieved by using a U-slot defected ground structure. The parametric study is carried out to understand the mutual coupling. Surface current distributions and equivalent circuit are used to illustrate the notched mechanism. The performance of this antenna both by simulation and by experiment indicates that the proposed antenna is suitable and a good candidate for UWB applications

DESIGN AND DEVELOPMENT OF DUAL BAND CPW FED ANTENNA FOR WLAN AND WIFI APPLICATIONS

A dual band coplanar waveguide (CPW) fed antenna is constructed, analyzed, and designed for WLAN and WiFi applications in this paper. The antenna has a compact size of 25 × 25 × 1.5 mm3. The antenna structure comprises of a slotted radiating patch over FR4 substrate surrounded by staircase shaped ground plane. As part of the analysis of the characteristics parameters such as the return loss, VSWR, and radiation pattern, HFSS 11.1 is utilized. There is a resonance at two frequencies of 3.3 GHz and 5.82 GHz, with an upper frequency bandwidth of 1.89 GHz. In addition to the antenna design, measurement results are presented. Mobile handheld devices can use the proposed antenna for WLAN and WiFi applications that operate in ISM bands

Miniature Planar Antenna Design for Ultra-Wideband Systems

Demand for antennas that are compact and operate over an ultra‐wideband (UWB) frequency range is growing rapidly as UWB systems offer high resolution imaging capability and high data rate transmission in the order of Gb/s that is required by the next generation of wireless communication systems. Hence, over the recent years the research and development of UWB antennas has been widely reported in literature. The main performance requirements sought from such antennas include: (1) low VSWR of <2; (2) operation over 7.6 GHz from 3 to 10.6 GHz; and (3) good overall radiation characteristics. Significant size reduction and low manufacturing cost are also important criteria in order to realize a cost‐effective and miniature system. Other desirable requirements include compatibility and ease of integration with RF electronics

Novel High Isolation Antennas for Simultaneous Transmit and Receive (STAR) Applications

Radio frequency (RF) spectrum congestion is a major challenge for the growing need of wireless bandwidth. Notably, in 2015, the Federal Communications Commission (FCC) auctioned just 65 MHz (a bandwidth smaller than that used for WiFi) for more than $40 billion, indicating the high value of the microwave spectrum. Current radios use one-half of their bandwidth resource for transmission, and the other half for reception. Therefore, by enabling radios to transmit and receive across their entire bandwidth allocation, spectral efficiency is doubled. Concurrently, data rates for wireless links also double. This technology leads to a new class of radios and RF frontends. Current full-duplex techniques resort to either time- or frequency-division duplexing (TDD and FDD respectively) to partition the transmit and receive functions across time and frequency, respectively, to avoid self-interference. But these approaches do not translate to spectral efficiency. Simultaneous transmit and receive (STAR) radios must isolate the transmitter from the receiver to avoid self-interference (SI). This SI prevents reception and must therefore be cancelled. Self-interference may be cancelled with one or more stages involving the antenna, RF or analog circuits, or digital filters. With this in mind, the antenna stage is the most critical to reduce the SI level and avoid circuit saturation and total system failure. This dissertation presents techniques for achieving STAR radios. The initial sections of the dissertation provide the general approach of stage to stage cancellation to achieve as much as 100 dB isolation between the receiver and transmitter. The subsequent chapters focus on different antennas to achieve strong transmit/receive isolation. As much as 35 dB isolation is shown using a new spiral antenna array with operation across a 2:1 bandwidth. Also, a new antenna feed is presented showing 42 dB isolation across a 250 MHz bandwidth. Reflections in the presence of a dynamic environment are also considered

A new compact small circular patch antenna for UWB communication

A new small circular patch antenna for ultrawideband (UWB) applications is presented. By studying this structure, it is shown that the insertion of a slot with the desired length and width in the ground plane, can lead to a large bandwidth. Our antenna, whose dimensions are 18×12×1.58 mm3, was fed by an SMA female connector with characteristic impedance of 50Ω in order to measure the return loss and VSWR and to compare them with the simulation results. The bandwidth obtained from measurements ranges from 3.52 to 13.67 GHz for VSWR < 2 and from 3.26 GHzto14.23GHz for VSWR < 3. The radiation pattern is omnidirectional on most of the operating band. High Frequency Structure Simulator (HFSS) was used for simulation whose results are in good agreement with the measured parameters

Ground defected planar super-wideband antenna: a suitable transceiver for short distance wireless communication

A planar microstrip patch super-wideband antenna is presented for short distance wireless communication applications. The antenna is comprised of a simple patch and a ground plane and etched on two sides of a 1.6 mm-thick standard FR4 substrate material with a relative permittivity of 4.5 and loss tangent (0.02). The proposed antenna possesses a compact size of 29 × 20.5 mm2 with an electrical dimension of 0.25 λ × 0.18 λ. To enhance the operating bandwidth, the ground plane is modified by adding seven small rectangular slots on its upper side. Through numerical studies, it is found that insertion of the slots enhances the coupling between the patch and ground plane resulting in achievement of a super-wide operating band. From the measurements, it is observed that the fabricated prototype antenna has a bandwidth from 2.63 to more than 18 GHz, a symmetric omnidirectional radiation characteristic and the maximum peak gain of 5.85 dBi which makes it a suitable transceiver for short distance communication applications

Design and characterization of frequency reconfigurable honey bee antenna for cognitive radio application

In this article, a frequency reconfigurable honey-bee compact microstrip monopole antenna is proposed which is fed by a microstrip line (50 Ω) having the capability of providing dual-band as well as triple-band operation in eight distinct modes. By embedding three PIN diodes overs the honey bee arms, the effective current distribution is controlled hence resonant frequency is also changed in eight distinct modes in real-time. This is the reason the proposed antenna is portrayed as a frequency reconfigurable antenna in this paper which is suitable for cognitive radio application. This proposed antenna can be used for various wireless application such as Bluetooth, Wi-Fi, worldwide interoperability for microwave access (WiMAX), wireless local area network (WLAN), C-band, and X-band applications. The proposed antenna possesses a planner geometry of 39×34×0.87 mm3 which is printed on a substrate as flexible FR-4 (lossy) (εr=4.4 and tanδ=0.019). The proposed antenna exhibits voltage standing wave ratio (VSWR)&lt;2 for all 19 resonant frequencies of interest and perceptible radiation pattern over entire frequency bands with a positive gain. CST microwave studio is used to find out all simulated results of antenna parameters