Reconfigurable Circular Patch Antenna Research Articles

Frequency reconfigurable circular microstrip patch antenna with slots for cognitive radio

In this paper, a novel multi-frequency microstrip antenna with complementary ring slot resonator (CRSR) structure that satisfies Bluetooth, worldwide interoperability for microwave access (WiMAX), and wireless local area network (WLAN) applications is proposed. The conventional antenna consists of a circular microstrip patch at a resonance frequency band of 2.5 GHz. By loading two CRSR at the radiating element, three operating frequency bands 2.5 GHz, 3.6 GHz, and 5.2 GHz are achieved. The operational bands covered by the antenna are Bluetooth 2.5 GHz, WiMAX 3.6 GHz, and WLAN 5.2 GHz. The insertion of CRSR to patch antenna has made it possible to compact and simple design, and miniaturized antenna for cognitive radio. Moreover, the directivity of the proposed antenna is adequate with acceptable radiation properties and perfectly matches with the simulated and measured results.

Cantor-square Fractal Reconfigurable Circular Patch Antenna with Low Cross-polarization for X Band Applications

Cantor-square Fractal Reconfigurable Circular Patch Antenna with Low Cross-polarization for X Band Applications

A New Diminutive Octa Polarization Reconfigurable Circular Patch Antenna

This proposes a new diminutive octa polarization reconfigurable circular patch antenna design. This new antenna can operate in eight different polarizing states (6 different angles of linear polarization and 2 circular polarization states) with the help of a reconfigurable probe feed network. The antenna comprises of a circular layer of radiation with four equally spaced slits at the boundary of the circular patch to obtain size reduction. The bias voltages of six pairs of PIN diodes are interval between each state. A 3 dB hybrid coupler and a RF switch are used to produce reconfiguration between circular polarization states of the right and left hand. The proposed antenna was designed using CST microwave studio, fabricated as a prototype model and tested which produces desired values for various parameters of antenna including compact size. The designed antenna operates within 2.4-2.5 GHz frequencies suitable for wireless applications.

Design of a High Directive Gain Reconfigurable Circular Patch Antenna

A new probe-fed patch antenna polarization reconfiguration is presented in this proposed work. The antenna is composed of a circular radiating patch and a switchable feed network. By controlling the operating states of four pairs of pin diode in the feed network, the feed point of the circular patch can be switched. Therefore, a reconfiguration between four linear polarization directions at a 45 degree interval (22.5 degree, 67.5 degree, 112.5 degree and 157.5 degree) can be realized. All the different polarization states own similar matching and radiation characteristics. Simulated and measured results indicate that antenna can achieve reconfigurable quadri-polarization diversity features with an invariable operating frequency and excellent radiation performance, which are very attractive for wireless communications. In addition, the proposed design can offer more reconfigurable linear polarization directions by adding more switchable paths in the feed network.

Polarization Reconfigurable Circular Patch Antenna With a C-Shaped

Polarization reconfigurable circular patch antenna with a C-shaped slot is proposed in this communication. It is demonstrated that by introducing a reconfigurable C-shaped slot in a circular patch antenna, the polarization of the radiation of the antenna, operating either in a linearly or circularly polarized mode, can be switched effectively. It is switched between vertical and horizontal polarizations for a linearly polarized mode and switched between left hand circularly polarization and right hand circularly polarization for a circularly polarized mode. The polarization reconfigurable characteristic is realized by controlling the states of the two switching diodes mounted over a concentric circular slot incorporated on the patch, so as to vary the orientation of the C-slot. Prototypes of both linear polarization and circular polarization designs were developed and the performances were validated against measurements. Both antennas exhibit over 20% impedance bandwidth (standing wave ratio (SWR) < 2) and perform broadside radiation over the operating band. The 3-dB axial ratio bandwidth for the circularly polarized case is 4%.

Frequency Reconfigurable Circular Patch Antenna with an Arc-Shaped Slot Ground Controlled by PIN Diodes

In this paper, a compact frequency reconfigurable circular patch antenna with an arc-shaped slot loaded in the ground layer is proposed for multiband wireless communication applications. By controlling the ON/OFF states of the five PIN diodes mounted on the arc-shaped slot, the effective length of the arc-shaped slot and the effective length of antennas current are changed, and accordingly six-frequency band reconfiguration can be achieved. The simulated and measured results show that the antenna can operate from 1.82 GHz to 2.46 GHz, which is located in DCS1800 (1.71–1.88 GHz), UMTS (2.11–2.20 GHz), WiBro (2.3–2.4 GHz), and Bluetooth (2.4–2.48 GHz) frequency bands and so forth. Compared to the common rectangular slot circular patch antenna, the proposed arc-shaped slot circular patch antenna not only has a better rotational symmetry with the circular patch and substrate but also has more compact size. For the given operating frequency at 1.82 GHz, over 55% area reduction is achieved in this design with respect to the common design with rectangular slot. Since the promising frequency reconfiguration, this antenna may have potential applications in modern multiband and multifunctional mobile communication systems.

POLARIZATION RECONFIGURABLE ANTENNA THROUGH SWITCHABLE CPW FEEDING STRUCTURE

This paper presents the polarization reconfigurable circular patch antenna. The reconfigurability feature is realized through the alteration of the feeding network. The antenna consists of a circular patch as a radiator, and orthogonally fed by a co-planar waveguide (CPW) slotline which terminated with tapered transformer. The CPW slotline are interconnected with quarter wavelength phase delay slotline. Eight switches are placed at the CPW transmission slotline, to either activate or deactivate the phase delay slotline. Consequently, depending on the switch configurations, the polarization can be altered to the desired sense, either linear, right-hand circular or left-hand circular polarization.

An Electronically Reconfigurable Patch Antenna Design for Polarization Diversity with Fixed Resonant Frequency

In this paper, an electronically polarization re-configurable circular patch antenna, with fixed resonantfrequency and operating at Wireless Local Area Network(WLAN) frequency band (2.4–2.48 GHz,) is presented. Thestructure of the proposed design consists of a circularpatch as a radiating element fed by a coaxial probe, coop-erated with four equal-length slits etched on the edge alongthe x-axis and y-axis. A total of four switches were usedand embedded across the slits at specific locations, thuscontrolling the length of the slits. By activating and deacti-vating the switches (ON and OFF) across the slits, the cur-rent on the patch is changed, thus modifying the electricfield and polarization of the antenna. Consequently, thepolarization excited by the proposed antenna can beswitched into three types; linear polarization, left-handcircular polarization or right-hand circular polarization.This paper proposes a simple approach that enablesswitching the polarizations and excites at the same oper-ating frequency. Simulated and measured results of theideal case (using copper strip switches) and the real case(using PIN diode switches) are compared and presented todemonstrate the performance of the antenna.

Reconfigurable Inverted Circular Patch Antenna for Wireless Applications

This paper presents a frequency reconfigurable inverted circular patch antenna with Uslot. The incorporation of U-slot in the circular patch provides a wide impedance bandwidth than conventional patch antenna. By introducing shorts at appropriate position on U-slot and on feed, antenna can be made resonant at two frequency bands (1.80GHz-1.98GHz) and (2.10GHz-2.68GHz) in two modes. The proposed antenna not only avoid the interference problem faced in fixed dual band antenna but at the same time provides a good gain of nearly 8 dB in both mode of operation. The prototype of optimized antenna is fabricated and experimental results are in close agreement with the simulated one. This antenna can be used for different wireless application like Personal Communication System (PCS) and Bluetooth/WLAN.

A reconfigurable circular patch antenna with switchable slits for polarization diversity

ABSTRACTThis article proposes a novel circular patch antenna with polarization reconfigurability features. The antenna has a simple structure, which comprises of a radiating circular patch, embedded with two switches (PIN diode) and a pair of equal length slit on the top metal layer. By controlling the biased voltage of the PIN diodes, the polarization of the antenna can be reconfigured between three states; either linear polarization, right‐hand or left‐hand circular polarization. The details of the simulated and experimental results are presented and discussed. The proposed design has the potential application to improve channel reliability in a wireless communication system, especially in dealing with multipath‐rich and limited space environment. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2587–2590, 2014

Reconfigurable antennas and configuration selection methods for MIMO ad hoc networks

In this paper, we quantify the performance enhancements that can be provided by reconfigurable antennas in an ad hoc network where all nodes employ multiple input multiple output communication techniques. We present two types of reconfigurable antennas: a reconfigurable printed dipole array (RPDA), and a reconfigurable circular patch antenna (RCPA). The RPDA and RCPA have a different number of configurations as well as different degrees of pattern diversity between possible configurations. To effectively use these antennas in a network, we introduce and quantify the performance of centralized and decentralized antenna configuration selection schemes for reconfiguration at one or both link ends. We use the sum capacity of the network as a metric to quantify the performance of these antennas in measured and simulated network channels.

Reconfigurable Single Port Antenna With Circular Polarization Diversity

New design of a single feed reconfigurable circular patch antenna with polarization pattern diversity is presented. The radiating circular patch, printed on a thin substrate, is supported by non conductive posts on a conducting ground plane and is excited with a capacitively coupled feed. Wideband impedance matching is achieved. The pattern diversity is generated using two switch parasitic pins between the circular patch and the ground plane. By optimizing the position of the switching elements, two orthogonal patterns with the right-hand circular polarization (RHCP) and the left-hand circular polarization (LHCP) are generated. These patterns are used for diversity reception in indoor fading channel for wireless LAN applications. Detailed design of the antenna is described. Experimental results for return loss, radiation patterns, radiation efficiency, antenna gain, axial ratio and the diversity performance in Rayleigh fading channel are presented.

A novel reconfigurable circular polarization patch antenna

AbstractA novel design of a microstrip patch antenna with switchable branches is proposed to achieve circular polarization diversity. Two branches are incorporated into the patch and two switches are utilized to switch the branches on and off. By turning the switches on or off, this antenna can radiate with either right‐handed circular polarization or left‐handed circular polarization using the same feeding probe. Experimental results validate this concept. This design demonstrates useful features for wireless communication applications and future planetary missions. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 1921–1923, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23537