Antenna For Cognitive Radio Applications Research Articles

Design on CPW Quasi Dipole Meandered Printed Antenna for Cognitive Radio Applications

In this proposed paper, CPW-fed meandered printed antenna is designed and investigated for cognitive radio application. The suggested antenna is developed using two different substrates for varying the electrical properties. The first design is developed using an FR4 substrate and the second design is developed using jean material. Investigations are done on the design for wide bandwidth response for effective cognitive radio communication. The antennas are made to resonate at 2.45 GHz. The main focus in the proposed design is to achieve compactness and wider bandwidth. The proposed antenna is excited using coplanar waveguide (CPW) structure to reduce the antenna size and spurious radiations near the feed line. Two quarter-wavelength resonators with two separate current routes are part of the proposed antenna’s structure. It may therefore function in the WiMAX and WLAN (wireless local area network) frequency ranges. By adjusting the length of the appropriate resonators, the operational bands’ center frequencies can be separately controlled. The proposed antennas are designed and simulated for its resonance condition. A parametric study is done to identify the arm length of the proposed antenna for its appropriate resonance. Based on the suitable arm length, the antenna is designed and optimized for effective size reduction. The fabricated antenna module is integrated in the software defined radio (SDR) device for the real-time measurements. The footprint of the antenna is 48.5 mm × 25 mm. Both the simulated and measured results are in good concurrence.

Dual band Orthogonal Polarized 2-port MIMO Antenna for Cognitive Radio Applications

An arrangement of orthogonally aligned antennas over two planes of a substrate is designed in this paper. The design is a novel miniaturized cognitive model operating at LTE, C-band and X-band with sufficient band stop notch. The antenna is etched over a 0.8 mm thick FR-4 Epoxy substrate of dimension 15 mm x 15 mm. On one side the antenna is a hexagonal slotted microstrip antenna and on the other side is a partial CPW type hexagonal patch antenna. The top hexagonal patch antenna is a wide band from 1800 MHz to 12000 MHz. With the use of a slot on the patch creates one notch from 2240 MHz to 5090 MHz and another notch is created at 6200 MHz to 8100 MHz. Thus, the working bands comprise of LTE 1900, Wi-Fi 5G and X-band under a single polarization. Similarly, the second antenna has its first resonance at LTE 1900 and the second resonance at X-band with a polarization orthogonal to the antenna at top. Being a miniaturized antenna, the cognitive radio provides gain ranging from 2.0 dB at lower frequency to 5.4 dB at higher frequency. The isolation over the operating bands suggests non-interference between the antennas.

A New Approach for the Design of Frequency Reconfigurable Antenna for Cognitive Radio Applications

A New Approach for the Design of Frequency Reconfigurable Antenna for Cognitive Radio Applications

Frequency reconfigurable rectangular patch antenna for cognitive radio applications

<span>A frequency reconfigurable microstrip transformed rectangular patch antenna consisting of two slots able to radiate in S-band and C-band is proposed. Spectrum occupancy is first analyzed using the data from literature and internet sources and hence spectrum holes are identified. A rectangular radiating patch is then designed for 5.8 GHz resonant frequency. A coaxial feed is used in the bottom by a suitable feed point. Two slots at an angle of +45 degree are made at the two corners. The electrical length of the patch is changed by using two varactor diodes in the slots. The varactors enable frequency reconfiguration in the band of frequencies that are unused or the spectral occupancy is very less. The return loss, voltage standing wave ratio (VSWR), and 2D-radiation patterns are analyzed for various values of the capacitances. high-frequency structure simulator (HFSS) is used for simulation. FR4 substrate which is economical, is used with height, h=1.6 mm, width W=25.33 mm, and length L=21.34 mm. On the substrate the rectangular patch is of width 15.73 mm and length 11.74 mm. The return loss and radiation patterns for different values of capacitances is presented. The tunability ratio obtained is 1.93. The results obtained agree with the standards.</span>

Antenna for Cognitive Radio Applications — A Review

Antenna for Cognitive Radio Applications — A Review

High-isolated, low correlation and wide frequency reconfigurable (2.1–4.2 GHz) MIMO antenna for cognitive radio applications

ABSTRACT This paper proposes a unique and small (2508 mm2) penta-band frequency agile MIMO antenna based on RF switches for cognitive radio mobile, WLAN, WiMAX, and wireless sensing applications. Three RF switches generate five resonant bands at 2.1, 3, 3.5, 4, and 4.2 GHz in four usable states-100, 011, 111, 100, and 000, respectively. The proposed antenna's fractional bandwidth was 4.95 % (simulated) and 5.5 % (measured) in state-000, 3.09 % (simulated) and 2.8 % (measured) at a lower frequency (2.1 GHz), 2.12 % (simulated) and 2 % (measured) at higher frequency (4.2 GHz) in state-100, 12.5 % (simulated) and 12 % (measured) in state-011, and 4.6 % (simulated) and 4.7 % (measured) in state-111. A large peak gain of 3.6 dB at 4 GHz, maximum isolation of 32.2 dB at 3.5 GHz, significant radiation efficiency of 93.7% at 4GHz is obtained. At 4 GHz, a strong peak gain of 3.6 dB, maximum isolation of 32.2 dB at 3.5 GHz, and considerable radiation efficiency of 93.7 % are realised. For this work, MIMO parameters such as ECC (approx. 0), DG (approx.10dB), TARC (<0.5), MEG (−12 dB < MEG (dB) < −3 dB) and CCL (< 0.5 bit/s/Hz) were achieved. The suggested antenna was simulated, constructed, and tested, and the simulated results were found to be very close to the experimental findings.

Frequency selective reconfigurable microstrip antenna for cognitive radio applications

For the efficient utilization of electromagnetic radio spectrum cognitive radio communication system is employed, which deals with the spectrum scarcity. An efficient antenna is essential for the appropriate selection of the available frequencies. This paper presents the design and implementation of frequency reconfigurable antenna for cognitive radio applications. Reconfigurable inverted U-shape microstrip patch antenna feeding by 50 W microstrip line is designed and implemented. The designed and implemented antenna applied for switching frequency between 3.25 GHz to 4.1 GHz by choosing a specific sub-band from the specified wideband. The frequency reconfiguration was achieved by using twelve PIN diode switches by placing them on the slotted ground plane of the antenna. The PIN diodes were organized in such a way as to alter antenna bandwidth and to shift the operating band. The switching of PIN diodes controlled using the microcontroller to select the appropriate frequency. The performance of the simulated and fabricated antenna is investigated using different parameters.

Design and Fabrication of Micro Strip Patch Antenna for Cognitive Radio Applications

Design and Fabrication of Micro Strip Patch Antenna for Cognitive Radio Applications

Reconfigurable ultra wideband to narrowband antenna for cognitive radio applications using PIN diode

Frequency reconfigurable antennas are very attractive for many wireless applications.They offer many advantages such as simplicity and compactness. In this electronicpaper, we propose a reconfigurable antenna operating in the S and C bands. Theproposed antenna uses a BAP65-02 RF diode to switch between the ultra widebandfrom 2.92 to 6.19 GHz to the narrowband from 2.92 to 3.93 GHz. The ultra widebandis obtained by a partial rectangular ground plane with a symmetrical rectangular slotand the narrowband is obtained by adding a parasitic element electrically connectedto the ground plane by the PIN diode when it is positively biased. This patch antennaoperates in the Federal Communications Commission band (FCC) and can be used forbiomedical applications such as radiometry imaging. The numerical simulation resultsbased on the finite element method and the finite integral method show a very goodagreement between them.

Development of an Inverted-h Shaped Fractal Microstrip Patch Antenna for Cognitive Radio

In this paper, development of an inverted-h shaped multiband fractal microstrip antenna is presented for spectrum sensing in cognitive radio applications. An attempt is further made to optimize the proposed antenna using nature-inspired metaheuristic Moth flame optimization to achieve desired performance in 1.382 GHz, 2.623–3.101 GHz, 4.628–11.98 GHz and 13.22–20 GHz. This antenna is having multiple wide bands and almost omnidirectional radiation pattern, as per the requirements of spectrum sensing antennas for cognitive radio applications.

New compact multiband inverted-L frequency reconfigurable antenna for cognitive radio applications

This paper presents, new compact and multiband frequency reconfigurable antenna for cognitive radio applications. A UWB sensing and reconfigurable communicating antennas are contained at the same substrate, where the UWB sensing antenna is an elliptical printed monopole antenna operates on frequency band from (2.65-22.112) GHz which can cover the UWB frequency band from 3.1 to 10.6 GHz, while the communicating antenna is an inverted-L frequency reconfigurable antenna operates on three bands of 1.49 GHz, 5.58 GHz, and 5.6 GHz under (S11 ≤ -10 dB) with a fractional bandwidth of 5.872%, 6.02%, and 6.05% respectively. The proposed antenna used to operate in two modes one for cognitive radio applications to cover WLAN applications at 5.5 GHz and 5.6 GHz and the second mode for wireless Ethernet, GPS synchronization, and Internet of Things that Matter (IoTtM) at 1.49 GHz. The frequency reconfigurability is obtained by using only a single RF switch (PIN diode) for changing the operating frequency. The antenna overall dimensions are 72 x 36 x 1.6 mm&lt;sup&gt;3&lt;/sup&gt; printed on an FR-4 epoxy substrate of 4.3 relative-permittivity, loss tangent tan (δ) = 0.002 and 50 Ω micro stripline feed. The obtained simulated gain is ranging from 1.35 to 4.132 dBi. The S11 and isolation (S12) between the two antennas are under -20 dB and -17 dB respectively at the resonant frequencies.

Compact 3x1 Elements Reconfigurable MIMO Antenna for Cognitive Radio Applications

This paper presents, compact multiband frequency reconfigurable 3x1 MIMO antenna for cognitive radio applications. The antenna comprises 3-elements reconfigurable MIMO antenna and single element UWB sensing antenna. The frequency reconfigurability range under (S11 ≤ -10 dB) from 7-14.8 GHz using single PIN diode, while the UWB frequency range from 2.597-23.08 GHz. The antenna is designed and optimized to cover such wireless applications such as WiMAX, international telecommunication union (ITU), satellite, and broadband applications. The antenna is optimized using a Genetic Algorithm to operate in the MIMO and cognitive radio systems. The antenna dimensions for 3-elements MIMO antenna are 55 x 65 x 1.6 mm3 printed on an FR-4 epoxy substrate with relative dielectric constant εr = 4.3, loss tangent tan (δ) = 0.002 and 50 Ω microstrip feed line. The obtained simulated gain is ranging from 2.8-8.25 dB and the maximum simulated gain is 8.25 dB at 8.5 GHz. The return loss, Envelope Correlation Coefficient ECC, and Isolation are obtained to be less than -25 dB, less than 0.018, and less than -17 dB respectively. Detailed simulation results are explored and studied in this research. The CST software is used to simulate and optimize the proposed antenna.

An electronically switchable UWB to narrow band antenna for cognitive radio applications

AbstractCognitive radio (CR) is designed to achieve intelligent spectrum sensing and sharing, in order to solve spectrum underutilization problem. Conventional CR uses multiple/multiport antenna to switch between UWB and narrow band (NB) frequencies for primary and secondary users. In this article, we propose a compact frequency reconfigurable single port antenna using PIN diodes, to switch between UWB and NB frequencies. A circular disc monopole antenna with partial ground plane is designed to deliver UWB response. Three interdigital capacitors (IDC) are electrically connected to a partial ground plane and feed line using PIN diodes. OFF condition of all PIN diodes will provide the UWB response of 2.8 to 10.6 GHz and ON condition of the diodes will result in 36 different NB frequencies, completely covering the UWB spectrum. A simulation study carried out by incorporating a varactor diode into IDC, clearly shows that, the antenna resonance can be switched using PIN diodes and each resonant frequency can be fine‐tuned independently, with in the band of interest. This is the unique feature of proposed antenna, which facilitates the technology for CR based internet of things applications in 5G wireless communication networks.

Compact tri-band T-shaped frequency reconfigurable antenna for cognitive radio applications

This paper presents, new compact tri-band and broadband frequency reconfigurable antenna for cognitive radio applications. The proposed antenna consists of an Ultrawideband sensing antenna and reconfigurable communicating antenna at the same substrate. The sensing antenna is a UWB printed elliptical monopole antenna operates at frequency band from 2.72 to 23.8 GHz which can cover the entire UWB frequency band from 3.1 to 10.6 GHz and cover the broadband up to 20 GHz. The communicating antenna is a T-shaped frequency reconfigurable antenna operates on three bands of 7.925 GHz, 13.16 GHz, and 14.48 GHz under (S11≤-10 dB) with a fractional bandwidth of 14.55%, 6.2%, and 3.3% respectively. The proposed antenna used to operate in two modes one for cognitive radio applications to cover WiMAX, land, Fixed and Mobile satellite, Radar, and broadband applications. The frequency reconfigurability is obtained by using only one RF switch (PIN diode) for changing the operating frequency. The antenna overall dimensions are 42x30x1.6 mm3 printed on an FR-4 epoxy substrate with relative dielectric constant εr=4.3, loss tangent tan (δ)=0.002 and 50Ω microstrip line feed. The maximum obtained simulated gain is 8.5 dB at 13.16 GHz. The S11 is under -20 dB and coupling between the two antennas is less than -15 dB at the resonant frequencies.

Omega Shaped Complementary Split Ring Resonator Loaded Bandwidth Reconfigurable Antenna for Cognitive Radio Applications

Abstract This paper presents a bandwidth reconfigurable, circular monopole antenna loaded with omega shaped complementary split ring resonator (omega-CSRR). The CSRR is designed to produce band stop response at desired frequency, in order to control bandwidth. Two slots are connected to the CSRR using PIN diodes to form the arms of omega-CSRR. Switching the diodes, ON/OFF will vary the length of arms of omega. This will vary the stop band, resulting in tuning of impedance bandwidth. Two additional slots loaded on the ground plane, controls the lower and upper band limits. Ultra wide band (UWB) response (2.6GHz – 12GHz) and narrow band response are obtained. The bandwidth of narrow band is varied from 1.5GHz to 4.85GHz, by maintaining the center frequency at 6GHz. The impedance bandwidth percentage ranges from 26% to 82.2%, exhibiting an increase by a factor of 3.16.

Frequency reconfigurable antennas for cognitive radio applications: a review

&lt;span&gt;Wireless communication systems undergo tremendous growth these days and devices able to operate in a number of frequencybandsarehighlydemanded. Reconfiguration in antenna characteristic striggered the evolution of antennas that can workin multiple frequency, pattern&lt;span&gt; or polarization &lt;/span&gt;environment.The frequency reconfigurable antennas thuse mergedarewell suited in Cognitive Radios which take part in the effective utilization of unused bands of frequencies by continuously interacting with the RF environment. Thus, Cognitive Radios enhancetheutilization of frequency spectrum and establish reliable communication. The most recent research works carried out in the arena of Frequency Reconfigurable Antennas for Cognitive Radio applications are reviewed and summed up in this paper to present the attributes and categorization. Four techniques adopted to attain frequency reconfiguration are extensively compared in this paper to find the advantages and constraints of each methodology. The applications of the works reviewed here are not only limited to Cognitive radios, but extended to a number of wireless communication services like, WLAN, WiMAX, etc&lt;/span&gt;

A Compact Four-Port Coplanar Antenna Based on an Excitation Switching Reconfigurable Mechanism for Cognitive Radio Applications

In this paper, we propose a compact four-port coplanar antenna for cognitive radio applications. The proposed antenna consists of a coplanar waveguide (CPW)-fed ultra-wideband (UWB) antenna and three inner rectangular loop antennas. The dimensions of the proposed antenna are 42 mm × 50 mm × 0.8 mm. The UWB antenna is used for spectrum sensing and fully covers the UWB spectrum of 3.1–10.6 GHz. The three loop antennas cover the UWB frequency band partially for communication purposes. The first loop antenna for the low frequency range operates from 2.96 GHz to 5.38 GHz. The second loop antenna is in charge of the mid band from 5.31 GHz to 8.62 GHz. The third antenna operates from 8.48 GHz to 11.02 GHz, which is the high-frequency range. A high isolation level (greater than 17.3 dB) is realized among the UWB antenna and three loop antennas without applying any additional decoupling structures. The realized gains of the UWB antenna and three loop antennas are greater than 2.7 dBi and 1.38 dBi, respectively.

UWB Rectangular DRA Integrated with Reconfigurable Narrowband Antenna for Cognitive Radio Applications

ABSTRACT A new ultra-wideband (UWB) dielectric resonator antenna (DRA) integrated with a reconfigurable narrowband (NB) antenna is designed and analyzed for cognitive radio (CR) applications. The UWB antenna consists of a rectangular dielectric resonator which is fed by a microstrip line. The NB antenna composes of a rectangular ring patch and three stubs which is fed by a microstrip line. The UWB and reconfigurable NB antennas provide 2:1 VSWR bandwidth from 3 to 11 GHz and from (3.25 to 3.7 GHz, 5.5 to 6.5 GHz, and 8 to 8.4 GHz), respectively. There is a reasonable isolation between the antennas. The narrowband reconfigurability is achieved by two p-i-n diode switches within the antenna structure. A prototype of the integrated antenna was fabricated and its performance was verified. The dimensions of the antenna are 65 mm × 40 mm × 6.5 mm. The antenna represents good radiation characteristics. Also, in order to reduce mutual coupling, the space between the ground planes is 10 mm.

Frequency reconfigurable antenna for cognitive radios with sequential UWB mode of perception and multiband mode of operation

AbstractIn this work, an UWB/narrow band reconfigurable elliptical-shaped monopole antenna for cognitive radio applications with sequential perception and operation modes is presented. The proposed approach consists in integrating a reconfigurable filter, in an UWB antenna ground plan, by the mean of four horizontal slots and integrated switches that allow inserting/removing/varying zeros and poles in the frequency response. By acting on the slot lengths in order to alter their resonance frequencies, the different switch configurations allow the antenna to switch between an UWB mode that could be used for the perception (sensing) and different narrowband modes, mono-band and dual-band, that could be used for the operation at 2.4 or/and 3.5 GHz. To validate the concept, an experimental prototype has been fabricated and a good agreement between the simulated and the measured S-parameters has been obtained. While the presented work uses the presence/absence of a perfect conductive strip (PEC) to model real switch operation, it is believed that the obtained results conjugated with previous work using real switches on a very similar structure allows validating approach.

Study and analysis of single notched rectangular dielectric resonator antenna for cognitive radio applications

In this article a single notched ultra-wideband antenna which is integrated with dielectric ring resonator is proposed for cognitive radio applications. The proposed antenna consists of elliptical base and a split ring resonator on either side of the feedline for bandwidth enhancement. The rectangular dielectric resonator which is proposed is a rectangular dielectric resonator which give good isolation between the two ports. The proposed antenna has single rejection at 5.7GHz-8.4GHz at ultrawideband region. The proposed antenna has a peak gain of 6dB and average gain of 3. 1dB.Commercially equipped tool ANSYS EM 17 is used to characterise the proposed antenna. The proposed antenna provides good isolation between the two antenna ports confirming efficient integration. The antenna is best suitable for candidate of radar applications, medical imaging and cognitive radio systems.