Wideband Microstrip Antenna Using Hook-Shaped Feed

In this paper, we introduce a novel feeding technique for bandwidth enhancement of a rectangular microstrip antenna This antenna offers an impedance bandwidth of 22% without degrading the effciencv. The effect of the feed parameters upon patch characteristics such as resonant frequency, impedance bandwidth, and radiation pattern are studied in detail. The experimental results are verified using the FDTD results

A reconfiguration dual-frequency slot-loaded microstrip antenna controlled by pin diodes

A novel reconfigurable, single feed, dual frequency, dualpolarized operation of a hexagonal slot-loaded square mwrostrip antenna is presented in this paper. A pin diode incorporated in the slot is used to switch the two operating frequencies considerably, without significantly affecting the radiation characteristics and gain. The proposed antenna provides a size reduction up to 61% and 26% Jor the two resonating frequencies, compared to standard rectangular patches. This design also gives considerable bandwidth up to 3.3% and 4.27%, for the two frequencies with a low operating frequency ratio

Development of a varactor -controlled dual-frequency reconfigurable microstrip antenna

A new design for a compact electronically reconffgurable singlefeed dual frequency dual-polarized operation of a square-microstrip antenna capable of achieving tunable frequency ratios in the range 1.1 to 1.37 is proposed and experimentally studied. Varactor diodes inlegruted with the arms of the hexagonal slot and embedded in the square patch are used to tune the operating frequencies by applying reverse-bias voltage. The design has the advantage of size reduction up to 73.21% and 49.86% for the two resonant frequencies, respectively, as compared to standard rectangular patches. The antenna offers good bandwidth of 5.74% and 5.36% for the two operating frequencies. A highly simplified tuning circuitry without any transmission lines adds to the compactness of the design

A Compact Electronically Reconfigurable Dual Frequency Microstrip Antenna for L-Band Applications

A novel design of a computer electronically reconfigurable dual frequency dual polarized single feed hexagonal slot loaded microstrip antenna in L-band is introduced in this chapter. pin diodes are used to switch the operating frequencies considerably without much affecting the radiation characteristics and gain. the antenna can work with a frequency ratio varying in the wide range from 1.2 to 1.4. the proposed design has an added advantage of size reduction up to 72.21% and 46.84% for the two resonating frequencies compared to standard rectangular patches. the design also gives considerable bandwidth of up to 2.82% and 2.42 % for the operating frequencies.

DEVELOPMENT AND ANALYSIS OF DUAL FREQUENCY MICROSTRIP ANTENNAS

Department of Elecctronics, Cochin University of Science and Technology

An electromagnetically coupled dual-band dual-polarized microstrip antenna for WLAN applications

A new design of a dual-band dual-polarized electromagnetically coupled slot loaded square patch antenna, covering the WLAN 5.2 GHz and 5.8 GHz bands, achieving bandwidth enhancement by using tapered slot structure, is presented here. The proposed antenna covers 5.09–5.47 GHz and 5.7–5.88 GHz bands. Details of the antenna design along with experimental and simulated results are presented and discussed.

Compact dual band slot loaded circular microstrip antenna with a superstrate

Design of a compact dual frequency microstrip antenna is presented. The structure consists of a slotted circular patch with a dielectric superstrate. The superstrate,not only acts as a radome, but improves the bandwidth and lowers the resonant frequency also. The proposed design provides an overall size reduction of about 60% compared to an unslotted patch along with good efficiency,gain and bandwidth. The polarization planes at the two resonances are orthogonal and can be simultaneously excited using a coaxial feed. Parametric study of this configuration showed that the frequency ratio of the two resonances can be varied from 1.17 to 1.7 enabling its applications in the major wireless communication bands like AWS, DECT,PHS,Wi.Bro, ISM,and DMB. Design equations are also deduced for the proposed antenna and validated.

Compact dual-polarised square microstrip antenna with triangular slots for wireless communication

Design of a dual linearly-polarised microstrip patch antenna, excited by two orthogonal microstrip feed lines, is presented. A reduction in patch size of 35% is obtained when compared to a square patch operating at the same frequency. The polarisations are oriented at +45 and - 45 with an isolation of more than 36 dB between the ports. Unlike earlier designs, the proposed structure provides better gain.

Circular microstrip antenna with a sector-slot for dual-port operation

Design of a dual-port circular patch antenna with a sector-slot for dual-frequency operation is presented. The antenna resonates at two distinct frequencies with orthogonal polarizations and broad radiation characteristics. Unlike the conventional circular patch, this antenna can be microstrip-fed to operate at either of the resonances. The two polarizations can be simultaneously excited using two electromagnetically coupled ports with an isolation better than −30 dB between the ports. This antenna has the added advantage of size reduction of 44% compared to the conventional circular patch without any reduction in gain.

C-shaped slot loaded reconfigurable microstrip antenna

A new electronically reconfigurable dual frequency microstrip patch antenna with highly simplified varactor tuning circuitry is presented. The proposed design allows relatively independent selection of the two operating frequencies. Tuning ranges of 7.1 and 4.1% are realised for the two resonant frequencies without the use of any matching circuits.

Design of a Compact Multiband Microstrip Antenna

A compact microstrip multiband antenna on a modified ground plane which can operate over the bands starting from 900 MHz to 5.35 GHz which includes the GSM (880-960) GPS (1568-1592 MHz), DCS (1710-1880 MHz), and PCS (1850- 1990 MHz). UMTS (1920-2170 MHz), IEEE 802.11 b/g (2400- 2484) and WLAN IEEE 802.11a band (5.15-5.35) is reported in this paper. The overall dimension of the antenna is 33 x 33 mm2 including the top patch with a dimension 22 x 22 mm2. The experimental results of the antenna are presented in this paper. The results confirm that the antenna exhibits wide band characteristics and covers 7 bands of operation

Design of a Compact Genetic Microstrip Antenna with improved performance

In this paper the design issues of compact genetic microstrip antennas for mobile applications has been investigated. The antennas designed using Genetic Algorithms (GA) have an arbitrary shape and occupies less area (compact) compared to the traditionally designed antenna for the same frequency but with poor performance. An attempt has been made to improve the performance of the genetic microstrip antenna by optimizing the ground plane (GP) to have a fish bone like structure. The genetic antenna with the GP optimized is even better compared to the traditional and the genetic antenna.

Theoretical investigations of an annular elliptical ring microstrip antenna using Green‘s function technique

Analytical expressions for the Green’s function of an annular elliptical ring microstrip antenna (AERMA) are developed and reported. The modal, radiation and input impedance characteristics of the TM, modes are determined from these expressions. The resonant frequencies of odd modes are greater than that of the even modes for all TMnl modes (n = 1, 2, 3, ...) udke elliptical microstrip structures. The radiation pattern and input imedance curves of TMI2 mode on comparison with available experimental result shows good agreement whch provides an independent validation to this technique. The performance of the AERMA is then investigated as a function of thickness and substrate dielectric permittivity.

Compact Microstrip Slot Antenna for Broadband Operation

An arrow-shaped microstrip antenna with a pair of narrow slots embedded near the non-radiating edges gives wide impedance bandwidth. The experimental and simulated (!E3D) results show that antenna bandwidth is -3.5 times that of a conventional patch with the added advantage of reduced antenna size. The radiation characteristics are found to he uniform throughout the operating band