scholarly journals ANALYSIS OF RADIATION FROM A CYLINDRICAL-RECTANGUAR MICROSTRIP PATCH ANTENNA LOADED WITH A SUPERSRATE AND AN AIR GAP, USING THE ELECTRIC SURFACE CURRENT MODEL

2007 ◽  
Vol 67 ◽  
pp. 135-152 ◽  
Author(s):  
Francis R. Cooray ◽  
John S. Kot

Double Fibonacci spiral in a circle with microstrip line feeding technique is designed in the frequency range from 0.1GHz to 6GHz. The antenna is designed and simulated in computer simulation technology microwave studio software, substrate Fr-4 with thickness 1.59mm is used and antenna parameters such as return loss, surface current, E-field, H-field and gain are calculated for Double Fibonacci spiral microstrip patch (DFSM) antenna. The antenna is used for ISM (industrial, scientific and medical) frequency band (2.45GHz) and a new unutilized band for next generation services, gain is 2.22dB and 3.16dB and bandwidth is 25.94% and 22.83% on resonating frequencies.


2021 ◽  
Author(s):  
Suganthi Santhanam ◽  
Thiruvalar Selvan Palavesam

Abstract This paper presents the design of flexible trapezoidal radiating patch antenna array with FR4 substrate for onbody low frequency medical applications. The array resonates at 1.89 GHz with impedance bandwidth of 80 MHz and low return loss of -26.19 dB. The VSWR of 1.103 validate the activeness of the proposed antenna array having maximum surface current 133.1 (A/m) and directivity of 4.48 dBi. The antenna array exhibit the H-Field strength of 160.52 (A/m) and E-Field of 36093.4 (V/m) prove the radiation capability at low frequency on body application. These properties demonstrate the suitability of proposed array antenna for on body medical wireless applications.


Author(s):  
Prabal Pratap ◽  
Ravinder Singh Bhatia ◽  
Binod Kumar

Purpose – The purpose of this paper is to study and calculate the electrical characteristic of an equilateral triangular microstrip patch antenna that is proposed for dual frequency operation using the pin diode. The electrical characteristic of an equilateral triangular microstrip patch antenna is proposed for dual-frequency operation. Spur lines and ON/OFF condition of the pin diode are utilized to switch the resonant frequency of the patch. The presence of spur lines excites the surface current of the patch which is dependent on the resonant frequency of an equilateral triangular microstrip patch. Insertion of the diode in the spur lines gives a better result and compactness in patch design, which improves the miniaturization in size of patch. Design/methodology/approach – Antenna Design Aspects: A basic structure of an equilateral triangular microstrip antenna (ETMA) having two spur lines and one pin diode positioned in between the spur line is considered in this paper. The design parameters are chosen on the basis of substrate materials having relative permittivity less than three. Specification of the antenna is given in Table I. Substrate material used is RT Duroid 5,880; relative permittivity of the substrate er is 2.2; thickness of dielectric substrate h is 1.5 mm; sides of equilateral triangular patch a are 10 mm, spur width s is 0.5 mm; and spur length b is 2.0 mm. Findings – This paper gives an account of achieving polarization swiftness with coplanar waveguide (CPW) feed. The miniaturized size of the antenna is 35 × 30 mm2. Switchable microstrip equilateral triangular antenna has been demonstrated for dual-frequency operations. The resonant frequency of an ETMA can be adjusted by setting the diode in an ON and OFF state. The design improves the miniaturization in size with a discussion of radiation density. The excited patch surface current is limited to flow around just the mid of the patch in simple ETMA with a single slit cut. It is observed that for an ETMA, when the diode is in the ON state at 9.16 GHz, the excited patch surface current is highly distributed in the patch compared to when the diode is in the ON state at 11 GHz. Similarly, it is observed that the excited surface patch current is highly distributed when the diode is in the OFF state in both frequencies (9 and 11.96 GHz). The mode is changed by the use of a switch at time and it is suitable for wireless communication applications. Originality/value – Spur lines and the ON/OFF condition of the pin diode are utilized to switch the resonant frequency of the patch. The presence of spur lines excites the surface current of the patch which is dependent on the resonant frequency of an equilateral triangular microstrip patch. Insertion of the diode in spur lines gives a better result and compactness in patch design, which improves the miniaturization in size of the patch.


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