Measurement techniques for input impedance, radiation pattern and conversion loss of a 90GHz quasi-optical annular slot receiver

Author(s):  
S.B. Yeap
Author(s):  
Otman Oulhaj ◽  
Amar Touhami Naima ◽  
Aghoutante Mohamed

In this chapter, the authors present different techniques used to miniature microstrip antennas, particularly planar antennas array, for different applications demanding small dimensions. This will cover DGS, slot technique, and metamaterials. After the presentation of these techniques based on theoretical studies, the second part of this chapter will be about the authors' contribution in the miniaturization of microstrip antennas arrays. This part will include the presentation of some miniature antennas array which they have validated into simulation and measurement by using DGS techniques. The different structures were validated into simulation by using tow electromagnetic solvers ADS (advanced design system) and CST-MW (computer simulation technology) which permit one to validate and to verify the different performances of antennas arrays as radiation pattern, matching input impedance and small dimensions.


1975 ◽  
Vol 11 (13) ◽  
pp. 282
Author(s):  
P.S. Hall ◽  
B. Chambers ◽  
P.A. Mcinnes

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Gokmen Isik ◽  
Serkan Topaloglu

An ultrawideband antenna is designed, simulated, and realized. To overcome the narrow bandwidth characteristics of basic patch antennas, the structure of the radiation pattern is optimized by the aid of elliptical and rectangular patches. Also triangular patches are applied to the antenna edge in order to enhance the VSWR and gain properties. A typical VSWR of 1.5 (less than 2 in the whole frequency range) and a typical gain of 2 dBi (mainly above 1 dBi in the whole frequency range) are observed. The simulations present that the designed antenna has a bandwidth ratio of ~5 : 1 within the frequency range of 4–19.1 GHz with compact dimensions of 25 × 26 mm2. It is fabricated on a 0.5 mm thick, RO3035 substrate. The input impedance, gain, and radiation characteristics of the antenna are also presented. With these properties, it is verified that, with its novel shape, the proposed antenna can be used for various UWB applications.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Hai-Na Song ◽  
Zhao-Hui Chen ◽  
Jian-Feng Li

A triband patch antenna with monopole-like and patch-like radiation patterns for multifunctional wireless systems is proposed. The antenna consists of a single square radiation patch with an annular slot, a ground plane, and a top-loaded metal sheet. The top-loaded metal sheet is shorted to the ground plane for producing a zeroth-order resonant (ZOR) mode, which has an omnidirectional radiation pattern at the lowest operation band, and its performance is robust to the location of the probe feed. With the annular slot and the off-center probe feed, a dual-resonant TM01 mode is excited, yielding unidirectional radiation patterns for the two upper operation bands. The ZOR and the dual-resonant TM01 modes can be independently controlled, and a triband antenna prototype with a square patch of 24 mm is fabricated and tested. The first bandwidth is 2.5–2.7 GHz with omnidirectional radiation pattern, the second and the third bandwidths with unidirectional radiation are 3.3–3.9 GHz and 4.8–6.1 GHz, and the realized gains over the three bands are about 2.6, 6.5, and 7.5 dBi, respectively.


Author(s):  
Mohamed Ihamji ◽  
Elhassane Abdelmounim ◽  
Hamid Bennis ◽  
Mostafa Hefnawi ◽  
Mohamed Latrach

In this paper, a multiband and miniature rectangular microstrip antenna is designed and analyzed for Radio Frequency Identification (RFID) reader applications. The miniaturization is achieved using fractal technique and the physical parameters of the structure as well as its ground plane are optimized using CST Microwave Studio. The total area of the final structure is 71.6 x 94 mm<sup>2</sup>. The results show that the proposed antenna has good matching input impedance with a stable radiation pattern at 915 MHz, 2.45 GHz, and 5.8 GHz.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Janilson L. de Souza ◽  
Karlo Q. da Costa ◽  
Victor Dmitriev ◽  
Felipe Bamberg

This paper presents a broadband nanoantenna fed by a two-wire optical transmission line (OTL). The antenna is defined by a combination of a dipole and a loop, where only the dipole element is connected to the OTL. The analysis is fulfilled by the linear method of moments with equivalent surface impedance to model the conductors. Firstly, the nanoantenna alone is investigated, where the input impedance, current distribution, reflection coefficient, fractional bandwidth, radiation efficiency, and radiation pattern are analyzed. Then, the input impedance matching of this antenna with the OTL is considered. In this case the current, near field distribution, radiation pattern, and reflection coefficient are calculated for different geometrical parameters. The results show that the loop inserted in the circuit can increase the bandwidth up to 42% and decreases the reflection coefficient in the OTL to −25 dB.


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