A compact low-profile wideband omni-directional microstrip patch loading composite right/left-handed transmission line

2008 ◽  
Author(s):  
Yu Wu ◽  
Zhang-shan Duan ◽  
Shao-bo Qu ◽  
Jie-qiu Zhang
Keyword(s):  
Transmission Line ◽  
Microstrip Patch ◽  
Left Handed ◽  
Low Profile ◽  
Patch Loading

scholarly journals Bandwidth and gain enhancement of composite right left handed metamaterial transmission line planar antenna employing a non foster impedance matching circuit board

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mohammad Alibakhshikenari ◽  
Bal S. Virdee ◽  
Ayman A. Althuwayb ◽  
Leyre Azpilicueta ◽  
Naser Ojaroudi Parchin ◽  
...  
Keyword(s):  
Transmission Line ◽  
Impedance Matching ◽  
Circuit Board ◽  
Operating Frequency ◽  
Planar Antenna ◽  
Effective Technique ◽  
Input Capacitance ◽  
Gain Enhancement ◽  
Microstrip Patch ◽  
Left Handed

AbstractThe paper demonstrates an effective technique to significantly enhance the bandwidth and radiation gain of an otherwise narrowband composite right/left-handed transmission-line (CRLH-TL) antenna using a non-Foster impedance matching circuit (NF-IMC) without affecting the antenna’s stability. This is achieved by using the negative reactance of the NF-IMC to counteract the input capacitance of the antenna. Series capacitance of the CRLH-TL unit-cell is created by etching a dielectric spiral slot inside a rectangular microstrip patch that is grounded through a spiraled microstrip inductance. The overall size of the antenna, including the NF-IMC at its lowest operating frequency is 0.335λ0 × 0.137λ0 × 0.003λ0, where λ0 is the free-space wavelength at 1.4 GHz. The performance of the antenna was verified through actual measurements. The stable bandwidth of the antenna for |S11|≤ − 18 dB is greater than 1 GHz (1.4–2.45 GHz), which is significantly wider than the CRLH-TL antenna without the proposed impedance matching circuit. In addition, with the proposed technique the measured radiation gain and efficiency of the antenna are increased on average by 3.2 dBi and 31.5% over the operating frequency band.

scholarly journals Design and Characterization of VHF Band Small Antenna Using CRLH Transmission Line and Non-Foster Matching Circuit

2020 ◽  
Vol 10 (18) ◽  
pp. 6366
Author(s):  
Soyeong Lee ◽  
Jonghyup Lee ◽  
Seongro Choi ◽  
Yong-Hyeok Lee ◽  
Jae-Young Chung ◽  
...  
Keyword(s):  
Transmission Line ◽  
Spiral Inductor ◽  
Potential Candidate ◽  
Very High Frequency ◽  
Electrically Small Antenna ◽  
Left Handed ◽  
Received Power ◽  
Low Profile ◽  
Power Enhancement ◽  
Small Antenna

In this paper, we propose an electrically small antenna consisting of a composite right/left-handed (CRLH) transmission line (TL) and a non-Foster matching circuit. An interdigital capacitor (IDC) and spiral inductor are used to fabricate the very high frequency (VHF) band antenna based on CRLH TL. The size of the proposed antenna is as small as 0.025 × 0.014 × 0.0008 λ at 145.5 MHz using the zeroth-order resonant generated by the CRLH TL. The antenna operation bandwidth is extended by the non-Foster circuit (NFC) consisting of a pair of transistors in a cross-coupled manner. An antenna prototype is fabricated and the input impedance, the received power, and gain of the proposed antenna are measured. The results show that the broadband characteristic is maintained while the form factor is extremely small compared to the wavelength. The average received power enhancement and increased bandwidth of antenna are 17.3 dB and 335.5 MHz (from 249.2–268.2 to 145.5–500 MHz), respectively. The calculated gain of the proposed antenna with the non-Foster is about −45 dBi at 155 MHz. The proposed antenna can be considered as a potential candidate of a low-profile antenna for military ground communications at the VHF band.

Novel dual band patch antenna With Gap coupled composite right/left-handed transmission line

2018 ◽  
Vol 11 (1) ◽  
pp. 87-93
Author(s):  
Z. Ahmed ◽  
M. M. Ahmed ◽  
M. B. Ihsan ◽  
A. A. Chaudhary ◽  
J. K. Arif
Keyword(s):  
Transmission Line ◽  
Patch Antenna ◽  
Frequency Ratio ◽  
Unit Cell ◽  
Dual Band ◽  
Rectangular Patch ◽  
Left Handed ◽  
At Resonance ◽  
Low Profile ◽  
Resonance Frequencies

AbstractA novel low profile dual band patch antenna is presented. It consists of a composite right/left-handed transmission line (CRLH TL) unit cell gap coupled with the radiating edge of a rectangular patch antenna. The dual band behavior is achieved by coupling the zeroth order resonance mode of CRLH TL and TM10mode of the patch antenna. It is shown that frequency ratio can be changed by varying the gap between the patch and CRLH TL unit cell. The proposed configuration enables frequency reconfigurability by changing the CRLH TL unit cell using a switch. A prototype of the antenna having frequency ratiof2/f1= 1.08 is designed and fabricated. The proposed antenna shows measuredS11≤ −10 dB bandwidth of 100 and 50 MHz at resonance frequencies off1= 4.84 andf2= 5.22 GHz, respectively. A 2 × 2 dual band CRLH TL coupled patch array is also presented, showing more than 12.7 dBi gain at both resonance frequencies.

Composite right/left-handed transmission line with array of thermocouples for generating terahertz radiation

2020 ◽  
Vol 92 (2) ◽  
pp. 20502
Author(s):  
Behrokh Beiranvand ◽  
Alexander S. Sobolev ◽  
Anton V. Kudryashov
Keyword(s):  
Transmission Line ◽  
Terahertz Radiation ◽  
Transmission Lines ◽  
Software Package ◽  
Optical Pulses ◽  
Capacitively Coupled ◽  
Voltage Difference ◽  
Left Handed ◽  
Microwave Transmission ◽  
Commercial Software Package

We present a new concept of the thermoelectric structure that generates microwave and terahertz signals when illuminated by femtosecond optical pulses. The structure consists of a series array of capacitively coupled thermocouples. The array acts as a hybrid type microwave transmission line with anomalous dispersion and phase velocity higher than the velocity of light. This allows for adding up the responces from all the thermocouples in phase. The array is easily integrable with microstrip transmission lines. Dispersion curves obtained from both the lumped network scheme and numerical simulations are presented. The connection of the thermocouples is a composite right/left-handed transmission line, which can receive terahertz radiation from the transmission line ports. The radiation of the photon to the surface of the thermocouple structure causes a voltage difference with the bandwidth of terahertz. We examined a lossy composite right/left-handed transmission line to extract the circuit elements. The calculated properties of the design are extracted by employing commercial software package CST STUDIO SUITE.

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